aboutsummaryrefslogtreecommitdiff
path: root/target/riscv/csr.c
AgeCommit message (Collapse)Author
2020-02-27target/riscv: Emulate TIME CSRs for privileged modeAnup Patel
Currently, TIME CSRs are emulated only for user-only mode. This patch add TIME CSRs emulation for privileged mode. For privileged mode, the TIME CSRs will return value provided by rdtime callback which is registered by QEMU machine/platform emulation (i.e. CLINT emulation). If rdtime callback is not available then the monitor (i.e. OpenSBI) will trap-n-emulate TIME CSRs in software. We see 25+% performance improvement in hackbench numbers when TIME CSRs are not trap-n-emulated. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-27target/riscv: Add support for the 32-bit MSTATUSH CSRAlistair Francis
Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-27target/riscv: Extend the SIP CSR to support virtulisationAlistair Francis
Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-27target/riscv: Extend the MIE CSR to support virtulisationAlistair Francis
Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-27target/riscv: Set VS bits in mideleg for Hyp extensionAlistair Francis
Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-27target/riscv: Add Hypervisor machine CSRs accessesAlistair Francis
Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-27target/riscv: Add Hypervisor virtual CSRs accessesAlistair Francis
Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-27target/riscv: Add Hypervisor CSR access functionsAlistair Francis
Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-27target/riscv: Fix CSR perm checking for HS modeAlistair Francis
Update the CSR permission checking to work correctly when we are in HS-mode. Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-27target/riscv: Add support for the new execption numbersAlistair Francis
The v0.5 Hypervisor spec add new execption numbers, let's add support for those. Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-01-16target/riscv: update mstatus.SD when FS is set dirtyShihPo Hung
remove the check becuase SD bit should summarize FS and XS fields unconditionally. Signed-off-by: ShihPo Hung <shihpo.hung@sifive.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2019-11-14target/riscv: Remove atomic accesses to MIP CSRAlistair Francis
Instead of relying on atomics to access the MIP register let's update our helper function to instead just lock the IO mutex thread before writing. This follows the same concept as used in PPC for handling interrupts Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Palmer Dabbelt <palmer@dabbelt.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2019-10-28riscv: Skip checking CSR privilege level in debugger modeBin Meng
If we are in debugger mode, skip the CSR privilege level checking so that we can read/write all CSRs. Otherwise we get: (gdb) p/x $mtvec Could not fetch register "mtvec"; remote failure reply 'E14' when the hart is currently in S-mode. Reported-by: Zong Li <zong.li@sifive.com> Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-09-17target/riscv: Fix mstatus dirty maskAlistair Francis
This is meant to mask off the hypervisor bits, but a typo caused it to mask MPP instead. Fixes: 1f0419cb04 ("target/riscv: Allow setting mstatus virtulisation bits") Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-09-17target/riscv: Create function to test if FP is enabledAlistair Francis
Let's create a function that tests if floating point support is enabled. We can then protect all floating point operations based on if they are enabled. This patch so far doesn't change anything, it's just preparing for the Hypervisor support for floating point operations. Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Christophe de Dinechin <dinechin@redhat.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-06-25RISC-V: Add support for the Zicsr extensionPalmer Dabbelt
The various CSR instructions have been split out of the base ISA as part of the ratification process. This patch adds a Zicsr argument, which disables all the CSR instructions. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2019-06-25target/riscv: Add support for disabling/enabling CountersAlistair Francis
Add support for disabling/enabling the "Counters" extension. Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-06-25target/riscv: Add the mcountinhibit CSRAlistair Francis
1.11 defines mcountinhibit, which has the same numeric CSR value as mucounteren from 1.09.1 but has different semantics. This patch enables the CSR for 1.11-based targets, which is trivial to implement because the counters in QEMU never tick (legal according to the spec). Signed-off-by: Alistair Francis <alistair.francis@wdc.com> [Palmer: Fix counter access semantics, change commit message to indicate the behavior is fully emulated.] Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-06-10target/riscv: Use env_cpu, env_archcpuRichard Henderson
Cleanup in the boilerplate that each target must define. Replace riscv_env_get_cpu with env_archcpu. The combination CPU(riscv_env_get_cpu) should have used ENV_GET_CPU to begin; use env_cpu now. Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-05-24target/riscv: Only flush TLB if SATP.ASID changesJonathan Behrens
There is an analogous change for ARM here: https://patchwork.kernel.org/patch/10649857 Signed-off-by: Jonathan Behrens <jonathan@fintelia.io> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-05-24target/riscv: More accurate handling of `sip` CSRJonathan Behrens
According to the spec, "All bits besides SSIP, USIP, and UEIP in the sip register are read-only." Further, if an interrupt is not delegated to mode x, then "the corresponding bits in xip [...] should appear to be hardwired to zero. This patch implements both of those requirements. Signed-off-by: Jonathan Behrens <jonathan@fintelia.io> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-05-24target/riscv: Allow setting mstatus virtulisation bitsAlistair Francis
Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Revieweb-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-05-24target/riscv: Trigger interrupt on MIP update asynchronouslyAlistair Francis
The requirement of holding the iothread_mutex is burdersome when swapping the background and foreground registers in the Hypervisor extension. To avoid the requrirement let's set the interrupt asynchronously. Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-19RISC-V: Add support for vectored interruptsMichael Clark
