summaryrefslogtreecommitdiff
path: root/arch/riscv
AgeCommit message (Collapse)Author
2023-04-19riscv: Rework kasan population functionsAlexandre Ghiti
Our previous kasan population implementation used to have the final kasan shadow region mapped with kasan_early_shadow_page, because we did not clean the early mapping and then we had to populate the kasan region "in-place" which made the code cumbersome. So now we clear the early mapping, establish a temporary mapping while we populate the kasan shadow region with just the kernel regions that will be used. This new version uses the "generic" way of going through a page table that may be folded at runtime (avoid the XXX_next macros). It was tested with outline instrumentation on an Ubuntu kernel configuration successfully. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230203075232.274282-3-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-19riscv: Split early and final KASAN population functionsAlexandre Ghiti
This is a preliminary work that allows to make the code more understandable. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230203075232.274282-2-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18Merge patch series "riscv: Use PUD/P4D/PGD pages for the linear mapping"Palmer Dabbelt
Alexandre Ghiti <alexghiti@rivosinc.com> says: This patchset intends to improve tlb utilization by using hugepages for the linear mapping. As reported by Anup in v6, when STRICT_KERNEL_RWX is enabled, we must take care of isolating the kernel text and rodata so that they are not mapped with a PUD mapping which would then assign wrong permissions to the whole region: it is achieved the same way as arm64 by using the memblock nomap API which isolates those regions and re-merge them afterwards thus avoiding any issue with the system resources tree creation. arch/riscv/include/asm/page.h | 19 ++++++- arch/riscv/mm/init.c | 102 ++++++++++++++++++++++++++-------- arch/riscv/mm/physaddr.c | 16 ++++++ drivers/of/fdt.c | 11 ++-- 4 files changed, 118 insertions(+), 30 deletions(-) * b4-shazam-merge: riscv: Use PUD/P4D/PGD pages for the linear mapping riscv: Move the linear mapping creation in its own function riscv: Get rid of riscv_pfn_base variable Link: https://lore.kernel.org/r/20230324155421.271544-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18riscv: Use PUD/P4D/PGD pages for the linear mappingAlexandre Ghiti
During the early page table creation, we used to set the mapping for PAGE_OFFSET to the kernel load address: but the kernel load address is always offseted by PMD_SIZE which makes it impossible to use PUD/P4D/PGD pages as this physical address is not aligned on PUD/P4D/PGD size (whereas PAGE_OFFSET is). But actually we don't have to establish this mapping (ie set va_pa_offset) that early in the boot process because: - first, setup_vm installs a temporary kernel mapping and among other things, discovers the system memory, - then, setup_vm_final creates the final kernel mapping and takes advantage of the discovered system memory to create the linear mapping. During the first phase, we don't know the start of the system memory and then until the second phase is finished, we can't use the linear mapping at all and phys_to_virt/virt_to_phys translations must not be used because it would result in a different translation from the 'real' one once the final mapping is installed. So here we simply delay the initialization of va_pa_offset to after the system memory discovery. But to make sure noone uses the linear mapping before, we add some guard in the DEBUG_VIRTUAL config. Finally we can use PUD/P4D/PGD hugepages when possible, which will result in a better TLB utilization. Note that: - this does not apply to rv32 as the kernel mapping lies in the linear mapping. - we rely on the firmware to protect itself using PMP. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Rob Herring <robh@kernel.org> # DT bits Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Anup Patel <anup@brainfault.org> Tested-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20230324155421.271544-4-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18riscv: Move the linear mapping creation in its own functionAlexandre Ghiti
No change intended, it just splits the linear mapping creation from setup_vm_final: this prepares for upcoming additions to the linear mapping creation. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Anup Patel <anup@brainfault.org> Tested-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20230324155421.271544-3-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18riscv: Get rid of riscv_pfn_base variableAlexandre Ghiti
