diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2023-09-12 15:04:33 +0100 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2023-09-21 16:07:14 +0100 |
commit | 5d7b37b5f675d9cee0c9c1f8b386b3daa3cc2d9a (patch) | |
tree | a7aa41e32d40a59f920a1b9522463877dcb0bfe7 /target | |
parent | 69c51dc3723bdcb8d020f812f0d25d17b466d959 (diff) |
target/arm: Implement the CPY* instructions
The FEAT_MOPS CPY* instructions implement memory copies. These
come in both "always forwards" (memcpy-style) and "overlap OK"
(memmove-style) flavours.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230912140434.1333369-12-peter.maydell@linaro.org
Diffstat (limited to 'target')
-rw-r--r-- | target/arm/tcg/a64.decode | 14 | ||||
-rw-r--r-- | target/arm/tcg/helper-a64.c | 454 | ||||
-rw-r--r-- | target/arm/tcg/helper-a64.h | 7 | ||||
-rw-r--r-- | target/arm/tcg/translate-a64.c | 60 |
4 files changed, 535 insertions, 0 deletions
diff --git a/target/arm/tcg/a64.decode b/target/arm/tcg/a64.decode index a202faa17b..0cf1147074 100644 --- a/target/arm/tcg/a64.decode +++ b/target/arm/tcg/a64.decode @@ -575,3 +575,17 @@ SETE 00 011001110 ..... 10 . . 01 ..... ..... @set SETGP 00 011101110 ..... 00 . . 01 ..... ..... @set SETGM 00 011101110 ..... 01 . . 01 ..... ..... @set SETGE 00 011101110 ..... 10 . . 01 ..... ..... @set + +# Memmove/Memcopy: the CPY insns allow overlapping src/dest and +# copy in the correct direction; the CPYF insns always copy forwards. +# +# options has the nontemporal and unpriv bits for src and dest +&cpy rs rn rd options +@cpy .. ... . ..... rs:5 options:4 .. rn:5 rd:5 &cpy + +CPYFP 00 011 0 01000 ..... .... 01 ..... ..... @cpy +CPYFM 00 011 0 01010 ..... .... 01 ..... ..... @cpy +CPYFE 00 011 0 01100 ..... .... 01 ..... ..... @cpy +CPYP 00 011 1 01000 ..... .... 01 ..... ..... @cpy +CPYM 00 011 1 01010 ..... .... 01 ..... ..... @cpy +CPYE 00 011 1 01100 ..... .... 01 ..... ..... @cpy diff --git a/target/arm/tcg/helper-a64.c b/target/arm/tcg/helper-a64.c index 2cf89184d7..84f54750fc 100644 --- a/target/arm/tcg/helper-a64.c +++ b/target/arm/tcg/helper-a64.c @@ -1049,6 +1049,15 @@ static uint64_t page_limit(uint64_t addr) } /* + * Return the number of bytes we can copy starting from addr and working + * backwards without crossing a page boundary. + */ +static uint64_t page_limit_rev(uint64_t addr) +{ + return (addr & ~TARGET_PAGE_MASK) + 1; +} + +/* * Perform part of a memory set on an area of guest memory starting at * toaddr (a dirty address) and extending for setsize bytes. * @@ -1392,3 +1401,448 @@ void HELPER(setge)(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc) { do_sete(env, syndrome, mtedesc, set_step_tags, true, GETPC()); } + +/* + * Perform part of a memory copy from the guest memory at fromaddr + * and extending for copysize bytes, to the guest memory at + * toaddr. Both addreses are dirty. + * + * Returns the number of bytes actually set, which might be less than + * copysize; the caller should loop until the whole copy has been done. + * The caller should ensure that the guest registers are correct + * for the possibility that the first byte of the copy encounters + * an