If Zicbom is present but there was no riscv,cbom-blocks-size property found
during the cpu feeatures probe, or the cbom-block-size is not valid, then
the extension will be disabled. Make the print explicitly say this is
disabled to ensure that there is no confusion about what is being done.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230317134512.254627-1-ben.dooks@codethink.co.uk
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Andy Chiu <andy.chiu@sifive.com> says:
This is the v21 patch series for adding Vector extension support in
Linux. Please refer to [1] for the introduction of the patchset. The
v21 patch series was aimed to solve build issues from v19, provide usage
guideline for the prctl interface, and address review comments on v20.
Thank every one who has been reviewing, suggesting on the topic. Hope
this get a step closer to the final merge.
* b4-shazam-merge: (27 commits)
selftests: add .gitignore file for RISC-V hwprobe
selftests: Test RISC-V Vector prctl interface
riscv: Add documentation for Vector
riscv: Enable Vector code to be built
riscv: detect assembler support for .option arch
riscv: Add sysctl to set the default vector rule for new processes
riscv: Add prctl controls for userspace vector management
riscv: hwcap: change ELF_HWCAP to a function
riscv: KVM: Add vector lazy save/restore support
riscv: kvm: Add V extension to KVM ISA
riscv: prevent stack corruption by reserving task_pt_regs(p) early
riscv: signal: validate altstack to reflect Vector
riscv: signal: Report signal frame size to userspace via auxv
riscv: signal: Add sigcontext save/restore for vector
riscv: signal: check fp-reserved words unconditionally
riscv: Add ptrace vector support
riscv: Allocate user's vector context in the first-use trap
riscv: Add task switch support for vector
riscv: Introduce struct/helpers to save/restore per-task Vector state
riscv: Introduce riscv_v_vsize to record size of Vector context
...
Link: https://lore.kernel.org/r/20230605110724.21391-1-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This patch add two riscv-specific prctls, to allow usespace control the
use of vector unit:
* PR_RISCV_V_SET_CONTROL: control the permission to use Vector at next,
or all following execve for a thread. Turning off a thread's Vector
live is not possible since libraries may have registered ifunc that
may execute Vector instructions.
* PR_RISCV_V_GET_CONTROL: get the same permission setting for the
current thread, and the setting for following execve(s).
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Vincent Chen <vincent.chen@sifive.com>
Link: https://lore.kernel.org/r/20230605110724.21391-22-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Using a function is flexible to represent ELF_HWCAP. So the kernel may
encode hwcap reflecting supported hardware features just at the moment of
the start of each program.
This will be helpful when we introduce prctl/sysctl interface to control
per-process availability of Vector extension in following patches.
Programs started with V disabled should see V masked off in theirs
ELF_HWCAP.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230605110724.21391-21-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This patch is used to detect the size of CPU vector registers and use
riscv_v_vsize to save the size of all the vector registers. It assumes all
harts has the same capabilities in a SMP system. If a core detects VLENB
that is different from the boot core, then it warns and turns off V
support for user space.
Co-developed-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Co-developed-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230605110724.21391-9-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Yangyu Chen <cyy@cyyself.name> says:
This patchset allows case-insensitive ISA string parsing, which is
needed in the ACPI environment. As the RISC-V Hart Capabilities Table
(RHCT) description in UEFI Forum ECR[1] shows the format of the ISA
string is defined in the RISC-V unprivileged specification[2]. However,
the RISC-V unprivileged specification defines the ISA naming strings are
case-insensitive while the current ISA string parser in the kernel only
accepts lowercase letters. In this case, the kernel should allow
case-insensitive ISA string parsing. Moreover, this reason has been
discussed in Conor's patch[3]. And I have also checked the current ISA
string parsing in the recent ACPI support patch[4] will also call
`riscv_fill_hwcap` function as DT we use now.
The original motivation for my patch v1[5] is that some SoC generators
will provide generated DT with illegal ISA string in dt-binding such as
rocket-chip, which will even cause kernel panic in some cases as I
mentioned in v1[5]. Now, the rocket-chip has been fixed in PR #3333[6].
However, when using some specific version of rocket-chip with
illegal ISA string in DT, this patchset will also work for parsing
uppercase letters correctly in DT, thus will have better compatibility.
In summary, this patch not only works for case-insensitive ISA string
parsing to meet the requirements in ECR[1] but also can be a workaround
for some specific versions of rocket-chip.
* b4-shazam-merge:
dt-bindings: riscv: drop invalid comment about riscv,isa lower-case reasoning
riscv: allow case-insensitive ISA string parsing
Link: https://lore.kernel.org/r/tencent_E6911C8D71F5624E432A1AFDF86804C3B509@qq.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
According to RISC-V Hart Capabilities Table (RHCT) description in UEFI
Forum ECR, the format of the ISA string is defined in the RISC-V
unprivileged specification which is case-insensitive. However, the
current ISA string parser in the kernel does not support ISA strings
with uppercase letters.
This patch modifies the ISA string parser in the kernel to support
case-insensitive ISA string parsing.
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Yangyu Chen <cyy@cyyself.name>
Link: https://lore.kernel.org/r/tencent_B30EED51C7235CA1988890E5C658BE35C107@qq.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
On ACPI based systems, the information about the hart
like ISA is provided by the RISC-V Hart Capabilities Table (RHCT).
Enable filling up hwcap structure based on the information in RHCT.
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230515054928.2079268-15-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
During boot we call riscv_of_processor_hartid() for each hart that we
add to the possible cpus list. Repeating the call again here is not
required, if we iterate over the list of possible CPUs, rather than the
list of all CPUs.
The call to of_property_read_string() for "riscv,isa" cannot fail
either, as it has previously succeeded in riscv_of_processor_hartid(),
but leaving in the error checking makes the operation of the loop more
obvious & provides leeway for future refactoring of
riscv_of_processor_hartid().
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Co-developed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230515054928.2079268-14-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* Support for hibernation.
* .rela.dyn has been moved to init.