Use directly phys_ram_base instead, riscv_pfn_base is just the pfn of the address contained in phys_ram_base. Even if there is no functional change intended in this patch, actually setting phys_ram_base that early changes the behaviour of kernel_mapping_pa_to_va during the early boot: phys_ram_base used to be zero before this patch and now it is set to the physical start address of the kernel. But it does not break the conversion of a kernel physical address into a virtual address since kernel_mapping_pa_to_va should only be used on kernel physical addresses, i.e. addresses greater than the physical start address of the kernel. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Anup Patel <anup@brainfault.org> Tested-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20230324155421.271544-2-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18RISC-V: align ISA extension Kconfig help text with each otherConor Dooley
Other extensions only capitalise the first letter in the text visible in Kconfig menus, and provide a short comment about the extension's meaning. Do the same for Svnapot & Svpbmt. The precedent for capitalisation in the Kconfig text was set by Zicbom & sorta followed for Zicboz. The RVI styling used for multi-letter extensions only capitalises the first letter, so do the same here. If nothing else, my OCD likes it when the extensions follow a consistent pattern. While editing one of the lines, reformat the "spelling" of 64-bit. Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230405-pucker-cogwheel-3a999a94a2f2@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18riscv: Kconfig: enable SCHED_MC kconfigSong Shuai
RISC-V now builds the sched domain based on the simple possible map. Enable SCHED_MC to make the building based on cpu_coregroup_mask() which also takes care of the NUMA and cores with LLC. Signed-off-by: Song Shuai <suagrfillet@gmail.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230310110336.970985-1-suagrfillet@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18riscv: export cpu/freq invariant to schedulerSong Shuai
RISC-V now manages CPU topology using arch_topology which provides CPU capacity and frequency related interfaces to access the cpu/freq invariant in possible heterogeneous or DVFS-enabled platforms. Here adds topology.h file to export the arch_topology interfaces for replacing the scheduler's constant-based cpu/freq invariant accounting. Signed-off-by: Song Shuai <suagrfillet@gmail.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Ley Foon Tan <lftan@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230323123924.3032174-1-suagrfillet@gmail.com [Palmer: Fix the whitespace issues.] Signed-off-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: Add hwprobe vDSO function and dataEvan Green
Add a vDSO function __vdso_riscv_hwprobe, which can sit in front of the riscv_hwprobe syscall and answer common queries. We stash a copy of static answers for the "all CPUs" case in the vDSO data page. This data is private to the vDSO, so we can decide later to change what's stored there or under what conditions we defer to the syscall. Currently all data can be discovered at boot, so the vDSO function answers all queries when the cpumask is set to the "all CPUs" hint. There's also a boolean in the data that lets the vDSO function know that all CPUs are the same. In that case, the vDSO will also answer queries for arbitrary CPU masks in addition to the "all CPUs" hint. Signed-off-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20230407231103.2622178-7-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>
2023-04-18RISC-V: hwprobe: Add support for RISCV_HWPROBE_BASE_BEHAVIOR_IMAEvan Green
We have an implicit set of base behaviors that userspace depends on, which are mostly defined in various ISA specifications. Co-developed-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Evan Green <evan@rivosinc.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: Paul Walmsley <paul.walmsley@sifive.com> Link: https://lore.kernel.org/r/20230407231103.2622178-4-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18RISC-V: Add a syscall for HW probingEvan Green
We don't have enough space for these all in ELF_HWCAP{,2} and there's no system call that quite does this, so let's just provide an arch-specific one to probe for hardware capabilities. This currently just provides m{arch,imp,vendor}id, but with the key-value pairs we can pass more in the future. Co-developed-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Evan Green <evan@rivosinc.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: Paul Walmsley <paul.walmsley@sifive.com> Link: https://lore.kernel.org/r/20230407231103.2622178-3-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18RISC-V: Move struct riscv_cpuinfo to new headerEvan Green
