From 5bcf8ed9401e62c73158ba110864ee1375558bf7 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:35:58 +0100 Subject: target/arm: Make sure M-profile FPSCR RES0 bits are not settable Enforce that for M-profile various FPSCR bits which are RES0 there but have defined meanings on A-profile are never settable. This ensures that M-profile code can't enable the A-profile behaviour (notably vector length/stride handling) by accident. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-2-peter.maydell@linaro.org --- target/arm/vfp_helper.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'target') diff --git a/target/arm/vfp_helper.c b/target/arm/vfp_helper.c index 2468fc1629..7a46d99148 100644 --- a/target/arm/vfp_helper.c +++ b/target/arm/vfp_helper.c @@ -105,6 +105,14 @@ void HELPER(vfp_set_fpscr)(CPUARMState *env, uint32_t val) val &= ~FPCR_FZ16; } + if (arm_feature(env, ARM_FEATURE_M)) { + /* + * M profile FPSCR is RES0 for the QC, STRIDE, FZ16, LEN bits + * and also for the trapped-exception-handling bits IxE. + */ + val &= 0xf7c0009f; + } + /* * We don't implement trapped exception handling, so the * trap enable bits, IDE|IXE|UFE|OFE|DZE|IOE are all RAZ/WI (not RES0!) -- cgit v1.2.3 From d33abe82c7c9847284a23e575e1078cccab540b5 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:35:58 +0100 Subject: target/arm: Implement dummy versions of M-profile FP-related registers The M-profile floating point support has three associated config registers: FPCAR, FPCCR and FPDSCR. It also makes the registers CPACR and NSACR have behaviour other than reads-as-zero. Add support for all of these as simple reads-as-written registers. We will hook up actual functionality later. The main complexity here is handling the FPCCR register, which has a mix of banked and unbanked bits. Note that we don't share storage with the A-profile cpu->cp15.nsacr and cpu->cp15.cpacr_el1, though the behaviour is quite similar, for two reasons: * the M profile CPACR is banked between security states * it preserves the invariant that M profile uses no state inside the cp15 substruct Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-4-peter.maydell@linaro.org --- target/arm/cpu.c | 5 +++++ target/arm/cpu.h | 34 ++++++++++++++++++++++++++++++++++ target/arm/machine.c | 16 ++++++++++++++++ 3 files changed, 55 insertions(+) (limited to 'target') diff --git a/target/arm/cpu.c b/target/arm/cpu.c index bb9fdc6304..be81e197ee 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -281,6 +281,11 @@ static void arm_cpu_reset(CPUState *s) env->v7m.ccr[M_REG_S] |= R_V7M_CCR_UNALIGN_TRP_MASK; } + if (arm_feature(env, ARM_FEATURE_VFP)) { + env->v7m.fpccr[M_REG_NS] = R_V7M_FPCCR_ASPEN_MASK; + env->v7m.fpccr[M_REG_S] = R_V7M_FPCCR_ASPEN_MASK | + R_V7M_FPCCR_LSPEN_MASK | R_V7M_FPCCR_S_MASK; + } /* Unlike A/R profile, M profile defines the reset LR value */ env->regs[14] = 0xffffffff; diff --git a/target/arm/cpu.h b/target/arm/cpu.h index f7f2f5a99c..67e4e95d44 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -533,6 +533,11 @@ typedef struct CPUARMState { uint32_t scr[M_REG_NUM_BANKS]; uint32_t msplim[M_REG_NUM_BANKS]; uint32_t psplim[M_REG_NUM_BANKS]; + uint32_t fpcar[M_REG_NUM_BANKS]; + uint32_t fpccr[M_REG_NUM_BANKS]; + uint32_t fpdscr[M_REG_NUM_BANKS]; + uint32_t cpacr[M_REG_NUM_BANKS]; + uint32_t nsacr; } v7m; /* Information associated with an exception about to be taken: @@ -1576,6 +1581,35 @@ FIELD(V7M_CSSELR, LEVEL, 1, 3) */ FIELD(V7M_CSSELR, INDEX, 0, 4) +/* v7M FPCCR bits */ +FIELD(V7M_FPCCR, LSPACT, 0, 1) +FIELD(V7M_FPCCR, USER, 1, 1) +FIELD(V7M_FPCCR, S, 2, 1) +FIELD(V7M_FPCCR, THREAD, 3, 1) +FIELD(V7M_FPCCR, HFRDY, 4, 1) +FIELD(V7M_FPCCR, MMRDY, 5, 1) +FIELD(V7M_FPCCR, BFRDY, 6, 1) +FIELD(V7M_FPCCR, SFRDY, 7, 1) +FIELD(V7M_FPCCR, MONRDY, 8, 1) +FIELD(V7M_FPCCR, SPLIMVIOL, 9, 1) +FIELD(V7M_FPCCR, UFRDY, 10, 1) +FIELD(V7M_FPCCR, RES0, 11, 15) +FIELD(V7M_FPCCR, TS, 26, 1) +FIELD(V7M_FPCCR, CLRONRETS, 27, 1) +FIELD(V7M_FPCCR, CLRONRET, 28, 1) +FIELD(V7M_FPCCR, LSPENS, 29, 1) +FIELD(V7M_FPCCR, LSPEN, 30, 1) +FIELD(V7M_FPCCR, ASPEN, 31, 1) +/* These bits are banked. Others are non-banked and live in the M_REG_S bank */ +#define R_V7M_FPCCR_BANKED_MASK \ + (R_V7M_FPCCR_LSPACT_MASK | \ + R_V7M_FPCCR_USER_MASK | \ + R_V7M_FPCCR_THREAD_MASK | \ + R_V7M_FPCCR_MMRDY_MASK | \ + R_V7M_FPCCR_SPLIMVIOL_MASK | \ + R_V7M_FPCCR_UFRDY_MASK | \ + R_V7M_FPCCR_ASPEN_MASK) + /* * System register ID fields. */ diff --git a/target/arm/machine.c b/target/arm/machine.c index b292549614..09567d4fc6 100644 --- a/target/arm/machine.c +++ b/target/arm/machine.c @@ -305,6 +305,21 @@ static const VMStateDescription vmstate_m_v8m = { } }; +static const VMStateDescription vmstate_m_fp = { + .name = "cpu/m/fp", + .version_id = 1, + .minimum_version_id = 1, + .needed = vfp_needed, + .fields = (VMStateField[]) { + VMSTATE_UINT32_ARRAY(env.v7m.fpcar, ARMCPU, M_REG_NUM_BANKS), + VMSTATE_UINT32_ARRAY(env.v7m.fpccr, ARMCPU, M_REG_NUM_BANKS), + VMSTATE_UINT32_ARRAY(env.v7m.fpdscr, ARMCPU, M_REG_NUM_BANKS), + VMSTATE_UINT32_ARRAY(env.v7m.cpacr, ARMCPU, M_REG_NUM_BANKS), + VMSTATE_UINT32(env.v7m.nsacr, ARMCPU), + VMSTATE_END_OF_LIST() + } +}; + static const VMStateDescription vmstate_m = { .name = "cpu/m", .version_id = 4, @@ -330,6 +345,7 @@ static const VMStateDescription vmstate_m = { &vmstate_m_scr, &vmstate_m_other_sp, &vmstate_m_v8m, + &vmstate_m_fp, NULL } }; -- cgit v1.2.3 From ef9aae2522c22c05df17dd898099dd5c3f20d688 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:35:58 +0100 Subject: target/arm: Disable most VFP sysregs for M-profile The only "system register" that M-profile floating point exposes via the VMRS/VMRS instructions is FPSCR, and it does not have the odd special case for rd==15. Add a check to ensure we only expose FPSCR. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-5-peter.maydell@linaro.org --- target/arm/translate.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'target') diff --git a/target/arm/translate.c b/target/arm/translate.c index 4ea4018e2b..a978453506 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -3513,12 +3513,27 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn) } } } else { /* !dp */ + bool is_sysreg; + if ((insn & 0x6f) != 0x00) return 1; rn = VFP_SREG_N(insn); + + is_sysreg = extract32(insn, 21, 1); + + if (arm_dc_feature(s, ARM_FEATURE_M)) { + /* + * The only M-profile VFP vmrs/vmsr sysreg is FPSCR. + * Writes to R15 are UNPREDICTABLE; we choose to undef. + */ + if (is_sysreg && (rd == 15 || (rn >> 1) != ARM_VFP_FPSCR)) { + return 1; + } + } + if (insn & ARM_CP_RW_BIT) { /* vfp->arm */ - if (insn & (1 << 21)) { + if (is_sysreg) { /* system register */ rn >>= 1; @@ -3585,7 +3600,7 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn) } } else { /* arm->vfp */ - if (insn & (1 << 21)) { + if (is_sysreg) { rn >>= 1; /* system register */ switch (rn) { -- cgit v1.2.3 From d87513c0abcbcd856f8e1dee2f2d18903b2c3ea2 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:35:58 +0100 Subject: target/arm: Honour M-profile FP enable bits Like AArch64, M-profile floating point has no FPEXC enable bit to gate floating point; so always set the VFPEN TB flag. M-profile also has CPACR and NSACR similar to A-profile; they behave slightly differently: * the CPACR is banked between Secure and Non-Secure * if the NSACR forces a trap then this is taken to the Secure state, not the Non-Secure state Honour the CPACR and NSACR settings. The NSACR handling requires us to borrow the exception.target_el field (usually meaningless for M profile) to distinguish the NOCP UsageFault taken to Secure state from the more usual fault taken to the current security state. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-6-peter.maydell@linaro.org --- target/arm/helper.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++--- target/arm/translate.c | 10 +++++++-- 2 files changed, 60 insertions(+), 5 deletions(-) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index 57ef75b3fc..c3d5fe09cd 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -7556,6 +7556,25 @@ uint32_t arm_phys_excp_target_el(CPUState *cs, uint32_t excp_idx, return target_el; } +/* + * Return true if the v7M CPACR permits access to the FPU for the specified + * security state and privilege level. + */ +static bool v7m_cpacr_pass(CPUARMState *env, bool is_secure, bool is_priv) +{ + switch (extract32(env->v7m.cpacr[is_secure], 20, 2)) { + case 0: + case 2: /* UNPREDICTABLE: we treat like 0 */ + return false; + case 1: + return is_priv; + case 3: + return true; + default: + g_assert_not_reached(); + } +} + static bool v7m_stack_write(ARMCPU *cpu, uint32_t addr, uint32_t value, ARMMMUIdx mmu_idx, bool ignfault) { @@ -8815,9 +8834,23 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_UNDEFINSTR_MASK; break; case EXCP_NOCP: - armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); - env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_NOCP_MASK; + { + /* + * NOCP might be directed to something other than the current + * security state if this fault is because of NSACR; we indicate + * the target security state using exception.target_el. + */ + int target_secstate; + + if (env->exception.target_el == 3) { + target_secstate = M_REG_S; + } else { + target_secstate = env->v7m.secure; + } + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, target_secstate); + env->v7m.cfsr[target_secstate] |= R_V7M_CFSR_NOCP_MASK; break; + } case EXCP_INVSTATE: armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVSTATE_MASK; @@ -12751,6 +12784,22 @@ int fp_exception_el(CPUARMState *env, int cur_el) return 0; } + if (arm_feature(env, ARM_FEATURE_M)) { + /* CPACR can cause a NOCP UsageFault taken to current security state */ + if (!v7m_cpacr_pass(env, env->v7m.secure, cur_el != 0)) { + return 1; + } + + if (arm_feature(env, ARM_FEATURE_M_SECURITY) && !env->v7m.secure) { + if (!extract32(env->v7m.nsacr, 10, 1)) { + /* FP insns cause a NOCP UsageFault taken to Secure */ + return 3; + } + } + + return 0; + } + /* The CPACR controls traps to EL1, or PL1 if we're 32 bit: * 0, 2 : trap EL0 and EL1/PL1 accesses * 1 : trap only EL0 accesses @@ -12938,7 +12987,7 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, flags = FIELD_DP32(flags, TBFLAG_A32, SCTLR_B, arm_sctlr_b(env)); flags = FIELD_DP32(flags, TBFLAG_A32, NS, !access_secure_reg(env)); if (env->vfp.xregs[ARM_VFP_FPEXC] & (1 << 30) - || arm_el_is_aa64(env, 1)) { + || arm_el_is_aa64(env, 1) || arm_feature(env, ARM_FEATURE_M)) { flags = FIELD_DP32(flags, TBFLAG_A32, VFPEN, 1); } flags = FIELD_DP32(flags, TBFLAG_A32, XSCALE_CPAR, env->cp15.c15_cpar); diff --git a/target/arm/translate.c b/target/arm/translate.c index a978453506..6a11921d0b 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -3399,8 +3399,14 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn) * for attempts to execute invalid vfp/neon encodings with FP disabled. */ if (s->fp_excp_el) { - gen_exception_insn(s, 4, EXCP_UDEF, - syn_fp_access_trap(1, 0xe, false), s->fp_excp_el); + if (arm_dc_feature(s, ARM_FEATURE_M)) { + gen_exception_insn(s, 4, EXCP_NOCP, syn_uncategorized(), + s->fp_excp_el); + } else { + gen_exception_insn(s, 4, EXCP_UDEF, + syn_fp_access_trap(1, 0xe, false), + s->fp_excp_el); + } return 0; } -- cgit v1.2.3 From 8859ba3c9625e7ceb5599f457a344bcd7c5e112b Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:35:59 +0100 Subject: target/arm: Decode FP instructions for M profile Correct the decode of the M-profile "coprocessor and floating-point instructions" space: * op0 == 0b11 is always unallocated * if the CPU has an FPU then all insns with op1 == 0b101 are floating point and go to disas_vfp_insn() For the moment we leave VLLDM and VLSTM as NOPs; in a later commit we will fill in the proper implementation for the case where an FPU is present. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-7-peter.maydell@linaro.org --- target/arm/translate.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) (limited to 'target') diff --git a/target/arm/translate.c b/target/arm/translate.c index 6a11921d0b..0747f7847a 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -11728,10 +11728,19 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn) case 6: case 7: case 14: case 15: /* Coprocessor. */ if (arm_dc_feature(s, ARM_FEATURE_M)) { - /* We don't currently implement M profile FP support, - * so this entire space should give a NOCP fault, with - * the exception of the v8M VLLDM and VLSTM insns, which - * must be NOPs in Secure state and UNDEF in Nonsecure state. + /* 0b111x_11xx_xxxx_xxxx_xxxx_xxxx_xxxx_xxxx */ + if (extract32(insn, 24, 2) == 3) { + goto illegal_op; /* op0 = 0b11 : unallocated */ + } + + /* + * Decode VLLDM and VLSTM first: these are nonstandard because: + * * if there is no FPU then these insns must NOP in + * Secure state and UNDEF in Nonsecure state + * * if there is an FPU then these insns do not have + * the usual behaviour that disas_vfp_insn() provides of + * being controlled by CPACR/NSACR enable bits or the + * lazy-stacking logic. */ if (arm_dc_feature(s, ARM_FEATURE_V8) && (insn & 0xffa00f00) == 0xec200a00) { @@ -11745,6 +11754,15 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn) /* Just NOP since FP support is not implemented */ break; } + if (arm_dc_feature(s, ARM_FEATURE_VFP) && + ((insn >> 8) & 0xe) == 10) { + /* FP, and the CPU supports it */ + if (disas_vfp_insn(s, insn)) { + goto illegal_op; + } + break; + } + /* All other insns: NOCP */ gen_exception_insn(s, 4, EXCP_NOCP, syn_uncategorized(), default_exception_el(s)); -- cgit v1.2.3 From 1702071302934af77a072b7ee7c5eadc45b37573 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:35:59 +0100 Subject: target/arm: Clear CONTROL_S.SFPA in SG insn if FPU present If the floating point extension is present, then the SG instruction must clear the CONTROL_S.SFPA bit. Implement this. (On a no-FPU system the bit will always be zero, so we don't need to make the clearing of the bit conditional on ARM_FEATURE_VFP.) Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-8-peter.maydell@linaro.org --- target/arm/helper.c | 1 + 1 file changed, 1 insertion(+) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index c3d5fe09cd..45a9d92e50 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8804,6 +8804,7 @@ static bool v7m_handle_execute_nsc(ARMCPU *cpu) qemu_log_mask(CPU_LOG_INT, "...really an SG instruction at 0x%08" PRIx32 ", executing it\n", env->regs[15]); env->regs[14] &= ~1; + env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK; switch_v7m_security_state(env, true); xpsr_write(env, 0, XPSR_IT); env->regs[15] += 4; -- cgit v1.2.3 From 2e1c5bcd32014c9ede1b604ae6c2c653de17fc53 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:35:59 +0100 Subject: target/arm: Handle SFPA and FPCA bits in reads and writes of CONTROL The M-profile CONTROL register has two bits -- SFPA and FPCA -- which relate to floating-point support, and should be RES0 otherwise. Handle them correctly in the MSR/MRS register access code. Neither is banked between security states, so they are stored in v7m.control[M_REG_S] regardless of current security state. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-9-peter.maydell@linaro.org --- target/arm/helper.c | 57 +++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 49 insertions(+), 8 deletions(-) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index 45a9d92e50..e801744673 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -12027,7 +12027,14 @@ uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg) return xpsr_read(env) & mask; break; case 20: /* CONTROL */ - return env->v7m.control[env->v7m.secure]; + { + uint32_t value = env->v7m.control[env->v7m.secure]; + if (!env->v7m.secure) { + /* SFPA is RAZ/WI from NS; FPCA is stored in the M_REG_S bank */ + value |= env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK; + } + return value; + } case 0x94: /* CONTROL_NS */ /* We have to handle this here because unprivileged Secure code * can read the NS CONTROL register. @@ -12035,7 +12042,8 @@ uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg) if (!env->v7m.secure) { return 0; } - return env->v7m.control[M_REG_NS]; + return env->v7m.control[M_REG_NS] | + (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK); } if (el == 0) { @@ -12141,9 +12149,13 @@ void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val) */ uint32_t mask = extract32(maskreg, 8, 4); uint32_t reg = extract32(maskreg, 0, 8); + int cur_el = arm_current_el(env); - if (arm_current_el(env) == 0 && reg > 7) { - /* only xPSR sub-fields may be written by unprivileged */ + if (cur_el == 0 && reg > 7 && reg != 20) { + /* + * only xPSR sub-fields and CONTROL.SFPA may be written by + * unprivileged code + */ return; } @@ -12202,6 +12214,15 @@ void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val) env->v7m.control[M_REG_NS] &= ~R_V7M_CONTROL_NPRIV_MASK; env->v7m.control[M_REG_NS] |= val & R_V7M_CONTROL_NPRIV_MASK; } + /* + * SFPA is RAZ/WI from NS. FPCA is RO if NSACR.CP10 == 0, + * RES0 if the FPU is not present, and is stored in the S bank + */ + if (arm_feature(env, ARM_FEATURE_VFP) && + extract32(env->v7m.nsacr, 10, 1)) { + env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK; + env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_FPCA_MASK; + } return; case 0x98: /* SP_NS */ { @@ -12304,21 +12325,41 @@ void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val) env->v7m.faultmask[env->v7m.secure] = val & 1; break; case 20: /* CONTROL */ - /* Writing to the SPSEL bit only has an effect if we are in + /* + * Writing to the SPSEL bit only has an effect if we are in * thread mode; other bits can be updated by any privileged code. * write_v7m_control_spsel() deals with updating the SPSEL bit in * env->v7m.control, so we only need update the others. * For v7M, we must just ignore explicit writes to SPSEL in handler * mode; for v8M the write is permitted but will have no effect. + * All these bits are writes-ignored from non-privileged code, + * except for SFPA. */ - if (arm_feature(env, ARM_FEATURE_V8) || - !arm_v7m_is_handler_mode(env)) { + if (cur_el > 0 && (arm_feature(env, ARM_FEATURE_V8) || + !arm_v7m_is_handler_mode(env))) { write_v7m_control_spsel(env, (val & R_V7M_CONTROL_SPSEL_MASK) != 0); } - if (arm_feature(env, ARM_FEATURE_M_MAIN)) { + if (cur_el > 0 && arm_feature(env, ARM_FEATURE_M_MAIN)) { env->v7m.control[env->v7m.secure] &= ~R_V7M_CONTROL_NPRIV_MASK; env->v7m.control[env->v7m.secure] |= val & R_V7M_CONTROL_NPRIV_MASK; } + if (arm_feature(env, ARM_FEATURE_VFP)) { + /* + * SFPA is RAZ/WI from NS or if no FPU. + * FPCA is RO if NSACR.CP10 == 0, RES0 if the FPU is not present. + * Both are stored in the S bank. + */ + if (env->v7m.secure) { + env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK; + env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_SFPA_MASK; + } + if (cur_el > 0 && + (env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_SECURITY) || + extract32(env->v7m.nsacr, 10, 1))) { + env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK; + env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_FPCA_MASK; + } + } break; default: bad_reg: -- cgit v1.2.3 From 3432c79a4e7345818d2defcf9e61a1bcb2907f9f Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:35:59 +0100 Subject: target/arm/helper: don't return early for STKOF faults during stacking Currently the code in v7m_push_stack() which detects a violation of the v8M stack limit simply returns early if it does so. This is OK for the current integer-only code, but won't work for the floating point handling we're about to add. We need to continue executing the rest of the function so that we check for other exceptions like not having permission to use the FPU and so that we correctly set the FPCCR state if we are doing lazy stacking. Refactor to avoid the early return. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-10-peter.maydell@linaro.org --- target/arm/helper.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index e801744673..142d301b65 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8182,7 +8182,7 @@ static bool v7m_push_stack(ARMCPU *cpu) * should ignore further stack faults trying to process * that derived exception.) */ - bool stacked_ok; + bool stacked_ok = true, limitviol = false; CPUARMState *env = &cpu->env; uint32_t xpsr = xpsr_read(env); uint32_t frameptr = env->regs[13]; @@ -8213,7 +8213,14 @@ static bool v7m_push_stack(ARMCPU *cpu) armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); env->regs[13] = limit; - return true; + /* + * We won't try to perform any further memory accesses but + * we must continue through the following code to check for + * permission faults during FPU state preservation, and we + * must update FPCCR if lazy stacking is enabled. + */ + limitviol = true; + stacked_ok = false; } } @@ -8222,7 +8229,7 @@ static bool v7m_push_stack(ARMCPU *cpu) * (which may be taken in preference to the one we started with * if it has higher priority). */ - stacked_ok = + stacked_ok = stacked_ok && v7m_stack_write(cpu, frameptr, env->regs[0], mmu_idx, false) && v7m_stack_write(cpu, frameptr + 4, env->regs[1], mmu_idx, false) && v7m_stack_write(cpu, frameptr + 8, env->regs[2], mmu_idx, false) && @@ -8232,8 +8239,14 @@ static bool v7m_push_stack(ARMCPU *cpu) v7m_stack_write(cpu, frameptr + 24, env->regs[15], mmu_idx, false) && v7m_stack_write(cpu, frameptr + 28, xpsr, mmu_idx, false); - /* Update SP regardless of whether any of the stack accesses failed. */ - env->regs[13] = frameptr; + /* + * If we broke a stack limit then SP was already updated earlier; + * otherwise we update SP regardless of whether any of the stack + * accesses failed or we took some other kind of fault. + */ + if (!limitviol) { + env->regs[13] = frameptr; + } return !stacked_ok; } -- cgit v1.2.3 From 0ed377a8013f40653a83f6ad2c9693897522d7dc Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:00 +0100 Subject: target/arm: Handle floating point registers in exception entry Handle floating point registers in exception entry. This corresponds to the FP-specific parts of the pseudocode functions ActivateException() and PushStack(). We defer the code corresponding to UpdateFPCCR() to a later patch. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-11-peter.maydell@linaro.org --- target/arm/helper.