* A fix for the SBI probing to allow for implementation-defined
behavior.
* Various other fixes and cleanups throughout the tree.
-----BEGIN PGP SIGNATURE-----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=xoqj
-----END PGP SIGNATURE-----
Merge tag 'riscv-for-linus-6.4-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull more RISC-V updates from Palmer Dabbelt:
- Support for hibernation
- The .rela.dyn section has been moved to the init area
- A fix for the SBI probing to allow for implementation-defined
behavior
- Various other fixes and cleanups throughout the tree
* tag 'riscv-for-linus-6.4-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
RISC-V: include cpufeature.h in cpufeature.c
riscv: Move .rela.dyn to the init sections
dt-bindings: riscv: explicitly mention assumption of Zicsr & Zifencei support
riscv: compat_syscall_table: Fixup compile warning
RISC-V: fixup in-flight collision with ARCH_WANT_OPTIMIZE_VMEMMAP rename
RISC-V: fix sifive and thead section mismatches in errata
RISC-V: Align SBI probe implementation with spec
riscv: mm: remove redundant parameter of create_fdt_early_page_table
riscv: Adjust dependencies of HAVE_DYNAMIC_FTRACE selection
RISC-V: Add arch functions to support hibernation/suspend-to-disk
RISC-V: mm: Enable huge page support to kernel_page_present() function
RISC-V: Factor out common code of __cpu_resume_enter()
RISC-V: Change suspend_save_csrs and suspend_restore_csrs to public function
Automation complains:
warning: symbol '__pcpu_scope_misaligned_access_speed' was not declared. Should it be static?
cpufeature.c doesn't actually include the header of the same name, as it
had not previously used anything from it.
The per-cpu variable is declared there, so include it to silence the
complaints.
Fixes: 62a31d6e38 ("RISC-V: hwprobe: Support probing of misaligned access performance")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Evan Green <evan@rivosinc.com>
Link: https://lore.kernel.org/r/20230420-wound-gizzard-2b2b589d9bea@spud
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
We have two extension names for AIA ISA support: Smaia (M-mode AIA CSRs)
and Ssaia (S-mode AIA CSRs).
We extend the ISA string parsing to detect Smaia and Ssaia extensions.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Evan Green <evan@rivosinc.com> says:
There's been a bunch of off-list discussions about this, including at
Plumbers. The original plan was to do something involving providing an
ISA string to userspace, but ISA strings just aren't sufficient for a
stable ABI any more: in order to parse an ISA string users need the
version of the specifications that the string is written to, the version
of each extension (sometimes at a finer granularity than the RISC-V
releases/versions encode), and the expected use case for the ISA string
(ie, is it a U-mode or M-mode string). That's a lot of complexity to
try and keep ABI compatible and it's probably going to continue to grow,
as even if there's no more complexity in the specifications we'll have
to deal with the various ISA string parsing oddities that end up all
over userspace.
Instead this patch set takes a very different approach and provides a set
of key/value pairs that encode various bits about the system. The big
advantage here is that we can clearly define what these mean so we can
ensure ABI stability, but it also allows us to encode information that's
unlikely to ever appear in an ISA string (see the misaligned access
performance, for example). The resulting interface looks a lot like
what arm64 and x86 do, and will hopefully fit well into something like
ACPI in the future.
The actual user interface is a syscall, with a vDSO function in front of
it. The vDSO function can answer some queries without a syscall at all,
and falls back to the syscall for cases it doesn't have answers to.
Currently we prepopulate it with an array of answers for all keys and
a CPU set of "all CPUs". This can be adjusted as necessary to provide
fast answers to the most common queries.
An example series in glibc exposing this syscall and using it in an
ifunc selector for memcpy can be found at [1].
I was asked about the performance delta between this and something like
sysfs. I created a small test program and ran it on a Nezha D1
Allwinner board. Doing each operation 100000 times and dividing, these
operations take the following amount of time:
- open()+read()+close() of /sys/kernel/cpu_byteorder: 3.8us
- access("/sys/kernel/cpu_byteorder", R_OK): 1.3us
- riscv_hwprobe() vDSO and syscall: .0094us
- riscv_hwprobe() vDSO with no syscall: 0.0091us
These numbers get farther apart if we query multiple keys, as sysfs will
scale linearly with the number of keys, where the dedicated syscall
stays the same. To frame these numbers, I also did a tight
fork/exec/wait loop, which I measured as 4.8ms. So doing 4
open/read/close operations is a delta of about 0.3%, versus a single vDSO
call is a delta of essentially zero.
[1] https://patchwork.ozlabs.org/project/glibc/list/?series=343050
* b4-shazam-merge:
RISC-V: Add hwprobe vDSO function and data
selftests: Test the new RISC-V hwprobe interface
RISC-V: hwprobe: Support probing of misaligned access performance
RISC-V: hwprobe: Add support for RISCV_HWPROBE_BASE_BEHAVIOR_IMA
RISC-V: Add a syscall for HW probing
RISC-V: Move struct riscv_cpuinfo to new header
Link: https://lore.kernel.org/r/20230407231103.2622178-1-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This allows userspace to select various routines to use based on the
performance of misaligned access on the target hardware.
Rather than adding DT bindings, this change taps into the alternatives
mechanism used to probe CPU errata. Add a new function pointer alongside
the vendor-specific errata_patch_func() that probes for desirable errata
(otherwise known as "features"). Unlike the errata_patch_func(), this
function is called on each CPU as it comes up, so it can save
feature information per-CPU.