In preparation for tracking and exposing microarchitectural details to userspace (like whether or not unaligned accesses are fast), move the riscv_cpuinfo struct out to its own new cpufeatures.h header. It will need to be used by more than just cpu.c. Signed-off-by: Evan Green <evan@rivosinc.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: Paul Walmsley <paul.walmsley@sifive.com> Link: https://lore.kernel.org/r/20230407231103.2622178-2-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18Merge tag 'arm-fixes-6.3-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM SoC fixes from Arnd Bergmann: "There are a number of updates for devicetree files for Qualcomm, Rockchips, and NXP i.MX platforms, addressing mistakes in the DT contents: - Wrong GPIO polarity on some boards - Lower SD card interface speed for better stability - Incorrect power supply, clock, pmic, cache properties - Disable broken hbr3 on sc7280-herobrine - Devicetree warning fixes The only other changes are: - A regression fix for the Amlogic performance monitoring unit driver, along with two related DT changes. - imx_v6_v7_defconfig enables PCI support again. - Trivial fixes for tee, optee and psci firmware drivers, addressing compiler warning and error output" * tag 'arm-fixes-6.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (32 commits) firmware/psci: demote suspend-mode warning to info level arm64: dts: qcom: sc7280: remove hbr3 support on herobrine boards ARM: imx_v6_v7_defconfig: Fix unintentional disablement of PCI arm64: dts: rockchip: correct panel supplies on some rk3326 boards arm64: dts: rockchip: use just "port" in panel on RockPro64 arm64: dts: rockchip: use just "port" in panel on Pinebook Pro ARM: dts: imx6ull-colibri: Remove unnecessary #address-cells/#size-cells ARM: dts: imx7d-remarkable2: Remove unnecessary #address-cells/#size-cells arm64: dts: imx8mp-verdin: correct off-on-delay arm64: dts: imx8mm-verdin: correct off-on-delay arm64: dts: imx8mm-evk: correct pmic clock source arm64: dts: qcom: sc8280xp-pmics: fix pon compatible and registers arm64: dts: rockchip: Remove non-existing pwm-delay-us property arm64: dts: rockchip: Add clk_rtc_32k to Anbernic xx3 Devices tee: Pass a pointer to virt_to_page() perf/amlogic: adjust register offsets arm64: dts: meson-g12-common: resolve conflict between canvas & pmu arm64: dts: meson-g12-common: specify full DMC range arm64: dts: imx8mp: fix address length for LCDIF2 riscv: dts: canaan: drop invalid spi-max-frequency ...
2023-04-16Merge tag 'kbuild-fixes-v6.3-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Drop debug info from purgatory objects again - Document that kernel.org provides prebuilt LLVM toolchains - Give up handling untracked files for source package builds - Avoid creating corrupted cpio when KBUILD_BUILD_TIMESTAMP is given with a pre-epoch data. - Change panic_show_mem() to a macro to handle variable-length argument - Compress tarballs on-the-fly again * tag 'kbuild-fixes-v6.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: do not create intermediate *.tar for tar packages kbuild: do not create intermediate *.tar for source tarballs kbuild: merge cmd_archive_linux and cmd_archive_perf init/initramfs: Fix argument forwarding to panic() in panic_show_mem() initramfs: Check negative timestamp to prevent broken cpio archive kbuild: give up untracked files for source package builds Documentation/llvm: Add a note about prebuilt kernel.org toolchains purgatory: fix disabling debug info
2023-04-14Merge tag 'riscv-for-linus-6.3-rc7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: - A fix for a missing fence when generating the NOMMU sigreturn trampoline - A set of fixes for early DTB handling of reserved memory nodes * tag 'riscv-for-linus-6.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: No need to relocate the dtb as it lies in the fixmap region riscv: Do not set initial_boot_params to the linear address of the dtb riscv: Move early dtb mapping into the fixmap region riscv: add icache flush for nommu sigreturn trampoline
2023-04-14Merge tag 'sunxi-dt-for-6.4-1' of ↵Arnd Bergmann
https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into soc/dt - added D1 crypto node - enabled DVFS on OrangePi PC2 board - added GPIO line names on Nezha D1 board - added suniv USB nodes and enabled on licheepi-nano - new suniv boards: PopStick v1.1 and Lctech Pi - added Allwinner T113-s DTSI - added MangoPi MQ-R T113-s board variant - swapped DMA names for A23, A31, A33, D1, H3, H5, V3s * tag 'sunxi-dt-for-6.4-1' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux: riscv: dts: allwinner: d1: Switch dma-names order for snps,dw-apb-uart nodes ARM: dts: sunxi: h3/h5: Switch dma-names order for snps,dw-apb-uart nodes ARM: dts: sun8i: v3s: Switch dma-names order for snps,dw-apb-uart nodes ARM: dts: sun8i: a23/a33: Switch dma-names order for snps,dw-apb-uart nodes ARM: dts: sun6i: a31: Switch dma-names order for snps,dw-apb-uart nodes ARM: dts: sunxi: add MangoPi MQ-R-T113 board dt-bindings: arm: sunxi: document MangoPi MQ-R board names ARM: dts: sunxi: add Allwinner T113-s SoC .dtsi dts: add riscv include prefix link ARM: dts: suniv: Add Lctech Pi F1C200s devicetree ARM: dts: suniv: add device tree for PopStick v1.1 dt-binding: arm: sunxi: add two board compatible strings dt-bindings: vendor-prefixes: add Source Parts and Lctech names ARM: dts: suniv: licheepi-nano: enable USB ARM: dts: suniv: add USB-related device nodes riscv: dts: nezha-d1: add gpio-line-names arm64: dts: allwinner: h5: OrangePi PC2: add OPP table to enable DVFS riscv: dts: allwinner: d1: Add crypto engine node Link: https://lore.kernel.org/r/20230408125156.GA17050@jernej-laptop Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-04-13riscv: No need to relocate the dtb as it lies in the fixmap regionAlexandre Ghiti
We used to access the dtb via its linear mapping address but now that the dtb early mapping was moved in the fixmap region, we can keep using this address since it is present in swapper_pg_dir, and remove the dtb relocation. Note that the relocation was wrong anyway since early_memremap() is restricted to 256K whereas the maximum fdt size is 2MB. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230329081932.79831-4-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-13riscv: Do not set initial_boot_params to the linear address of the dtbAlexandre Ghiti
early_init_dt_verify() is already called in parse_dtb() and since the dtb address does not change anymore (it is now in the fixmap region), no need to reset initial_boot_params by calling early_init_dt_verify() again. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230329081932.79831-3-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-13riscv: Move early dtb mapping into the fixmap regionAlexandre Ghiti
riscv establishes 2 virtual mappings: - early_pg_dir maps the kernel which allows to discover the system memory - swapper_pg_dir installs the final mapping (linear mapping included) We used to map the dtb in early_pg_dir using DTB_EARLY_BASE_VA, and this mapping was not carried over in swapper_pg_dir. It happens that early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is setup otherwise we could allocate reserved memory defined in the dtb. And this function initializes reserved_mem variable with addresses that lie in the early_pg_dir dtb mapping: when those addresses are reused with swapper_pg_dir, this mapping does not exist and then we trap. The previous "fix" was incorrect as early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is set up otherwise we could allocate in reserved memory defined in the dtb. So move the dtb mapping in the fixmap region which is established in early_pg_dir and handed over to swapper_pg_dir. Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob") Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap") Fixes: 50e63dd8ed92 ("riscv: fix reserved memory setup") Reported-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/all/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/ Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230329081932.79831-2-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-13riscv: cacheinfo: Adjust includes to remove of_device.hRob Herring
Now that of_cpu_device_node_get() is defined in of.h, of_device.h is just implicitly including other includes, and is no longer needed. Adjust the include files with what was implicitly included by of_device.h (cpu.h and of.h) and drop including of_device.h. Link: https://lore.kernel.org/r/20230329-dt-cpu-header-cleanups-v1-9-581e2605fe47@kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
2023-04-13riscv: Add explicit include for cpu.hRob Herring
Removing the include of cpu.h from of_device.h (included by of_platform.h) causes an error in setup.c: arch/riscv/kernel/setup.c:313:22: error: arithmetic on a pointer to an incomplete type 'typeof(struct cpu)' (aka 'struct cpu') The of_platform.h header is not necessary either, so it can be dropped. Link: https://lore.kernel.org/r/20230329-dt-cpu-header-cleanups-v1-8-581e2605fe47@kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
2023-04-11Revert "riscv: Set more data to cacheinfo"Song Shuai
This reverts commit baf7cbd94b5688f167443a2cc3dcea3300132099. There are some duplicate cache attributes populations executed in both ci_leaf_init() and later cache_setup_properties(). Revert the commit baf7cbd94b56 ("riscv: Set more data to cacheinfo") to setup only the level and type attributes at this early place. Signed-off-by: Song Shuai <suagrfillet@gmail.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230308064734.512457-1-suagrfillet@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-11riscv: add icache flush for nommu sigreturn trampolineMathis Salmen
