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2023-07-12RISC-V: Don't include Zicsr or Zifencei in I from ACPIPalmer Dabbelt
ACPI ISA strings are based on a specification after Zicsr and Zifencei were split out of I, so we shouldn't be treating them as part of I. We haven't release an ACPI-based kernel yet, so we don't need to worry about compatibility with the old ISA strings. Fixes: 07edc32779e3 ("RISC-V: always report presence of extensions formerly part of the base ISA") Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Sunil V L <sunilvl@ventanamicro.com> Link: https://lore.kernel.org/r/20230711224600.10879-1-palmer@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-23Merge patch series "ISA string parser cleanups"Palmer Dabbelt
Conor Dooley <conor@kernel.org> says: From: Conor Dooley <conor.dooley@microchip.com> Here are some bits that were discussed with Drew on the "should we allow caps" threads that I have now created patches for: - splitting of riscv_of_processor_hartid() into two distinct functions, one for use purely during early boot, prior to the establishment of the possible-cpus mask & another to fit the other current use-cases - that then allows us to then completely skip some validation of the hartid in the parser - the biggest diff in the series is a rework of the comments in the parser, as I have mostly found the existing (sparse) ones to not be all that helpful whenever I have to go back and look at it - from writing the comments, I found a conditional doing a bit of a dance that I found counter-intuitive, so I've had a go at making that match what I would expect a little better - `i` implies 4 other extensions, so add them as extensions and set them for the craic. Sure why not like... * b4-shazam-merge: RISC-V: always report presence of extensions formerly part of the base ISA dt-bindings: riscv: explicitly mention assumption of Zicntr & Zihpm support RISC-V: remove decrement/increment dance in ISA string parser RISC-V: rework comments in ISA string parser RISC-V: validate riscv,isa at boot, not during ISA string parsing RISC-V: split early & late of_node to hartid mapping RISC-V: simplify register width check in ISA string parsing Link: https://lore.kernel.org/r/20230607-audacity-overhaul-82bb867a825f@spud Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-21RISC-V: always report presence of extensions formerly part of the base ISAConor Dooley
Of these four extensions, two were part of the base ISA when the port was written and are required by the kernel. The other two are implied when `i` is in riscv,isa on DT systems. There's not much that userspace can do with this extra information, but there is no harm in reporting an ISA string that closer resembles the current versions of the specifications either. Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230607-nest-collision-5796b6be8be6@spud Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-21RISC-V: remove decrement/increment dance in ISA string parserConor Dooley
While expanding on the comments in the ISA string parsing code, I noticed that the conditional decrement of `isa` at the end of the loop was a bit odd. The parsing code expects that at the start of the for loop, `isa` will point to the first character of the next unparsed extension. However, depending on what the next extension is, this may not be true. Unless the next extension is a multi-letter extension preceded by an underscore, `isa` will either point to the string's null-terminator or to the first character of the next extension, once the switch statement has been evaluated. Obviously incrementing `isa` at the end of the loop could cause it to increment past the null terminator or miss a single letter extension, so `isa` is conditionally decremented, just so that the loop can increment it again. It's easier to understand the code if, instead of this decrement + increment dance, we instead use a while loop & rely on the handling of individual extension types to leave `isa` pointing to the first character of the next extension. As already mentioned, this won't be the case where the following extension is multi-letter & preceded by an underscore. To handle that, invert the check and increment rather than decrement. Hopefully this eliminates a "huh?!?" moment the next time somebody tries to understand this code. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Sunil V L <sunilvl@ventanamicro.com> Link: https://lore.kernel.org/r/20230607-estate-left-f20faabefb89@spud Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-21RISC-V: rework comments in ISA string parserConor Dooley
I have found these comments to not be at all helpful whenever I look at the parser. Further, the comments in the default case (single letter parser) are not quite right either. Group the comments into a larger one at the start of each case, that attempts to explain things at a higher level. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230607-headpiece-tannery-83ed5cc4856a@spud Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-21RISC-V: validate riscv,isa at boot, not during ISA string parsingConor Dooley