exception or watchpoint. We guarantee not to take any faults + * for bytes other than the first. + */ +static uint64_t copy_step(CPUARMState *env, uint64_t toaddr, uint64_t fromaddr, + uint64_t copysize, int wmemidx, int rmemidx, + uint32_t *wdesc, uint32_t *rdesc, uintptr_t ra) +{ + void *rmem; + void *wmem; + + /* Don't cross a page boundary on either source or destination */ + copysize = MIN(copysize, page_limit(toaddr)); + copysize = MIN(copysize, page_limit(fromaddr)); + /* + * Handle MTE tag checks: either handle the tag mismatch for byte 0, + * or else copy up to but not including the byte with the mismatch. + */ + if (*rdesc) { + uint64_t mtesize = mte_mops_probe(env, fromaddr, copysize, *rdesc); + if (mtesize == 0) { + mte_check_fail(env, *rdesc, fromaddr, ra); + *rdesc = 0; + } else { + copysize = MIN(copysize, mtesize); + } + } + if (*wdesc) { + uint64_t mtesize = mte_mops_probe(env, toaddr, copysize, *wdesc); + if (mtesize == 0) { + mte_check_fail(env, *wdesc, toaddr, ra); + *wdesc = 0; + } else { + copysize = MIN(copysize, mtesize); + } + } + + toaddr = useronly_clean_ptr(toaddr); + fromaddr = useronly_clean_ptr(fromaddr); + /* Trapless lookup of whether we can get a host memory pointer */ + wmem = tlb_vaddr_to_host(env, toaddr, MMU_DATA_STORE, wmemidx); + rmem = tlb_vaddr_to_host(env, fromaddr, MMU_DATA_LOAD, rmemidx); + +#ifndef CONFIG_USER_ONLY + /* + * If we don't have host memory for both source and dest then just + * do a single byte copy. This will handle watchpoints, invalid pages, + * etc correctly. For clean code pages, the next iteration will see + * the page dirty and will use the fast path. + */ + if (unlikely(!rmem || !wmem)) { + uint8_t byte; + if (rmem) { + byte = *(uint8_t *)rmem; + } else { + byte = cpu_ldub_mmuidx_ra(env, fromaddr, rmemidx, ra); + } + if (wmem) { + *(uint8_t *)wmem = byte; + } else { + cpu_stb_mmuidx_ra(env, toaddr, byte, wmemidx, ra); + } + return 1; + } +#endif + /* Easy case: just memmove the host memory */ + memmove(wmem, rmem, copysize); + return copysize; +} + +/* + * Do part of a backwards memory copy. Here toaddr and fromaddr point + * to the *last* byte to be copied. + */ +static uint64_t copy_step_rev(CPUARMState *env, uint64_t toaddr, + uint64_t fromaddr, + uint64_t copysize, int wmemidx, int rmemidx, + uint32_t *wdesc, uint32_t *rdesc, uintptr_t ra) +{ + void *rmem; + void *wmem; + + /* Don't cross a page boundary on either source or destination */ + copysize = MIN(copysize, page_limit_rev(toaddr)); + copysize = MIN(copysize, page_limit_rev(fromaddr)); + + /* + * Handle MTE tag checks: either handle the tag mismatch for byte 0, + * or else copy up to but not including the byte with the mismatch. + */ + if (*rdesc) { + uint64_t mtesize = mte_mops_probe_rev(env, fromaddr, copysize, *rdesc); + if (mtesize == 0) { + mte_check_fail(env, *rdesc, fromaddr, ra); + *rdesc = 0; + } else { + copysize = MIN(copysize, mtesize); + } + } + if (*wdesc) { + uint64_t mtesize = mte_mops_probe_rev(env, toaddr, copysize, *wdesc); + if (mtesize == 0) { + mte_check_fail(env, *wdesc, toaddr, ra); + *wdesc = 0; + } else { + copysize = MIN(copysize, mtesize); + } + } + + toaddr = useronly_clean_ptr(toaddr); + fromaddr = useronly_clean_ptr(fromaddr); + /* Trapless lookup of whether we can get a host memory pointer */ + wmem = tlb_vaddr_to_host(env, toaddr, MMU_DATA_STORE, wmemidx); + rmem = tlb_vaddr_to_host(env, fromaddr, MMU_DATA_LOAD, rmemidx); + +#ifndef CONFIG_USER_ONLY + /* + * If we don't have host memory for both source and dest then just + * do a single byte copy. This will handle watchpoints, invalid pages, + * etc correctly. For clean code pages, the next iteration will see + * the page dirty and will use the fast path. + */ + if (unlikely(!rmem || !wmem)) { + uint8_t byte; + if (rmem) { + byte = *(uint8_t *)rmem; + } else { + byte = cpu_ldub_mmuidx_ra(env, fromaddr, rmemidx, ra); + } + if (wmem) { + *(uint8_t *)wmem = byte; + } else { + cpu_stb_mmuidx_ra(env, toaddr, byte, wmemidx, ra); + } + return 1; + } +#endif + /* + * Easy case: just memmove the host memory. Note that wmem and + * rmem here point to the *last* byte to copy. + */ + memmove(wmem - (copysize - 1), rmem - (copysize - 1), copysize); + return copysize; +} + +/* + * for the Memory Copy operation, our implementation chooses always + * to use "option A", where we update Xd and Xs to the final addresses + * in the CPYP insn, and then in CPYM and CPYE only need to update Xn. + * + * @env: CPU + * @syndrome: syndrome value for mismatch exceptions + * (also contains the register numbers we need to use) + * @wdesc: MTE descriptor for the writes (destination) + * @rdesc: MTE descriptor for the reads (source) + * @move: true if this is CPY (memmove), false for CPYF (memcpy forwards) + */ +static void do_cpyp(CPUARMState *env, uint32_t syndrome, uint32_t wdesc, + uint32_t rdesc, uint32_t move, uintptr_t ra) +{ + int rd = mops_destreg(syndrome); + int rs = mops_srcreg(syndrome); + int rn = mops_sizereg(syndrome); + uint32_t rmemidx = FIELD_EX32(rdesc, MTEDESC, MIDX); + uint32_t wmemidx = FIELD_EX32(wdesc, MTEDESC, MIDX); + bool forwards = true; + uint64_t toaddr = env->xregs[rd]; + uint64_t fromaddr = env->xregs[rs]; + uint64_t copysize = env->xregs[rn]; + uint64_t stagecopysize, step; + + check_mops_enabled(env, ra); + + + if (move) { + /* + * Copy backwards if necessary. The direction for a non-overlapping + * copy is IMPDEF; we choose forwards. + */ + if (copysize > 0x007FFFFFFFFFFFFFULL) { + copysize = 0x007FFFFFFFFFFFFFULL; + } + uint64_t fs = extract64(fromaddr, 0, 56); + uint64_t ts = extract64(toaddr, 0, 56); + uint64_t fe = extract64(fromaddr + copysize, 0, 56); + + if (fs < ts && fe > ts) { + forwards = false; + } + } else { + if (copysize > INT64_MAX) { + copysize = INT64_MAX; + } + } + + if (!mte_checks_needed(fromaddr, rdesc)) { + rdesc = 0; + } + if (!mte_checks_needed(toaddr, wdesc)) { + wdesc = 0; + } + + if (forwards) { + stagecopysize = MIN(copysize, page_limit(toaddr)); + stagecopysize = MIN(stagecopysize, page_limit(fromaddr)); + while (stagecopysize) { + env->xregs[rd] = toaddr; + env->xregs[rs] = fromaddr; + env->xregs[rn] = copysize; + step = copy_step(env, toaddr, fromaddr, stagecopysize, + wmemidx, rmemidx, &wdesc, &rdesc, ra); + toaddr += step; + fromaddr += step; + copysize -= step; + stagecopysize -= step; + } + /* Insn completed, so update registers to the Option A format */ + env->xregs[rd] = toaddr + copysize; + env->xregs[rs] = fromaddr + copysize; + env->xregs[rn] = -copysize; + } else { + /* + * In a reverse copy the to and from addrs in Xs and Xd are the start + * of the range, but it's more convenient for us to work with pointers + * to the last byte being copied. + */ + toaddr += copysize - 1; + fromaddr += copysize - 1; + stagecopysize = MIN(copysize, page_limit_rev(toaddr)); + stagecopysize = MIN(stagecopysize, page_limit_rev(fromaddr)); + while (stagecopysize) { + env->xregs[rn] = copysize; + step = copy_step_rev(env, toaddr, fromaddr, stagecopysize, + wmemidx, rmemidx, &wdesc, &rdesc, ra); + copysize -= step; + stagecopysize -= step; + toaddr -= step; + fromaddr -= step; + } + /* + * Insn completed, so update registers to the Option A format. + * For a reverse copy this is no different to the CPYP input format. + */ + env->xregs[rn] = copysize; + } + + /* Set NZCV = 0000 to indicate we are an Option A implementation */ + env->NF = 0; + env->ZF = 1; /* our env->ZF encoding is inverted */ + env->CF = 0; + env->VF = 0; + return; +} + +void HELPER(cpyp)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc, + uint32_t rdesc) +{ + do_cpyp(env, syndrome, wdesc, rdesc, true, GETPC()); +} + +void HELPER(cpyfp)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc, + uint32_t rdesc) +{ + do_cpyp(env, syndrome, wdesc, rdesc, false, GETPC()); +} + +static void do_cpym(CPUARMState *env, uint32_t syndrome, uint32_t wdesc, + uint32_t rdesc, uint32_t move, uintptr_t ra) +{ + /* Main: we choose to copy until less than a page remaining */ + CPUState *cs = env_cpu(env); + int rd = mops_destreg(syndrome); + int rs = mops_srcreg(syndrome); + int rn = mops_sizereg(syndrome); + uint32_t rmemidx = FIELD_EX32(rdesc, MTEDESC, MIDX); + uint32_t wmemidx = FIELD_EX32(wdesc, MTEDESC, MIDX); + bool forwards = true; + uint64_t toaddr, fromaddr, copysize, step; + + check_mops_enabled(env, ra); + + /* We choose to NOP out "no data to copy" before consistency checks */ + if (env->xregs[rn] == 0) { + return; + } + + check_mops_wrong_option(env, syndrome, ra); + + if (move) { + forwards = (int64_t)env->xregs[rn] < 0; + } + + if (forwards) { + toaddr = env->xregs[rd] + env->xregs[rn]; + fromaddr = env->xregs[rs] + env->xregs[rn]; + copysize = -env->xregs[rn]; + } else { + copysize = env->xregs[rn]; + /* This toaddr and fromaddr point to the *last* byte to copy */ + toaddr = env->xregs[rd] + copysize - 1; + fromaddr = env->xregs[rs] + copysize - 1; + } + + if (!mte_checks_needed(fromaddr, rdesc)) { + rdesc = 0; + } + if (!mte_checks_needed(toaddr, wdesc)) { + wdesc = 0; + } + + /* Our implementation has no particular parameter requirements for CPYM */ + + /* Do the actual memmove */ + if (forwards) { + while (copysize >= TARGET_PAGE_SIZE) { + step = copy_step(env, toaddr, fromaddr, copysize, + wmemidx, rmemidx, &wdesc, &rdesc, ra); + toaddr += step; + fromaddr += step; + copysize -= step; + env->xregs[rn] = -copysize; + if (copysize >= TARGET_PAGE_SIZE && + unlikely(cpu_loop_exit_requested(cs))) { + cpu_loop_exit_restore(cs, ra); + } + } + } else { + while (copysize >= TARGET_PAGE_SIZE) { + step = copy_step_rev(env, toaddr, fromaddr, copysize, + wmemidx, rmemidx, &wdesc, &rdesc, ra); + toaddr -= step; + fromaddr -= step; + copysize -= step; + env->xregs[rn] = copysize; + if (copysize >= TARGET_PAGE_SIZE && + unlikely(cpu_loop_exit_requested(cs))) { + cpu_loop_exit_restore(cs, ra); + } + } + } +} + +void HELPER(cpym)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc, + uint32_t rdesc) +{ + do_cpym(env, syndrome, wdesc, rdesc, true, GETPC()); +} + +void HELPER(cpyfm)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc, + uint32_t rdesc) +{ + do_cpym(env, syndrome, wdesc, rdesc, false, GETPC()); +} + +static void do_cpye(CPUARMState *env, uint32_t syndrome, uint32_t wdesc, + uint32_t rdesc, uint32_t move, uintptr_t ra) +{ + /* Epilogue: do the last partial page */ + int rd = mops_destreg(syndrome); + int rs = mops_srcreg(syndrome); + int rn = mops_sizereg(syndrome); + uint32_t rmemidx = FIELD_EX32(rdesc, MTEDESC, MIDX); + uint32_t wmemidx = FIELD_EX32(wdesc, MTEDESC, MIDX); + bool forwards = true; + uint64_t toaddr, fromaddr, copysize, step; + + check_mops_enabled(env, ra); + + /* We choose to NOP out "no data to copy" before consistency checks */ + if (env->xregs[rn] == 0) { + return; + } + + check_mops_wrong_option(env, syndrome, ra); + + if (move) { + forwards = (int64_t)env->xregs[rn] < 0; + } + + if (forwards) { + toaddr = env->xregs[rd] + env->xregs[rn]; + fromaddr = env->xregs[rs] + env->xregs[rn]; + copysize = -env->xregs[rn]; + } else { + copysize = env->xregs[rn]; + /* This toaddr and fromaddr point to the *last* byte to copy */ + toaddr = env->xregs[rd] + copysize - 1; + fromaddr = env->xregs[rs] + copysize - 1; + } + + if (!mte_checks_needed(fromaddr, rdesc)) { + rdesc = 0; + } + if (!mte_checks_needed(toaddr, wdesc)) { + wdesc = 0; + } + + /* Check the size; we don't want to have do a check-for-interrupts */ + if (copysize >= TARGET_PAGE_SIZE) { + raise_exception_ra(env, EXCP_UDEF, syndrome, + mops_mismatch_exception_target_el(env), ra); + } + + /* Do the actual memmove */ + if (forwards) { + while (copysize > 0) { + step = copy_step(env, toaddr, fromaddr, copysize, + wmemidx, rmemidx, &wdesc, &rdesc, ra); + toaddr += step; + fromaddr += step; + copysize -= step; + env->xregs[rn] = -copysize; + } + } else { + while (copysize > 0) { + step = copy_step_rev(env, toaddr, fromaddr, copysize, + wmemidx, rmemidx, &wdesc, &rdesc, ra); + toaddr -= step; + fromaddr -= step; + copysize -= step; + env->xregs[rn] = copysize; + } + } +} + +void HELPER(cpye)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc, + uint32_t rdesc) +{ + do_cpye(env, syndrome, wdesc, rdesc, true, GETPC()); +} + +void HELPER(cpyfe)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc, + uint32_t rdesc) +{ + do_cpye(env, syndrome, wdesc, rdesc, false, GETPC()); +} diff --git a/target/arm/tcg/helper-a64.h b/target/arm/tcg/helper-a64.h index 10a9910712..575a5dab7d 100644 --- a/target/arm/tcg/helper-a64.h +++ b/target/arm/tcg/helper-a64.h @@ -124,3 +124,10 @@ DEF_HELPER_3(sete, void, env, i32, i32) DEF_HELPER_3(setgp, void, env, i32, i32) DEF_HELPER_3(setgm, void, env, i32, i32) DEF_HELPER_3(setge, void, env, i32, i32) + +DEF_HELPER_4(cpyp, void, env, i32, i32, i32) +DEF_HELPER_4(cpym, void, env, i32, i32, i32) +DEF_HELPER_4(cpye, void, env, i32, i32, i32) +DEF_HELPER_4(cpyfp, void, env, i32, i32, i32) +DEF_HELPER_4(cpyfm, void, env, i32, i32, i32) +DEF_HELPER_4(cpyfe, void, env, i32, i32, i32) diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c index 27bb3039b4..97f25b4451 100644 --- a/target/arm/tcg/translate-a64.c +++ b/target/arm/tcg/translate-a64.c @@ -4019,6 +4019,66 @@ TRANS_FEAT(SETGP, aa64_mops, do_SET, a, false, true, gen_helper_setgp) TRANS_FEAT(SETGM, aa64_mops, do_SET, a, false, true, gen_helper_setgm) TRANS_FEAT(SETGE, aa64_mops, do_SET, a, true, true, gen_helper_setge) +typedef void CpyFn(TCGv_env, TCGv_i32, TCGv_i32, TCGv_i32); + +static bool do_CPY(DisasContext *s, arg_cpy *a, bool is_epilogue, CpyFn fn) +{ + int rmemidx, wmemidx; + uint32_t syndrome, rdesc = 0, wdesc = 0; + bool wunpriv = extract32(a->options, 0, 1); + bool runpriv = extract32(a->options, 1, 1); + + /* + * UNPREDICTABLE cases: we choose to UNDEF, which allows + * us to pull this check before the CheckMOPSEnabled() test + * (which we do in the helper function) + */ + if (a->rs == a->rn || a->rs == a->rd || a->rn == a->rd || + a->rd == 31 || a->rs == 31 || a->rn == 31) { + return false; + } + + rmemidx = get_a64_user_mem_index(s, runpriv); + wmemidx = get_a64_user_mem_index(s, wunpriv); + + /* + * We pass option_a == true, matching our implementation; + * we pass wrong_option == false: helper function may set that bit. + */ + syndrome = syn_mop(false, false, a->options, is_epilogue, + false, true, a->rd, a->rs, a->rn); + + /* If we need to do MTE tag checking, assemble the descriptors */ + if (s->mte_active[runpriv]) { + rdesc = FIELD_DP32(rdesc, MTEDESC, TBI, s->tbid); + rdesc = FIELD_DP32(rdesc, MTEDESC, TCMA, s->tcma); + } + if (s->mte_active[wunpriv]) { + wdesc = FIELD_DP32(wdesc, MTEDESC, TBI, s->tbid); + wdesc = FIELD_DP32(wdesc, MTEDESC, TCMA, s->tcma); + wdesc = FIELD_DP32(wdesc, MTEDESC, WRITE, true); + } + /* The helper function needs these parts of the descriptor regardless */ + rdesc = FIELD_DP32(rdesc, MTEDESC, MIDX, rmemidx); + wdesc = FIELD_DP32(wdesc, MTEDESC, MIDX, wmemidx); + + /* + * The helper needs the register numbers, but since they're in + * the syndrome anyway, we let it extract them from there rather + * than passing in an extra three integer arguments. + */ + fn(cpu_env, tcg_constant_i32(syndrome), tcg_constant_i32(wdesc), + tcg_constant_i32(rdesc)); + return true; +} + +TRANS_FEAT(CPYP, aa64_mops, do_CPY, a, false, gen_helper_cpyp) +TRANS_FEAT(CPYM, aa64_mops, do_CPY, a, false, gen_helper_cpym) +TRANS_FEAT(CPYE, aa64_mops, do_CPY, a, true, gen_helper_cpye) +TRANS_FEAT(CPYFP, aa64_mops, do_CPY, a, false, gen_helper_cpyfp) +TRANS_FEAT(CPYFM, aa64_mops, do_CPY, a, false, gen_helper_cpyfm) +TRANS_FEAT(CPYFE, aa64_mops, do_CPY, a, true, gen_helper_cpyfe) + typedef void ArithTwoOp(TCGv_i64, TCGv_i64, TCGv_i64); static bool gen_rri(DisasContext *s, arg_rri_sf *a, |