In a NOMMU kernel, sigreturn trampolines are generated on the user stack by setup_rt_frame. Currently, these trampolines are not instruction fenced, thus their visibility to ifetch is not guaranteed. This patch adds a flush_icache_range in setup_rt_frame to fix this problem. Signed-off-by: Mathis Salmen <mathis.salmen@matsal.de> Fixes: 6bd33e1ece52 ("riscv: add nommu support") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230406101130.82304-1-mathis.salmen@matsal.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-11riscv: entry: Save a0 prior syscall_enter_from_user_mode()Björn Töpel
The RISC-V calling convention passes the first argument, and the return value in the a0 register. For this reason, the a0 register needs some extra care; When handling syscalls, the a0 register is saved into regs->orig_a0, so a0 can be properly restored for, e.g. interrupted syscalls. This functionality was broken with the introduction of the generic entry patches. Here, a0 was saved into orig_a0 after calling syscall_enter_from_user_mode(), which can change regs->a0 for some paths, incorrectly restoring a0. This is resolved, by saving a0 prior doing the syscall_enter_from_user_mode() call. Fixes: f0bddf50586d ("riscv: entry: Convert to generic entry") Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Reported-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Andy Chiu <andy.chiu@sifive.com> Link: https://lore.kernel.org/r/20230403065207.1070974-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-08riscv: dts: allwinner: d1: Switch dma-names order for snps,dw-apb-uart nodesCristian Ciocaltea
Commit 370f696e4474 ("dt-bindings: serial: snps-dw-apb-uart: add dma & dma-names properties") documented dma-names property to handle Allwinner D1 dtbs_check warnings, but relies on the rx->tx ordering, which is the reverse of what a bunch of different boards expect. The initial proposed solution was to allow a flexible dma-names order in the binding, due to potential ABI breakage concerns after fixing the DTS files. But luckily the Allwinner boards are not affected, since they are using a shared DMA channel for rx and tx. Hence, the first step in fixing the inconsistency was to change dma-names order in the binding to tx->rx. Do the same for the snps,dw-apb-uart nodes in the DTS file. Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230321215624.78383-7-cristian.ciocaltea@collabora.com Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
2023-04-08purgatory: fix disabling debug infoAlyssa Ross
Since 32ef9e5054ec, -Wa,-gdwarf-2 is no longer used in KBUILD_AFLAGS. Instead, it includes -g, the appropriate -gdwarf-* flag, and also the -Wa versions of both of those if building with Clang and GNU as. As a result, debug info was being generated for the purgatory objects, even though the intention was that it not be. Fixes: 32ef9e5054ec ("Makefile.debug: re-enable debug info for .S files") Signed-off-by: Alyssa Ross <hi@alyssa.is> Cc: stable@vger.kernel.org Acked-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-04-08RISC-V: Use IPIs for remote icache flush when possibleAnup Patel
If we have specialized interrupt controller (such as AIA IMSIC) which allows supervisor mode to directly inject IPIs without any assistance from M-mode or HS-mode then using such specialized interrupt controller, we can do remote icache flushe directly from supervisor mode instead of using the SBI RFENCE calls. This patch extends remote icache flush functions to use supervisor mode IPIs whenever direct supervisor mode IPIs.are supported by interrupt controller. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230328035223.1480939-7-apatel@ventanamicro.com
2023-04-08RISC-V: Use IPIs for remote TLB flush when possibleAnup Patel
If we have specialized interrupt controller (such as AIA IMSIC) which allows supervisor mode to directly inject IPIs without any assistance from M-mode or HS-mode then using such specialized interrupt controller, we can do remote TLB flushes directly from supervisor mode instead of using the SBI RFENCE calls. This patch extends remote TLB flush functions to use supervisor mode IPIs whenever direct supervisor mode IPIs.are supported by interrupt controller. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230328035223.1480939-6-apatel@ventanamicro.com
2023-04-08RISC-V: Allow marking IPIs as suitable for remote FENCEsAnup Patel
To do remote FENCEs (i.e. remote TLB flushes) using IPI calls on the RISC-V kernel, we need hardware mechanism to directly inject IPI from the supervisor mode (i.e. RISC-V kernel) instead of using SBI calls. The upcoming AIA IMSIC devices allow direct IPI injection from the supervisor mode (i.e. RISC-V kernel). To support this, we extend the riscv_ipi_set_virq_range() function so that IPI provider (i.e. irqchip drivers can mark IPIs as suitable for remote FENCEs. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230328035223.1480939-5-apatel@ventanamicro.com
