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2023-08-16riscv: Handle zicsr/zifencei issue between gcc and binutilsMingzheng Xing
Binutils-2.38 and GCC-12.1.0 bumped[0][1] the default ISA spec to the newer 20191213 version which moves some instructions from the I extension to the Zicsr and Zifencei extensions. So if one of the binutils and GCC exceeds that version, we should explicitly specifying Zicsr and Zifencei via -march to cope with the new changes. but this only occurs when binutils >= 2.36 and GCC >= 11.1.0. It's a different story when binutils < 2.36. binutils-2.36 supports the Zifencei extension[2] and splits Zifencei and Zicsr from I[3]. GCC-11.1.0 is particular[4] because it add support Zicsr and Zifencei extension for -march. binutils-2.35 does not support the Zifencei extension, and does not need to specify Zicsr and Zifencei when working with GCC >= 12.1.0. To make our lives easier, let's relax the check to binutils >= 2.36 in CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. For the other two cases, where clang < 17 or GCC < 11.1.0, we will deal with them in CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC. For more information, please refer to: commit 6df2a016c0c8 ("riscv: fix build with binutils 2.38") commit e89c2e815e76 ("riscv: Handle zicsr/zifencei issues between clang and binutils") Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc [0] Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd [1] Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=5a1b31e1e1cee6e9f1c92abff59cdcfff0dddf30 [2] Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=729a53530e86972d1143553a415db34e6e01d5d2 [3] Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=b03be74bad08c382da47e048007a78fa3fb4ef49 [4] Link: https://lore.kernel.org/all/20230308220842.1231003-1-conor@kernel.org Link: https://lore.kernel.org/all/20230223220546.52879-1-conor@kernel.org Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Guo Ren <guoren@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Mingzheng Xing <xingmingzheng@iscas.ac.cn> Link: https://lore.kernel.org/r/20230809165648.21071-1-xingmingzheng@iscas.ac.cn Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-16riscv: stack: Fixup independent softirq stack for CONFIG_FRAME_POINTER=nGuo Ren
The independent softirq stack uses s0 to save & restore sp, but s0 would be corrupted when CONFIG_FRAME_POINTER=n. So add s0 in the clobber list to fix the problem. Fixes: dd69d07a5a6c ("riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK") Cc: stable@vger.kernel.org Reported-by: Zhangjin Wu <falcon@tinylab.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Tested-by: Drew Fustini <dfustini@baylibre.com> Link: https://lore.kernel.org/r/20230716001506.3506041-3-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-16riscv: stack: Fixup independent irq stack for CONFIG_FRAME_POINTER=nGuo Ren
The independent irq stack uses s0 to save & restore sp, but s0 would be corrupted when CONFIG_FRAME_POINTER=n. So add s0 in the clobber list to fix the problem. Fixes: 163e76cc6ef4 ("riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK") Cc: stable@vger.kernel.org Reported-by: Zhangjin Wu <falcon@tinylab.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Tested-by: Drew Fustini <dfustini@baylibre.com> Link: https://lore.kernel.org/r/20230716001506.3506041-2-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-16riscv: entry: set a0 = -ENOSYS only when syscall != -1Celeste Liu
When we test seccomp with 6.4 kernel, we found errno has wrong value. If we deny NETLINK_AUDIT with EAFNOSUPPORT, after f0bddf50586d, we will get ENOSYS instead. We got same result with commit 9c2598d43510 ("riscv: entry: Save a0 prior syscall_enter_from_user_mode()"). After analysing code, we think that regs->a0 = -ENOSYS should only be executed when syscall != -1. In __seccomp_filter, when seccomp rejected this syscall with specified errno, they will set a0 to return number as syscall ABI, and then return -1. This return number is finally pass as return number of syscall_enter_from_user_mode, and then is compared with NR_syscalls after converted to ulong (so it will be ULONG_MAX). The condition syscall < NR_syscalls will always be false, so regs->a0 = -ENOSYS is always executed. It covered a0 set by seccomp, so we always get ENOSYS when match seccomp RET_ERRNO rule. Fixes: f0bddf50586d ("riscv: entry: Convert to generic entry") Reported-by: Felix Yan <felixonmars@archlinux.org> Co-developed-by: Ruizhe Pan <c141028@gmail.com> Signed-off-by: Ruizhe Pan <c141028@gmail.com> Co-developed-by: Shiqi Zhang <shiqi@isrc.iscas.ac.cn> Signed-off-by: Shiqi Zhang <shiqi@isrc.iscas.ac.cn> Signed-off-by: Celeste Liu <CoelacanthusHex@gmail.com> Tested-by: Felix Yan <felixonmars@archlinux.org> Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230801141607.435192-1-CoelacanthusHex@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-08riscv: Fix CPU feature detection with SMP disabledSamuel Holland
