Commit Graph

1336 Commits

Author SHA1 Message Date
Palmer Dabbelt
32d5f7add0
Merge patch series "RISC-V: hwprobe: Misaligned scalar perf fix and rename"
Evan Green <evan@rivosinc.com> says:

The CPUPERF0 hwprobe key was documented and identified in code as
a bitmask value, but its contents were an enum. This produced
incorrect behavior in conjunction with the WHICH_CPUS hwprobe flag.
The first patch in this series fixes the bitmask/enum problem by
creating a new hwprobe key that returns the same data, but is
properly described as a value instead of a bitmask. The second patch
renames the value definitions in preparation for adding vector misaligned
access info. As of this version, the old defines are kept in place to
maintain source compatibility with older userspace programs.

* b4-shazam-merge:
  RISC-V: hwprobe: Add SCALAR to misaligned perf defines
  RISC-V: hwprobe: Add MISALIGNED_PERF key

Link: https://lore.kernel.org/r/20240809214444.3257596-1-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-15 13:12:21 -07:00
Alexandre Ghiti
e01d48c699
riscv: Fix out-of-bounds when accessing Andes per hart vendor extension array
The out-of-bounds access is reported by UBSAN:

[    0.000000] UBSAN: array-index-out-of-bounds in ../arch/riscv/kernel/vendor_extensions.c:41:66
[    0.000000] index -1 is out of range for type 'riscv_isavendorinfo [32]'
[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.11.0-rc2ubuntu-defconfig #2
[    0.000000] Hardware name: riscv-virtio,qemu (DT)
[    0.000000] Call Trace:
[    0.000000] [<ffffffff94e078ba>] dump_backtrace+0x32/0x40
[    0.000000] [<ffffffff95c83c1a>] show_stack+0x38/0x44
[    0.000000] [<ffffffff95c94614>] dump_stack_lvl+0x70/0x9c
[    0.000000] [<ffffffff95c94658>] dump_stack+0x18/0x20
[    0.000000] [<ffffffff95c8bbb2>] ubsan_epilogue+0x10/0x46
[    0.000000] [<ffffffff95485a82>] __ubsan_handle_out_of_bounds+0x94/0x9c
[    0.000000] [<ffffffff94e09442>] __riscv_isa_vendor_extension_available+0x90/0x92
[    0.000000] [<ffffffff94e043b6>] riscv_cpufeature_patch_func+0xc4/0x148
[    0.000000] [<ffffffff94e035f8>] _apply_alternatives+0x42/0x50
[    0.000000] [<ffffffff95e04196>] apply_boot_alternatives+0x3c/0x100
[    0.000000] [<ffffffff95e05b52>] setup_arch+0x85a/0x8bc
[    0.000000] [<ffffffff95e00ca0>] start_kernel+0xa4/0xfb6

The dereferencing using cpu should actually not happen, so remove it.

Fixes: 23c996fc2b ("riscv: Extend cpufeature.c to detect vendor extensions")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240814192619.276794-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-15 13:12:16 -07:00
Evan Green
1f5288874d
RISC-V: hwprobe: Add SCALAR to misaligned perf defines
In preparation for misaligned vector performance hwprobe keys, rename
the hwprobe key values associated with misaligned scalar accesses to
include the term SCALAR. Leave the old defines in place to maintain
source compatibility.

This change is intended to be a functional no-op.

Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240809214444.3257596-3-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14 13:13:24 -07:00
Evan Green
c42e2f0767
RISC-V: hwprobe: Add MISALIGNED_PERF key
RISCV_HWPROBE_KEY_CPUPERF_0 was mistakenly flagged as a bitmask in
hwprobe_key_is_bitmask(), when in reality it was an enum value. This
causes problems when used in conjunction with RISCV_HWPROBE_WHICH_CPUS,
since SLOW, FAST, and EMULATED have values whose bits overlap with
each other. If the caller asked for the set of CPUs that was SLOW or
EMULATED, the returned set would also include CPUs that were FAST.

Introduce a new hwprobe key, RISCV_HWPROBE_KEY_MISALIGNED_PERF, which
returns the same values in response to a direct query (with no flags),
but is properly handled as an enumerated value. As a result, SLOW,
FAST, and EMULATED are all correctly treated as distinct values under
the new key when queried with the WHICH_CPUS flag.

Leave the old key in place to avoid disturbing applications which may
have already come to rely on the key, with or without its broken
behavior with respect to the WHICH_CPUS flag.

Fixes: e178bf146e ("RISC-V: hwprobe: Introduce which-cpus flag")
Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240809214444.3257596-2-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14 13:13:23 -07:00
Haibo Xu
a445699879
RISC-V: ACPI: NUMA: initialize all values of acpi_early_node_map to NUMA_NO_NODE
Currently, only acpi_early_node_map[0] was initialized to NUMA_NO_NODE.
To ensure all the values were properly initialized, switch to initialize
all of them to NUMA_NO_NODE.

Fixes: eabd9db64e ("ACPI: RISCV: Add NUMA support based on SRAT and SLIT")
Reported-by: Andrew Jones <ajones@ventanamicro.com>
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Haibo Xu <haibo1.xu@intel.com>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Link: https://lore.kernel.org/r/0d362a8ae50558b95685da4c821b2ae9e8cf78be.1722828421.git.haibo1.xu@intel.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14 13:12:41 -07:00
Celeste Liu
6111939463
riscv: entry: always initialize regs->a0 to -ENOSYS
Otherwise when the tracer changes syscall number to -1, the kernel fails
to initialize a0 with -ENOSYS and subsequently fails to return the error
code of the failed syscall to userspace. For example, it will break
strace syscall tampering.