2023-04-08RISC-V: Treat IPIs as normal Linux IRQsAnup Patel
Currently, the RISC-V kernel provides arch specific hooks (i.e. struct riscv_ipi_ops) to register IPI handling methods. The stats gathering of IPIs is also arch specific in the RISC-V kernel. Other architectures (such as ARM, ARM64, and MIPS) have moved away from custom arch specific IPI handling methods. Currently, these architectures have Linux irqchip drivers providing a range of Linux IRQ numbers to be used as IPIs and IPI triggering is done using generic IPI APIs. This approach allows architectures to treat IPIs as normal Linux IRQs and IPI stats gathering is done by the generic Linux IRQ subsystem. We extend the RISC-V IPI handling as-per above approach so that arch specific IPI handling methods (struct riscv_ipi_ops) can be removed and the IPI handling is done through the Linux IRQ subsystem. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230328035223.1480939-4-apatel@ventanamicro.com
2023-04-08irqchip/riscv-intc: Allow drivers to directly discover INTC hwnodeAnup Patel
Various RISC-V drivers (such as SBI IPI, SBI Timer, SBI PMU, and KVM RISC-V) don't have associated DT node but these drivers need standard per-CPU (local) interrupts defined by the RISC-V privileged specification. We add riscv_get_intc_hwnode() in arch/riscv which allows RISC-V drivers not having DT node to discover INTC hwnode which in-turn helps these drivers to map per-CPU (local) interrupts provided by the INTC driver. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230328035223.1480939-3-apatel@ventanamicro.com
2023-04-08RISC-V: Clear SIP bit only when using SBI IPI operationsAnup Patel
The software interrupt pending (i.e. [M|S]SIP) bit is writeable for S-mode but read-only for M-mode so we clear this bit only when using SBI IPI operations. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230328035223.1480939-2-apatel@ventanamicro.com
2023-04-07of: address: always use dma_default_coherent for default coherencyJiaxun Yang
As for now all arches have dma_default_coherent reflecting default DMA coherency for of devices, so there is no need to have a standalone config option. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Reviewed-by: Rob Herring <robh@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-04-06Merge tag 'riscv-dt-fixes-for-v6.3-final' of ↵Arnd Bergmann
https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux into arm/fixes RISC-V Devicetree fixes for v6.3-final A solitary fix here from Krzysztof for an invalid property that should've probably been removed months ago, but was missed due to it being in a dtb that doesn't build w/ defconfig. Signed-off-by: Conor Dooley <conor.dooley@microchip.com> * tag 'riscv-dt-fixes-for-v6.3-final' of https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux: riscv: dts: canaan: drop invalid spi-max-frequency Link: https://lore.kernel.org/r/20230406-negate-octagon-0fc2e47dbde5@spud Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-04-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Conflicts: drivers/net/ethernet/google/gve/gve.h 3ce934558097 ("gve: Secure enough bytes in the first TX desc for all TCP pkts") 75eaae158b1b ("gve: Add XDP DROP and TX support for GQI-QPL format") https://lore.kernel.org/all/20230406104927.45d176f5@canb.auug.org.au/ https://lore.kernel.org/all/c5872985-1a95-0bc8-9dcc-b6f23b439e9d@tessares.net/ Adjacent changes: net/can/isotp.c 051737439eae ("can: isotp: fix race between isotp_sendsmg() and isotp_release()") 96d1c81e6a04 ("can: isotp: add module parameter for maximum pdu size") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-05Merge branch 'riscv-jh7110_initial_dts' into riscv-dt-for-nextConor Dooley
Merge Hal's series adding support for the new StarFive JH7110 SoC. There's a few bindings here for core components that were not picked up by the various maintainers for the subsystems (previously Palmer would pick these up via the RISC-V tree) & the first two commits in the branch are shared with the clk tree, since the dts depends on defines in the dt-binding headers. This is based on -rc2, as the board does not actually boot on -rc1 due to the bug Linus introduced. Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2023-04-05Kconfig: introduce HAS_IOPORT option and select it as necessaryNiklas Schnelle