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 95 insertions(+), 3 deletions(-) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index 142d301b65..6e55da5c48 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8167,6 +8167,9 @@ static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, bool dotailchain, switch_v7m_security_state(env, targets_secure); write_v7m_control_spsel(env, 0); arm_clear_exclusive(env); + /* Clear SFPA and FPCA (has no effect if no FPU) */ + env->v7m.control[M_REG_S] &= + ~(R_V7M_CONTROL_FPCA_MASK | R_V7M_CONTROL_SFPA_MASK); /* Clear IT bits */ env->condexec_bits = 0; env->regs[14] = lr; @@ -8187,6 +8190,20 @@ static bool v7m_push_stack(ARMCPU *cpu) uint32_t xpsr = xpsr_read(env); uint32_t frameptr = env->regs[13]; ARMMMUIdx mmu_idx = arm_mmu_idx(env); + uint32_t framesize; + bool nsacr_cp10 = extract32(env->v7m.nsacr, 10, 1); + + if ((env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) && + (env->v7m.secure || nsacr_cp10)) { + if (env->v7m.secure && + env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK) { + framesize = 0xa8; + } else { + framesize = 0x68; + } + } else { + framesize = 0x20; + } /* Align stack pointer if the guest wants that */ if ((frameptr & 4) && @@ -8195,7 +8212,13 @@ static bool v7m_push_stack(ARMCPU *cpu) xpsr |= XPSR_SPREALIGN; } - frameptr -= 0x20; + xpsr &= ~XPSR_SFPA; + if (env->v7m.secure && + (env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) { + xpsr |= XPSR_SFPA; + } + + frameptr -= framesize; if (arm_feature(env, ARM_FEATURE_V8)) { uint32_t limit = v7m_sp_limit(env); @@ -8239,6 +8262,73 @@ static bool v7m_push_stack(ARMCPU *cpu) v7m_stack_write(cpu, frameptr + 24, env->regs[15], mmu_idx, false) && v7m_stack_write(cpu, frameptr + 28, xpsr, mmu_idx, false); + if (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) { + /* FPU is active, try to save its registers */ + bool fpccr_s = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK; + bool lspact = env->v7m.fpccr[fpccr_s] & R_V7M_FPCCR_LSPACT_MASK; + + if (lspact && arm_feature(env, ARM_FEATURE_M_SECURITY)) { + qemu_log_mask(CPU_LOG_INT, + "...SecureFault because LSPACT and FPCA both set\n"); + env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK; + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); + } else if (!env->v7m.secure && !nsacr_cp10) { + qemu_log_mask(CPU_LOG_INT, + "...Secure UsageFault with CFSR.NOCP because " + "NSACR.CP10 prevents stacking FP regs\n"); + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, M_REG_S); + env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_NOCP_MASK; + } else { + if (!(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPEN_MASK)) { + /* Lazy stacking disabled, save registers now */ + int i; + bool cpacr_pass = v7m_cpacr_pass(env, env->v7m.secure, + arm_current_el(env) != 0); + + if (stacked_ok && !cpacr_pass) { + /* + * Take UsageFault if CPACR forbids access. The pseudocode + * here does a full CheckCPEnabled() but we know the NSACR + * check can never fail as we have already handled that. + */ + qemu_log_mask(CPU_LOG_INT, + "...UsageFault with CFSR.NOCP because " + "CPACR.CP10 prevents stacking FP regs\n"); + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, + env->v7m.secure); + env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_NOCP_MASK; + stacked_ok = false; + } + + for (i = 0; i < ((framesize == 0xa8) ? 32 : 16); i += 2) { + uint64_t dn = *aa32_vfp_dreg(env, i / 2); + uint32_t faddr = frameptr + 0x20 + 4 * i; + uint32_t slo = extract64(dn, 0, 32); + uint32_t shi = extract64(dn, 32, 32); + + if (i >= 16) { + faddr += 8; /* skip the slot for the FPSCR */ + } + stacked_ok = stacked_ok && + v7m_stack_write(cpu, faddr, slo, mmu_idx, false) && + v7m_stack_write(cpu, faddr + 4, shi, mmu_idx, false); + } + stacked_ok = stacked_ok && + v7m_stack_write(cpu, frameptr + 0x60, + vfp_get_fpscr(env), mmu_idx, false); + if (cpacr_pass) { + for (i = 0; i < ((framesize == 0xa8) ? 32 : 16); i += 2) { + *aa32_vfp_dreg(env, i / 2) = 0; + } + vfp_set_fpscr(env, 0); + } + } else { + /* Lazy stacking enabled, save necessary info to stack later */ + /* TODO : equivalent of UpdateFPCCR() pseudocode */ + } + } + } + /* * If we broke a stack limit then SP was already updated earlier; * otherwise we update SP regardless of whether any of the stack @@ -8999,8 +9089,7 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) if (arm_feature(env, ARM_FEATURE_V8)) { lr = R_V7M_EXCRET_RES1_MASK | - R_V7M_EXCRET_DCRS_MASK | - R_V7M_EXCRET_FTYPE_MASK; + R_V7M_EXCRET_DCRS_MASK; /* The S bit indicates whether we should return to Secure * or NonSecure (ie our current state). * The ES bit indicates whether we're taking this exception @@ -9015,6 +9104,9 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) if (env->v7m.secure) { lr |= R_V7M_EXCRET_S_MASK; } + if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK)) { + lr |= R_V7M_EXCRET_FTYPE_MASK; + } } else { lr = R_V7M_EXCRET_RES1_MASK | R_V7M_EXCRET_S_MASK | -- cgit v1.2.3 From b593c2b81287040ab6f452afec6281e2f7ee487b Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:00 +0100 Subject: target/arm: Implement v7m_update_fpccr() Implement the code which updates the FPCCR register on an exception entry where we are going to use lazy FP stacking. We have to defer to the NVIC to determine whether the various exceptions are currently ready or not. Signed-off-by: Peter Maydell Message-id: 20190416125744.27770-12-peter.maydell@linaro.org --- target/arm/cpu.h | 14 +++++++++++ target/arm/helper.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 80 insertions(+), 1 deletion(-) (limited to 'target') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 67e4e95d44..eb989d773a 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -2044,6 +2044,20 @@ void armv7m_nvic_acknowledge_irq(void *opaque); * (Ignoring -1, this is the same as the RETTOBASE value before completion.) */ int armv7m_nvic_complete_irq(void *opaque, int irq, bool secure); +/** + * armv7m_nvic_get_ready_status(void *opaque, int irq, bool secure) + * @opaque: the NVIC + * @irq: the exception number to mark pending + * @secure: false for non-banked exceptions or for the nonsecure + * version of a banked exception, true for the secure version of a banked + * exception. + * + * Return whether an exception is "ready", i.e. whether the exception is + * enabled and is configured at a priority which would allow it to + * interrupt the current execution priority. This controls whether the + * RDY bit for it in the FPCCR is set. + */ +bool armv7m_nvic_get_ready_status(void *opaque, int irq, bool secure); /** * armv7m_nvic_raw_execution_priority: return the raw execution priority * @opaque: the NVIC diff --git a/target/arm/helper.c b/target/arm/helper.c index 6e55da5c48..547898581a 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8177,6 +8177,71 @@ static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, bool dotailchain, env->thumb = addr & 1; } +static void v7m_update_fpccr(CPUARMState *env, uint32_t frameptr, + bool apply_splim) +{ + /* + * Like the pseudocode UpdateFPCCR: save state in FPCAR and FPCCR + * that we will need later in order to do lazy FP reg stacking. + */ + bool is_secure = env->v7m.secure; + void *nvic = env->nvic; + /* + * Some bits are unbanked and live always in fpccr[M_REG_S]; some bits + * are banked and we want to update the bit in the bank for the + * current security state; and in one case we want to specifically + * update the NS banked version of a bit even if we are secure. + */ + uint32_t *fpccr_s = &env->v7m.fpccr[M_REG_S]; + uint32_t *fpccr_ns = &env->v7m.fpccr[M_REG_NS]; + uint32_t *fpccr = &env->v7m.fpccr[is_secure]; + bool hfrdy, bfrdy, mmrdy, ns_ufrdy, s_ufrdy, sfrdy, monrdy; + + env->v7m.fpcar[is_secure] = frameptr & ~0x7; + + if (apply_splim && arm_feature(env, ARM_FEATURE_V8)) { + bool splimviol; + uint32_t splim = v7m_sp_limit(env); + bool ign = armv7m_nvic_neg_prio_requested(nvic, is_secure) && + (env->v7m.ccr[is_secure] & R_V7M_CCR_STKOFHFNMIGN_MASK); + + splimviol = !ign && frameptr < splim; + *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, SPLIMVIOL, splimviol); + } + + *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, LSPACT, 1); + + *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, S, is_secure); + + *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, USER, arm_current_el(env) == 0); + + *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, THREAD, + !arm_v7m_is_handler_mode(env)); + + hfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_HARD, false); + *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, HFRDY, hfrdy); + + bfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_BUS, false); + *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, BFRDY, bfrdy); + + mmrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_MEM, is_secure); + *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, MMRDY, mmrdy); + + ns_ufrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_USAGE, false); + *fpccr_ns = FIELD_DP32(*fpccr_ns, V7M_FPCCR, UFRDY, ns_ufrdy); + + monrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_DEBUG, false); + *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, MONRDY, monrdy); + + if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { + s_ufrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_USAGE, true); + *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, UFRDY, s_ufrdy); + + sfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_SECURE, false); + *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, SFRDY, sfrdy); + } +} + static bool v7m_push_stack(ARMCPU *cpu) { /* Do the "set up stack frame" part of exception entry, @@ -8324,7 +8389,7 @@ static bool v7m_push_stack(ARMCPU *cpu) } } else { /* Lazy stacking enabled, save necessary info to stack later */ - /* TODO : equivalent of UpdateFPCCR() pseudocode */ + v7m_update_fpccr(env, frameptr + 0x20, true); } } } -- cgit v1.2.3 From 3cd6726f0ba7cc77342ee721bd86094e13b2a42a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:00 +0100 Subject: target/arm: Clear CONTROL.SFPA in BXNS and BLXNS For v8M floating point support, transitions from Secure to Non-secure state via BLNS and BLXNS must clear the CONTROL.SFPA bit. (This corresponds to the pseudocode BranchToNS() function.) Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-13-peter.maydell@linaro.org --- target/arm/helper.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index 547898581a..088852ceb9 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -7819,6 +7819,9 @@ void HELPER(v7m_bxns)(CPUARMState *env, uint32_t dest) /* translate.c should have made BXNS UNDEF unless we're secure */ assert(env->v7m.secure); + if (!(dest & 1)) { + env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK; + } switch_v7m_security_state(env, dest & 1); env->thumb = 1; env->regs[15] = dest & ~1; @@ -7876,6 +7879,7 @@ void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest) */ write_v7m_exception(env, 1); } + env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK; switch_v7m_security_state(env, 0); env->thumb = 1; env->regs[15] = dest; -- cgit v1.2.3 From 60fba59a2f9a092a44b688df5d058cdd6dd9c276 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:00 +0100 Subject: target/arm: Clean excReturn bits when tail chaining The TailChain() pseudocode specifies that a tail chaining exception should sanitize the excReturn all-ones bits and (if there is no FPU) the excReturn FType bits; we weren't doing this. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-14-peter.maydell@linaro.org --- target/arm/helper.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index 088852ceb9..da0b620240 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8076,6 +8076,14 @@ static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, bool dotailchain, qemu_log_mask(CPU_LOG_INT, "...taking pending %s exception %d\n", targets_secure ? "secure" : "nonsecure", exc); + if (dotailchain) { + /* Sanitize LR FType and PREFIX bits */ + if (!arm_feature(env, ARM_FEATURE_VFP)) { + lr |= R_V7M_EXCRET_FTYPE_MASK; + } + lr = deposit32(lr, 24, 8, 0xff); + } + if (arm_feature(env, ARM_FEATURE_V8)) { if (arm_feature(env, ARM_FEATURE_M_SECURITY) && (lr & R_V7M_EXCRET_S_MASK)) { -- cgit v1.2.3 From 0dc51d66fcfcc4c72011cdafb401fd876ca216e7 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:00 +0100 Subject: target/arm: Allow for floating point in callee stack integrity check The magic value pushed onto the callee stack as an integrity check is different if floating point is present. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-15-peter.maydell@linaro.org --- target/arm/helper.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index da0b620240..c7b1a8d231 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -7979,6 +7979,21 @@ load_fail: return false; } +static uint32_t v7m_integrity_sig(CPUARMState *env, uint32_t lr) +{ + /* + * Return the integrity signature value for the callee-saves + * stack frame section. @lr is the exception return payload/LR value + * whose FType bit forms bit 0 of the signature if FP is present. + */ + uint32_t sig = 0xfefa125a; + + if (!arm_feature(env, ARM_FEATURE_VFP) || (lr & R_V7M_EXCRET_FTYPE_MASK)) { + sig |= 1; + } + return sig; +} + static bool v7m_push_callee_stack(ARMCPU *cpu, uint32_t lr, bool dotailchain, bool ignore_faults) { @@ -7993,6 +8008,7 @@ static bool v7m_push_callee_stack(ARMCPU *cpu, uint32_t lr, bool dotailchain, bool stacked_ok; uint32_t limit; bool want_psp; + uint32_t sig; if (dotailchain) { bool mode = lr & R_V7M_EXCRET_MODE_MASK; @@ -8034,8 +8050,9 @@ static bool v7m_push_callee_stack(ARMCPU *cpu, uint32_t lr, bool dotailchain, /* Write as much of the stack frame as we can. A write failure may * cause us to pend a derived exception. */ + sig = v7m_integrity_sig(env, lr); stacked_ok = - v7m_stack_write(cpu, frameptr, 0xfefa125b, mmu_idx, ignore_faults) && + v7m_stack_write(cpu, frameptr, sig, mmu_idx, ignore_faults) && v7m_stack_write(cpu, frameptr + 0x8, env->regs[4], mmu_idx, ignore_faults) && v7m_stack_write(cpu, frameptr + 0xc, env->regs[5], mmu_idx, @@ -8640,12 +8657,11 @@ static void do_v7m_exception_exit(ARMCPU *cpu) if (return_to_secure && ((excret & R_V7M_EXCRET_ES_MASK) == 0 || (excret & R_V7M_EXCRET_DCRS_MASK) == 0)) { - uint32_t expected_sig = 0xfefa125b; uint32_t actual_sig; pop_ok = v7m_stack_read(cpu, &actual_sig, frameptr, mmu_idx); - if (pop_ok && expected_sig != actual_sig) { + if (pop_ok && v7m_integrity_sig(env, excret) != actual_sig) { /* Take a SecureFault on the current stack */ env->v7m.sfsr |= R_V7M_SFSR_INVIS_MASK; armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); -- cgit v1.2.3 From 6808c4d2d2826920087533f517472c09edc7b0d2 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:01 +0100 Subject: target/arm: Handle floating point registers in exception return Handle floating point registers in exception return. This corresponds to pseudocode functions ValidateExceptionReturn(), ExceptionReturn(), PopStack() and ConsumeExcStackFrame(). Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-16-peter.maydell@linaro.org --- target/arm/helper.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 141 insertions(+), 1 deletion(-) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index c7b1a8d231..14604f49a4 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8447,6 +8447,8 @@ static void do_v7m_exception_exit(ARMCPU *cpu) bool rettobase = false; bool exc_secure = false; bool return_to_secure; + bool ftype; + bool restore_s16_s31; /* If we're not in Handler mode then jumps to magic exception-exit * addresses don't have magic behaviour. However for the v8M @@ -8484,6 +8486,16 @@ static void do_v7m_exception_exit(ARMCPU *cpu) excret); } + ftype = excret & R_V7M_EXCRET_FTYPE_MASK; + + if (!arm_feature(env, ARM_FEATURE_VFP) && !ftype) { + qemu_log_mask(LOG_GUEST_ERROR, "M profile: zero FTYPE in exception " + "exit PC value 0x%" PRIx32 " is UNPREDICTABLE " + "if FPU not present\n", + excret); + ftype = true; + } + if (arm_feature(env, ARM_FEATURE_M_SECURITY)) { /* EXC_RETURN.ES validation check (R_SMFL). We must do this before * we pick which FAULTMASK to clear. @@ -8584,6 +8596,30 @@ static void do_v7m_exception_exit(ARMCPU *cpu) */ write_v7m_control_spsel_for_secstate(env, return_to_sp_process, exc_secure); + /* + * Clear scratch FP values left in caller saved registers; this + * must happen before any kind of tail chaining. + */ + if ((env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_CLRONRET_MASK) && + (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK)) { + if (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK) { + env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK; + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); + qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing " + "stackframe: error during lazy state deactivation\n"); + v7m_exception_taken(cpu, excret, true, false); + return; + } else { + /* Clear s0..s15 and FPSCR */ + int i; + + for (i = 0; i < 16; i += 2) { + *aa32_vfp_dreg(env, i / 2) = 0; + } + vfp_set_fpscr(env, 0); + } + } + if (sfault) { env->v7m.sfsr |= R_V7M_SFSR_INVER_MASK; armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); @@ -8745,8 +8781,105 @@ static void do_v7m_exception_exit(ARMCPU *cpu) } } + if (!ftype) { + /* FP present and we need to handle it */ + if (!return_to_secure && + (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK)) { + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); + env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK; + qemu_log_mask(CPU_LOG_INT, + "...taking SecureFault on existing stackframe: " + "Secure LSPACT set but exception return is " + "not to secure state\n"); + v7m_exception_taken(cpu, excret, true, false); + return; + } + + restore_s16_s31 = return_to_secure && + (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK); + + if (env->v7m.fpccr[return_to_secure] & R_V7M_FPCCR_LSPACT_MASK) { + /* State in FPU is still valid, just clear LSPACT */ + env->v7m.fpccr[return_to_secure] &= ~R_V7M_FPCCR_LSPACT_MASK; + } else { + int i; + uint32_t fpscr; + bool cpacr_pass, nsacr_pass; + + cpacr_pass = v7m_cpacr_pass(env, return_to_secure, + return_to_priv); + nsacr_pass = return_to_secure || + extract32(env->v7m.nsacr, 10, 1); + + if (!cpacr_pass) { + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, + return_to_secure); + env->v7m.cfsr[return_to_secure] |= R_V7M_CFSR_NOCP_MASK; + qemu_log_mask(CPU_LOG_INT, + "...taking UsageFault on existing " + "stackframe: CPACR.CP10 prevents unstacking " + "FP regs\n"); + v7m_exception_taken(cpu, excret, true, false); + return; + } else if (!nsacr_pass) { + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, true); + env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_INVPC_MASK; + qemu_log_mask(CPU_LOG_INT, + "...taking Secure UsageFault on existing " + "stackframe: NSACR.CP10 prevents unstacking " + "FP regs\n"); + v7m_exception_taken(cpu, excret, true, false); + return; + } + + for (i = 0; i < (restore_s16_s31 ? 32 : 16); i += 2) { + uint32_t slo, shi; + uint64_t dn; + uint32_t faddr = frameptr + 0x20 + 4 * i; + + if (i >= 16) { + faddr += 8; /* Skip the slot for the FPSCR */ + } + + pop_ok = pop_ok && + v7m_stack_read(cpu, &slo, faddr, mmu_idx) && + v7m_stack_read(cpu, &shi, faddr + 4, mmu_idx); + + if (!pop_ok) { + break; + } + + dn = (uint64_t)shi << 32 | slo; + *aa32_vfp_dreg(env, i / 2) = dn; + } + pop_ok = pop_ok && + v7m_stack_read(cpu, &fpscr, frameptr + 0x60, mmu_idx); + if (pop_ok) { + vfp_set_fpscr(env, fpscr); + } + if (!pop_ok) { + /* + * These regs are 0 if security extension present; + * otherwise merely UNKNOWN. We zero always. + */ + for (i = 0; i < (restore_s16_s31 ? 32 : 16); i += 2) { + *aa32_vfp_dreg(env, i / 2) = 0; + } + vfp_set_fpscr(env, 0); + } + } + } + env->v7m.control[M_REG_S] = FIELD_DP32(env->v7m.control[M_REG_S], + V7M_CONTROL, FPCA, !ftype); + /* Commit to consuming the stack frame */ frameptr += 0x20; + if (!ftype) { + frameptr += 0x48; + if (restore_s16_s31) { + frameptr += 0x40; + } + } /* Undo stack alignment (the SPREALIGN bit indicates that the original * pre-exception SP was not 8-aligned and we added a padding word to * align it, so we undo this by ORing in the bit that increases it @@ -8759,7 +8892,14 @@ static void do_v7m_exception_exit(ARMCPU *cpu) *frame_sp_p = frameptr; } /* This xpsr_write() will invalidate frame_sp_p as it may switch stack */ - xpsr_write(env, xpsr, ~XPSR_SPREALIGN); + xpsr_write(env, xpsr, ~(XPSR_SPREALIGN | XPSR_SFPA)); + + if (env->v7m.secure) { + bool sfpa = xpsr & XPSR_SFPA; + + env->v7m.control[M_REG_S] = FIELD_DP32(env->v7m.control[M_REG_S], + V7M_CONTROL, SFPA, sfpa); + } /* The restored xPSR exception field will be zero if we're * resuming in Thread mode. If that doesn't match what the -- cgit v1.2.3 From 7fbb535f7aeb22896fedfcf18a1eeff48165f1d7 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:01 +0100 Subject: target/arm: Move NS TBFLAG from bit 19 to bit 6 Move the NS TBFLAG down from bit 19 to bit 6, which has not been used since commit c1e3781090b9d36c60 in 2015, when we started passing the entire MMU index in the TB flags rather than just a 'privilege level' bit. This rearrangement is not strictly necessary, but means that we can put M-profile-only bits next to each other rather than scattered across the flag word. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-17-peter.maydell@linaro.org --- target/arm/cpu.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'target') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index eb989d773a..0ea448034b 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -3138,6 +3138,12 @@ FIELD(TBFLAG_ANY, BE_DATA, 23, 1) FIELD(TBFLAG_A32, THUMB, 0, 1) FIELD(TBFLAG_A32, VECLEN, 1, 3) FIELD(TBFLAG_A32, VECSTRIDE, 4, 2) +/* + * Indicates whether cp register reads and writes by guest code should access + * the secure or nonsecure bank of banked registers; note that this is not + * the same thing as the current security state of the processor! + */ +FIELD(TBFLAG_A32, NS, 6, 1) FIELD(TBFLAG_A32, VFPEN, 7, 1) FIELD(TBFLAG_A32, CONDEXEC, 8, 8) FIELD(TBFLAG_A32, SCTLR_B, 16, 1) @@ -3145,11 +3151,6 @@ FIELD(TBFLAG_A32, SCTLR_B, 16, 1) * checks on the other bits at runtime */ FIELD(TBFLAG_A32, XSCALE_CPAR, 17, 2) -/* Indicates whether cp register reads and writes by guest code should access - * the secure or nonsecure bank of banked registers; note that this is not - * the same thing as the current security state of the processor! - */ -FIELD(TBFLAG_A32, NS, 19, 1) /* For M profile only, Handler (ie not Thread) mode */ FIELD(TBFLAG_A32, HANDLER, 21, 1) /* For M profile only, whether we should generate stack-limit checks */ -- cgit v1.2.3 From ea7ac69d124c94c6e5579145e727adec9ccbefef Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:01 +0100 Subject: target/arm: Overlap VECSTRIDE and XSCALE_CPAR TB flags We are close to running out of TB flags for AArch32; we could start using the cs_base word, but before we do that we can economise on our usage by sharing the same bits for the VFP VECSTRIDE field and the XScale XSCALE_CPAR field. This works because no XScale CPU ever had VFP. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-18-peter.maydell@linaro.org --- target/arm/cpu.c | 7 +++++++ target/arm/cpu.h | 10 ++++++---- target/arm/helper.c | 6 +++++- target/arm/translate.c | 9 +++++++-- 4 files changed, 25 insertions(+), 7 deletions(-) (limited to 'target') diff --git a/target/arm/cpu.c b/target/arm/cpu.c index be81e197ee..7deccda240 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -1034,6 +1034,13 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp) set_feature(env, ARM_FEATURE_THUMB_DSP); } + /* + * We rely on no XScale CPU having VFP so we can use the same bits in the + * TB flags field for VECSTRIDE and XSCALE_CPAR. + */ + assert(!(arm_feature(env, ARM_FEATURE_VFP) && + arm_feature(env, ARM_FEATURE_XSCALE))); + if (arm_feature(env, ARM_FEATURE_V7) && !arm_feature(env, ARM_FEATURE_M) && !arm_feature(env, ARM_FEATURE_PMSA)) { diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 0ea448034b..99ccb4824d 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -3138,6 +3138,12 @@ FIELD(TBFLAG_ANY, BE_DATA, 23, 1) FIELD(TBFLAG_A32, THUMB, 0, 1) FIELD(TBFLAG_A32, VECLEN, 1, 3) FIELD(TBFLAG_A32, VECSTRIDE, 4, 2) +/* + * We store the bottom two bits of the CPAR as TB flags and handle + * checks on the other bits at runtime. This shares the same bits as + * VECSTRIDE, which is OK as no XScale CPU has VFP. + */ +FIELD(TBFLAG_A32, XSCALE_CPAR, 4, 2) /* * Indicates whether cp register reads and writes by guest code should access * the secure or nonsecure bank of banked registers; note that this is not @@ -3147,10 +3153,6 @@ FIELD(TBFLAG_A32, NS, 6, 1) FIELD(TBFLAG_A32, VFPEN, 7, 1) FIELD(TBFLAG_A32, CONDEXEC, 8, 8) FIELD(TBFLAG_A32, SCTLR_B, 16, 1) -/* We store the bottom two bits of the CPAR as TB flags and handle - * checks on the other bits at runtime - */ -FIELD(TBFLAG_A32, XSCALE_CPAR, 17, 2) /* For M profile only, Handler (ie not Thread) mode */ FIELD(TBFLAG_A32, HANDLER, 21, 1) /* For M profile only, whether we should generate stack-limit checks */ diff --git a/target/arm/helper.c b/target/arm/helper.c index 14604f49a4..9be5fe581d 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -13370,7 +13370,11 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, || arm_el_is_aa64(env, 1) || arm_feature(env, ARM_FEATURE_M)) { flags = FIELD_DP32(flags, TBFLAG_A32, VFPEN, 1); } - flags = FIELD_DP32(flags, TBFLAG_A32, XSCALE_CPAR, env->cp15.c15_cpar); + /* Note that XSCALE_CPAR shares bits with VECSTRIDE */ + if (arm_feature(env, ARM_FEATURE_XSCALE)) { + flags = FIELD_DP32(flags, TBFLAG_A32, + XSCALE_CPAR, env->cp15.c15_cpar); + } } flags = FIELD_DP32(flags, TBFLAG_ANY, MMUIDX, arm_to_core_mmu_idx(mmu_idx)); diff --git a/target/arm/translate.c b/target/arm/translate.c index 0747f7847a..ffaa4f1e09 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -13330,8 +13330,13 @@ static void arm_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) dc->fp_excp_el = FIELD_EX32(tb_flags, TBFLAG_ANY, FPEXC_EL); dc->vfp_enabled = FIELD_EX32(tb_flags, TBFLAG_A32, VFPEN); dc->vec_len = FIELD_EX32(tb_flags, TBFLAG_A32, VECLEN); - dc->vec_stride = FIELD_EX32(tb_flags, TBFLAG_A32, VECSTRIDE); - dc->c15_cpar = FIELD_EX32(tb_flags, TBFLAG_A32, XSCALE_CPAR); + if (arm_feature(env, ARM_FEATURE_XSCALE)) { + dc->c15_cpar = FIELD_EX32(tb_flags, TBFLAG_A32, XSCALE_CPAR); + dc->vec_stride = 0; + } else { + dc->vec_stride = FIELD_EX32(tb_flags, TBFLAG_A32, VECSTRIDE); + dc->c15_cpar = 0; + } dc->v7m_handler_mode = FIELD_EX32(tb_flags, TBFLAG_A32, HANDLER); dc->v8m_secure = arm_feature(env, ARM_FEATURE_M_SECURITY) && regime_is_secure(env, dc->mmu_idx); -- cgit v1.2.3 From 6d60c67a1a03be32c3342aff6604cdc5095088d1 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:01 +0100 Subject: target/arm: Set FPCCR.S when executing M-profile floating point insns The M-profile FPCCR.S bit indicates the security status of the floating point context. In the pseudocode ExecuteFPCheck() function it is unconditionally set to match the current security state whenever a floating point instruction is executed. Implement this by adding a new TB flag which tracks whether FPCCR.S is different from the current security state, so that we only need to emit the code to update it in the less-common case when it is not already set correctly. Note that we will add the handling for the other work done by ExecuteFPCheck() in later commits. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-19-peter.maydell@linaro.org --- target/arm/cpu.h | 2 ++ target/arm/helper.c | 5 +++++ target/arm/translate.c | 20 ++++++++++++++++++++ target/arm/translate.h | 1 + 4 files changed, 28 insertions(+) (limited to 'target') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 99ccb4824d..a2cf9aae3a 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -3153,6 +3153,8 @@ FIELD(TBFLAG_A32, NS, 6, 1) FIELD(TBFLAG_A32, VFPEN, 7, 1) FIELD(TBFLAG_A32, CONDEXEC, 8, 8) FIELD(TBFLAG_A32, SCTLR_B, 16, 1) +/* For M profile only, set if FPCCR.S does not match current security state */ +FIELD(TBFLAG_A32, FPCCR_S_WRONG, 20, 1) /* For M profile only, Handler (ie not Thread) mode */ FIELD(TBFLAG_A32, HANDLER, 21, 1) /* For M profile only, whether we should generate stack-limit checks */ diff --git a/target/arm/helper.c b/target/arm/helper.c index 9be5fe581d..8290f56c65 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -13417,6 +13417,11 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, flags = FIELD_DP32(flags, TBFLAG_A32, STACKCHECK, 1); } + if (arm_feature(env, ARM_FEATURE_M_SECURITY) && + FIELD_EX32(env->v7m.fpccr[M_REG_S], V7M_FPCCR, S) != env->v7m.secure) { + flags = FIELD_DP32(flags, TBFLAG_A32, FPCCR_S_WRONG, 1); + } + *pflags = flags; *cs_base = 0; } diff --git a/target/arm/translate.c b/target/arm/translate.c index ffaa4f1e09..f0332ac19e 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -3421,6 +3421,25 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn) } } + if (arm_dc_feature(s, ARM_FEATURE_M)) { + /* Handle M-profile lazy FP state mechanics */ + + /* Update ownership of FP context: set FPCCR.S to match current state */ + if (s->v8m_fpccr_s_wrong) { + TCGv_i32 tmp; + + tmp = load_cpu_field(v7m.fpccr[M_REG_S]); + if (s->v8m_secure) { + tcg_gen_ori_i32(tmp, tmp, R_V7M_FPCCR_S_MASK); + } else { + tcg_gen_andi_i32(tmp, tmp, ~R_V7M_FPCCR_S_MASK); + } + store_cpu_field(tmp, v7m.fpccr[M_REG_S]); + /* Don't need to do this for any further FP insns in this TB */ + s->v8m_fpccr_s_wrong = false; + } + } + if (extract32(insn, 28, 4) == 0xf) { /* * Encodings with T=1 (Thumb) or unconditional (ARM): @@ -13341,6 +13360,7 @@ static void arm_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) dc->v8m_secure = arm_feature(env, ARM_FEATURE_M_SECURITY) && regime_is_secure(env, dc->mmu_idx); dc->v8m_stackcheck = FIELD_EX32(tb_flags, TBFLAG_A32, STACKCHECK); + dc->v8m_fpccr_s_wrong = FIELD_EX32(tb_flags, TBFLAG_A32, FPCCR_S_WRONG); dc->cp_regs = cpu->cp_regs; dc->features = env->features; diff --git a/target/arm/translate.h b/target/arm/translate.h index 984617786d..93abff645a 100644 --- a/target/arm/translate.h +++ b/target/arm/translate.h @@ -40,6 +40,7 @@ typedef struct DisasContext { bool v7m_handler_mode; bool v8m_secure; /* true if v8M and we're in Secure mode */ bool v8m_stackcheck; /* true if we need to perform v8M stack limit checks */ + bool v8m_fpccr_s_wrong; /* true if v8M FPCCR.S != v8m_secure */ /* Immediate value in AArch32 SVC insn; must be set if is_jmp == DISAS_SWI * so that top level loop can generate correct syndrome information. */ -- cgit v1.2.3 From 6000531e19964756673a5f4b694a649ef883605a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:01 +0100 Subject: target/arm: Activate M-profile floating point context when FPCCR.ASPEN is set The M-profile FPCCR.ASPEN bit indicates that automatic floating-point context preservation is enabled. Before executing any floating-point instruction, if FPCCR.ASPEN is set and the CONTROL FPCA/SFPA bits indicate that there is no active floating point context then we must create a new context (by initializing FPSCR and setting FPCA/SFPA to indicate that the context is now active). In the pseudocode this is handled by ExecuteFPCheck(). Implement this with a new TB flag which tracks whether we need to create a new FP context. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-20-peter.maydell@linaro.org --- target/arm/cpu.h | 2 ++ target/arm/helper.c | 13 +++++++++++++ target/arm/translate.c | 29 +++++++++++++++++++++++++++++ target/arm/translate.h | 1 + 4 files changed, 45 insertions(+) (limited to 'target') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index a2cf9aae3a..d4996a4d20 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -3153,6 +3153,8 @@ FIELD(TBFLAG_A32, NS, 6, 1) FIELD(TBFLAG_A32, VFPEN, 7, 1) FIELD(TBFLAG_A32, CONDEXEC, 8, 8) FIELD(TBFLAG_A32, SCTLR_B, 16, 1) +/* For M profile only, set if we must create a new FP context */ +FIELD(TBFLAG_A32, NEW_FP_CTXT_NEEDED, 19, 1) /* For M profile only, set if FPCCR.S does not match current security state */ FIELD(TBFLAG_A32, FPCCR_S_WRONG, 20, 1) /* For M profile only, Handler (ie not Thread) mode */ diff --git a/target/arm/helper.c b/target/arm/helper.c index 8290f56c65..84e3790a9d 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -13422,6 +13422,19 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, flags = FIELD_DP32(flags, TBFLAG_A32, FPCCR_S_WRONG, 1); } + if (arm_feature(env, ARM_FEATURE_M) && + (env->v7m.fpccr[env->v7m.secure] & R_V7M_FPCCR_ASPEN_MASK) && + (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) || + (env->v7m.secure && + !