Fixes: 52449c17bd ("riscv: entry: set a0 = -ENOSYS only when syscall != -1")
Reported-by: "Dmitry V. Levin" <ldv@strace.io>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Celeste Liu <CoelacanthusHex@gmail.com>
Link: https://lore.kernel.org/r/20240627142338.5114-2-CoelacanthusHex@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14 13:12:22 -07:00
Alexandre Ghiti
ee9a68394b
riscv: Re-introduce global icache flush in patch_text_XXX()
commit edf2d546bf ("riscv: patch: Flush the icache right after
patching to avoid illegal insns") mistakenly removed the global icache
flush in patch_text_nosync() and patch_text_set_nosync() functions, so
reintroduce them.

Fixes: edf2d546bf ("riscv: patch: Flush the icache right after patching to avoid illegal insns")
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Closes: https://lore.kernel.org/linux-riscv/a28ddc26-d77a-470a-a33f-88144f717e86@sifive.com/
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240801191404.55181-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-06 06:49:14 -07:00
Linus Torvalds
948752d2e0 RISC-V Fixes for 6.11-rc2
* A fix to avoid dropping some of the internal pseudo-extensions, which
   breaks *envcfg dependency parsing.
 * The kernel entry address is now aligned in purgatory, which avoids a
   misaligned load that can lead to crash on systems that don't support
   misaligned accesses early in boot.
 * The FW_SFENCE_VMA_RECEIVED perf event was duplicated in a handful of
   perf JSON configurations, one of them been updated to
   FW_SFENCE_VMA_ASID_SENT.
 * The starfive cache driver is now restricted to 64-bit systems, as it
   isn't 32-bit clean.
 * A fix for to avoid aliasing legacy-mode perf counters with software
   perf counters.
 * VM_FAULT_SIGSEGV is now handled in the page fault code.
 * A fix for stalls during CPU hotplug due to IPIs being disabled.
 * A fix for memblock bounds checking.  This manifests as a crash on
   systems with discontinuous memory maps that have regions that don't
   fit in the linear map.
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Merge tag 'riscv-for-linus-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:

 - A fix to avoid dropping some of the internal pseudo-extensions, which
   breaks *envcfg dependency parsing

 - The kernel entry address is now aligned in purgatory, which avoids a
   misaligned load that can lead to crash on systems that don't support
   misaligned accesses early in boot

 - The FW_SFENCE_VMA_RECEIVED perf event was duplicated in a handful of
   perf JSON configurations, one of them been updated to
   FW_SFENCE_VMA_ASID_SENT

 - The starfive cache driver is now restricted to 64-bit systems, as it
   isn't 32-bit clean

 - A fix for to avoid aliasing legacy-mode perf counters with software
   perf counters

 - VM_FAULT_SIGSEGV is now handled in the page fault code

 - A fix for stalls during CPU hotplug due to IPIs being disabled

 - A fix for memblock bounds checking. This manifests as a crash on
   systems with discontinuous memory maps that have regions that don't
   fit in the linear map

* tag 'riscv-for-linus-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Fix linear mapping checks for non-contiguous memory regions
  RISC-V: Enable the IPI before workqueue_online_cpu()
  riscv/mm: Add handling for VM_FAULT_SIGSEGV in mm_fault_error()
  perf: riscv: Fix selecting counters in legacy mode
  cache: StarFive: Require a 64-bit system
  perf arch events: Fix duplicate RISC-V SBI firmware event name
  riscv/purgatory: align riscv_kernel_entry
  riscv: cpufeature: Do not drop Linux-internal extensions
2024-08-02 09:33:35 -07:00
Arnd Bergmann
343416f0c1 syscalls: fix syscall macros for newfstat/newfstatat
The __NR_newfstat and __NR_newfstatat macros accidentally got renamed
in the conversion to the syscall.tbl format, dropping the 'new' portion
of the name.

In an unrelated change, the two syscalls are no longer architecture
specific but are once more defined on all 64-bit architectures, so the
'newstat' ABI keyword can be dropped from the table as a simplification.

Fixes: Fixes: 4fe53bf2ba ("syscalls: add generic scripts/syscall.tbl")
Closes: https://lore.kernel.org/lkml/838053e0-b186-4e9f-9668-9a3384a71f23@app.fastmail.com/T/#t
Reported-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-08-02 15:20:47 +02:00
Nick Hu
3908ba2e0b
RISC-V: Enable the IPI before workqueue_online_cpu()
Sometimes the hotplug cpu stalls at the arch_cpu_idle() for a while after
workqueue_online_cpu(). When cpu stalls at the idle loop, the reschedule
IPI is pending. However the enable bit is not enabled yet so the cpu stalls
at WFI until watchdog timeout. Therefore enable the IPI before the
workqueue_online_cpu() to fix the issue.

Fixes: 63c5484e74 ("workqueue: Add multiple affinity scopes and interface to select them")
Signed-off-by: Nick Hu <nick.hu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240717031714.1946036-1-nick.hu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-01 07:15:43 -07:00
Samuel Holland
b75a22e7d4
riscv: cpufeature: Do not drop Linux-internal extensions
The Linux-internal Xlinuxenvcfg ISA extension is omitted from the
riscv_isa_ext array because it has no DT binding and should not appear
in /proc/cpuinfo. The logic added in commit 625034abd5 ("riscv: add
ISA extensions validation callback") assumes all extensions are included
in riscv_isa_ext, and so riscv_resolve_isa() wrongly drops Xlinuxenvcfg
from the final ISA string. Instead, accept such Linux-internal ISA
extensions as if they have no validation callback.

Fixes: 625034abd5 ("riscv: add ISA extensions validation callback")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240718213011.2600150-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-31 09:53:13 -07:00
Palmer Dabbelt
52420e483d
RISC-V: Provide the frequency of time CSR via hwprobe
The RISC-V architecture makes a real time counter CSR (via RDTIME
instruction) available for applications in U-mode but there is no
architected mechanism for an application to discover the frequency
the counter is running at. Some applications (e.g., DPDK) use the
time counter for basic performance analysis as well as fine grained
time-keeping.