We introduce a new HAS_IOPORT Kconfig option to indicate support for I/O Port access. In a future patch HAS_IOPORT=n will disable compilation of the I/O accessor functions inb()/outb() and friends on architectures which can not meaningfully support legacy I/O spaces such as s390. The following architectures do not select HAS_IOPORT: * ARC * C-SKY * Hexagon * Nios II * OpenRISC * s390 * User-Mode Linux * Xtensa All other architectures select HAS_IOPORT at least conditionally. The "depends on" relations on HAS_IOPORT in drivers as well as ifdefs for HAS_IOPORT specific sections will be added in subsequent patches on a per subsystem basis. Co-developed-by: Arnd Bergmann <arnd@kernel.org> Signed-off-by: Arnd Bergmann <arnd@kernel.org> Acked-by: Johannes Berg <johannes@sipsolutions.net> # for ARCH=um Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-04-05riscv: dts: starfive: Add StarFive JH7110 VisionFive 2 board device treeEmil Renner Berthing
Add a minimal device tree for StarFive JH7110 VisionFive 2 board which has version A and version B. Support booting and basic clock/reset/pinctrl/uart drivers. Tested-by: Tommaso Merciai <tomm.merciai@gmail.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Emil Renner Berthing <kernel@esmil.dk> Co-developed-by: Jianlong Huang <jianlong.huang@starfivetech.com> Signed-off-by: Jianlong Huang <jianlong.huang@starfivetech.com> Co-developed-by: Hal Feng <hal.feng@starfivetech.com> Signed-off-by: Hal Feng <hal.feng@starfivetech.com> Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2023-04-05riscv: dts: starfive: Add StarFive JH7110 pin function definitionsJianlong Huang
Add pin function definitions for StarFive JH7110 SoC. Tested-by: Tommaso Merciai <tomm.merciai@gmail.com> Co-developed-by: Emil Renner Berthing <kernel@esmil.dk> Signed-off-by: Emil Renner Berthing <kernel@esmil.dk> Signed-off-by: Jianlong Huang <jianlong.huang@starfivetech.com> Signed-off-by: Hal Feng <hal.feng@starfivetech.com> Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2023-04-05riscv: dts: starfive: Add initial StarFive JH7110 device treeEmil Renner Berthing
Add initial device tree for the JH7110 RISC-V SoC by StarFive Technology Ltd. Tested-by: Tommaso Merciai <tomm.merciai@gmail.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Emil Renner Berthing <kernel@esmil.dk> Co-developed-by: Jianlong Huang <jianlong.huang@starfivetech.com> Signed-off-by: Jianlong Huang <jianlong.huang@starfivetech.com> Co-developed-by: Hal Feng <hal.feng@starfivetech.com> Signed-off-by: Hal Feng <hal.feng@starfivetech.com> [conor: squashed in the removal of the S7's non-existent mmu] Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2023-04-05kvm: Remove "select SRCU"Paul E. McKenney
Now that the SRCU Kconfig option is unconditionally selected, there is no longer any point in selecting it. Therefore, remove the "select SRCU" Kconfig statements from the various KVM Kconfig files. Acked-by: Sean Christopherson <seanjc@google.com> (x86) Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Sean Christopherson <seanjc@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <kvm@vger.kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> (arm64) Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Anup Patel <anup@brainfault.org> (riscv) Acked-by: Heiko Carstens <hca@linux.ibm.com> (s390) Reviewed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
2023-03-31Merge tag 'riscv-for-linus-6.3-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: - A fix for FPU probing in XIP kernels - Always enable the alternative framework for non-XIP kernels * tag 'riscv-for-linus-6.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely()
2023-03-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Conflicts: drivers/net/ethernet/mediatek/mtk_ppe.c 3fbe4d8c0e53 ("net: ethernet: mtk_eth_soc: ppe: add support for flow accounting") 924531326e2d ("net: ethernet: mtk_eth_soc: add missing ppe cache flush when deleting a flow") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-29RISC-V: convert new selectors of RISCV_ALTERNATIVE to dependenciesConor Dooley
for-next contains two additional extensions that select RISCV_ALTERNATIVE. RISCV_ALTERNATIVE no longer needs to be selected by individual config options as it is now selected for !XIP_KERNEL builds by the top level RISCV option. These extensions rely on the alternative framework, so convert the "select"s to "depends on"s instead. Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230324121240.3594777-1-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-03-29Merge patch series "RISC-V: Fixes for riscv_has_extension[un]likely()'s ↵Palmer Dabbelt