commit 914d6f44fc50 ("RISC-V: only iterate over possible CPUs in ISA string parser") changed riscv_fill_hwcap() from iterating over CPU DT nodes to iterating over logical CPU IDs. Since this function runs long before cpu_dev_init() creates CPU devices, it hits the fallback path in of_cpu_device_node_get(), which itself iterates over the DT nodes, searching for a node with the requested CPU ID. (Incidentally, this makes riscv_fill_hwcap() now take quadratic time.) riscv_fill_hwcap() passes a logical CPU ID to of_cpu_device_node_get(), which uses the arch_match_cpu_phys_id() hook to translate the logical ID to a physical ID as found in the DT. arch_match_cpu_phys_id() has a generic weak definition, and RISC-V provides a strong definition using cpuid_to_hartid_map(). However, the RISC-V specific implementation is located in arch/riscv/kernel/smp.c, and that file is only compiled when SMP is enabled. As a result, when SMP is disabled, the generic definition is used, and riscv_isa gets initialized based on the ISA string of hart 0, not the boot hart. On FU740, this means has_fpu() returns false, and userspace crashes when trying to use floating-point instructions. Fix this by moving arch_match_cpu_phys_id() to a file which is always compiled. Fixes: 70114560b285 ("RISC-V: Add RISC-V specific arch_match_cpu_phys_id") Fixes: 914d6f44fc50 ("RISC-V: only iterate over possible CPUs in ISA string parser") Reported-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230803012608.3540081-1-samuel.holland@sifive.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-04Merge patch series "RISC-V: Fix a few kexec_file_load(2) failures"Palmer Dabbelt
Petr Tesarik <petrtesarik@huaweicloud.com> says: From: Petr Tesarik <petr.tesarik.ext@huawei.com> The kexec_file_load(2) syscall does not work at least in some kernel builds. For details see the relevant section in this blog post: https://sigillatum.tesarici.cz/2023-07-21-state-of-riscv64-kdump.html This patch series handles an additional relocation types, removes the need to implement a Global Offset Table (GOT) for the purgatory and fixes the placement of initrd. * b4-shazam-merge: riscv/kexec: load initrd high in available memory riscv/kexec: handle R_RISCV_CALL_PLT relocation type Link: https://lore.kernel.org/r/cover.1690365011.git.petr.tesarik.ext@huawei.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-04riscv/kexec: load initrd high in available memoryTorsten Duwe
When initrd is loaded low, the secondary kernel fails like this: INITRD: 0xdc581000+0x00eef000 overlaps in-use memory region This initrd load address corresponds to the _end symbol, but the reservation is aligned on PMD_SIZE, as explained by a comment in setup_bootmem(). It is technically possible to align the initrd load address accordingly, leaving a hole between the end of kernel and the initrd, but it is much simpler to allocate the initrd top-down. Fixes: 838b3e28488f ("RISC-V: Load purgatory in kexec_file") Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Cc: stable@vger.kernel.org Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/all/67c8eb9eea25717c2c8208d9bfbfaa39e6e2a1c6.1690365011.git.petr.tesarik.ext@huawei.com/ Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-04riscv/kexec: handle R_RISCV_CALL_PLT relocation typeTorsten Duwe
R_RISCV_CALL has been deprecated and replaced by R_RISCV_CALL_PLT. See Enum 18-19 in Table 3. Relocation types here: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc It was deprecated in ("Deprecated R_RISCV_CALL, prefer R_RISCV_CALL_PLT"): https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a0dced85018d7a0ec17023c9389cbd70b1dbc1b0 Recent tools (at least GNU binutils-2.40) already use R_RISCV_CALL_PLT. Kernels built with such binutils fail kexec_load_file(2) with: kexec_image: Unknown rela relocation: 19 kexec_image: Error loading purgatory ret=-8 The binary code at the call site remains the same, so tell arch_kexec_apply_relocations_add() to handle _PLT alike. Fixes: 838b3e28488f ("RISC-V: Load purgatory in kexec_file") Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Cc: Li Zhengyu <lizhengyu3@huawei.com> Cc: stable@vger.kernel.org Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/all/b046b164af8efd33bbdb7d4003273bdf9196a5b0.1690365011.git.petr.tesarik.ext@huawei.com/ Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-02riscv: Export va_kernel_pa_offset in vmcoreinfoSong Shuai
Since RISC-V Linux v6.4, the commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") changes phys_ram_base from the physical start of the kernel to the actual start of the DRAM. The Crash-utility's VTOP() still uses phys_ram_base and kernel_map.virt_addr to translate kernel virtual address, that failed the Crash with Linux v6.4 [1]. Export kernel_map.va_kernel_pa_offset in vmcoreinfo to help Crash translate the kernel virtual address correctly. Fixes: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") Link: https://lore.kernel.org/linux-riscv/20230724040649.220279-1-suagrfillet@gmail.com/ [1] Signed-off-by: Song Shuai <suagrfillet@gmail.com> Reviewed-by: Xianting Tian  <xianting.tian@linux.alibaba.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230724100917.309061-1-suagrfillet@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-02RISC-V: ACPI: Fix acpi_os_ioremap to return iomem addressSunil V L