The T-head C906 has fast unaligned access, both as defined by GCC [1],
and in performing a basic benchmark, which determined that byte copies
are >50% slower than a misaligned word copy of the same data size (source
for this test at [2]):
bytecopy size f000 count 50000 offset 0 took 31664899 us
wordcopy size f000 count 50000 offset 0 took 5180919 us
wordcopy size f000 count 50000 offset 1 took 13416949 us
[1] https://github.com/gcc-mirror/gcc/blob/master/gcc/config/riscv/riscv.cc#L353
[2] https://pastebin.com/EPXvDHSW
Co-developed-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com>
Link: https://lore.kernel.org/r/20230407231103.2622178-5-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Andrew Jones <ajones@ventanamicro.com> says:
When the Zicboz extension is available we can more rapidly zero naturally
aligned Zicboz block sized chunks of memory. As pages are always page
aligned and are larger than any Zicboz block size will be, then
clear_page() appears to be a good candidate for the extension. While cycle
count and energy consumption should also be considered, we can be pretty
certain that implementing clear_page() with the Zicboz extension is a win
by comparing the new dynamic instruction count with its current count[1].
Doing so we see that the new count is just over a quarter of the old count
(see patch6's commit message for more details).
For those of you who reviewed v1[2], you may be looking for the memset()
patches. As pointed out in v1, and a couple follow-up emails, it's not
clear that patching memset() is a win yet. When I get a chance to test
on real hardware with a comprehensive benchmark collection then I can
post the memset() patches separately (assuming the benchmarks show it's
worthwhile).
* b4-shazam-merge:
RISC-V: KVM: Expose Zicboz to the guest
RISC-V: KVM: Provide UAPI for Zicboz block size
RISC-V: Use Zicboz in clear_page when available
RISC-V: cpufeatures: Put the upper 16 bits of patch ID to work
RISC-V: Add Zicboz detection and block size parsing
dt-bindings: riscv: Document cboz-block-size
RISC-V: Factor out body of riscv_init_cbom_blocksize loop
RISC-V: alternatives: Support patching multiple insns in assembly
Link: https://lore.kernel.org/r/20230224162631.405473-1-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Using memset() to zero a 4K page takes 563 total instructions, where
20 are branches. clear_page(), with Zicboz and a 64 byte block size,
takes 169 total instructions, where 4 are branches and 33 are nops.
Even though the block size is a variable, thanks to alternatives, we
can still implement a Duff device without having to do any preliminary
calculations. This is achieved by using the alternatives' cpufeature
value (the upper 16 bits of patch_id). The value used is the maximum
zicboz block size order accepted at the patch site. This enables us
to stop patching / unrolling when 4K bytes have been zeroed (we would
loop and continue after 4K if the page size would be larger)
For 4K pages, unrolling 16 times allows block sizes of 64 and 128 to
only loop a few times and larger block sizes to not loop at all. Since
cbo.zero doesn't take an offset, we also need an 'add' after each
instruction, making the loop body 112 to 160 bytes. Hopefully this
is small enough to not cause icache misses.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230224162631.405473-7-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
cpufeature IDs are consecutive integers starting at 26, so a 32-bit
patch ID allows an aircraft carrier load of feature IDs. Repurposing
the upper 16 bits still leaves a boat load of feature IDs and gains
16 bits which may be used to control patching on a per patch-site
basis.
This will be initially used in Zicboz's application to clear_page(),
as Zicboz's block size must also be considered. In that case, the
upper 16-bit value's role will be to convey the maximum block size
which the Zicboz clear_page() implementation supports.
cpufeature patch sites which need to check for the existence or
absence of other cpufeatures may also be able to make use of this.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230224162631.405473-6-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Parse "riscv,cboz-block-size" from the DT by piggybacking on Zicbom's
riscv_init_cbom_blocksize(). Additionally check the DT for the presence
of the "zicboz" extension and, when it's present, validate the parsed
cboz block size as we do Zicbom's cbom block size with
riscv_isa_extension_check().
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230224162631.405473-5-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Andrew Jones <ajones@ventanamicro.com> says:
This series has no intended functional change. These cleanups were
found while renaming errata_id to patch_id in order to better
convey that its purpose is larger than errata (it's also for
cpufeatures).
* b4-shazam-merge:
riscv: cpufeature: Drop errata_list.h and other unused includes
riscv: lib: Include hwcap.h directly
riscv: alternatives: Rename errata_id to patch_id
riscv: alternatives: Remove unnecessary define and unused struct
riscv: Rename Kconfig.erratas to Kconfig.errata
riscv: Clarify RISCV_ALTERNATIVE help text
Link: https://lore.kernel.org/r/20230224154601.88163-1-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Drop errata_list.h, since cpufeature.c includes hwcap.h directly to
get cpufeature IDs. And, while there, prune the rest of the unused
includes too.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20230224154601.88163-7-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Alternatives are used for both errata and cpufeatures. Use a more
generic name, 'patch_id', as in "ID of code patching site", to
avoid confusion when alternatives are used for cpufeatures.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20230224154601.88163-5-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Qinglin Pan <panqinglin00@gmail.com> says:
Svnapot is a RISC-V extension for marking contiguous 4K pages as a non-4K
page. This patch set is for using Svnapot in hugetlb fs and huge vmap.
This patchset adds a Kconfig item for using Svnapot in
"Platform type"->"SVNAPOT extension support". Its default value is on,
and people can set it off if they don't allow kernel to detect Svnapot
hardware support and leverage it.
Tested on:
- qemu rv64 with "Svnapot support" off and svnapot=true.
- qemu rv64 with "Svnapot support" on and svnapot=true.
- qemu rv64 with "Svnapot support" off and svnapot=false.
- qemu rv64 with "Svnapot support" on and svnapot=false.
* b4-shazam-merge:
riscv: mm: support Svnapot in huge vmap
riscv: mm: support Svnapot in hugetlb page
riscv: mm: modify pte format for Svnapot
Link: https://lore.kernel.org/r/20230209131647.17245-1-panqinglin00@gmail.com
[Palmer: fix up the feature ordering in the merge]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Add one alternative to enable/disable svnapot support, enable this static
key when "svnapot" is in the "riscv,isa" field of fdt and SVNAPOT compile
option is set. It will influence the behavior of has_svnapot. All code
dependent on svnapot should make sure that has_svnapot return true firstly.
Modify PTE definition for Svnapot, and creates some functions in pgtable.h
to mark a PTE as napot and check if it is a Svnapot PTE. Until now, only
64KB napot size is supported in spec, so some macros has only 64KB version.