Add support to the hwprobe system call to export the time CSR
frequency to code running in U-mode.

Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Reviewed-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Acked-by: Punit Agrawal <punit.agrawal@bytedance.com>
Link: https://lore.kernel.org/r/20240702033731.71955-2-cuiyunhui@bytedance.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26 05:50:51 -07:00
Palmer Dabbelt
3aa1a7d013
Merge patch series "RISC-V: Select ACPI PPTT drivers"
This series adds support for ACPI PPTT via cacheinfo.

* b4-shazam-merge:
  RISC-V: Select ACPI PPTT drivers
  riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT
  riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init()

Link: https://lore.kernel.org/r/20240617131425.7526-1-cuiyunhui@bytedance.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26 05:50:49 -07:00
Palmer Dabbelt
ec1dc56b54
Merge patch "Enable SPCR table for console output on RISC-V"
Sia Jee Heng <jeeheng.sia@starfivetech.com> says:

The ACPI SPCR code has been used to enable console output for ARM64 and
X86. The same code can be reused for RISC-V. Furthermore, SPCR table is
mandated for headless system as outlined in the RISC-V BRS
Specification, chapter 6.

* b4-shazam-merge:
  RISC-V: ACPI: Enable SPCR table for console output on RISC-V

Link: https://lore.kernel.org/r/20240502073751.102093-1-jeeheng.sia@starfivetech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26 05:50:48 -07:00
Jisheng Zhang
b5db73fb18
riscv: enable HAVE_ARCH_STACKLEAK
Add support for the stackleak feature. Whenever the kernel returns to user
space the kernel stack is filled with a poison value.

At the same time, disables the plugin in EFI stub code because EFI stub
is out of scope for the protection.

Tested on qemu and milkv duo:
/ # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
[   38.675575] lkdtm: Performing direct entry STACKLEAK_ERASING
[   38.678448] lkdtm: stackleak stack usage:
[   38.678448]   high offset: 288 bytes
[   38.678448]   current:     496 bytes
[   38.678448]   lowest:      1328 bytes
[   38.678448]   tracked:     1328 bytes
[   38.678448]   untracked:   448 bytes
[   38.678448]   poisoned:    14312 bytes
[   38.678448]   low offset:  8 bytes
[   38.689887] lkdtm: OK: the rest of the thread stack is properly erased

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240623235316.2010-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26 05:50:47 -07:00
Zhongqiu Han
1d20e5d437
riscv: signal: Remove unlikely() from WARN_ON() condition
"WARN_ON(unlikely(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Signed-off-by: Zhongqiu Han <quic_zhonhan@quicinc.com>
Reviewed-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Andy Chiu <andy.chiu@sifive.com>
Link: https://lore.kernel.org/r/20240620033434.3778156-1-quic_zhonhan@quicinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26 05:50:46 -07:00
Anton Blanchard
5d5fc33ce5
riscv: Improve exception and system call latency
Many CPUs implement return address branch prediction as a stack. The
RISCV architecture refers to this as a return address stack (RAS). If
this gets corrupted then the CPU will mispredict at least one but
potentally many function returns.

There are two issues with the current RISCV exception code:

- We are using the alternate link stack (x5/t0) for the indirect branch
  which makes the hardware think this is a function return. This will
  corrupt the RAS.

- We modify the return address of handle_exception to point to
  ret_from_exception. This will also corrupt the RAS.

Testing the null system call latency before and after the patch:

Visionfive2 (StarFive JH7110 / U74)
baseline: 189.87 ns
patched:  176.76 ns

Lichee pi 4a (T-Head TH1520 / C910)
baseline: 666.58 ns
patched:  636.90 ns

Just over 7% on the U74 and just over 4% on the C910.

Signed-off-by: Anton Blanchard <antonb@tenstorrent.com>
Signed-off-by: Cyril Bur <cyrilbur@tenstorrent.com>
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20240607061335.2197383-1-cyrilbur@tenstorrent.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26 05:50:45 -07:00
Yunhui Cui
604f32ea69
riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT
Before cacheinfo can be built correctly, we need to initialize level
and type. Since RISC-V currently does not have a register group that
describes cache-related attributes like ARM64, we cannot obtain them
directly, so now we obtain cache leaves from the ACPI PPTT table
(acpi_get_cache_info()) and set the cache type through split_levels.

Suggested-by: Jeremy Linton <jeremy.linton@arm.com>
Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Link: https://lore.kernel.org/r/20240617131425.7526-2-cuiyunhui@bytedance.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-24 07:39:36 -07:00
Yunhui Cui
ee3fab10cb
riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init()
ci_leaf_init() is a declared static function. The implementation of the
function body and the caller do not use the parameter (struct device_node
*node) input parameter, so remove it.

Fixes: 6a24915145 ("Revert "riscv: Set more data to cacheinfo"")
Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20240617131425.7526-1-cuiyunhui@bytedance.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-24 07:39:35 -07:00
Sia Jee Heng
38738947db
RISC-V: ACPI: Enable SPCR table for console output on RISC-V
The ACPI SPCR code has been used to enable console output for ARM64 and
X86. The same code can be reused for RISC-V. Furthermore, SPCR table is
mandated for headless system as outlined in the RISC-V BRS
Specification, chapter 6.