Since riscv_fill_hwcap() now only iterates over possible cpus, the basic validation of whether riscv,isa contains "rv<width>" can be moved to riscv_early_of_processor_hartid(). Further, "ima" support is required by the kernel, so reject any CPU not fitting the bill. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Sunil V L <sunilvl@ventanamicro.com> Link: https://lore.kernel.org/r/20230607-guts-blurry-67e711acf328@spud Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-21RISC-V: simplify register width check in ISA string parsingConor Dooley
Saving off the `isa` pointer to a temp variable, followed by checking if it has been incremented is a bit of an odd pattern. Perhaps it was done to avoid a funky looking if statement mixed with the ifdeffery. Now that we use IS_ENABLED() here just return from the parser as soon as we detect a mismatch between the string and the currently running kernel. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Sunil V L <sunilvl@ventanamicro.com> Link: https://lore.kernel.org/r/20230607-splatter-bacterium-a75bb9f0d0b7@spud Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-19Merge patch series "RISC-V: Export Zba, Zbb to usermode via hwprobe"Palmer Dabbelt
Evan Green <evan@rivosinc.com> says: This change detects the presence of Zba, Zbb, and Zbs extensions and exports them per-hart to userspace via the hwprobe mechanism. Glibc can then use these in setting up hwcaps-based library search paths. There's a little bit of extra housekeeping here: the first change adds Zba and Zbs to the set of extensions the kernel recognizes, and the second change starts tracking ISA features per-hart (in addition to the ANDed mask of features across all harts which the kernel uses to make decisions). Now that we track the ISA information per-hart, we could even fix up /proc/cpuinfo to accurately report extension per-hart, though I've left that out of this series for now. * b4-shazam-merge: RISC-V: hwprobe: Expose Zba, Zbb, and Zbs RISC-V: Track ISA extensions per hart RISC-V: Add Zba, Zbs extension probing Link: https://lore.kernel.org/r/20230509182504.2997252-1-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-19RISC-V: Track ISA extensions per hartEvan Green
The kernel maintains a mask of ISA extensions ANDed together across all harts. Let's also keep a bitmap of ISA extensions for each CPU. Although the kernel is currently unlikely to enable a feature that exists only on some CPUs, we want the ability to report asymmetric CPU extensions accurately to usermode. Note that riscv_fill_hwcaps() runs before the per_cpu_offsets are built, which is why I've used a [NR_CPUS] array rather than per_cpu() data. Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230509182504.2997252-3-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-19RISC-V: Add Zba, Zbs extension probingEvan Green
Add the Zba address bit manipulation extension and Zbs single bit instructions extension into those the kernel is aware of and maintains in its riscv_isa bitmap. Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230509182504.2997252-2-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-14riscv: say disabling zicbom if no or bad riscv,cbom-block-size foundBen Dooks
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>
2023-06-08Merge patch series "riscv: Add vector ISA support"Palmer Dabbelt
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>
2023-06-08riscv: Add prctl controls for userspace vector managementAndy Chiu
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>
2023-06-08riscv: hwcap: change ELF_HWCAP to a functionAndy Chiu
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>
2023-06-08riscv: Introduce riscv_v_vsize to record size of Vector contextGreentime Hu
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>
2023-06-08riscv: Extending cpufeature.c to detect V-extensionGuo Ren
Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Co-developed-by: Andy Chiu <andy.chiu@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/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-06Merge patch series "riscv: allow case-insensitive ISA string parsing"Palmer Dabbelt
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>
2023-06-06riscv: allow case-insensitive ISA string parsingYangyu Chen
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>
2023-06-01RISC-V: cpufeature: Add ACPI support in riscv_fill_hwcap()Sunil V L
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>
2023-06-01RISC-V: only iterate over possible CPUs in ISA string parserSunil V L
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>
2023-05-05Merge tag 'riscv-for-linus-6.4-mw2' of ↵Linus Torvalds
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
2023-05-05Merge tag 'kvm-riscv-6.4-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini
KVM/riscv changes for 6.4 - ONE_REG interface to enable/disable SBI extensions - Zbb extension for Guest/VM - AIA CSR virtualization
2023-05-01RISC-V: include cpufeature.h in cpufeature.cConor Dooley
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: 62a31d6e38bd ("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>
2023-04-21RISC-V: Detect AIA CSRs from ISA stringAnup Patel
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>
2023-04-18Merge patch series "RISC-V Hardware Probing User Interface"Palmer Dabbelt
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>
2023-04-18RISC-V: hwprobe: Support probing of misaligned access performanceEvan Green
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>
