Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20211210075704.23951-6-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20211210075704.23951-5-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20211210075704.23951-4-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The position of this read-only field is dependent on the current xlen.
Rather than having to compute that difference in many places, compute
it only on read.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20211020031709.359469-16-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Begin adding support for switching XLEN at runtime. Extract the
effective XLEN from MISA and MSTATUS and store for use during translation.
Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20211020031709.359469-6-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Shortly, the set of supported XL will not be just 32 and 64,
and representing that properly using the enumeration will be
imperative.
Two places, booting and gdb, intentionally use misa_mxl_max
to emphasize the use of the reset value of misa.mxl, and not
the current cpu state.
Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20211020031709.359469-5-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The hw representation of misa.mxl is at the high bits of the
misa csr. Representing this in the same way inside QEMU
results in overly complex code trying to check that field.
Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20211020031709.359469-4-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The macro name HCOUNTEREN_CY suggests it is for CSR HCOUNTEREN, but
in fact it applies to M-mode and S-mode CSR too. Rename these macros
to have the COUNTEREN_ prefix.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210915084601.24304-1-bmeng.cn@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
These variables should be target_ulong. If truncated to int,
the bool conditions they indicate will be wrong.
As satp is very important for Linux, this bug almost fails every boot.
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210901124539.222868-1-zhiwei_liu@c-sky.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
We failed to write into *val for these read functions;
replace them with read_zero. Only warn about unsupported
non-zero value when writing a non-zero value.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210823195529.560295-18-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
We distinguish write-only by passing ret_value as NULL.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210823195529.560295-17-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
For U-mode CSRs, read-only check is also needed.
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Message-id: 20210810014552.4884-1-zhiwei_liu@c-sky.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
When privilege check fails, RISCV_EXCP_ILLEGAL_INST is returned,
not -1 (RISCV_EXCP_NONE).
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210807141025.31808-1-bmeng.cn@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The specification mandates for certain bits to be hardwired in the
hypervisor delegation registers. This was not being enforced.
Signed-off-by: Jose Martins <josemartins90@gmail.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210522155902.374439-1-josemartins90@gmail.com
[ Changes by AF:
- Improve indentation
- Convert delegable_excps to a #define to avoid failures with GCC 8
]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The following check:
if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
return -RISCV_EXCP_ILLEGAL_INST;
}
is redundant in fflags/frm/fcsr read/write routines, as the check was
already done in fs().
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210627120604.11116-1-bmeng.cn@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Qemu doesn't support RISC-V privilege specification v1.9. Remove the
remaining v1.9 specific references from the implementation.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20210319194534.2082397-2-atish.patra@wdc.com>
[Changes by AF:
- Rebase on latest patches
- Bump the vmstate_riscv_cpu version_id and minimum_version_id
]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The previous implementation was broken in many ways:
- Used mideleg instead of hideleg to mask accesses
- Used MIP_VSSIP instead of VS_MODE_INTERRUPTS to mask writes to vsie
- Did not shift between S bits and VS bits (VSEIP <-> SEIP, ...)
Signed-off-by: Georg Kotheimer <georg.kotheimer@kernkonzept.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210311094738.1376795-1-georg.kotheimer@kernkonzept.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Georg Kotheimer <georg.kotheimer@kernkonzept.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210311094902.1377593-1-georg.kotheimer@kernkonzept.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
vs() should return -RISCV_EXCP_ILLEGAL_INST instead of -1 if rvv feature
is not enabled.
If -1 is returned, exception will be raised and cs->exception_index will
be set to the negative return value. The exception will then be treated
as an instruction access fault instead of illegal instruction fault.
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210223065935.20208-1-frank.chang@sifive.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
In preparation to generate the CSR register list for GDB stub
dynamically, let's add the CSR name in the CSR function table.
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 1610427124-49887-3-git-send-email-bmeng.cn@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
In preparation to generate the CSR register list for GDB stub
dynamically, change csr_ops[] to non-static so that it can be
referenced externally.
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 1610427124-49887-2-git-send-email-bmeng.cn@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Fix code style. Space required before the open parenthesis '('.
Signed-off-by: Xinhao Zhang <zhangxinhao1@huawei.com>
Signed-off-by: Kai Deng <dengkai1@huawei.com>
Reported-by: Euler Robot <euler.robot@huawei.com>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20201030004815.4172849-1-zhangxinhao1@huawei.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
mstatus/mstatush and vsstatus/vsstatush are two halved for RISCV32.
This patch expands mstatus and vsstatus to uint64_t instead of
target_ulong so that it can be saved as one unit and reduce some
ifdefs in the code.
Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
Signed-off-by: Yipeng Yin <yinyipeng1@huawei.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20201026115530.304-2-jiangyifei@huawei.com
refactoring of cpus.c continues with cpu timer state extraction.
cpu-timers: responsible for the softmmu cpu timers state,
including cpu clocks and ticks.
icount: counts the TCG instructions executed. As such it is specific to
the TCG accelerator. Therefore, it is built only under CONFIG_TCG.
One complication is due to qtest, which uses an icount field to warp time
as part of qtest (qtest_clock_warp).
In order to solve this problem, provide a separate counter for qtest.
This requires fixing assumptions scattered in the code that
qtest_enabled() implies icount_enabled(), checking each specific case.
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[remove redundant initialization with qemu_spice_init]
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[fix lingering calls to icount_get]
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
At present the CLINT timestamp is using a hard-coded timebase
frequency value SIFIVE_CLINT_TIMEBASE_FREQ. This might not be
true for all boards.
Add a new 'timebase-freq' property to the CLINT device, and
update various functions to accept this as a parameter.
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <1598924352-89526-16-git-send-email-bmeng.cn@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
When performing a CSR access let's return a negative exception value on
an error instead of -1. This will allow us to specify the exception in
future patches.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: a487dad60c9b8fe7a2b992c5e0dcc2504a9000a7.1597259519.git.alistair.francis@wdc.com
Message-Id: <a487dad60c9b8fe7a2b992c5e0dcc2504a9000a7.1597259519.git.alistair.francis@wdc.com>
The range of Physical Memory Protection should be from CSR_PMPCFG0
to CSR_PMPCFG3, not to CSR_PMPADDR9.
Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Message-Id: <eae49e9252c9596e4f3bdb471772f79235141a87.1595335112.git.zong.li@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The v0.7.1 specification does not define vector status within mstatus.
A future revision will define the privileged portion of the vector status.
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200701152549.1218-4-zhiwei_liu@c-sky.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The RISC-V ISA spec version 1.09.1 has been deprecated in QEMU since
4.1. It's not commonly used so let's remove support for it.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
* 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>
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>
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>
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>
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>
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>