Signed-off-by: Sia Jee Heng <jeeheng.sia@starfivetech.com>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>
Link: https://lore.kernel.org/r/20240502073751.102093-2-jeeheng.sia@starfivetech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-24 07:33:37 -07:00
Jinjie Ruan
3308172276
trace: riscv: Remove deprecated kprobe on ftrace support
Since commit 7caa976546 ("ftrace: riscv: move from REGS to ARGS"),
kprobe on ftrace is not supported by riscv, because riscv's support for
FTRACE_WITH_REGS has been replaced with support for FTRACE_WITH_ARGS, and
KPROBES_ON_FTRACE will be supplanted by FPROBES. So remove the deprecated
kprobe on ftrace support, which is misunderstood.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240613111347.1745379-1-ruanjinjie@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-24 06:14:05 -07:00
Palmer Dabbelt
b9a603da42
Merge patch series "riscv: Separate vendor extensions from standard extensions"
Charlie Jenkins <charlie@rivosinc.com> says:

All extensions, both standard and vendor, live in one struct
"riscv_isa_ext". There is currently one vendor extension, xandespmu, but
it is likely that more vendor extensions will be added to the kernel in
the future. As more vendor extensions (and standard extensions) are
added, riscv_isa_ext will become more bloated with a mix of vendor and
standard extensions.

This also allows each vendor to be conditionally enabled through
Kconfig.

* b4-shazam-merge:
  riscv: cpufeature: Extract common elements from extension checking
  riscv: Introduce vendor variants of extension helpers
  riscv: Add vendor extensions to /proc/cpuinfo
  riscv: Extend cpufeature.c to detect vendor extensions

Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-0-0af7587bbec0@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-22 15:37:01 -07:00
Charlie Jenkins
9448d9accd
riscv: Add vendor extensions to /proc/cpuinfo
All of the supported vendor extensions that have been listed in
riscv_isa_vendor_ext_list can be exported through /proc/cpuinfo.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-2-0af7587bbec0@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-22 15:36:55 -07:00
Charlie Jenkins
23c996fc2b
riscv: Extend cpufeature.c to detect vendor extensions
Instead of grouping all vendor extensions into the same riscv_isa_ext
that standard instructions use, create a struct
"riscv_isa_vendor_ext_data_list" that allows each vendor to maintain
their vendor extensions independently of the standard extensions.
xandespmu is currently the only vendor extension so that is the only
extension that is affected by this change.

An additional benefit of this is that the extensions of each vendor can
be conditionally enabled. A config RISCV_ISA_VENDOR_EXT_ANDES has been
added to allow for that.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andy Chiu <andy.chiu@sifive.com>
Tested-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>
Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-1-0af7587bbec0@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-22 15:36:54 -07:00
Conor Dooley
3d8d459c8b
RISC-V: hwprobe: sort EXT_KEY()s in hwprobe_isa_ext0() alphabetically
Currently the entries appear to be in a random order (although according
to Palmer he has tried to sort them by key value) which makes it harder
to find entries in a growing list, and more likely to have conflicts as
all patches are adding to the end of the list. Sort them alphabetically
instead.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Clément Léger <cleger@rivosinc.com>
Link: https://lore.kernel.org/r/20240717-dedicate-squeamish-7e4ab54df58f@spud
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-22 10:57:41 -07:00
Palmer Dabbelt
6a4aa4c94b
Merge patch series "Add ACPI NUMA support for RISC-V"
Haibo Xu <haibo1.xu@intel.com> says:

This patch series enable RISC-V ACPI NUMA support which was based on
the recently approved ACPI ECR[1].

Patch 1/4 add RISC-V specific acpi_numa.c file to parse NUMA information
from SRAT and SLIT ACPI tables.
Patch 2/4 add the common SRAT RINTC affinity structure handler.
Patch 3/4 change the ACPI_NUMA to a hidden option since it would be selected
by default on all supported platform.
Patch 4/4 replace pr_info with pr_debug in arch_acpi_numa_init() to avoid
potential boot noise on ACPI platforms that are not NUMA.

Based-on: https://github.com/linux-riscv/linux-riscv/tree/for-next

[1] https://drive.google.com/file/d/1YTdDx2IPm5IeZjAW932EYU-tUtgS08tX/view?usp=sharing

Testing:
Since the ACPI AIA/PLIC support patch set is still under upstream review,
hence it is tested using the poll based HVC SBI console and RAM disk.
1) Build latest Qemu with the following patch backported
   42bd4eeefd

2) Build latest EDK-II
   https://github.com/tianocore/edk2/blob/master/OvmfPkg/RiscVVirt/README.md

3) Build Linux with the following configs enabled
   CONFIG_RISCV_SBI_V01=y
   CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
   CONFIG_NONPORTABLE=y
   CONFIG_HVC_RISCV_SBI=y
   CONFIG_NUMA=y
   CONFIG_ACPI_NUMA=y

4) Build buildroot rootfs.cpio

5) Launch the Qemu machine
   qemu-system-riscv64 -nographic \
   -machine virt,pflash0=pflash0,pflash1=pflash1 -smp 4 -m 8G \
   -blockdev node-name=pflash0,driver=file,read-only=on,filename=RISCV_VIRT_CODE.fd \
   -blockdev node-name=pflash1,driver=file,filename=RISCV_VIRT_VARS.fd \
   -object memory-backend-ram,size=4G,id=m0 \
   -object memory-backend-ram,size=4G,id=m1 \
   -numa node,memdev=m0,cpus=0-1,nodeid=0 \
   -numa node,memdev=m1,cpus=2-3,nodeid=1 \
   -numa dist,src=0,dst=1,val=30 \
   -kernel linux/arch/riscv/boot/Image \
   -initrd buildroot/output/images/rootfs.cpio \
   -append "root=/dev/ram ro console=hvc0 earlycon=sbi"

[    0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x80000000-0x17fffffff]
[    0.000000] ACPI: SRAT: Node 1 PXM 1 [mem 0x180000000-0x27fffffff]
[    0.000000] NUMA: NODE_DATA [mem 0x17fe3bc40-0x17fe3cfff]
[    0.000000] NUMA: NODE_DATA [mem 0x27fff4c40-0x27fff5fff]
...
[    0.000000] ACPI: NUMA: SRAT: PXM 0 -> HARTID 0x0 -> Node 0
[    0.000000] ACPI: NUMA: SRAT: PXM 0 -> HARTID 0x1 -> Node 0
[    0.000000] ACPI: NUMA: SRAT: PXM 1 -> HARTID 0x2 -> Node 1
[    0.000000] ACPI: NUMA: SRAT: PXM 1 -> HARTID 0x3 -> Node 1