(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)))) { + /* + * ASPEN is set, but FPCA/SFPA indicate that there is no active + * FP context; we must create a new FP context before executing + * any FP insn. + */ + flags = FIELD_DP32(flags, TBFLAG_A32, NEW_FP_CTXT_NEEDED, 1); + } + *pflags = flags; *cs_base = 0; } diff --git a/target/arm/translate.c b/target/arm/translate.c index f0332ac19e..edb66e7be8 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -3438,6 +3438,33 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn) /* Don't need to do this for any further FP insns in this TB */ s->v8m_fpccr_s_wrong = false; } + + if (s->v7m_new_fp_ctxt_needed) { + /* + * Create new FP context by updating CONTROL.FPCA, CONTROL.SFPA + * and the FPSCR. + */ + TCGv_i32 control, fpscr; + uint32_t bits = R_V7M_CONTROL_FPCA_MASK; + + fpscr = load_cpu_field(v7m.fpdscr[s->v8m_secure]); + gen_helper_vfp_set_fpscr(cpu_env, fpscr); + tcg_temp_free_i32(fpscr); + /* + * We don't need to arrange to end the TB, because the only + * parts of FPSCR which we cache in the TB flags are the VECLEN + * and VECSTRIDE, and those don't exist for M-profile. + */ + + if (s->v8m_secure) { + bits |= R_V7M_CONTROL_SFPA_MASK; + } + control = load_cpu_field(v7m.control[M_REG_S]); + tcg_gen_ori_i32(control, control, bits); + store_cpu_field(control, v7m.control[M_REG_S]); + /* Don't need to do this for any further FP insns in this TB */ + s->v7m_new_fp_ctxt_needed = false; + } } if (extract32(insn, 28, 4) == 0xf) { @@ -13361,6 +13388,8 @@ static void arm_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) regime_is_secure(env, dc->mmu_idx); dc->v8m_stackcheck = FIELD_EX32(tb_flags, TBFLAG_A32, STACKCHECK); dc->v8m_fpccr_s_wrong = FIELD_EX32(tb_flags, TBFLAG_A32, FPCCR_S_WRONG); + dc->v7m_new_fp_ctxt_needed = + FIELD_EX32(tb_flags, TBFLAG_A32, NEW_FP_CTXT_NEEDED); dc->cp_regs = cpu->cp_regs; dc->features = env->features; diff --git a/target/arm/translate.h b/target/arm/translate.h index 93abff645a..ed8ae2e7e3 100644 --- a/target/arm/translate.h +++ b/target/arm/translate.h @@ -41,6 +41,7 @@ typedef struct DisasContext { bool v8m_secure; /* true if v8M and we're in Secure mode */ bool v8m_stackcheck; /* true if we need to perform v8M stack limit checks */ bool v8m_fpccr_s_wrong; /* true if v8M FPCCR.S != v8m_secure */ + bool v7m_new_fp_ctxt_needed; /* ASPEN set but no active FP context */ /* Immediate value in AArch32 SVC insn; must be set if is_jmp == DISAS_SWI * so that top level loop can generate correct syndrome information. */ -- cgit v1.2.3 From fa6252a988dbe440cd6087bf93cbe0887f0c401b Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:02 +0100 Subject: target/arm: New helper function arm_v7m_mmu_idx_all() Add a new helper function which returns the MMU index to use for v7M, where the caller specifies all of the security state, privilege level and whether the execution priority is negative, and reimplement the existing arm_v7m_mmu_idx_for_secstate_and_priv() in terms of it. We are going to need this for the lazy-FP-stacking code. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-21-peter.maydell@linaro.org --- target/arm/cpu.h | 7 +++++++ target/arm/helper.c | 14 +++++++++++--- 2 files changed, 18 insertions(+), 3 deletions(-) (limited to 'target') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index d4996a4d20..920cf36702 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -2911,6 +2911,13 @@ static inline int arm_mmu_idx_to_el(ARMMMUIdx mmu_idx) } } +/* + * Return the MMU index for a v7M CPU with all relevant information + * manually specified. + */ +ARMMMUIdx arm_v7m_mmu_idx_all(CPUARMState *env, + bool secstate, bool priv, bool negpri); + /* Return the MMU index for a v7M CPU in the specified security and * privilege state. */ diff --git a/target/arm/helper.c b/target/arm/helper.c index 84e3790a9d..1ed5f1a251 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -13230,8 +13230,8 @@ int fp_exception_el(CPUARMState *env, int cur_el) return 0; } -ARMMMUIdx arm_v7m_mmu_idx_for_secstate_and_priv(CPUARMState *env, - bool secstate, bool priv) +ARMMMUIdx arm_v7m_mmu_idx_all(CPUARMState *env, + bool secstate, bool priv, bool negpri) { ARMMMUIdx mmu_idx = ARM_MMU_IDX_M; @@ -13239,7 +13239,7 @@ ARMMMUIdx arm_v7m_mmu_idx_for_secstate_and_priv(CPUARMState *env, mmu_idx |= ARM_MMU_IDX_M_PRIV; } - if (armv7m_nvic_neg_prio_requested(env->nvic, secstate)) { + if (negpri) { mmu_idx |= ARM_MMU_IDX_M_NEGPRI; } @@ -13250,6 +13250,14 @@ ARMMMUIdx arm_v7m_mmu_idx_for_secstate_and_priv(CPUARMState *env, return mmu_idx; } +ARMMMUIdx arm_v7m_mmu_idx_for_secstate_and_priv(CPUARMState *env, + bool secstate, bool priv) +{ + bool negpri = armv7m_nvic_neg_prio_requested(env->nvic, secstate); + + return arm_v7m_mmu_idx_all(env, secstate, priv, negpri); +} + /* Return the MMU index for a v7M CPU in the specified security state */ ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, bool secstate) { -- cgit v1.2.3 From a99ba8ab1601904e0fa20325192fc850362ce80e Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:02 +0100 Subject: target/arm: New function armv7m_nvic_set_pending_lazyfp() In the v7M architecture, if an exception is generated in the process of doing the lazy stacking of FP registers, the handling of possible escalation to HardFault is treated differently to the normal approach: it works based on the saved information about exception readiness that was stored in the FPCCR when the stack frame was created. Provide a new function armv7m_nvic_set_pending_lazyfp() which pends exceptions during lazy stacking, and implements this logic. This corresponds to the pseudocode TakePreserveFPException(). Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-22-peter.maydell@linaro.org --- target/arm/cpu.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'target') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 920cf36702..ed3069341d 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -2008,6 +2008,18 @@ void armv7m_nvic_set_pending(void *opaque, int irq, bool secure); * a different exception). */ void armv7m_nvic_set_pending_derived(void *opaque, int irq, bool secure); +/** + * armv7m_nvic_set_pending_lazyfp: mark this lazy FP exception as pending + * @opaque: the NVIC + * @irq: the exception number to mark pending + * @secure: false for non-banked exceptions or for the nonsecure + * version of a banked exception, true for the secure version of a banked + * exception. + * + * Similar to armv7m_nvic_set_pending(), but specifically for exceptions + * generated in the course of lazy stacking of FP registers. + */ +void armv7m_nvic_set_pending_lazyfp(void *opaque, int irq, bool secure); /** * armv7m_nvic_get_pending_irq_info: return highest priority pending * exception, and whether it targets Secure state -- cgit v1.2.3 From a356dacf647506bccdf8ecd23574246a8bf615ac Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:02 +0100 Subject: target/arm: Add lazy-FP-stacking support to v7m_stack_write() Pushing registers to the stack for v7M needs to handle three cases: * the "normal" case where we pend exceptions * an "ignore faults" case where we set FSR bits but do not pend exceptions (this is used when we are handling some kinds of derived exception on exception entry) * a "lazy FP stacking" case, where different FSR bits are set and the exception is pended differently Implement this by changing the existing flag argument that tells us whether to ignore faults or not into an enum that specifies which of the 3 modes we should handle. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-23-peter.maydell@linaro.org --- target/arm/helper.c | 118 +++++++++++++++++++++++++++++++++++----------------- 1 file changed, 79 insertions(+), 39 deletions(-) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index 1ed5f1a251..4153139085 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -7575,8 +7575,18 @@ static bool v7m_cpacr_pass(CPUARMState *env, bool is_secure, bool is_priv) } } +/* + * What kind of stack write are we doing? This affects how exceptions + * generated during the stacking are treated. + */ +typedef enum StackingMode { + STACK_NORMAL, + STACK_IGNFAULTS, + STACK_LAZYFP, +} StackingMode; + static bool v7m_stack_write(ARMCPU *cpu, uint32_t addr, uint32_t value, - ARMMMUIdx mmu_idx, bool ignfault) + ARMMMUIdx mmu_idx, StackingMode mode) { CPUState *cs = CPU(cpu); CPUARMState *env = &cpu->env; @@ -7594,15 +7604,31 @@ static bool v7m_stack_write(ARMCPU *cpu, uint32_t addr, uint32_t value, &attrs, &prot, &page_size, &fi, NULL)) { /* MPU/SAU lookup failed */ if (fi.type == ARMFault_QEMU_SFault) { - qemu_log_mask(CPU_LOG_INT, - "...SecureFault with SFSR.AUVIOL during stacking\n"); - env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK | R_V7M_SFSR_SFARVALID_MASK; + if (mode == STACK_LAZYFP) { + qemu_log_mask(CPU_LOG_INT, + "...SecureFault with SFSR.LSPERR " + "during lazy stacking\n"); + env->v7m.sfsr |= R_V7M_SFSR_LSPERR_MASK; + } else { + qemu_log_mask(CPU_LOG_INT, + "...SecureFault with SFSR.AUVIOL " + "during stacking\n"); + env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK; + } + env->v7m.sfsr |= R_V7M_SFSR_SFARVALID_MASK; env->v7m.sfar = addr; exc = ARMV7M_EXCP_SECURE; exc_secure = false; } else { - qemu_log_mask(CPU_LOG_INT, "...MemManageFault with CFSR.MSTKERR\n"); - env->v7m.cfsr[secure] |= R_V7M_CFSR_MSTKERR_MASK; + if (mode == STACK_LAZYFP) { + qemu_log_mask(CPU_LOG_INT, + "...MemManageFault with CFSR.MLSPERR\n"); + env->v7m.cfsr[secure] |= R_V7M_CFSR_MLSPERR_MASK; + } else { + qemu_log_mask(CPU_LOG_INT, + "...MemManageFault with CFSR.MSTKERR\n"); + env->v7m.cfsr[secure] |= R_V7M_CFSR_MSTKERR_MASK; + } exc = ARMV7M_EXCP_MEM; exc_secure = secure; } @@ -7612,8 +7638,13 @@ static bool v7m_stack_write(ARMCPU *cpu, uint32_t addr, uint32_t value, attrs, &txres); if (txres != MEMTX_OK) { /* BusFault trying to write the data */ - qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.STKERR\n"); - env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_STKERR_MASK; + if (mode == STACK_LAZYFP) { + qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.LSPERR\n"); + env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_LSPERR_MASK; + } else { + qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.STKERR\n"); + env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_STKERR_MASK; + } exc = ARMV7M_EXCP_BUS; exc_secure = false; goto pend_fault; @@ -7628,11 +7659,19 @@ pend_fault: * later if we have two derived exceptions. * The only case when we must not pend the exception but instead * throw it away is if we are doing the push of the callee registers - * and we've already generated a derived exception. Even in this - * case we will still update the fault status registers. + * and we've already generated a derived exception (this is indicated + * by the caller passing STACK_IGNFAULTS). Even in this case we will + * still update the fault status registers. */ - if (!ignfault) { + switch (mode) { + case STACK_NORMAL: armv7m_nvic_set_pending_derived(env->nvic, exc, exc_secure); + break; + case STACK_LAZYFP: + armv7m_nvic_set_pending_lazyfp(env->nvic, exc, exc_secure); + break; + case STACK_IGNFAULTS: + break; } return false; } @@ -8009,6 +8048,7 @@ static bool v7m_push_callee_stack(ARMCPU *cpu, uint32_t lr, bool dotailchain, uint32_t limit; bool want_psp; uint32_t sig; + StackingMode smode = ignore_faults ? STACK_IGNFAULTS : STACK_NORMAL; if (dotailchain) { bool mode = lr & R_V7M_EXCRET_MODE_MASK; @@ -8052,23 +8092,15 @@ static bool v7m_push_callee_stack(ARMCPU *cpu, uint32_t lr, bool dotailchain, */ sig = v7m_integrity_sig(env, lr); stacked_ok = - v7m_stack_write(cpu, frameptr, sig, mmu_idx, ignore_faults) && - v7m_stack_write(cpu, frameptr + 0x8, env->regs[4], mmu_idx, - ignore_faults) && - v7m_stack_write(cpu, frameptr + 0xc, env->regs[5], mmu_idx, - ignore_faults) && - v7m_stack_write(cpu, frameptr + 0x10, env->regs[6], mmu_idx, - ignore_faults) && - v7m_stack_write(cpu, frameptr + 0x14, env->regs[7], mmu_idx, - ignore_faults) && - v7m_stack_write(cpu, frameptr + 0x18, env->regs[8], mmu_idx, - ignore_faults) && - v7m_stack_write(cpu, frameptr + 0x1c, env->regs[9], mmu_idx, - ignore_faults) && - v7m_stack_write(cpu, frameptr + 0x20, env->regs[10], mmu_idx, - ignore_faults) && - v7m_stack_write(cpu, frameptr + 