If vectored interrupts are enabled (bits[1:0] of mtvec/stvec == 1) then use the following logic for trap entry address calculation: pc = mtvec + cause * 4 In addition to adding support for vectored interrupts this patch simplifies the interrupt delivery logic by making sync/async cause decoding and encoding steps distinct. The cause code and the sign bit indicating sync/async is split at the beginning of the function and fixed cause is renamed to cause. The MSB setting for async traps is delayed until setting mcause/scause to allow redundant variables to be eliminated. Some variables are renamed for conciseness and moved so that decls are at the start of the block. Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Alistair Francis <Alistair.Francis@wdc.com> Signed-off-by: Michael Clark <mjc@sifive.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-19RISC-V: Allow interrupt controllers to claim interruptsMichael Clark
We can't allow the supervisor to control SEIP as this would allow the supervisor to clear a pending external interrupt which will result in lost a interrupt in the case a PLIC is attached. The SEIP bit must be hardware controlled when a PLIC is attached. This logic was previously hard-coded so SEIP was always masked even if no PLIC was attached. This patch adds riscv_cpu_claim_interrupts so that the PLIC can register control of SEIP. In the case of models without a PLIC (spike), the SEIP bit remains software controlled. This interface allows for hardware control of supervisor timer and software interrupts by other interrupt controller models. Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Sagar Karandikar <sagark@eecs.berkeley.edu> Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> Cc: Alistair Francis <Alistair.Francis@wdc.com> Signed-off-by: Michael Clark <mjc@sifive.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-03-19RISC-V: Add debug support for accessing CSRs.Jim Wilson
Add a debugger field to CPURISCVState. Add riscv_csrrw_debug function to set it. Disable mode checks when debugger field true. Signed-off-by: Jim Wilson <jimw@sifive.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-Id: <20190212230903.9215-1-jimw@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11target/riscv: fix counter-enable checks in ctr()Xi Wang
Access to a counter in U-mode is permitted only if the corresponding bit is set in both mcounteren and scounteren. The current code ignores mcounteren and checks scounteren only for U-mode access. Signed-off-by: Xi Wang <xi.wang@gmail.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11RISC-V: Add misa runtime write supportMichael Clark
This patch adds support for writing misa. misa is validated based on rules in the ISA specification. 'E' is mutually exclusive with all other extensions. 'D' depends on 'F' so 'D' bit is dropped if 'F' is not present. A conservative approach to consistency is taken by flushing the translation cache on misa writes. misa_mask is added to the CPU struct to store the original set of extensions. Signed-off-by: Michael Clark <mjc@sifive.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11RISC-V: Use riscv prefix consistently on cpu helpersMichael Clark
* Add riscv prefix to raise_exception function * Add riscv prefix to CSR read/write functions * Add riscv prefix to signal handler function * Add riscv prefix to get fflags function * Remove redundant declaration of riscv_cpu_init and rename cpu_riscv_init to riscv_cpu_init * rename riscv_set_mode to riscv_cpu_set_mode Signed-off-by: Michael Clark <mjc@sifive.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11RISC-V: Implement mstatus.TSR/TW/TVMMichael Clark
This adds the necessary minimum to support S-mode virtualization for priv ISA >= v1.10 Signed-off-by: Michael Clark <mjc@sifive.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Co-authored-by: Matthew Suozzo <msuozzo@google.com> Co-authored-by: Michael Clark <mjc@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11RISC-V: Mark mstatus.fs dirtyRichard Henderson
Modifed from Richard Henderson's patch [1] to integrate with the new control and status register implementation. [1] https://lists.nongnu.org/archive/html/qemu-devel/2018-03/msg07034.html Note: the f* CSRs already mark mstatus.FS dirty using env->mstatus |= mstatus.FS so the bug in the first spin of this patch has been fixed in a prior commit. Signed-off-by: Michael Clark <mjc@sifive.com> Reviewed-by: Michael Clark <mjc@sifive.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Co-authored-by: Richard Henderson <richard.henderson@linaro.org> Co-authored-by: Michael Clark <mjc@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-09RISC-V: Implement existential predicates for CSRsMichael Clark
CSR predicate functions are added to the CSR table. mstatus.FS and counter enable checks are moved to predicate functions and two new predicates are added to check misa.S for s* CSRs and a new PMP CPU feature for pmp* CSRs. Processors that don't implement S-mode will trap on access to s* CSRs and processors that don't implement PMP will trap on accesses to pmp* CSRs. PMP checks are disabled in riscv_cpu_handle_mmu_fault when the PMP CPU feature is not present. Signed-off-by: Michael Clark <mjc@sifive.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-09RISC-V: Implement atomic mip/sip CSR updatesMichael Clark
Use the new CSR read/modify/write interface to implement atomic updates to mip/sip. Signed-off-by: Michael Clark <mjc@sifive.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-08RISC-V: Implement modular CSR helper interfaceMichael Clark
Previous CSR code uses csr_read_helper and csr_write_helper to update CSR registers however this interface prevents atomic read/modify/write CSR operations; in addition there is no trap-free method to access to CSRs due to the monolithic CSR functions call longjmp. The current iCSR interface is not safe to be called by target/riscv/gdbstub.c as privilege checks or missing CSRs may call longjmp to generate exceptions. It needs to indicate existence so traps can be generated in the CSR instruction helpers. This commit moves CSR access from the monolithic switch statements in target/riscv/op_helper.c into modular read/write functions in target/riscv/csr.c using a new function pointer table for dispatch (which can later be used to allow CPUs to hook up model specific CSRs). A read/modify/write interface is added to support atomic CSR operations and a non-trapping interface is added to allow exception-free access to CSRs by the debugger. The CSR functions and CSR dispatch table are ordered to match The RISC-V Instruction Set Manual, Volume II: Privileged Architecture Version 1.10, 2.2 CSR Listing. An API is added to allow derived cpu instances to modify or implement new CSR operations. Signed-off-by: Michael Clark <mjc@sifive.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
generated by cgit v1.2.3 (git 2.26.2) at 2024-11-28 05:00:00 +0000