acpi_os_ioremap() currently is a wrapper to memremap() on RISC-V. But the callers of acpi_os_ioremap() expect it to return __iomem address and hence sparse tool reports a new warning. Fix this issue by type casting to __iomem type. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202307230357.egcTAefj-lkp@intel.com/ Fixes: a91a9ffbd3a5 ("RISC-V: Add support to build the ACPI core") Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230724100346.1302937-1-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-02RISC-V: cpu: refactor deprecated strncpyJustin Stitt
`strncpy` is deprecated for use on NUL-terminated destination strings [1]. Favor not copying strings onto stack and instead use strings directly. This avoids hard-coding sizes and buffer lengths all together. Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230802-arch-riscv-kernel-v2-1-24266e85bc96@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: provide Kconfig & commandline options to control parsing "riscv,isa"Conor Dooley
As it says on the tin, provide Kconfig option to control parsing the "riscv,isa" devicetree property. If either option is used, the kernel will fall back to parsing "riscv,isa", where "riscv,isa-base" and "riscv,isa-extensions" are not present. The Kconfig options are set up so that the default kernel configuration will enable the fallback path, without needing the commandline option. Suggested-by: Andrew Jones <ajones@ventanamicro.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-aviator-plausibly-a35662485c2c@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: try new extension properties in of_early_processor_hartid()Conor Dooley
To fully deprecate the kernel's use of "riscv,isa", of_early_processor_hartid() needs to first try using the new properties, before falling back to "riscv,isa". Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-tablet-jimmy-987fea0eb2e1@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: enable extension detection from dedicated propertiesConor Dooley
Add support for parsing the new riscv,isa-extensions property in riscv_fill_hwcap(), by means of a new "property" member of the riscv_isa_ext_data struct. For now, this shadows the name of the extension for all users, however this may not be the case for all extensions, based on how the dt-binding is written. For the sake of backwards compatibility, fall back to the old scheme if the new properties are not detected. For now, just inform, rather than warn, when that happens. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-vocation-profane-39a74b3c2649@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: split riscv_fill_hwcap() in 3Conor Dooley
Before adding more complexity to it, split riscv_fill_hwcap() into 3 distinct sections: - riscv_fill_hwcap() still is the top level function, into which the additional complexity will be added. - riscv_fill_hwcap_from_isa_string() handles getting the information from the riscv,isa/ACPI equivalent across harts & the various quirks there - riscv_parse_isa_string() does what it says on the tin. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-daylight-puritan-37aeb41a4d9b@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: add single letter extensions to riscv_isa_extConor Dooley
So that riscv_fill_hwcap() can use riscv_isa_ext to probe for single letter extensions, add them to it. As a result, what gets spat out in /proc/cpuinfo will become borked, as single letter extensions will be printed as part of the base extensions and while printing from riscv_isa_arr. Take the opportunity to unify the printing of the isa string, using the new member of riscv_isa_ext_data in the process. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-despite-bright-de00ac888cc7@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: repurpose riscv_isa_ext array in riscv_fill_hwcap()Conor Dooley
In riscv_fill_hwcap() riscv_isa_ext array can be looped over, rather than duplicating the list of extensions with individual SET_ISA_EXT_MAP() usage. While at it, drop the statement-of-the-obvious comments from the struct, rename uprop to something more suitable for its new use & constify the members. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-dastardly-affiliate-4cf819dccde2@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: shunt isa_ext_arr to cpufeature.cConor Dooley
To facilitate using one struct to define extensions, rather than having several, shunt isa_ext_arr to cpufeature.c, where it will be used for probing extension presence also. As that scope of the array as widened, prefix it with riscv & drop the type from the variable name. Since the new array is const, print_isa() needs a wee bit of cleanup to avoid complaints about losing the const qualifier. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Evan Green <evan@rivosinc.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-spirits-upside-a2c61c65fd5a@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: drop a needless check in print_isa_ext()Conor Dooley