0x24, env->regs[11], mmu_idx, - ignore_faults); + v7m_stack_write(cpu, frameptr, sig, mmu_idx, smode) && + v7m_stack_write(cpu, frameptr + 0x8, env->regs[4], mmu_idx, smode) && + v7m_stack_write(cpu, frameptr + 0xc, env->regs[5], mmu_idx, smode) && + v7m_stack_write(cpu, frameptr + 0x10, env->regs[6], mmu_idx, smode) && + v7m_stack_write(cpu, frameptr + 0x14, env->regs[7], mmu_idx, smode) && + v7m_stack_write(cpu, frameptr + 0x18, env->regs[8], mmu_idx, smode) && + v7m_stack_write(cpu, frameptr + 0x1c, env->regs[9], mmu_idx, smode) && + v7m_stack_write(cpu, frameptr + 0x20, env->regs[10], mmu_idx, smode) && + v7m_stack_write(cpu, frameptr + 0x24, env->regs[11], mmu_idx, smode); /* Update SP regardless of whether any of the stack accesses failed. */ *frame_sp_p = frameptr; @@ -8347,14 +8379,20 @@ static bool v7m_push_stack(ARMCPU *cpu) * if it has higher priority). */ stacked_ok = stacked_ok && - v7m_stack_write(cpu, frameptr, env->regs[0], mmu_idx, false) && - v7m_stack_write(cpu, frameptr + 4, env->regs[1], mmu_idx, false) && - v7m_stack_write(cpu, frameptr + 8, env->regs[2], mmu_idx, false) && - v7m_stack_write(cpu, frameptr + 12, env->regs[3], mmu_idx, false) && - v7m_stack_write(cpu, frameptr + 16, env->regs[12], mmu_idx, false) && - v7m_stack_write(cpu, frameptr + 20, env->regs[14], mmu_idx, false) && - v7m_stack_write(cpu, frameptr + 24, env->regs[15], mmu_idx, false) && - v7m_stack_write(cpu, frameptr + 28, xpsr, mmu_idx, false); + v7m_stack_write(cpu, frameptr, env->regs[0], mmu_idx, STACK_NORMAL) && + v7m_stack_write(cpu, frameptr + 4, env->regs[1], + mmu_idx, STACK_NORMAL) && + v7m_stack_write(cpu, frameptr + 8, env->regs[2], + mmu_idx, STACK_NORMAL) && + v7m_stack_write(cpu, frameptr + 12, env->regs[3], + mmu_idx, STACK_NORMAL) && + v7m_stack_write(cpu, frameptr + 16, env->regs[12], + mmu_idx, STACK_NORMAL) && + v7m_stack_write(cpu, frameptr + 20, env->regs[14], + mmu_idx, STACK_NORMAL) && + v7m_stack_write(cpu, frameptr + 24, env->regs[15], + mmu_idx, STACK_NORMAL) && + v7m_stack_write(cpu, frameptr + 28, xpsr, mmu_idx, STACK_NORMAL); if (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) { /* FPU is active, try to save its registers */ @@ -8404,12 +8442,14 @@ static bool v7m_push_stack(ARMCPU *cpu) faddr += 8; /* skip the slot for the FPSCR */ } stacked_ok = stacked_ok && - v7m_stack_write(cpu, faddr, slo, mmu_idx, false) && - v7m_stack_write(cpu, faddr + 4, shi, mmu_idx, false); + v7m_stack_write(cpu, faddr, slo, + mmu_idx, STACK_NORMAL) && + v7m_stack_write(cpu, faddr + 4, shi, + mmu_idx, STACK_NORMAL); } stacked_ok = stacked_ok && v7m_stack_write(cpu, frameptr + 0x60, - vfp_get_fpscr(env), mmu_idx, false); + vfp_get_fpscr(env), mmu_idx, STACK_NORMAL); if (cpacr_pass) { for (i = 0; i < ((framesize == 0xa8) ? 32 : 16); i += 2) { *aa32_vfp_dreg(env, i / 2) = 0; -- cgit v1.2.3 From e33cf0f8d8c9998a7616684f9d6aa0d181b88803 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:02 +0100 Subject: target/arm: Implement M-profile lazy FP state preservation The M-profile architecture floating point system supports lazy FP state preservation, where FP registers are not pushed to the stack when an exception occurs but are instead only saved if and when the first FP instruction in the exception handler is executed. Implement this in QEMU, corresponding to the check of LSPACT in the pseudocode ExecuteFPCheck(). Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-24-peter.maydell@linaro.org --- target/arm/cpu.h | 3 ++ target/arm/helper.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++++ target/arm/helper.h | 2 + target/arm/translate.c | 22 ++++++++++ target/arm/translate.h | 1 + 5 files changed, 140 insertions(+) (limited to 'target') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index ed3069341d..0b10aefb93 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -57,6 +57,7 @@ #define EXCP_NOCP 17 /* v7M NOCP UsageFault */ #define EXCP_INVSTATE 18 /* v7M INVSTATE UsageFault */ #define EXCP_STKOF 19 /* v8M STKOF UsageFault */ +#define EXCP_LAZYFP 20 /* v7M fault during lazy FP stacking */ /* NB: add new EXCP_ defines to the array in arm_log_exception() too */ #define ARMV7M_EXCP_RESET 1 @@ -3172,6 +3173,8 @@ FIELD(TBFLAG_A32, NS, 6, 1) FIELD(TBFLAG_A32, VFPEN, 7, 1) FIELD(TBFLAG_A32, CONDEXEC, 8, 8) FIELD(TBFLAG_A32, SCTLR_B, 16, 1) +/* For M profile only, set if FPCCR.LSPACT is set */ +FIELD(TBFLAG_A32, LSPACT, 18, 1) /* For M profile only, set if we must create a new FP context */ FIELD(TBFLAG_A32, NEW_FP_CTXT_NEEDED, 19, 1) /* For M profile only, set if FPCCR.S does not match current security state */ diff --git a/target/arm/helper.c b/target/arm/helper.c index 4153139085..b11f8aa14d 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -7378,6 +7378,12 @@ void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest) g_assert_not_reached(); } +void HELPER(v7m_preserve_fp_state)(CPUARMState *env) +{ + /* translate.c should never generate calls here in user-only mode */ + g_assert_not_reached(); +} + uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op) { /* The TT instructions can be used by unprivileged code, but in @@ -7737,6 +7743,97 @@ pend_fault: return false; } +void HELPER(v7m_preserve_fp_state)(CPUARMState *env) +{ + /* + * Preserve FP state (because LSPACT was set and we are about + * to execute an FP instruction). This corresponds to the + * PreserveFPState() pseudocode. + * We may throw an exception if the stacking fails. + */ + ARMCPU *cpu = arm_env_get_cpu(env); + bool is_secure = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK; + bool negpri = !(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_HFRDY_MASK); + bool is_priv = !(env->v7m.fpccr[is_secure] & R_V7M_FPCCR_USER_MASK); + bool splimviol = env->v7m.fpccr[is_secure] & R_V7M_FPCCR_SPLIMVIOL_MASK; + uint32_t fpcar = env->v7m.fpcar[is_secure]; + bool stacked_ok = true; + bool ts = is_secure && (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK); + bool take_exception; + + /* Take the iothread lock as we are going to touch the NVIC */ + qemu_mutex_lock_iothread(); + + /* Check the background context had access to the FPU */ + if (!v7m_cpacr_pass(env, is_secure, is_priv)) { + armv7m_nvic_set_pending_lazyfp(env->nvic, ARMV7M_EXCP_USAGE, is_secure); + env->v7m.cfsr[is_secure] |= R_V7M_CFSR_NOCP_MASK; + stacked_ok = false; + } else if (!is_secure && !extract32(env->v7m.nsacr, 10, 1)) { + armv7m_nvic_set_pending_lazyfp(env->nvic, ARMV7M_EXCP_USAGE, M_REG_S); + env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_NOCP_MASK; + stacked_ok = false; + } + + if (!splimviol && stacked_ok) { + /* We only stack if the stack limit wasn't violated */ + int i; + ARMMMUIdx mmu_idx; + + mmu_idx = arm_v7m_mmu_idx_all(env, is_secure, is_priv, negpri); + for (i = 0; i < (ts ? 32 : 16); i += 2) { + uint64_t dn = *aa32_vfp_dreg(env, i / 2); + uint32_t faddr = fpcar + 4 * i; + uint32_t slo = extract64(dn, 0, 32); + uint32_t shi = extract64(dn, 32, 32); + + if (i >= 16) { + faddr += 8; /* skip the slot for the FPSCR */ + } + stacked_ok = stacked_ok && + v7m_stack_write(cpu, faddr, slo, mmu_idx, STACK_LAZYFP) && + v7m_stack_write(cpu, faddr + 4, shi, mmu_idx, STACK_LAZYFP); + } + + stacked_ok = stacked_ok && + v7m_stack_write(cpu, fpcar + 0x40, + vfp_get_fpscr(env), mmu_idx, STACK_LAZYFP); + } + + /* + * We definitely pended an exception, but it's possible that it + * might not be able to be taken now. If its priority permits us + * to take it now, then we must not update the LSPACT or FP regs, + * but instead jump out to take the exception immediately. + * If it's just pending and won't be taken until the current + * handler exits, then we do update LSPACT and the FP regs. + */ + take_exception = !stacked_ok && + armv7m_nvic_can_take_pending_exception(env->nvic); + + qemu_mutex_unlock_iothread(); + + if (take_exception) { + raise_exception_ra(env, EXCP_LAZYFP, 0, 1, GETPC()); + } + + env->v7m.fpccr[is_secure] &= ~R_V7M_FPCCR_LSPACT_MASK; + + if (ts) { + /* Clear s0 to s31 and the FPSCR */ + int i; + + for (i = 0; i < 32; i += 2) { + *aa32_vfp_dreg(env, i / 2) = 0; + } + vfp_set_fpscr(env, 0); + } + /* + * Otherwise s0 to s15 and FPSCR are UNKNOWN; we choose to leave them + * unchanged. + */ +} + /* Write to v7M CONTROL.SPSEL bit for the specified security bank. * This may change the current stack pointer between Main and Process * stack pointers if it is done for the CONTROL register for the current @@ -9062,6 +9159,7 @@ static void arm_log_exception(int idx) [EXCP_NOCP] = "v7M NOCP UsageFault", [EXCP_INVSTATE] = "v7M INVSTATE UsageFault", [EXCP_STKOF] = "v8M STKOF UsageFault", + [EXCP_LAZYFP] = "v7M exception during lazy FP stacking", }; if (idx >= 0 && idx < ARRAY_SIZE(excnames)) { @@ -9355,6 +9453,12 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) return; } break; + case EXCP_LAZYFP: + /* + * We already pended the specific exception in the NVIC in the + * v7m_preserve_fp_state() helper function. + */ + break; default: cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index); return; /* Never happens. Keep compiler happy. */ @@ -13483,6 +13587,14 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, flags = FIELD_DP32(flags, TBFLAG_A32, NEW_FP_CTXT_NEEDED, 1); } + if (arm_feature(env, ARM_FEATURE_M)) { + bool is_secure = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK; + + if (env->v7m.fpccr[is_secure] & R_V7M_FPCCR_LSPACT_MASK) { + flags = FIELD_DP32(flags, TBFLAG_A32, LSPACT, 1); + } + } + *pflags = flags; *cs_base = 0; } diff --git a/target/arm/helper.h b/target/arm/helper.h index a09566f795..0a3a80528c 100644 --- a/target/arm/helper.h +++ b/target/arm/helper.h @@ -69,6 +69,8 @@ DEF_HELPER_2(v7m_blxns, void, env, i32) DEF_HELPER_3(v7m_tt, i32, env, i32, i32) +DEF_HELPER_1(v7m_preserve_fp_state, void, env) + DEF_HELPER_2(v8m_stackcheck, void, env, i32) DEF_HELPER_4(access_check_cp_reg, void, env, ptr, i32, i32) diff --git a/target/arm/translate.c b/target/arm/translate.c index edb66e7be8..4f29d09a28 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -3424,6 +3424,27 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn) if (arm_dc_feature(s, ARM_FEATURE_M)) { /* Handle M-profile lazy FP state mechanics */ + /* Trigger lazy-state preservation if necessary */ + if (s->v7m_lspact) { + /* + * Lazy state saving affects external memory and also the NVIC, + * so we must mark it as an IO operation for icount. + */ + if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) { + gen_io_start(); + } + gen_helper_v7m_preserve_fp_state(cpu_env); + if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) { + gen_io_end(); + } + /* + * If the preserve_fp_state helper doesn't throw an exception + * then it will clear LSPACT; we don't need to repeat this for + * any further FP insns in this TB. + */ + s->v7m_lspact = false; + } + /* Update ownership of FP context: set FPCCR.S to match current state */ if (s->v8m_fpccr_s_wrong) { TCGv_i32 tmp; @@ -13390,6 +13411,7 @@ static void arm_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) dc->v8m_fpccr_s_wrong = FIELD_EX32(tb_flags, TBFLAG_A32, FPCCR_S_WRONG); dc->v7m_new_fp_ctxt_needed = FIELD_EX32(tb_flags, TBFLAG_A32, NEW_FP_CTXT_NEEDED); + dc->v7m_lspact = FIELD_EX32(tb_flags, TBFLAG_A32, LSPACT); dc->cp_regs = cpu->cp_regs; dc->features = env->features; diff --git a/target/arm/translate.h b/target/arm/translate.h index ed8ae2e7e3..c2348def0d 100644 --- a/target/arm/translate.h +++ b/target/arm/translate.h @@ -42,6 +42,7 @@ typedef struct DisasContext { bool v8m_stackcheck; /* true if we need to perform v8M stack limit checks */ bool v8m_fpccr_s_wrong; /* true if v8M FPCCR.S != v8m_secure */ bool v7m_new_fp_ctxt_needed; /* ASPEN set but no active FP context */ + bool v7m_lspact; /* FPCCR.LSPACT set */ /* Immediate value in AArch32 SVC insn; must be set if is_jmp == DISAS_SWI * so that top level loop can generate correct syndrome information. */ -- cgit v1.2.3 From 019076b036da4444494de38388218040d9d3a26c Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:03 +0100 Subject: target/arm: Implement VLSTM for v7M CPUs with an FPU Implement the VLSTM instruction for v7M for the FPU present case. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-25-peter.maydell@linaro.org --- target/arm/cpu.h | 2 ++ target/arm/helper.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++ target/arm/helper.h | 2 ++ target/arm/translate.c | 15 ++++++++- 4 files changed, 102 insertions(+), 1 deletion(-) (limited to 'target') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 0b10aefb93..22bc6e00ab 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -58,6 +58,8 @@ #define EXCP_INVSTATE 18 /* v7M INVSTATE UsageFault */ #define EXCP_STKOF 19 /* v8M STKOF UsageFault */ #define EXCP_LAZYFP 20 /* v7M fault during lazy FP stacking */ +#define EXCP_LSERR 21 /* v8M LSERR SecureFault */ +#define EXCP_UNALIGNED 22 /* v7M UNALIGNED UsageFault */ /* NB: add new EXCP_ defines to the array in arm_log_exception() too */ #define ARMV7M_EXCP_RESET 1 diff --git a/target/arm/helper.c b/target/arm/helper.c index b11f8aa14d..b821037c3b 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -7384,6 +7384,12 @@ void HELPER(v7m_preserve_fp_state)(CPUARMState *env) g_assert_not_reached(); } +void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr) +{ + /* translate.c should never generate calls here in user-only mode */ + g_assert_not_reached(); +} + uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op) { /* The TT instructions can be used by unprivileged code, but in @@ -8400,6 +8406,74 @@ static void v7m_update_fpccr(CPUARMState *env, uint32_t frameptr, } } +void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr) +{ + /* fptr is the value of Rn, the frame pointer we store the FP regs to */ + bool s = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK; + bool lspact = env->v7m.fpccr[s] & R_V7M_FPCCR_LSPACT_MASK; + + assert(env->v7m.secure); + + if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) { + return; + } + + /* Check access to the coprocessor is permitted */ + if (!v7m_cpacr_pass(env, true, arm_current_el(env) != 0)) { + raise_exception_ra(env, EXCP_NOCP, 0, 1, GETPC()); + } + + if (lspact) { + /* LSPACT should not be active when there is active FP state */ + raise_exception_ra(env, EXCP_LSERR, 0, 1, GETPC()); + } + + if (fptr & 7) { + raise_exception_ra(env, EXCP_UNALIGNED, 0, 1, GETPC()); + } + + /* + * Note that we do not use v7m_stack_write() here, because the + * accesses should not set the FSR bits for stacking errors if they + * fail. (In pseudocode terms, they are AccType_NORMAL, not AccType_STACK + * or AccType_LAZYFP). Faults in cpu_stl_data() will throw exceptions + * and longjmp out. + */ + if (!(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPEN_MASK)) { + bool ts = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK; + int i; + + for (i = 0; i < (ts ? 32 : 16); i += 2) { + uint64_t dn = *aa32_vfp_dreg(env, i / 2); + uint32_t faddr = fptr + 4 * i; + uint32_t slo = extract64(dn, 0, 32); + uint32_t shi = extract64(dn, 32, 32); + + if (i >= 16) { + faddr += 8; /* skip the slot for the FPSCR */ + } + cpu_stl_data(env, faddr, slo); + cpu_stl_data(env, faddr + 4, shi); + } + cpu_stl_data(env, fptr + 0x40, vfp_get_fpscr(env)); + + /* + * If TS is 0 then s0 to s15 and FPSCR are UNKNOWN; we choose to + * leave them unchanged, matching our choice in v7m_preserve_fp_state. + */ + if (ts) { + for (i = 0; i < 32; i += 2) { + *aa32_vfp_dreg(env, i / 2) = 0; + } + vfp_set_fpscr(env, 0); + } + } else { + v7m_update_fpccr(env, fptr, false); + } + + env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK; +} + static bool v7m_push_stack(ARMCPU *cpu) { /* Do the "set up stack frame" part of exception entry, @@ -9160,6 +9234,8 @@ static void arm_log_exception(int idx) [EXCP_INVSTATE] = "v7M INVSTATE UsageFault", [EXCP_STKOF] = "v8M STKOF UsageFault", [EXCP_LAZYFP] = "v7M exception during lazy FP stacking", + [EXCP_LSERR] = "v8M LSERR UsageFault", + [EXCP_UNALIGNED] = "v7M UNALIGNED UsageFault", }; if (idx >= 0 && idx < ARRAY_SIZE(excnames)) { @@ -9334,6 +9410,14 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK; break; + case EXCP_LSERR: + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false); + env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK; + break; + case EXCP_UNALIGNED: + armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure); + env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_UNALIGNED_MASK; + break; case EXCP_SWI: /* The PC already points to the next instruction. */ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SVC, env->v7m.secure); diff --git a/target/arm/helper.h b/target/arm/helper.h index 0a3a80528c..62051ae6d5 100644 --- a/target/arm/helper.h +++ b/target/arm/helper.h @@ -71,6 +71,8 @@ DEF_HELPER_3(v7m_tt, i32, env, i32, i32) DEF_HELPER_1(v7m_preserve_fp_state, void, env) +DEF_HELPER_2(v7m_vlstm, void, env, i32) + DEF_HELPER_2(v8m_stackcheck, void, env, i32) DEF_HELPER_4(access_check_cp_reg, void, env, ptr, i32, i32) diff --git a/target/arm/translate.c b/target/arm/translate.c index 4f29d09a28..99b38dd5f2 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -11818,7 +11818,20 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn) if (!s->v8m_secure || (insn & 0x0040f0ff)) { goto illegal_op; } - /* Just NOP since FP support is not implemented */ + + if (arm_dc_feature(s, ARM_FEATURE_VFP)) { + TCGv_i32 fptr = load_reg(s, rn); + + if (extract32(insn, 20, 1)) { + /* VLLDM */ + } else { + gen_helper_v7m_vlstm(cpu_env, fptr); + } + tcg_temp_free_i32(fptr); + + /* End the TB, because we have updated FP control bits */ + s->base.is_jmp = DISAS_UPDATE; + } break; } if (arm_dc_feature(s, ARM_FEATURE_VFP) && -- cgit v1.2.3 From 956fe143b4f254356496a0a1c479fa632376dfec Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:03 +0100 Subject: target/arm: Implement VLLDM for v7M CPUs with an FPU Implement the VLLDM instruction for v7M for the FPU present cas. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-26-peter.maydell@linaro.org --- target/arm/helper.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++ target/arm/helper.h | 1 + target/arm/translate.c | 2 +- 3 files changed, 56 insertions(+), 1 deletion(-) (limited to 'target') diff --git a/target/arm/helper.c b/target/arm/helper.c index b821037c3b..81a92ab491 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -7390,6 +7390,12 @@ void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr) g_assert_not_reached(); } +void HELPER(v7m_vlldm)(CPUARMState *env, uint32_t fptr) +{ + /* translate.c should never generate calls here in user-only mode */ + g_assert_not_reached(); +} + uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op) { /* The TT instructions can be used by unprivileged code, but in @@ -8474,6 +8480,54 @@ void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr) env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK; } +void HELPER(v7m_vlldm)(CPUARMState *env, uint32_t fptr) +{ + /* fptr is the value of Rn, the frame pointer we load the FP regs from */ + assert(env->v7m.secure); + + if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) { + return; + } + + /* Check access to the coprocessor is permitted */ + if (!v7m_cpacr_pass(env, true, arm_current_el(env) != 0)) { + raise_exception_ra(env, EXCP_NOCP, 0, 1, GETPC()); + } + + if (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK) { + /* State in FP is still valid */ + env->v7m.fpccr[M_REG_S] &= ~R_V7M_FPCCR_LSPACT_MASK; + } else { + bool ts = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK; + int i; + uint32_t fpscr; + + if (fptr & 7) { + raise_exception_ra(env, EXCP_UNALIGNED, 0, 1, GETPC()); + } + + for (i = 0; i < (ts ? 32 : 16); i += 2) { + uint32_t slo, shi; + uint64_t dn; + uint32_t faddr = fptr + 4 * i; + + if (i >= 16) { + faddr += 8; /* skip the slot for the FPSCR */ + } + + slo = cpu_ldl_data(env, faddr); + shi = cpu_ldl_data(env, faddr + 4); + + dn = (uint64_t) shi << 32 | slo; + *aa32_vfp_dreg(env, i / 2) = dn; + } + fpscr = cpu_ldl_data(env, fptr + 0x40); + vfp_set_fpscr(env, fpscr); + } + + env->v7m.control[M_REG_S] |= R_V7M_CONTROL_FPCA_MASK; +} + static bool v7m_push_stack(ARMCPU *cpu) { /* Do the "set up stack frame" part of exception entry, diff --git a/target/arm/helper.h b/target/arm/helper.h index 62051ae6d5..50cb036378 100644 --- a/target/arm/helper.h +++ b/target/arm/helper.h @@ -72,6 +72,7 @@ DEF_HELPER_3(v7m_tt, i32, env, i32, i32) DEF_HELPER_1(v7m_preserve_fp_state, void, env) DEF_HELPER_2(v7m_vlstm, void, env, i32) +DEF_HELPER_2(v7m_vlldm, void, env, i32) DEF_HELPER_2(v8m_stackcheck, void, env, i32) diff --git a/target/arm/translate.c b/target/arm/translate.c index 99b38dd5f2..10bc53f91c 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -11823,7 +11823,7 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn) TCGv_i32 fptr = load_reg(s, rn); if (extract32(insn, 20, 1)) { - /* VLLDM */ + gen_helper_v7m_vlldm(cpu_env, fptr); } else { gen_helper_v7m_vlstm(cpu_env, fptr); } -- cgit v1.2.3 From 14fd0c31e26b88a2189b3f459b864d5e1faf302a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 29 Apr 2019 17:36:03 +0100 Subject: target/arm: Enable FPU for Cortex-M4 and Cortex-M33 Enable the FPU by default for the Cortex-M4 and Cortex-M33. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20190416125744.27770-27-peter.maydell@linaro.org --- target/arm/cpu.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'target') diff --git a/target/arm/cpu.c b/target/arm/cpu.c index 7deccda240..a181fa8dc1 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -1493,8 +1493,12 @@ static void cortex_m4_initfn(Object *obj) set_feature(&cpu->env, ARM_FEATURE_M); set_feature(&cpu->env, ARM_FEATURE_M_MAIN); set_feature(&cpu->env, ARM_FEATURE_THUMB_DSP); + set_feature(&cpu->env, ARM_FEATURE_VFP4); cpu->midr = 0x410fc240; /* r0p0 */ cpu->pmsav7_dregion = 8; + cpu->isar.mvfr0 = 0x10110021; + cpu->isar.mvfr1 = 0x11000011; + cpu->isar.mvfr2 = 0x00000000; cpu->id_pfr0 = 0x00000030; cpu->id_pfr1 = 0x00000200; cpu->id_dfr0 = 0x00100000; @@ -1521,9 +1525,13 @@ static void cortex_m33_initfn(Object *obj) set_feature(&cpu->env, ARM_FEATURE_M_MAIN); set_feature(&cpu->env, ARM_FEATURE_M_SECURITY); set_feature(&cpu->env, ARM_FEATURE_THUMB_DSP); + set_feature(&cpu->env, ARM_FEATURE_VFP4); cpu->midr = 0x410fd213; /* r0p3 */ cpu->pmsav7_dregion = 16; cpu->sau_sregion = 8; + cpu->isar.mvfr0 = 0x10110021; + cpu->isar.mvfr1 = 0x11000011; + cpu->isar.mvfr2 = 0x00000040; cpu->id_pfr0 = 0x00000030; cpu->id_pfr1 = 0x00000210; cpu->id_dfr0 = 0x00200000; -- cgit v1.2.3