* b4-shazam-merge:
  ACPI: NUMA: replace pr_info with pr_debug in arch_acpi_numa_init
  ACPI: NUMA: change the ACPI_NUMA to a hidden option
  ACPI: NUMA: Add handler for SRAT RINTC affinity structure
  ACPI: RISCV: Add NUMA support based on SRAT and SLIT

Link: https://lore.kernel.org/r/cover.1718268003.git.haibo1.xu@intel.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-22 10:31:51 -07:00
Haibo Xu
eabd9db64e
ACPI: RISCV: Add NUMA support based on SRAT and SLIT
Add acpi_numa.c file to enable parse NUMA information from
ACPI SRAT and SLIT tables. SRAT table provide CPUs(Hart) and
memory nodes to proximity domain mapping, while SLIT table
provide the distance metrics between proximity domains.

Signed-off-by: Haibo Xu <haibo1.xu@intel.com>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Link: https://lore.kernel.org/r/65dbad1fda08a32922c44886e4581e49b4a2fecc.1718268003.git.haibo1.xu@intel.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-22 07:13:06 -07:00
Linus Torvalds
f557af081d RISC-V Patches for the 6.11 Merge Window, Part 1
* Support for various new ISA extensions:
     * The Zve32[xf] and Zve64[xfd] sub-extensios of the vector
       extension.
     * Zimop and Zcmop for may-be-operations.
     * The Zca, Zcf, Zcd and Zcb sub-extensions of the C extension.
     * Zawrs,
 * riscv,cpu-intc is now dtschema.
 * A handful of performance improvements and cleanups to text patching.
 * Support for memory hot{,un}plug
 * The highest user-allocatable virtual address is now visible in
   hwprobe.
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Merge tag 'riscv-for-linus-6.11-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for various new ISA extensions:
     * The Zve32[xf] and Zve64[xfd] sub-extensios of the vector
       extension
     * Zimop and Zcmop for may-be-operations
     * The Zca, Zcf, Zcd and Zcb sub-extensions of the C extension
     * Zawrs

 - riscv,cpu-intc is now dtschema

 - A handful of performance improvements and cleanups to text patching

 - Support for memory hot{,un}plug

 - The highest user-allocatable virtual address is now visible in
   hwprobe

* tag 'riscv-for-linus-6.11-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (58 commits)
  riscv: lib: relax assembly constraints in hweight
  riscv: set trap vector earlier
  KVM: riscv: selftests: Add Zawrs extension to get-reg-list test
  KVM: riscv: Support guest wrs.nto
  riscv: hwprobe: export Zawrs ISA extension
  riscv: Add Zawrs support for spinlocks
  dt-bindings: riscv: Add Zawrs ISA extension description
  riscv: Provide a definition for 'pause'
  riscv: hwprobe: export highest virtual userspace address
  riscv: Improve sbi_ecall() code generation by reordering arguments
  riscv: Add tracepoints for SBI calls and returns
  riscv: Optimize crc32 with Zbc extension
  riscv: Enable DAX VMEMMAP optimization
  riscv: mm: Add support for ZONE_DEVICE
  virtio-mem: Enable virtio-mem for RISC-V
  riscv: Enable memory hotplugging for RISC-V
  riscv: mm: Take memory hotplug read-lock during kernel page table dump
  riscv: mm: Add memory hotplugging support
  riscv: mm: Add pfn_to_kaddr() implementation
  riscv: mm: Refactor create_linear_mapping_range() for memory hot add
  ...
2024-07-20 09:11:27 -07:00
Linus Torvalds
d80f2996b8 asm-generic updates for 6.11
Most of this is part of my ongoing work to clean up the system call
 tables. In this bit, all of the newer architectures are converted to
 use the machine readable syscall.tbl format instead in place of complex
 macros in include/uapi/asm-generic/unistd.h.
 
 This follows an earlier series that fixed various API mismatches
 and in turn is used as the base for planned simplifications.
 
 The other two patches are dead code removal and a warning fix.
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Merge tag 'asm-generic-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm-generic updates from Arnd Bergmann:
 "Most of this is part of my ongoing work to clean up the system call
  tables. In this bit, all of the newer architectures are converted to
  use the machine readable syscall.tbl format instead in place of
  complex macros in include/uapi/asm-generic/unistd.h.

  This follows an earlier series that fixed various API mismatches and
  in turn is used as the base for planned simplifications.

  The other two patches are dead code removal and a warning fix"

* tag 'asm-generic-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  vmlinux.lds.h: catch .bss..L* sections into BSS")
  fixmap: Remove unused set_fixmap_offset_io()
  riscv: convert to generic syscall table
  openrisc: convert to generic syscall table
  nios2: convert to generic syscall table
  loongarch: convert to generic syscall table
  hexagon: use new system call table
  csky: convert to generic syscall table
  arm64: rework compat syscall macros
  arm64: generate 64-bit syscall.tbl
  arm64: convert unistd_32.h to syscall.tbl format
  arc: convert to generic syscall table
  clone3: drop __ARCH_WANT_SYS_CLONE3 macro
  kbuild: add syscall table generation to scripts/Makefile.asm-headers
  kbuild: verify asm-generic header list
  loongarch: avoid generating extra header files
  um: don't generate asm/bpf_perf_event.h
  csky: drop asm/gpio.h wrapper
  syscalls: add generic scripts/syscall.tbl
2024-07-16 12:09:03 -07:00
yang.zhang
6ad8735994
riscv: set trap vector earlier
The exception vector of the booting hart is not set before enabling
the mmu and then still points to the value of the previous firmware,
typically _start. That makes it hard to debug setup_vm() when bad
things happen. So fix that by setting the exception vector earlier.

Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: yang.zhang <yang.zhang@hexintek.com>
Link: https://lore.kernel.org/r/20240508022445.6131-1-gaoshanliukou@163.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-12 08:55:31 -07:00
Palmer Dabbelt
5ee121a393
Merge patch series "riscv: Apply Zawrs when available"
Andrew Jones <ajones@ventanamicro.com> says:

Zawrs provides two instructions (wrs.nto and wrs.sto), where both are
meant to allow the hart to enter a low-power state while waiting on a
store to a memory location. The instructions also both wait an
implementation-defined "short" duration (unless the implementation
terminates the stall for another reason). The difference is that while
wrs.sto will terminate when the duration elapses, wrs.nto, depending on
configuration, will either just keep waiting or an ILL exception will be
raised. Linux will use wrs.nto, so if platforms have an implementation
which falls in the "just keep waiting" category (which is not expected),
then it should _not_ advertise Zawrs in the hardware description.

Like wfi (and with the same {m,h}status bits to configure it), when
wrs.nto is configured to raise exceptions it's expected that the higher
privilege level will see the instruction was a wait instruction, do
something, and then resume execution following the instruction. For
example, KVM does configure exceptions for wfi (hstatus.VTW=1) and
therefore also for wrs.nto. KVM does this for wfi since it's better to
allow other tasks to be scheduled while a VCPU waits for an interrupt.
For waits such as those where wrs.nto/sto would be used, which are
typically locks, it is also a good idea for KVM to be involved, as it
can attempt to schedule the lock holding VCPU.

This series starts with Christoph's addition of the riscv
smp_cond_load_relaxed function which applies wrs.sto when available.
That patch has been reworked to use wrs.nto and to use the same approach
as Arm for the wait loop, since we can't have arbitrary C code between
the load-reserved and the wrs. Then, hwprobe support is added (since the
instructions are also usable from usermode), and finally KVM is
taught about wrs.nto, allowing guests to see and use the Zawrs
extension.

We still don't have test results from hardware, and it's not possible to
prove that using Zawrs is a win when testing on QEMU, not even when
oversubscribing VCPUs to guests. However, it is possible to use KVM
selftests to force a scenario where we can prove Zawrs does its job and
does it well. [4] is a test which does this and, on my machine, without
Zawrs it takes 16 seconds to complete and with Zawrs it takes 0.25
seconds.

This series is also available here [1]. In order to use QEMU for testing
a build with [2] is needed. In order to enable guests to use Zawrs with
KVM using kvmtool, the branch at [3] may be used.

[1] https://github.com/jones-drew/linux/commits/riscv/zawrs-v3/
[2] https://lore.kernel.org/all/20240312152901.512001-2-ajones@ventanamicro.com/
[3] https://github.com/jones-drew/kvmtool/commits/riscv/zawrs/
[4] cb2beccebc

Link: https://lore.kernel.org/r/20240426100820.14762-8-ajones@ventanamicro.com

* b4-shazam-merge:
  KVM: riscv: selftests: Add Zawrs extension to get-reg-list test
  KVM: riscv: Support guest wrs.nto
  riscv: hwprobe: export Zawrs ISA extension
  riscv: Add Zawrs support for spinlocks
  dt-bindings: riscv: Add Zawrs ISA extension description
  riscv: Provide a definition for 'pause'

Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-12 08:55:29 -07:00
Andrew Jones
244c18fbf6
riscv: hwprobe: export Zawrs ISA extension
Export Zawrs ISA extension through hwprobe.

[Palmer: there's a gap in the numbers here as there will be a merge
conflict when this is picked up.  To avoid confusion I just set the
hwprobe ID to match what it would be post-merge.]

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Clément Léger <cleger@rivosinc.com>
Link: https://lore.kernel.org/r/20240426100820.14762-12-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-12 08:53:50 -07:00
Christoph Müllner
b8ddb0df30
riscv: Add Zawrs support for spinlocks
RISC-V code uses the generic ticket lock implementation, which calls
the macros smp_cond_load_relaxed() and smp_cond_load_acquire().
Introduce a RISC-V specific implementation of smp_cond_load_relaxed()
which applies WRS.NTO of the Zawrs extension in order to reduce power
consumption while waiting and allows hypervisors to enable guests to
trap while waiting. smp_cond_load_acquire() doesn't need a RISC-V
specific implementation as the generic implementation is based on
smp_cond_load_relaxed() and smp_acquire__after_ctrl_dep() sufficiently
provides the acquire semantics.

This implementation is heavily based on Arm's approach which is the
approach Andrea Parri also suggested.

The Zawrs specification can be found here:
https://github.com/riscv/riscv-zawrs/blob/main/zawrs.adoc

Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Co-developed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240426100820.14762-11-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-12 03:16:42 -07:00
Clément Léger
c9b8cd139c
riscv: hwprobe: export highest virtual userspace address
Some userspace applications (OpenJDK for instance) uses the free MSBs
in pointers to insert additional information for their own logic and
need to get this information from somewhere. Currently they rely on
parsing /proc/cpuinfo "mmu=svxx" string to obtain the current value of
virtual address usable bits [1]. Since this reflect the raw supported
MMU mode, it might differ from the logical one used internally which is
why arch_get_mmap_end() is used. Exporting the highest mmapable address
through hwprobe will allow a more stable interface to be used. For that
purpose, add a new hwprobe key named
RISCV_HWPROBE_KEY_HIGHEST_VIRT_ADDRESS which will export the highest
userspace virtual address.

Link: https://github.com/openjdk/jdk/blob/master/src/hotspot/os_cpu/linux_riscv/vm_version_linux_riscv.cpp#L171 [1]
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240410144558.1104006-1-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-11 08:57:33 -07:00
Alexandre Ghiti
16badacd8a
riscv: Improve sbi_ecall() code generation by reordering arguments
The sbi_ecall() function arguments are not in the same order as the
ecall arguments, so we end up re-ordering the registers before the
ecall which is useless and costly.