Signed-off-by: Qinglin Pan <panqinglin00@gmail.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230209131647.17245-2-panqinglin00@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Jisheng Zhang <jszhang@kernel.org> says:
Generally, riscv ISA extensions are fixed for any specific hardware
platform, so a hart's features won't change after booting, this
chacteristic makes it straightforward to use a static branch to check
a specific ISA extension is supported or not to optimize performance.
However, some ISA extensions such as SVPBMT and ZICBOM are handled
via. the alternative sequences.
Basically, for ease of maintenance, we prefer to use static branches
in C code, but recently, Samuel found that the static branch usage in
cpu_relax() breaks building with CONFIG_CC_OPTIMIZE_FOR_SIZE[1]. As
Samuel pointed out, "Having a static branch in cpu_relax() is
problematic because that function is widely inlined, including in some
quite complex functions like in the VDSO. A quick measurement shows
this static branch is responsible by itself for around 40% of the jump
table."
Samuel's findings pointed out one of a few downsides of static branches
usage in C code to handle ISA extensions detected at boot time:
static branch's metadata in the __jump_table section, which is not
discarded after ISA extensions are finalized, wastes some space.
I want to try to solve the issue for all possible dynamic handling of
ISA extensions at boot time. Inspired by Mark[2], this patch introduces
riscv_has_extension_*() helpers, which work like static branches but
are patched using alternatives, thus the metadata can be freed after
patching.
[1]https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/
[2]https://lore.kernel.org/linux-arm-kernel/20220912162210.3626215-8-mark.rutland@arm.com/
[3]https://lore.kernel.org/linux-riscv/20221130225614.1594256-1-heiko@sntech.de/
* b4-shazam-merge:
riscv: remove riscv_isa_ext_keys[] array and related usage
riscv: KVM: Switch has_svinval() to riscv_has_extension_unlikely()
riscv: cpu_relax: switch to riscv_has_extension_likely()
riscv: alternative: patch alternatives in the vDSO
riscv: switch to relative alternative entries
riscv: module: Add ADD16 and SUB16 rela types
riscv: module: move find_section to module.h
riscv: fpu: switch has_fpu() to riscv_has_extension_likely()
riscv: introduce riscv_has_extension_[un]likely()
riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensions
riscv: hwcap: make ISA extension ids can be used in asm
riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier
riscv: move riscv_noncoherent_supported() out of ZICBOM probe
Link: https://lore.kernel.org/r/20230128172856.3814-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
All users have switched to riscv_has_extension_*, remove unused
definitions, vars and related setting code.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230128172856.3814-14-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Instead of using absolute addresses for both the old instrucions and
the alternative instructions, use offsets relative to the alt_entry
values. So this not only cuts the size of the alternative entry, but
also meets the prerequisite for patching alternatives in the vDSO,
since absolute alternative entries are subject to dynamic relocation,
which is incompatible with the vDSO building.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-10-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
riscv_cpufeature_patch_func() currently only scans a limited set of
cpufeatures, explicitly defined with macros. Extend it to probe for all
ISA extensions.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-5-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Currently riscv_cpufeature_patch_func() does nothing at the
RISCV_ALTERNATIVES_EARLY_BOOT stage. Add a check to detect whether we
are in this stage and exit early. This will allow us to use
riscv_cpufeature_patch_func() for scanning of all ISA extensions.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-3-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
It's a bit weird to call riscv_noncoherent_supported() each time when
insmoding a module. Move the calling out of feature patch func.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-2-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Add handling for ZBB extension and add support for using it as a
variant for optimized string functions.
Support for the Zbb-str-variants is limited to the GNU-assembler
for now, as LLVM has not yet acquired the functionality to
selectively change the arch option in assembler code.
This is still under review at
https://reviews.llvm.org/D123515
Co-developed-by: Christoph Muellner <christoph.muellner@vrull.eu>
Signed-off-by: Christoph Muellner <christoph.muellner@vrull.eu>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230113212301.3534711-3-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This cleans up the ISA string handling to more closely match a version
of the ISA spec. This is visible in /proc/cpuinfo and the ordering
changes may break something in userspace, but these orderings have
changed before without issues so with any luck that's still the case.
This also adds documentation so userspace has a better idea of what is
intended when it comes to compatibility for /proc/cpuinfo, which should
help everyone as this will likely keep changing.
* b4-shazam-merge:
Documentation: riscv: add a section about ISA string ordering in /proc/cpuinfo
RISC-V: resort all extensions in consistent orders
RISC-V: clarify ISA string ordering rules in cpu.c
Link: https://lore.kernel.org/r/20221205144525.2148448-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Ordering between each and every list of extensions is wildly
inconsistent. Per discussion on the lists pick the following policy:
- The array defining order in /proc/cpuinfo follows a narrow
interpretation of the ISA specifications, described in a comment
immediately presiding it.
- All other lists of extensions are sorted alphabetically.
This will hopefully allow for easier review & future additions, and
reduce conflicts between patchsets as the number of extensions grows.
Link: https://lore.kernel.org/all/20221129144742.2935581-2-conor.dooley@microchip.com/
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221205144525.2148448-3-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Alternatives live in a different section, so addresses used by call
functions will point to wrong locations after the patch got applied.
Similar to arm64, adjust the location to consider that offset.
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-13-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
When a DT puts zicbom in the isa string, but does not provide a block
size, ALT_CMO_OP() will attempt to do cache operations on address
zero since the start address will be ANDed with zero. We can't simply
BUG() in riscv_init_cbom_blocksize() when we fail to find a block
size because the failure will happen before logging works, leaving
users to scratch their heads as to why the boot hung. Instead, ensure
Zicbom is disabled and output an error which will hopefully alert
people that the DT needs to be fixed. While at it, add a check that
the block size is a power-of-2 too.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20221129143447.49714-4-ajones@ventanamicro.com
[Palmer: base on 5c20a3a9df ("RISC-V: Fix compilation without RISCV_ISA_ZICBOM"]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Currently any isa extension found in the isa string is set in the
isa bitmap. An isa extension set in the bitmap indicates that the
extension is present and may be used (a.k.a is enabled). However,
when an extension cannot be used due to missing dependencies or
errata it should not be added to the bitmap. Introduce a function
where additional checks may be placed in order to determine if an
extension should be enabled or not.