isa_ext_arr cannot be empty, as some of the extensions within it are always built into the kernel. When this code was first added, back in commit a9b202606c69 ("RISC-V: Improve /proc/cpuinfo output for ISA extensions"), the array was empty and needed a dummy item & thus there could be no extensions present. When the first multi-letter ones did get added, it was Sscofpmf - which didn't have a Kconfig symbol to disable it. Remove this check, as it has been redundant since Sscofpmf was added. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-veggie-mug-3d3bf6787ae2@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: don't parse dt/acpi isa string to get rv32/rv64Heiko Stuebner
When filling hwcap the kernel already expects the isa string to start with rv32 if CONFIG_32BIT and rv64 if CONFIG_64BIT. So when recreating the runtime isa-string we can also just go the other way to get the correct starting point for it. Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Evan Green <evan@rivosinc.com> Co-developed-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-masculine-saddlebag-67a94966b091@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-25RISC-V: Provide a more helpful error message on invalid ISA stringsPalmer Dabbelt
Right now we provide a somewhat unhelpful error message on systems with invalid error messages, something along the lines of CPU with hartid=0 is not available ------------[ cut here ]------------ kernel BUG at arch/riscv/kernel/smpboot.c:174! Kernel BUG [#1] Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.4.0-rc1-00096-ge0097d2c62d5-dirty #1 Hardware name: Microchip PolarFire-SoC Icicle Kit (DT) epc : of_parse_and_init_cpus+0x16c/0x16e ra : of_parse_and_init_cpus+0x9a/0x16e epc : ffffffff80c04e0a ra : ffffffff80c04d38 sp : ffffffff81603e20 gp : ffffffff8182d658 tp : ffffffff81613f80 t0 : 000000000000006e t1 : 0000000000000064 t2 : 0000000000000000 s0 : ffffffff81603e80 s1 : 0000000000000000 a0 : 0000000000000000 a1 : 0000000000000000 a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000 a5 : 0000000000001fff a6 : 0000000000001fff a7 : ffffffff816148b0 s2 : 0000000000000001 s3 : ffffffff81492a4c s4 : ffffffff81a4b090 s5 : ffffffff81506030 s6 : 0000000000000040 s7 : 0000000000000000 s8 : 00000000bfb6f046 s9 : 0000000000000001 s10: 0000000000000000 s11: 00000000bf389700 t3 : 0000000000000000 t4 : 0000000000000000 t5 : ffffffff824dd188 t6 : ffffffff824dd187 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [<ffffffff80c04e0a>] of_parse_and_init_cpus+0x16c/0x16e [<ffffffff80c04c96>] setup_smp+0x1e/0x26 [<ffffffff80c03ffe>] setup_arch+0x6e/0xb2 [<ffffffff80c00384>] start_kernel+0x72/0x400 Code: 80e7 4a00 a603 0009 b795 1097 ffe5 80e7 92c0 9002 (9002) 715d ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Fatal exception in interrupt Add a warning for the cases where the ISA string isn't valid. It's still above the BUG_ON cut, but hopefully it's at least a bit easier for users. Reviewed-by: Evan Green <evan@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230713-endless-spearhead-62a5a4b149bd@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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>
2023-07-07Merge tag 'riscv-for-linus-6.5-mw2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull more RISC-V updates from Palmer Dabbelt: - A bunch of fixes/cleanups from the first part of the merge window, mostly related to ACPI and vector as those were large - Some documentation improvements, mostly related to the new code - The "riscv,isa" DT key is deprecated - Support for link-time dead code elimination - Support for minor fault registration in userfaultd - A handful of cleanups around CMO alternatives * tag 'riscv-for-linus-6.5-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (23 commits) riscv: mm: mark noncoherent_supported as __ro_after_init riscv: mm: mark CBO relate initialization funcs as __init riscv: errata: thead: only set cbom size & noncoherent during boot riscv: Select HAVE_ARCH_USERFAULTFD_MINOR RISC-V: Document the ISA string parsing rules for ACPI risc-v: Fix order of IPI enablement vs RCU startup mm: riscv: fix an unsafe pte read in huge_pte_alloc() dt-bindings: riscv: deprecate riscv,isa RISC-V: drop error print from riscv_hartid_to_cpuid() riscv: Discard vector state on syscalls riscv: move memblock_allow_resize() after linear mapping is ready riscv: Enable ARCH_SUSPEND_POSSIBLE for s2idle riscv: vdso: include vdso/vsyscall.h for vdso_data selftests: Test RISC-V Vector's first-use handler riscv: vector: clear V-reg in the first-use trap riscv: vector: only enable interrupts in the first-use trap RISC-V: Fix up some vector state related build failures RISC-V: Document that V registers are clobbered on syscalls riscv: disable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for LLD riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION ...