2023-03-15Merge patch series "RISC-V: Apply Zicboz to clear_page"Palmer Dabbelt
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>
2023-03-14RISC-V: Use Zicboz in clear_page when availableAndrew Jones
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>
2023-03-14RISC-V: cpufeatures: Put the upper 16 bits of patch ID to workAndrew Jones
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>
2023-03-14RISC-V: Add Zicboz detection and block size parsingAndrew Jones
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>
2023-03-14Merge patch series "riscv: alternative/cpufeature related cleanups"Palmer Dabbelt
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>
2023-03-14riscv: cpufeature: Drop errata_list.h and other unused includesAndrew Jones
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>
2023-03-14riscv: alternatives: Rename errata_id to patch_idAndrew Jones
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>
2023-03-09Merge patch series "riscv, mm: detect svnapot cpu support at runtime"Palmer Dabbelt
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>
2023-03-07riscv: mm: modify pte format for SvnapotQinglin Pan
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>
2023-02-21RISC-V: take text_mutex during alternative patchingConor Dooley
Guenter reported a splat during boot, that Samuel pointed out was the lockdep assertion failing in patch_insn_write(): WARNING: CPU: 0 PID: 0 at arch/riscv/kernel/patch.c:63 patch_insn_write+0x222/0x2f6 epc : patch_insn_write+0x222/0x2f6 ra : patch_insn_write+0x21e/0x2f6 epc : ffffffff800068c6 ra : ffffffff800068c2 sp : ffffffff81803df0 gp : ffffffff81a1ab78 tp : ffffffff81814f80 t0 : ffffffffffffe000 t1 : 0000000000000001 t2 : 4c45203a76637369 s0 : ffffffff81803e40 s1 : 0000000000000004 a0 : 0000000000000000 a1 : ffffffffffffffff a2 : 0000000000000004 a3 : 0000000000000000 a4 : 0000000000000001 a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000052464e43 s2 : ffffffff80b4889c s3 : 000000000000082c s4 : ffffffff80b48828 s5 : 0000000000000828 s6 : ffffffff8131a0a0 s7 : 0000000000000fff s8 : 0000000008000200 s9 : ffffffff8131a520 s10: 0000000000000018 s11: 000000000000000b t3 : 0000000000000001 t4 : 000000000000000d t5 : ffffffffd8180000 t6 : ffffffff81803bc8 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [<ffffffff800068c6>] patch_insn_write+0x222/0x2f6 [<ffffffff80006a36>] patch_text_nosync+0xc/0x2a [<ffffffff80003b86>] riscv_cpufeature_patch_func+0x52/0x98 [<ffffffff80003348>] _apply_alternatives+0x46/0x86 [<ffffffff80c02d36>] apply_boot_alternatives+0x3c/0xfa [<ffffffff80c03ad8>] setup_arch+0x584/0x5b8 [<ffffffff80c0075a>] start_kernel+0xa2/0x8f8 This issue was exposed by 702e64550b12 ("riscv: fpu: switch has_fpu() to riscv_has_extension_likely()"), as it is the patching in has_fpu() that triggers the splats in Guenter's report. Take the text_mutex before doing any code patching to satisfy lockdep. Fixes: ff689fd21cb1 ("riscv: add RISC-V Svpbmt extension support") Fixes: a35707c3d850 ("riscv: add memory-type errata for T-Head") Fixes: 1a0e5dbd3723 ("riscv: sifive: Add SiFive alternative ports") Reported-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/all/20230212154333.GA3760469@roeck-us.net/ Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Samuel Holland <samuel@sholland.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230212194735.491785-1-conor@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-01Merge patch series "riscv: improve boot time isa extensions handling"Palmer Dabbelt
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>
2023-01-31riscv: remove riscv_isa_ext_keys[] array and related usageJisheng Zhang
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>
2023-01-31riscv: switch to relative alternative entriesJisheng Zhang
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>
2023-01-31riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensionsJisheng Zhang
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>
2023-01-31riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlierJisheng Zhang
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>
2023-01-31riscv: move riscv_noncoherent_supported() out of ZICBOM probeJisheng Zhang
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>
2023-01-31RISC-V: add zbb support to string functionsHeiko Stuebner
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>
2023-01-19Merge patch series "Putting some basic order on isa extension lists"Palmer Dabbelt
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>
2023-01-17RISC-V: resort all extensions in consistent ordersConor Dooley
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>
2022-12-29RISC-V: fix auipc-jalr addresses in patched alternativesHeiko Stuebner
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>
2022-12-09RISC-V: Ensure Zicbom has a valid block sizeAndrew Jones
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 5c20a3a9df19 ("RISC-V: Fix compilation without RISCV_ISA_ZICBOM"] Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-09RISC-V: Introduce riscv_isa_extension_checkAndrew Jones
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>
2022-12-09RISC-V: Improve use of isa2hwcap[]Andrew Jones
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>
2022-10-14Merge tag 'riscv-for-linus-6.1-mw2' of ↵Linus Torvalds
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 ...