Note, the checks may simply indicate an issue with the DT, but,
since extensions may be used in early boot, it's not always possible
to simply produce an error at the point the issue is determined.
It's best to keep the extension disabled and produce an error.
No functional change intended, as the function is only introduced
and always returns true. A later patch will provide checks for an
isa extension.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20221129143447.49714-3-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Improve isa2hwcap[] by removing it from static storage, as
riscv_fill_hwcap() is only called once, and by reducing its size
from 256 bytes to 26. The latter improvement is possible because
isa2hwcap[] will never be indexed with capital letters and we can
precompute the offsets from 'a'.
No functional change intended.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20221129143447.49714-2-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* A handful of DT updates for the PolarFire SOC.
* A fix to correct the handling of write-only mappings.
* m{vetndor,arcd,imp}id is now in /proc/cpuinfo
* The SiFive L2 cache controller support has been refactored to also
support L3 caches.
There's also a handful of fixes, cleanups and improvements throughout
the tree.
-----BEGIN PGP SIGNATURE-----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=iCOr
-----END PGP SIGNATURE-----
Merge tag 'riscv-for-linus-6.1-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull more RISC-V updates from Palmer Dabbelt:
- DT updates for the PolarFire SOC
- a fix to correct the handling of write-only mappings
- m{vetndor,arcd,imp}id is now in /proc/cpuinfo
- the SiFive L2 cache controller support has been refactored to also
support L3 caches
- misc fixes, cleanups and improvements throughout the tree
* tag 'riscv-for-linus-6.1-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits)
MAINTAINERS: add RISC-V's patchwork
RISC-V: Make port I/O string accessors actually work
riscv: enable software resend of irqs
RISC-V: Re-enable counter access from userspace
riscv: vdso: fix NULL deference in vdso_join_timens() when vfork
riscv: Add cache information in AUX vector
soc: sifive: ccache: define the macro for the register shifts
soc: sifive: ccache: use pr_fmt() to remove CCACHE: prefixes
soc: sifive: ccache: reduce printing on init
soc: sifive: ccache: determine the cache level from dts
soc: sifive: ccache: Rename SiFive L2 cache to Composable cache.
dt-bindings: sifive-ccache: change Sifive L2 cache to Composable cache
riscv: check for kernel config option in t-head memory types errata
riscv: use BIT() marco for cpufeature probing
riscv: use BIT() macros in t-head errata init
riscv: drop some idefs from CMO initialization
riscv: cleanup svpbmt cpufeature probing
riscv: Pass -mno-relax only on lld < 15.0.0
RISC-V: Avoid dereferening NULL regs in die()
dt-bindings: riscv: add new riscv,isa strings for emulators
...
Heiko Stuebner <heiko@sntech.de> says:
As noted by some people, some parts of the recently added extensions
(svpbmt, zicbom) + t-head errata could use some styling upgrades.
So this series provides these.
changes in v2:
- add patch also converting cpufeature probe to BIT()
- update commit message in patch1 (Conor)
Heiko Stuebner (5):
riscv: cleanup svpbmt cpufeature probing
riscv: drop some idefs from CMO initialization
riscv: use BIT() macros in t-head errata init
riscv: use BIT() marco for cpufeature probing
riscv: check for kernel config option in t-head memory types errata
arch/riscv/errata/thead/errata.c | 14 ++++++-----
arch/riscv/include/asm/cacheflush.h | 2 ++
arch/riscv/kernel/cpufeature.c | 39 ++++++++++++-----------------
3 files changed, 26 insertions(+), 29 deletions(-)
Link: https://lore.kernel.org/r/20220905111027.2463297-1-heiko@sntech.de
* b4-shazam-merge:
riscv: check for kernel config option in t-head memory types errata
riscv: use BIT() marco for cpufeature probing
riscv: use BIT() macros in t-head errata init
riscv: drop some idefs from CMO initialization
riscv: cleanup svpbmt cpufeature probing
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Wrapping things in #ifdefs makes the code harder to read
while we also have IS_ENABLED() macros to do this in regular code
and the extension detection is not _that_ runtime critical.
So define a stub for riscv_noncoherent_supported() in the
non-CONFIG_RISCV_DMA_NONCOHERENT case and move the code to
us IS_ENABLED.
Suggested-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20220905111027.2463297-3-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
For better readability (and compile time coverage) use IS_ENABLED
instead of ifdef and drop the new unneeded switch statement.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20220905111027.2463297-2-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Just like other ISA extensions, we allow callers/users to detect the
presence of Svinval extension from ISA string.
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
riscv_isa_ext_keys[] is an array of static keys used in the unified
ISA extension framework. The keys added to this array may be used
anywhere, including in modules. Ensure the keys remain writable by
placing them in the data section.
The need to change riscv_isa_ext_keys[]'s section was found when the
kvm module started failing to load. Commit 8eb060e101 ("arch/riscv:
add Zihintpause support") adds a static branch check for a newly
added isa-ext key to cpu_relax(), which kvm uses.
Fixes: c360cbec35 ("riscv: introduce unified static key mechanism for ISA extensions")
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Cc: stable@vger.kernel.org
Reported-by: Ron Economos <re@w6rz.net>
Reported-by: Anup Patel <apatel@ventanamicro.com>
Reported-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20220816163058.3004536-1-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This series implements Sstc extension support which was ratified
recently. Before the Sstc extension, an SBI call is necessary to
generate timer interrupts as only M-mode have access to the timecompare
registers. Thus, there is significant latency to generate timer
interrupts at kernel. For virtualized enviornments, its even worse as
the KVM handles the SBI call and uses a software timer to emulate the
timecomapre register.