2023-07-05risc-v: Fix order of IPI enablement vs RCU startupMarc Zyngier
Conor reports that risc-v tries to enable IPIs before telling the core code to enable RCU. With the introduction of the mapple tree as a backing store for the irq descriptors, this results in a very shouty boot sequence, as RCU is legitimately upset. Restore some sanity by moving the risc_ipi_enable() call after notify_cpu_starting(), which explicitly enables RCU on the calling CPU. Fixes: 832f15f42646 ("RISC-V: Treat IPIs as normal Linux IRQs") Reported-by: Conor Dooley <conor@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230703-dupe-frying-79ae2ccf94eb@spud Cc: Anup Patel <apatel@ventanamicro.com> Cc: Palmer Dabbelt <palmer@rivosinc.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230703183126.1567625-1-maz@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-04RISC-V: drop error print from riscv_hartid_to_cpuid()Conor Dooley
As of commit 2ac874343749 ("RISC-V: split early & late of_node to hartid mapping") my CI complains about newly added pr_err() messages during boot, for example: [ 0.000000] Couldn't find cpu id for hartid [0] [ 0.000000] riscv-intc: unable to find hart id for /cpus/cpu@0/interrupt-controller Before the split, riscv_of_processor_hartid() contained a check for whether the cpu was "available", before calling riscv_hartid_to_cpuid(), but after the split riscv_of_processor_hartid() can be called for cpus that are disabled. Most callers of riscv_hartid_to_cpuid() already report custom errors where it falls, making this print superfluous in those case. In other places, the print adds nothing - see riscv_intc_init() for example. Fixes: 2ac874343749 ("RISC-V: split early & late of_node to hartid mapping") Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230629-paternity-grafted-b901b76d04a0@wendy Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-04riscv: Discard vector state on syscallsBjörn Töpel
The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-04riscv: vdso: include vdso/vsyscall.h for vdso_dataBen Dooks
Add include of <vdso/vsyscall.h> to pull in the defition of vdso_data to remove the following sparse warning: arch/riscv/kernel/vdso.c:39:18: warning: symbol 'vdso_data' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Link: https://lore.kernel.org/r/20230616114357.159601-1-ben.dooks@codethink.co.uk Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-01riscv: vector: clear V-reg in the first-use trapAndy Chiu
If there is no context switch happens after we enable V for a process, then we return to user space with whatever left on the CPU's V registers accessible to the process. The leaked data could belong to another process's V-context saved from last context switch, impacting process's confidentiality on the system. To prevent this from happening, we clear V registers by restoring zero'd V context after turining on V. Fixes: cd054837243b ("riscv: Allocate user's vector context in the first-use trap") Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230627015556.12329-2-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-01riscv: vector: only enable interrupts in the first-use trapAndy Chiu
The function irqentry_exit_to_user_mode() must be called with interrupt disabled. The caller of do_trap_insn_illegal() also assumes running without interrupts. So, we should turn off interrupts after riscv_v_first_use_handler() returns. Fixes: cd054837243b ("riscv: Allocate user's vector context in the first-use trap") Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230625155416.18629-1-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-01Merge patch series "riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION"Palmer Dabbelt