So simply reorder the arguments in the same way as expected by ecall.
Instead of reordering directly the arguments of sbi_ecall(), use a proxy
macro since the current ordering is more natural.

Before:

Dump of assembler code for function sbi_ecall:
   0xffffffff800085e0 <+0>: add sp,sp,-32
   0xffffffff800085e2 <+2>: sd s0,24(sp)
   0xffffffff800085e4 <+4>: mv t1,a0
   0xffffffff800085e6 <+6>: add s0,sp,32
   0xffffffff800085e8 <+8>: mv t3,a1
   0xffffffff800085ea <+10>: mv a0,a2
   0xffffffff800085ec <+12>: mv a1,a3
   0xffffffff800085ee <+14>: mv a2,a4
   0xffffffff800085f0 <+16>: mv a3,a5
   0xffffffff800085f2 <+18>: mv a4,a6
   0xffffffff800085f4 <+20>: mv a5,a7
   0xffffffff800085f6 <+22>: mv a6,t3
   0xffffffff800085f8 <+24>: mv a7,t1
   0xffffffff800085fa <+26>: ecall
   0xffffffff800085fe <+30>: ld s0,24(sp)
   0xffffffff80008600 <+32>: add sp,sp,32
   0xffffffff80008602 <+34>: ret

After:

Dump of assembler code for function __sbi_ecall:
   0xffffffff8000b6b2 <+0>:	add	sp,sp,-32
   0xffffffff8000b6b4 <+2>:	sd	s0,24(sp)
   0xffffffff8000b6b6 <+4>:	add	s0,sp,32
   0xffffffff8000b6b8 <+6>:	ecall
   0xffffffff8000b6bc <+10>:	ld	s0,24(sp)
   0xffffffff8000b6be <+12>:	add	sp,sp,32
   0xffffffff8000b6c0 <+14>:	ret

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Yunhui Cui <cuiyunhui@bytedance.com>
Link: https://lore.kernel.org/r/20240322112629.68170-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-10 13:30:56 -07:00
Samuel Holland
56c1c1a09a
riscv: Add tracepoints for SBI calls and returns
These are useful for measuring the latency of SBI calls. The SBI HSM
extension is excluded because those functions are called from contexts
such as cpuidle where instrumentation is not allowed.

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240321230131.1838105-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-10 13:23:09 -07:00
Arnd Bergmann
3db80c999d riscv: convert to generic syscall table
The uapi/asm/unistd_{32,64}.h and asm/syscall_table_{32,64}.h headers can
now be generated from scripts/syscall.tbl, which makes this consistent
with the other architectures that have their own syscall.tbl.

riscv has two extra system call that gets added to scripts/syscall.tbl.

The newstat and rlimit entries in the syscall_abis_64 line are for system
calls that were part of the generic ABI when riscv64 got added but are
no longer enabled by default for new architectures. Both riscv32 and
riscv64 also implement memfd_secret, which is optional for all
architectures.

Unlike all the other 32-bit architectures, the time32 and stat64
sets of syscalls are not enabled on riscv32.

Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-07-10 14:23:38 +02:00
Song Shuai
c562ba719d
riscv: kexec: Avoid deadlock in kexec crash path
If the kexec crash code is called in the interrupt context, the
machine_kexec_mask_interrupts() function will trigger a deadlock while
trying to acquire the irqdesc spinlock and then deactivate irqchip in
irq_set_irqchip_state() function.

Unlike arm64, riscv only requires irq_eoi handler to complete EOI and
keeping irq_set_irqchip_state() will only leave this possible deadlock
without any use. So we simply remove it.

Link: https://lore.kernel.org/linux-riscv/20231208111015.173237-1-songshuaishuai@tinylab.org/
Fixes: b17d19a531 ("riscv: kexec: Fixup irq controller broken in kexec crash path")
Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
Reviewed-by: Ryo Takakura <takakura@valinux.co.jp>
Link: https://lore.kernel.org/r/20240626023316.539971-1-songshuaishuai@tinylab.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-03 13:11:30 -07:00
Puranjay Mohan
393da6cbb2
riscv: stacktrace: fix usage of ftrace_graph_ret_addr()
ftrace_graph_ret_addr() takes an `idx` integer pointer that is used to
optimize the stack unwinding. Pass it a valid pointer to utilize the
optimizations that might be available in the future.

The commit is making riscv's usage of ftrace_graph_ret_addr() match
x86_64.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20240618145820.62112-1-puranjay@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-03 13:10:03 -07:00
Linus Torvalds
de0a9f4486 RISC-V Fixes for 6.10-rc6
* A fix for vector load/store instruction decoding, which could result
   in reserved vector element length encodings decoding as valid vector
   instructions.
 * Instruction patching now aggressively flushes the local instruction
   cache, to avoid situations where patching functions on the flush path
   results in torn instructions being fetched.
 * A fix to prevent the stack walker from showing up as part of traces.
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Merge tag 'riscv-for-linus-6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:

 - A fix for vector load/store instruction decoding, which could result
   in reserved vector element length encodings decoding as valid vector
   instructions.

 - Instruction patching now aggressively flushes the local instruction
   cache, to avoid situations where patching functions on the flush path
   results in torn instructions being fetched.

 - A fix to prevent the stack walker from showing up as part of traces.

* tag 'riscv-for-linus-6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: stacktrace: convert arch_stack_walk() to noinstr
  riscv: patch: Flush the icache right after patching to avoid illegal insns
  RISC-V: fix vector insn load/store width mask
2024-06-28 16:14:59 -07:00
Palmer Dabbelt
914e618b43
Merge patch series "Add support for a few Zc* extensions, Zcmop and Zimop"
Clément Léger <cleger@rivosinc.com> says:

Add support for (yet again) more RVA23U64 missing extensions. Add
support for Zimop, Zcmop, Zca, Zcf, Zcd and Zcb extensions ISA string
parsing, hwprobe and kvm support. Zce, Zcmt and Zcmp extensions have
been left out since they target microcontrollers/embedded CPUs and are
not needed by RVA23U64.