Sstc extension solves both these problems by defining a
stimecmp/vstimecmp at supervisor (host/guest) level. It allows kernel to
program a timer and recieve interrupt without supervisor execution
enviornment (M-mode/HS mode) intervention.
* palmer/riscv-sstc:
RISC-V: Prefer sstc extension if available
RISC-V: Enable sstc extension parsing from DT
RISC-V: Add SSTC extension CSR details
The ISA extension framework now allows parsing any multi-letter
ISA extension.
Enable that for sstc extension.
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20220722165047.519994-3-atishp@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This series is based on the alternatives changes done in my svpbmt
series and thus also depends on Atish's isa-extension parsing series.
It implements using the cache-management instructions from the Zicbom-
extension to handle cache flush, etc actions on platforms needing them.
SoCs using cpu cores from T-Head like the Allwinne D1 implement a
different set of cache instructions. But while they are different,
instructions they provide the same functionality, so a variant can easly
hook into the existing alternatives mechanism on those.
[Palmer: Some minor fixups, including a RISCV_ISA_ZICBOM dependency on
MMU that's probably not strictly necessary. The Zicbom support will
trip up sparse for users that have new toolchains, I just sent a patch.]
Link: https://lore.kernel.org/all/20220706231536.2041855-1-heiko@sntech.de/
Link: https://lore.kernel.org/linux-sparse/20220811033138.20676-1-palmer@rivosinc.com/T/#u
* palmer/riscv-zicbom:
riscv: implement cache-management errata for T-Head SoCs
riscv: Add support for non-coherent devices using zicbom extension
dt-bindings: riscv: document cbom-block-size
of: also handle dma-noncoherent in of_dma_is_coherent()
The Zicbom ISA-extension was ratified in november 2021
and introduces instructions for dcache invalidate, clean
and flush operations.
Implement cache management operations for non-coherent devices
based on them.
Of course not all cores will support this, so implement an
alternative-based mechanism that replaces empty instructions
with ones done around Zicbom instructions.
As discussed in previous versions, assume the platform
being coherent by default so that non-coherent devices need
to get marked accordingly by firmware.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20220706231536.2041855-4-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The hartid can be a 64bit value on RV64 platforms. This series updates
the code so that 64bit hartid can be supported on RV64 platforms.
* 'riscv-64bit_hartid' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git:
riscv/efi_stub: Add 64bit boot-hartid support on RV64
riscv: cpu: Add 64bit hartid support on RV64
riscv: smp: Add 64bit hartid support on RV64
riscv: spinwait: Fix hartid variable type
riscv: cpu_ops_sbi: Add 64bit hartid support on RV64
The hartid can be a 64bit value on RV64 platforms.
Add support for 64bit hartid in riscv_of_processor_hartid() and
update its callers.
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20220527051743.2829940-5-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Some additionals comments and notes from autobuilders received after the
series got applied, warranted some changes.
* 'riscv-svpbmt' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/palmer/linux:
riscv: remove usage of function-pointers from cpufeatures and t-head errata
riscv: make patch-function pointer more generic in cpu_manufacturer_info struct
riscv: Improve description for RISCV_ISA_SVPBMT Kconfig symbol
riscv: drop cpufeature_apply_feature tracking variable
riscv: fix dependency for t-head errata
Having a list of alternatives to check with a per-entry function pointer
to a check function is nice style-wise. But in case of early-alternatives
it can clash with the non-relocated kernel and the function pointer in
the list pointing to a completely wrong location.
This isn't an issue with one or two list entries, as in that case the
compiler seems to unroll the loop and even usage of the list structure
and then only does relative jumps into the check functions based on this.
When adding a third entry to either list though, the issue that was
hiding there from the beginning is triggered resulting a jump to a
memory address that isn't part of the kernel at all.
The list of features/erratas only contained an unused name and the
pointer to the check function, so an easy solution for the problem
is to just unroll the loop in code, dismantle the whole list structure
and just call the relevant check functions one by one ourself.
For the T-Head errata this includes moving the stage-check inside
the check functions.
The issue is only relevant for things that might be called for early-
alternatives (T-Head and possible future main extensions), so the
SiFive erratas were not affected from the beginning, as they got
an early return for early-alternatives in the original patchset.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20220526205646.258337-6-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The variable was tracking which feature patches got applied
but that information was never actually used - and thus resulted
in a warning as well.
Drop the variable.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20220526205646.258337-2-heiko@sntech.de
Fixes: ff689fd21c ("riscv: add RISC-V Svpbmt extension support")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This is to use the unified static key mechanism instead of putting
static key related here and there.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20220522153543.2656-3-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Currently, riscv has several extensions which may not be supported on
all riscv platforms, for example, FPU and so on. To support unified
kernel Image style, we need to check whether the feature is supported
or not. If the check sits at hot code path, then performance will be
impacted a lot. static key can be used to solve the issue. In the past,
FPU support has been converted to use static key mechanism. I believe
we will have similar cases in the future.
This patch tries to add an unified mechanism to use static keys for
some ISA extensions by implementing an array of default-false static keys
and enabling them when detected.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20220522153543.2656-2-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This series includes the following patchsets:
- bitmap: optimize bitmap_weight() usage(w/o bitmap_weight_cmp), from me;
- lib/bitmap.c make bitmap_print_bitmask_to_buf parseable, from Mauro
Carvalho Chehab;
- include/linux/find: Fix documentation, from Anna-Maria Behnsen;
- bitmap: fix conversion from/to fix-sized arrays, from me;
- bitmap: Fix return values to be unsigned, from Kees Cook.
It has been in linux-next for at least a week with no problems.