Jisheng Zhang <jszhang@kernel.org> says: When trying to run linux with various opensource riscv core on resource limited FPGA platforms, for example, those FPGAs with less than 16MB SDRAM, I want to save mem as much as possible. One of the major technologies is kernel size optimizations, I found that riscv does not currently support HAVE_LD_DEAD_CODE_DATA_ELIMINATION, which passes -fdata-sections, -ffunction-sections to CFLAGS and passes the --gc-sections flag to the linker. This not only benefits my case on FPGA but also benefits defconfigs. Here are some notable improvements from enabling this with defconfigs: nommu_k210_defconfig: text data bss dec hex 1112009 410288 59837 1582134 182436 before 962838 376656 51285 1390779 1538bb after rv32_defconfig: text data bss dec hex 8804455 2816544 290577 11911576 b5c198 before 8692295 2779872 288977 11761144 b375f8 after defconfig: text data bss dec hex 9438267 3391332 485333 13314932 cb2b74 before 9285914 3350052 483349 13119315 c82f53 after patch1 and patch2 are clean ups. patch3 fixes a typo. patch4 finally enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for riscv. * b4-shazam-merge: riscv: disable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for LLD riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION vmlinux.lds.h: use correct .init.data.* section name riscv: vmlinux-xip.lds.S: remove .alternative section riscv: move options to keep entries sorted riscv: Fix orphan section warnings caused by kernel/pi Link: https://lore.kernel.org/r/20230523165502.2592-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-30Merge tag 'trace-v6.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Add new feature to have function graph tracer record the return value. Adds a new option: funcgraph-retval ; when set, will show the return value of a function in the function graph tracer. - Also add the option: funcgraph-retval-hex where if it is not set, and the return value is an error code, then it will return the decimal of the error code, otherwise it still reports the hex value. - Add the file /sys/kernel/tracing/osnoise/per_cpu/cpu<cpu>/timerlat_fd That when a application opens it, it becomes the task that the timer lat tracer traces. The application can also read this file to find out how it's being interrupted. - Add the file /sys/kernel/tracing/available_filter_functions_addrs that works just the same as available_filter_functions but also shows the addresses of the functions like kallsyms, except that it gives the address of where the fentry/mcount jump/nop is. This is used by BPF to make it easier to attach BPF programs to ftrace hooks. - Replace strlcpy with strscpy in the tracing boot code. * tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Fix warnings when building htmldocs for function graph retval riscv: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL tracing/boot: Replace strlcpy with strscpy tracing/timerlat: Add user-space interface tracing/osnoise: Skip running osnoise if all instances are off tracing/osnoise: Switch from PF_NO_SETAFFINITY to migrate_disable ftrace: Show all functions with addresses in available_filter_functions_addrs selftests/ftrace: Add funcgraph-retval test case LoongArch: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL x86/ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL arm64: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL tracing: Add documentation for funcgraph-retval and funcgraph-retval-hex function_graph: Support recording and printing the return value of function fgraph: Add declaration of "struct fgraph_ret_regs"
2023-06-30Merge tag 'riscv-for-linus-6.5-mw1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for ACPI - Various cleanups to the ISA string parsing, including making them case-insensitive - Support for the vector extension - Support for independent irq/softirq stacks - Our CPU DT binding now has "unevaluatedProperties: false" * tag 'riscv-for-linus-6.5-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (78 commits) riscv: hibernate: remove WARN_ON in save_processor_state dt-bindings: riscv: cpus: switch to unevaluatedProperties: false dt-bindings: riscv: cpus: add a ref the common cpu schema riscv: stack: Add config of thread stack size riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK 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 perf: RISC-V: Limit the number of counters returned from SBI riscv: replace deprecated scall with ecall riscv: uprobes: Restore thread.bad_cause riscv: mm: try VMA lock-based page fault handling first riscv: mm: Pre-allocate PGD entries for vmalloc/modules area RISC-V: hwprobe: Expose Zba, Zbb, and Zbs RISC-V: Track ISA extensions per hart ...