Since Zc* extensions states that C implies Zca, Zcf (if F and RV32), Zcd
(if D), this series modifies the way ISA string is parsed and now does
it in two phases. First one parses the string and the second one
validates it for the final ISA description.

* b4-shazam-merge:
  KVM: riscv: selftests: Add Zcmop extension to get-reg-list test
  RISC-V: KVM: Allow Zcmop extension for Guest/VM
  riscv: hwprobe: export Zcmop ISA extension
  riscv: add ISA extension parsing for Zcmop
  dt-bindings: riscv: add Zcmop ISA extension description
  KVM: riscv: selftests: Add some Zc* extensions to get-reg-list test
  RISC-V: KVM: Allow Zca, Zcf, Zcd and Zcb extensions for Guest/VM
  riscv: hwprobe: export Zca, Zcf, Zcd and Zcb ISA extensions
  riscv: add ISA parsing for Zca, Zcf, Zcd and Zcb
  riscv: add ISA extensions validation callback
  dt-bindings: riscv: add Zca, Zcf, Zcd and Zcb ISA extension description
  KVM: riscv: selftests: Add Zimop extension to get-reg-list test
  RISC-V: KVM: Allow Zimop extension for Guest/VM
  riscv: hwprobe: export Zimop ISA extension
  riscv: add ISA extension parsing for Zimop
  dt-bindings: riscv: add Zimop ISA extension description

Link: https://lore.kernel.org/r/20240619113529.676940-1-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:55:02 -07:00
Clément Léger
fc078ea317
riscv: hwprobe: export Zcmop ISA extension
Export Zcmop ISA extension through hwprobe.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Evan Green <evan@rivosinc.com>
Link: https://lore.kernel.org/r/20240619113529.676940-15-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:54:58 -07:00
Clément Léger
164d644059
riscv: add ISA extension parsing for Zcmop
Add parsing for Zcmop ISA extension which was ratified in commit
c732a4f39a4c ("Zcmop is ratified/1.0") of the riscv-isa-manual.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240619113529.676940-14-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:54:57 -07:00
Clément Léger
0ad70db5eb
riscv: hwprobe: export Zca, Zcf, Zcd and Zcb ISA extensions
Export Zca, Zcf, Zcd and Zcb ISA extension through hwprobe.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240619113529.676940-10-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:54:53 -07:00
Clément Léger
ba4cd85583
riscv: add ISA parsing for Zca, Zcf, Zcd and Zcb
The Zc* standard extension for code reduction introduces new extensions.
This patch adds support for Zca, Zcf, Zcd and Zcb. Zce, Zcmt and Zcmp
are left out of this patch since they are targeting microcontrollers/
embedded CPUs instead of application processors.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240619113529.676940-9-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:54:52 -07:00
Clément Léger
625034abd5
riscv: add ISA extensions validation callback
Since a few extensions (Zicbom/Zicboz) already needs validation and
future ones will need it as well (Zc*) add a validate() callback to
struct riscv_isa_ext_data. This require to rework the way extensions are
parsed and split it in two phases. First phase is isa string or isa
extension list parsing and consists in enabling all the extensions in a
temporary bitmask (source isa) without any validation. The second step
"resolves" the final isa bitmap, handling potential missing dependencies.
The mechanism is quite simple and simply validate each extension
described in the source bitmap before enabling it in the resolved isa
bitmap. validate() callbacks can return either 0 for success,
-EPROBEDEFER if extension needs to be validated again at next loop. A
previous ISA bitmap is kept to avoid looping multiple times if an
extension dependencies are never satisfied until we reach a stable
state. In order to avoid any potential infinite looping, allow looping
a maximum of the number of extension we handle. Zicboz and Zicbom
extensions are modified to use this validation mechanism.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240619113529.676940-8-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:54:51 -07:00
Clément Léger
36f8960de8
riscv: hwprobe: export Zimop ISA extension
Export Zimop ISA extension through hwprobe.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240619113529.676940-4-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:54:47 -07:00
Clément Léger
2467c2104f
riscv: add ISA extension parsing for Zimop
Add parsing for Zimop ISA extension which was ratified in commit
58220614a5f of the riscv-isa-manual.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240619113529.676940-3-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:54:46 -07:00
Palmer Dabbelt
cc2c169e34
Merge patch "riscv: stacktrace: convert arch_stack_walk() to noinstr"
This first patch in the larger series is a fix, so I'm merging it into
fixes while the rest of the patch set is still under development.

* b4-shazam-merge:
  riscv: stacktrace: convert arch_stack_walk() to noinstr

Link: https://lore.kernel.org/r/20240613-dev-andyc-dyn-ftrace-v4-v1-0-1a538e12c01e@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:38:02 -07:00
Andy Chiu
23b2188920
riscv: stacktrace: convert arch_stack_walk() to noinstr
arch_stack_walk() is called intensively in function_graph when the
kernel is compiled with CONFIG_TRACE_IRQFLAGS. As a result, the kernel
logs a lot of arch_stack_walk and its sub-functions into the ftrace
buffer. However, these functions should not appear on the trace log
because they are part of the ftrace itself. This patch references what
arm64 does for the smae function. So it further prevent the re-enter
kprobe issue, which is also possible on riscv.

Related-to: commit 0fbcd8abf3 ("arm64: Prohibit instrumentation on arch_stack_walk()")
Fixes: 680341382d ("riscv: add CALLER_ADDRx support")
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240613-dev-andyc-dyn-ftrace-v4-v1-1-1a538e12c01e@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26 07:37:59 -07:00