-----BEGIN PGP SIGNATURE-----
iQGzBAABCgAdFiEEi8GdvG6xMhdgpu/4sUSA/TofvsgFAmKaEzYACgkQsUSA/Tof
vsiGKwv8Dgr3G0mLbSfmHZqdFMIsmSmwhxlEH6eBNtX6vjQbGafe/Buhj/1oSY8N
NYC4+5Br6s7MmMRth3Kp6UECdl94TS3Ka06T+lVBKkG+C+B1w1/svqUMM2ZCQF3e
Z5R/HhR6av9X9Qb2mWSasWLkWp629NjdtRsJSDWiVt1emVVwh+iwxQnMH9VuE+ao
z3mvaQfSRhe4h+xCZOiohzFP+0jZb1EnPrQAIVzNUjigo7mglpNvVyO7p/8LU7gD
dIjfGmSbtsHU72J+/0lotRqjhjORl1F/EILf8pIzx5Ga7ExUGhOzGWAj7/3uZxfA
Cp1Z/QV271MGwv/sNdSPwCCJHf51eOmsbyOyUScjb3gFRwIStEa1jB4hKwLhS5wF
3kh4kqu3WGuIQAdxkUpDBsy3CQjAPDkvtRJorwyWGbjwa9xUETESAgH7XCCTsgWc
0sIuldWWaxC581+fAP1Dzmo8uuWBURTaOrVmRMILQHMTw54zoFyLY+VI9gEAT9aV
gnPr3M4F
=U7DN
-----END PGP SIGNATURE-----
Merge tag 'bitmap-for-5.19-rc1' of https://github.com/norov/linux
Pull bitmap updates from Yury Norov:
- bitmap: optimize bitmap_weight() usage, from me
- lib/bitmap.c make bitmap_print_bitmask_to_buf parseable, from Mauro
Carvalho Chehab
- include/linux/find: Fix documentation, from Anna-Maria Behnsen
- bitmap: fix conversion from/to fix-sized arrays, from me
- bitmap: Fix return values to be unsigned, from Kees Cook
It has been in linux-next for at least a week with no problems.
* tag 'bitmap-for-5.19-rc1' of https://github.com/norov/linux: (31 commits)
nodemask: Fix return values to be unsigned
bitmap: Fix return values to be unsigned
KVM: x86: hyper-v: replace bitmap_weight() with hweight64()
KVM: x86: hyper-v: fix type of valid_bank_mask
ia64: cleanup remove_siblinginfo()
drm/amd/pm: use bitmap_{from,to}_arr32 where appropriate
KVM: s390: replace bitmap_copy with bitmap_{from,to}_arr64 where appropriate
lib/bitmap: add test for bitmap_{from,to}_arr64
lib: add bitmap_{from,to}_arr64
lib/bitmap: extend comment for bitmap_(from,to)_arr32()
include/linux/find: Fix documentation
lib/bitmap.c make bitmap_print_bitmask_to_buf parseable
MAINTAINERS: add cpumask and nodemask files to BITMAP_API
arch/x86: replace nodes_weight with nodes_empty where appropriate
mm/vmstat: replace cpumask_weight with cpumask_empty where appropriate
clocksource: replace cpumask_weight with cpumask_empty in clocksource.c
genirq/affinity: replace cpumask_weight with cpumask_empty where appropriate
irq: mips: replace cpumask_weight with cpumask_empty where appropriate
drm/i915/pmu: replace cpumask_weight with cpumask_empty where appropriate
arch/x86: replace cpumask_weight with cpumask_empty where appropriate
...
bitmap_empty() is better than bitmap_weight() because it may return
earlier, and improves on readability.
CC: Albert Ou <aou@eecs.berkeley.edu>
CC: Anup Patel <anup@brainfault.org>
CC: Atish Patra <atishp@atishpatra.org>
CC: Jisheng Zhang <jszhang@kernel.org>
CC: Palmer Dabbelt <palmer@dabbelt.com>
CC: Paul Walmsley <paul.walmsley@sifive.com>
CC: Tsukasa OI <research_trasio@irq.a4lg.com>
CC: linux-riscv@lists.infradead.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Some current cpus based on T-Head cores implement memory-types
way different than described in the svpbmt spec even going
so far as using PTE bits marked as reserved.
Add the T-Head vendor-id and necessary errata code to
replace the affected instructions.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20220511192921.2223629-13-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Svpbmt (the S should be capitalized) is the
"Supervisor-mode: page-based memory types" extension
that specifies attributes for cacheability, idempotency
and ordering.
The relevant settings are done in special bits in PTEs:
Here is the svpbmt PTE format:
| 63 | 62-61 | 60-8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
N MT RSW D A G U X W R V
^
Of the Reserved bits [63:54] in a leaf PTE, the high bit is already
allocated (as the N bit), so bits [62:61] are used as the MT (aka
MemType) field. This field specifies one of three memory types that
are close equivalents (or equivalent in effect) to the three main x86
and ARMv8 memory types - as shown in the following table.
RISC-V
Encoding &
MemType RISC-V Description
---------- ------------------------------------------------
00 - PMA Normal Cacheable, No change to implied PMA memory type
01 - NC Non-cacheable, idempotent, weakly-ordered Main Memory
10 - IO Non-cacheable, non-idempotent, strongly-ordered I/O memory
11 - Rsvd Reserved for future standard use
As the extension will not be present on all implementations,
implement a method to handle cpufeatures via alternatives
to not incur runtime penalties on cpu variants not supporting
specific extensions and patch relevant code parts at runtime.
Co-developed-by: Wei Fu <wefu@redhat.com>
Signed-off-by: Wei Fu <wefu@redhat.com>
Co-developed-by: Liu Shaohua <liush@allwinnertech.com>
Signed-off-by: Liu Shaohua <liush@allwinnertech.com>
Co-developed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
[moved to use the alternatives mechanism]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Link: https://lore.kernel.org/r/20220511192921.2223629-10-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The sscofpmf extension allows counter overflow and filtering for
programmable counters. Enable the perf driver to handle the overflow
interrupt. The overflow interrupt is a hart local interrupt.
Thus, per cpu overflow interrupts are setup as a child under the root
INTC irq domain.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The isa string should begin with either rv64 or rv32. Otherwise, it is
an incorrect isa string. Currently, the string parsing continues even if
it doesnot begin with current XLEN.