2023-06-26Merge tag 'smp-core-2023-06-26' of ↵Linus Torvalds
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP updates from Thomas Gleixner: "A large update for SMP management: - Parallel CPU bringup The reason why people are interested in parallel bringup is to shorten the (kexec) reboot time of cloud servers to reduce the downtime of the VM tenants. The current fully serialized bringup does the following per AP: 1) Prepare callbacks (allocate, intialize, create threads) 2) Kick the AP alive (e.g. INIT/SIPI on x86) 3) Wait for the AP to report alive state 4) Let the AP continue through the atomic bringup 5) Let the AP run the threaded bringup to full online state There are two significant delays: #3 The time for an AP to report alive state in start_secondary() on x86 has been measured in the range between 350us and 3.5ms depending on vendor and CPU type, BIOS microcode size etc. #4 The atomic bringup does the microcode update. This has been measured to take up to ~8ms on the primary threads depending on the microcode patch size to apply. On a two socket SKL server with 56 cores (112 threads) the boot CPU spends on current mainline about 800ms busy waiting for the APs to come up and apply microcode. That's more than 80% of the actual onlining procedure. This can be reduced significantly by splitting the bringup mechanism into two parts: 1) Run the prepare callbacks and kick the AP alive for each AP which needs to be brought up. The APs wake up, do their firmware initialization and run the low level kernel startup code including microcode loading in parallel up to the first synchronization point. (#1 and #2 above) 2) Run the rest of the bringup code strictly serialized per CPU (#3 - #5 above) as it's done today. Parallelizing that stage of the CPU bringup might be possible in theory, but it's questionable whether required surgery would be justified for a pretty small gain. If the system is large enough the first AP is already waiting at the first synchronization point when the boot CPU finished the wake-up of the last AP. That reduces the AP bringup time on that SKL from ~800ms to ~80ms, i.e. by a factor ~10x. The actual gain varies wildly depending on the system, CPU, microcode patch size and other factors. There are some opportunities to reduce the overhead further, but that needs some deep surgery in the x86 CPU bringup code. For now this is only enabled on x86, but the core functionality obviously works for all SMP capable architectures. - Enhancements for SMP function call tracing so it is possible to locate the scheduling and the actual execution points. That allows to measure IPI delivery time precisely" * tag 'smp-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits) trace,smp: Add tracepoints for scheduling remotelly called functions trace,smp: Add tracepoints around remotelly called functions MAINTAINERS: Add CPU HOTPLUG entry x86/smpboot: Fix the parallel bringup decision x86/realmode: Make stack lock work in trampoline_compat() x86/smp: Initialize cpu_primary_thread_mask late cpu/hotplug: Fix off by one in cpuhp_bringup_mask() x86/apic: Fix use of X{,2}APIC_ENABLE in asm with older binutils x86/smpboot/64: Implement arch_cpuhp_init_parallel_bringup() and enable it x86/smpboot: Support parallel startup of secondary CPUs x86/smpboot: Implement a bit spinlock to protect the realmode stack x86/apic: Save the APIC virtual base address cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE x86/apic: Provide cpu_primary_thread mask x86/smpboot: Enable split CPU startup cpu/hotplug: Provide a split up CPUHP_BRINGUP mechanism cpu/hotplug: Reset task stack state in _cpu_up() cpu/hotplug: Remove unused state functions riscv: Switch to hotplug core state synchronization parisc: Switch to hotplug core state synchronization ...
2023-06-25riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATIONZhangjin Wu
Select CONFIG_HAVE_LD_DEAD_CODE_DATA_ELIMINATION for RISC-V, allowing the user to enable dead code elimination. In order for this to work, ensure that we keep the alternative table by annotating them with KEEP. This boots well on qemu with both rv32_defconfig & rv64 defconfig, but it only shrinks their builds by ~1%, a smaller config is thereforce customized to test this feature: | rv32 | rv64 --------|------------------------|--------------------- No DCE | 4460684 | 4893488 DCE | 3986716 | 4376400 Shrink | 473968 (~10.6%) | 517088 (~10.5%) The config used above only reserves necessary options to boot on qemu with serial console, more like the size-critical embedded scenes: - rv64 config: https://pastebin.com/crz82T0s - rv32 config: rv64 config + 32-bit.config Here is Jisheng's original commit-msg: When trying to run linux with various opensource riscv core on resource limited FPGA platforms, for example, those FPGAs with less than 16MB SDRAM, I want to save mem as much as possible. One of the major technologies is kernel size optimizations, I found that riscv does not currently support HAVE_LD_DEAD_CODE_DATA_ELIMINATION, which passes -fdata-sections, -ffunction-sections to CFLAGS and passes the --gc-sections flag to the linker. This not only benefits my case on FPGA but also benefits defconfigs. Here are some notable improvements from enabling this with defconfigs: nommu_k210_defconfig: text data bss dec hex 1112009 410288 59837 1582134 182436 before 962838 376656 51285 1390779 1538bb after rv32_defconfig: text data bss dec hex 8804455 2816544 290577 11911576 b5c198 before 8692295 2779872 288977 11761144 b375f8 after defconfig: text data bss dec hex 9438267 3391332 485333 13314932 cb2b74 before 9285914 3350052 483349 13119315 c82f53 after Signed-off-by: Zhangjin Wu <falcon@tinylab.org> Co-developed-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Guo Ren <guoren@kernel.org> Tested-by: Bin Meng <bmeng@tinylab.org> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> # build Link: https://lore.kernel.org/r/20230523165502.2592-5-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-25riscv: vmlinux-xip.lds.S: remove .alternative sectionJisheng Zhang