alternative dependency" Conor Dooley <conor.dooley@microchip.com> says: Here's my attempt at fixing both the use of an FPU on XIP kernels and the issue that Jason ran into where CONFIG_FPU, which needs the alternatives frame work for has_fpu() checks, could be enabled without the alternatives actually being present. For the former, a "slow" fallback that does not use alternatives is added to riscv_has_extension_[un]likely() that can be used with XIP. Obviously, we want to make use of Jisheng's alternatives based approach where possible, so any users of riscv_has_extension_[un]likely() will want to make sure that they select RISCV_ALTERNATIVE. If they don't however, they'll hit the fallback path which (should, sparing a silly mistake from me!) behave in the same way, thus succeeding silently. Sounds like a To prevent "depends on !XIP_KERNEL; select RISCV_ALTERNATIVE" spreading like the plague through the various places that want to check for the presence of extensions, and sidestep the potential silent "success" mentioned above, all users RISCV_ALTERNATIVE are converted from selects to dependencies, with the option being selected for all !XIP_KERNEL builds. I know that the VDSO was a key place that Jisheng wanted to use the new helper rather than static branches, and I think the fallback path should not cause issues there. See the thread at [1] for the prior discussion. 1 - https://lore.kernel.org/linux-riscv/20230128172856.3814-1-jszhang@kernel.org/T/#m21390d570997145d31dd8bb95002fd61f99c6573 [Palmer: these were also merged into fixes, but there's a cleanup that depends on the merge so I'm taking it into for-next as well.] * b4-shazam-merge: RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely() Link: https://lore.kernel.org/r/20230324100538.3514663-1-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> * commit '1ee7fc3f4d0a93831a20d5566f203d5ad6d44de8': RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely()
2023-03-29Merge patch series "RISC-V: Fixes for riscv_has_extension[un]likely()'s ↵Palmer Dabbelt
alternative dependency" Conor Dooley <conor.dooley@microchip.com> says: Here's my attempt at fixing both the use of an FPU on XIP kernels and the issue that Jason ran into where CONFIG_FPU, which needs the alternatives frame work for has_fpu() checks, could be enabled without the alternatives actually being present. For the former, a "slow" fallback that does not use alternatives is added to riscv_has_extension_[un]likely() that can be used with XIP. Obviously, we want to make use of Jisheng's alternatives based approach where possible, so any users of riscv_has_extension_[un]likely() will want to make sure that they select RISCV_ALTERNATIVE. If they don't however, they'll hit the fallback path which (should, sparing a silly mistake from me!) behave in the same way, thus succeeding silently. Sounds like a To prevent "depends on !XIP_KERNEL; select RISCV_ALTERNATIVE" spreading like the plague through the various places that want to check for the presence of extensions, and sidestep the potential silent "success" mentioned above, all users RISCV_ALTERNATIVE are converted from selects to dependencies, with the option being selected for all !XIP_KERNEL builds. I know that the VDSO was a key place that Jisheng wanted to use the new helper rather than static branches, and I think the fallback path should not cause issues there. See the thread at [1] for the prior discussion. 1 - https://lore.kernel.org/linux-riscv/20230128172856.3814-1-jszhang@kernel.org/T/#m21390d570997145d31dd8bb95002fd61f99c6573 [Palmer: merging in the fixes as a branch as there's some features that depend on it.] * b4-shazam-merge: RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely() Link: https://lore.kernel.org/r/20230324100538.3514663-1-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-03-29RISC-V: always select RISCV_ALTERNATIVE for non-xip kernelsConor Dooley
When moving switch_to's has_fpu() over to using riscv_has_extension_likely() rather than static branches, the FPU code gained a dependency on the alternatives framework. That dependency has now been removed, as riscv_has_extension_ikely() now contains a fallback path, using __riscv_isa_extension_available(), but if CONFIG_RISCV_ALTERNATIVE isn't selected when CONFIG_FPU is, has_fpu() checks will not benefit from the "fast path" that the alternatives framework provides. We want to ensure that alternatives are available whenever riscv_has_extension_[un]likely() is used, rather than silently falling back to the slow path, but rather than rely on selecting RISCV_ALTERNATIVE in the myriad of locations that may use riscv_has_extension_[un]likely(), select it (almost) always instead by adding it to the main RISCV config entry. xip kernels cannot make use of the alternatives framework, so it is not enabled for those configurations, although this is the status quo. All current sites that select RISCV_ALTERNATIVE are converted to dependencies on the option instead. The explicit dependencies on !XIP_KERNEL can be dropped, as RISCV_ALTERNATIVE is not user selectable. Fixes: 702e64550b12 ("riscv: fpu: switch has_fpu() to riscv_has_extension_likely()") Link: https://lore.kernel.org/all/ZBruFRwt3rUVngPu@zx2c4.com/ Reported-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20230324100538.3514663-3-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>