Fix this by checking if it found "rv64" or "rv32" in the beginning.
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Multi-letter extensions can be probed using exising
riscv_isa_extension_available API now. It doesn't support versioning
right now as there is no use case for it.
Individual extension specific implementation will be added during
each extension support.
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Currently, there is no usage for version numbers in extensions as
any ratified non base ISA extension will always at v1.0.
Extract the extension names in place for future parsing.
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Tsukasa OI <research_trasio@irq.a4lg.com>
[Improved commit text and comments]
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Current hart ISA ("riscv,isa") parser don't correctly parse:
1. Multi-letter extensions
2. Version numbers
All ISA extensions ratified recently has multi-letter extensions
(except 'H'). The current "riscv,isa" parser that is easily confused
by multi-letter extensions and "p" in version numbers can be a huge
problem for adding new extensions through the device tree.
Leaving it would create incompatible hacks and would make "riscv,isa"
value unreliable.
This commit implements minimal parser for "riscv,isa" strings. With this,
we can safely ignore multi-letter extensions and version numbers.
[Improved commit text and fixed a bug around 's' in base extension]
Signed-off-by: Atish Patra <atishp@rivosinc.com>
[Fixed workaround for QEMU]
Signed-off-by: Tsukasa OI <research_trasio@irq.a4lg.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit replaces BITS_PER_LONG with number of alphabet letters.
Current ISA pretty-printing code expects extension 'a' (bit 0) through
'z' (bit 25). Although bit 26 and higher is not currently used (thus never
cause an issue in practice), it will be an annoying problem if we start to
use those in the future.
This commit disables printing high bits for now.
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Tsukasa OI <research_trasio@irq.a4lg.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
These functions are not needed after booting, so mark them as __init
to move them to the __init section.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
The has_fpu check sits at hot code path: switch_to(). Currently, has_fpu
is a bool variable if FPU=y, switch_to() checks it each time, we can
optimize out this check by turning the has_fpu into a static key.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This patch adds riscv_isa bitmap which represents Host ISA features
common across all Host CPUs. The riscv_isa is not same as elf_hwcap
because elf_hwcap will only have ISA features relevant for user-space
apps whereas riscv_isa will have ISA features relevant to both kernel
and user-space apps.
One of the use-case for riscv_isa bitmap is in KVM hypervisor where
we will use it to do following operations:
1. Check whether hypervisor extension is available
2. Find ISA features that need to be virtualized (e.g. floating
point support, vector extension, etc.)
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
sparse identifies several missing prototypes caused by missing
preprocessor include directives:
arch/riscv/kernel/cpufeature.c:16:6: warning: symbol 'has_fpu' was not declared. Should it be static?
arch/riscv/kernel/process.c:26:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static?
arch/riscv/kernel/reset.c:15:6: warning: symbol 'pm_power_off' was not declared. Should it be static?
arch/riscv/kernel/syscall_table.c:15:6: warning: symbol 'sys_call_table' was not declared. Should it be static?
arch/riscv/kernel/traps.c:149:13: warning: symbol 'trap_init' was not declared. Should it be static?
arch/riscv/kernel/vdso.c:54:5: warning: symbol 'arch_setup_additional_pages' was not declared. Should it be static?
arch/riscv/kernel/smp.c:64:6: warning: symbol 'arch_match_cpu_phys_id' was not declared. Should it be static?
arch/riscv/kernel/module-sections.c:89:5: warning: symbol 'module_frob_arch_sections' was not declared. Should it be static?
arch/riscv/mm/context.c:42:6: warning: symbol 'switch_mm' was not declared. Should it be static?
Fix by including the appropriate header files in the appropriate
source files.
This patch should have no functional impact.
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 503 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, we set hwcap based on first valid hart from DT. This may not
be correct always as that hart might not be current booting cpu or may
have a different capability.
Set hwcap as the capabilities supported by all possible harts with "okay"
status.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Use the new for_each_of_cpu_node() helper to iterate over cpu nodes
instead of open coding. Note that this will allow matching also on the
node name instead of the (for FDT) deprecated device_type property.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Add missing newline characters to printk messages.
Also replace two pr_warning with the shorter pr_warn, and fix up the
tense of one error message while at it.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Fix of_node* refcount at various places by using of_node_put.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
On the Hifive-U platform, cpu 0 is a masked cpu with less capabilities
than the other cpus. Ignore it for the purpose of determining the
hardware capabilities of the system.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This patchset adds an option, CONFIG_FPU, to enable/disable floating-
point support within the kernel. The kernel's new behavior will be as
follows:
* with CONFIG_FPU=y
All FPU codes are reserved. If no FPU is found during booting, a
global flag will be set, and those functions will be bypassed with
condition check to that flag.
* with CONFIG_FPU=n
No floating-point instructions in kernel and all related settings
are excluded.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
The RISC-V Linux port doesn't support systems that have the F extension
but don't have the D extension -- we actually don't support systems
without D either, but Alan's patch set is rectifying that soon. For now
I think we can leave this in a semi-broken state and just wait for
Alan's patch set to get merged for proper non-FPU support -- the patch
set is starting to look good, so doing something in-between doesn't seem
like it's worth the work.
I don't think it's worth fretting about support for systems with F but
not D for now: our glibc ABIs are IMAC and IMAFDC so they probably won't
end up being popular. We can always extend this in the future.
CC: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
We expect that a kernel with CONFIG_FPU=y can still support no-FPU
machines. To do so, the kernel should first examine the existence of a
FPU, then do nothing if a FPU does exist; otherwise, it should
disable/bypass all FPU-related functions.
In this patch, a new global variable, has_fpu, is created and determined
when parsing the hardware capability from device tree during booting.
This variable is used in those FPU-related functions.
Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This patch contains code that is in some way visible to the user:
including via system calls, the VDSO, module loading and signal
handling. It also contains some generic code that is ABI visible.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