ALTERNATIVE mechanism can't work on XIP, and this is also reflected by below Kconfig dependency: RISCV_ALTERNATIVE ... depends on !XIP_KERNEL ... So there's no .alternative section at all for XIP case, remove it. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> # build Link: https://lore.kernel.org/r/20230523165502.2592-3-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-23riscv: hibernate: remove WARN_ON in save_processor_stateSong Shuai
During hibernation or restoration, freeze_secondary_cpus checks num_online_cpus via BUG_ON, and the subsequent save_processor_state also does the checking with WARN_ON. In the case of CONFIG_PM_SLEEP_SMP=n, freeze_secondary_cpus is not defined, but the sole possible condition to disable CONFIG_PM_SLEEP_SMP is !SMP where num_online_cpus is always 1. We also don't have to check it in save_processor_state. So remove the unnecessary checking in save_processor_state. Fixes: c0317210012e ("RISC-V: Add arch functions to support hibernation/suspend-to-disk") Signed-off-by: Song Shuai <songshuaishuai@tinylab.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230609075049.2651723-4-songshuaishuai@tinylab.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-23Merge patch series "riscv: Add independent irq/softirq stacks support"Palmer Dabbelt
guoren@kernel.org <guoren@kernel.org> says: From: Guo Ren <guoren@linux.alibaba.com> This patch series adds independent irq/softirq stacks to decrease the press of the thread stack. Also, add a thread STACK_SIZE config for users to adjust the proper size during compile time. * b4-shazam-merge: riscv: stack: Add config of thread stack size riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK Link: https://lore.kernel.org/r/20230614013018.2168426-1-guoren@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>
2023-06-22riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACKGuo Ren
Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config, and the irq and softirq use the same irq_stack of percpu. Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230614013018.2168426-3-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-22riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACKGuo Ren
Add independent irq stacks for percpu to prevent kernel stack overflows. It is also compatible with VMAP_STACK by arch_alloc_vmap_stack. Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Cc: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20230614013018.2168426-2-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-22riscv: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVALDonglin Peng
The previous patch ("function_graph: Support recording and printing the return value of function") has laid the groundwork for the for the funcgraph-retval, and this modification makes it available on the RISC-V platform. We introduce a new structure called fgraph_ret_regs for the RISC-V platform to hold return registers and the frame pointer. We then fill its content in the return_to_handler and pass its address to the function ftrace_return_to_handler to record the return value. Link: https://lore.kernel.org/linux-trace-kernel/a8d71b12259f90e7e63d0ea654fcac95b0232bbc.1680954589.git.pengdonglin@sangfor.com.cn Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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: split early & late of_node to hartid mappingConor Dooley
Some back and forth with Drew [1] about riscv_fill_hwcap() resulted in the realisation that it is not very useful to parse the DT & perform validation of riscv,isa every time we would like to get the id for a hart. Although it is no longer called in riscv_fill_hwcap(), riscv_of_processor_hartid() is called in several other places. Notably in setup_smp() it forms part of the logic for filling the mask of possible CPUs. Since a possible CPU must have passed this basic validation of riscv,isa, a repeat validation is not required. Rename riscv_of_processor_id() to riscv_early_of_processor_id(), which will be called from setup_smp() & introduce a new riscv_of_processor_id() which makes use of the pre-populated mask of possible cpus. Link: https://lore.kernel.org/linux-riscv/xvdswl3iyikwvamny7ikrxo2ncuixshtg3f6uucjahpe3xpc5c@ud4cz4fkg5dj/ [1] 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-glade-pastel-d8cbd9d9f3c6@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>
2023-06-20riscv: replace deprecated scall with ecallFangrui Song
scall is a deprecated alias for ecall. ecall is used in several places, so there is no assembler compatibility concern. Signed-off-by: Fangrui Song <maskray@google.com> Link: https://lore.kernel.org/r/20230423223210.126948-1-maskray@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-20riscv: uprobes: Restore thread.bad_causeTiezhu Yang
thread.bad_cause is saved in arch_uprobe_pre_xol(), it should be restored in arch_uprobe_{post,abort}_xol() accordingly, otherwise the save operation is meaningless, this change is similar with x86 and powerpc. Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Guo Ren <guoren@kernel.org> Fixes: 74784081aac8 ("riscv: Add uprobes supported") Link: https://lore.kernel.org/r/1682214146-3756-1-git-send-email-yangtiezhu@loongson.cn 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>