- 06 Nov, 2023 8 commits
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Clément Léger authored
ENTRY()/END()/WEAK() macros are deprecated and we should make use of the new SYM_*() macros [1] for better annotation of symbols. Replace the deprecated ones with the new ones and fix wrong usage of END()/ENDPROC() to correctly describe the symbols. [1] https://docs.kernel.org/core-api/asm-annotations.htmlSigned-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20231024132655.730417-3-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Clément Léger authored
For the sake of coherency, use local labels in assembly when applicable. This also avoid kprobes being confused when applying a kprobe since the size of function is computed by checking where the next visible symbol is located. This might end up in computing some function size to be way shorter than expected and thus failing to apply kprobes to the specified offset. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20231024132655.730417-2-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Geert Uytterhoeven authored
When flashing loader.bin for K210 using kflash: [ERROR] This is an ELF file and cannot be programmed to flash directly: arch/riscv/boot/loader.bin Before, loader.bin relied on "OBJCOPYFLAGS := -O binary" in the main RISC-V Makefile to create a boot image with the right format. With this removed, the image is now created in the wrong (ELF) format. Fix this by adding an explicit rule. Fixes: 505b0295 ("riscv: Remove duplicate objcopy flag") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/1086025809583809538dfecaa899892218f44e7e.1698159066.git.geert+renesas@glider.beSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Alexandre Ghiti <alexghiti@rivosinc.com> says: This series optimizes the tlb flushes on riscv which used to simply flush the whole tlb whatever the size of the range to flush or the size of the stride. Patch 3 introduces a threshold that is microarchitecture specific and will very likely be modified by vendors, not sure though which mechanism we'll use to do that (dt? alternatives? vendor initialization code?). * b4-shazam-merge: riscv: Improve flush_tlb_kernel_range() riscv: Make __flush_tlb_range() loop over pte instead of flushing the whole tlb riscv: Improve flush_tlb_range() for hugetlb pages riscv: Improve tlb_flush() Link: https://lore.kernel.org/r/20231030133027.19542-1-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Alexandre Ghiti authored
This function used to simply flush the whole tlb of all harts, be more subtile and try to only flush the range. The problem is that we can only use PAGE_SIZE as stride since we don't know the size of the underlying mapping and then this function will be improved only if the size of the region to flush is < threshold * PAGE_SIZE. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Tested-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20231030133027.19542-5-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Alexandre Ghiti authored
Currently, when the range to flush covers more than one page (a 4K page or a hugepage), __flush_tlb_range() flushes the whole tlb. Flushing the whole tlb comes with a greater cost than flushing a single entry so we should flush single entries up to a certain threshold so that: threshold * cost of flushing a single entry < cost of flushing the whole tlb. Co-developed-by: Mayuresh Chitale <mchitale@ventanamicro.com> Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Tested-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20231030133027.19542-4-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Alexandre Ghiti authored
flush_tlb_range() uses a fixed stride of PAGE_SIZE and in its current form, when a hugetlb mapping needs to be flushed, flush_tlb_range() flushes the whole tlb: so set a stride of the size of the hugetlb mapping in order to only flush the hugetlb mapping. However, if the hugepage is a NAPOT region, all PTEs that constitute this mapping must be invalidated, so the stride size must actually be the size of the PTE. Note that THPs are directly handled by flush_pmd_tlb_range(). Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC Link: https://lore.kernel.org/r/20231030133027.19542-3-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Alexandre Ghiti authored
For now, tlb_flush() simply calls flush_tlb_mm() which results in a flush of the whole TLB. So let's use mmu_gather fields to provide a more fine-grained flush of the TLB. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC Link: https://lore.kernel.org/r/20231030133027.19542-2-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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- 05 Nov, 2023 17 commits
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Jisheng Zhang authored
Update T-Head memory type definitions according to C910 doc [1] For NC and IO, SH property isn't configurable, hardcoded as SH, so set SH for NOCACHE and IO. And also set bit[61](Bufferable) for NOCACHE according to the table 6.1 in the doc [1]. Link: https://github.com/T-head-Semi/openc910 [1] Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Guo Ren <guoren@kernel.org> Tested-by: Drew Fustini <dfustini@baylibre.com> Link: https://lore.kernel.org/r/20230912072510.2510-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Jisheng Zhang <jszhang@kernel.org> says: This series renews one of my last year RFC patch[1], tries to improve the vdso layout a bit. patch1 removes useless symbols patch2 merges .data section of vdso into .rodata because they are readonly patch3 is the real renew patch, it removes hardcoded 0x800 .text start addr. But I rewrite the commit msg per Andrew's suggestions and move move .note, .eh_frame_hdr, and .eh_frame between .rodata and .text to keep the actual code well away from the non-instruction data. * b4-shazam-merge: riscv: vdso.lds.S: remove hardcoded 0x800 .text start addr riscv: vdso.lds.S: merge .data section into .rodata section riscv: vdso.lds.S: drop __alt_start and __alt_end symbols Link: https://lore.kernel.org/linux-riscv/20221123161805.1579-1-jszhang@kernel.org/ [1] Link: https://lore.kernel.org/r/20230912072015.2424-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jisheng Zhang authored
I believe the hardcoded 0x800 and related comments come from the long history VDSO_TEXT_OFFSET in x86 vdso code, but commit 5b930493 ("x86 vDSO: generate vdso-syms.lds") and commit f6b46ebf ("x86 vDSO: new layout") removes the comment and hard coding for x86. Similar as x86 and other arch, riscv doesn't need the rigid layout using VDSO_TEXT_OFFSET since it "no longer matters to the kernel". so we could remove the hard coding now, and removing it brings a small vdso.so and aligns with other architectures. Also, having enough separation between data and text is important for I-cache, so similar as x86, move .note, .eh_frame_hdr, and .eh_frame between .rodata and .text. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Link: https://lore.kernel.org/r/20230912072015.2424-4-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jisheng Zhang authored
The .data section doesn't need to be separate from .rodata section, they are both readonly. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Link: https://lore.kernel.org/r/20230912072015.2424-3-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jisheng Zhang authored
These two symbols are not used, remove them. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Link: https://lore.kernel.org/r/20230912072015.2424-2-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Yunhui Cui authored
Add userland instruction dump and rename dump_kernel_instr() to dump_instr(). An example: [ 0.822439] Freeing unused kernel image (initmem) memory: 6916K [ 0.823817] Run /init as init process [ 0.839411] init[1]: unhandled signal 4 code 0x1 at 0x000000000005be18 in bb[10000+5fb000] [ 0.840751] CPU: 0 PID: 1 Comm: init Not tainted 5.14.0-rc4-00049-gbd644290aa72-dirty #187 [ 0.841373] Hardware name: , BIOS [ 0.841743] epc : 000000000005be18 ra : 0000000000079e74 sp : 0000003fffcafda0 [ 0.842271] gp : ffffffff816e9dc8 tp : 0000000000000000 t0 : 0000000000000000 [ 0.842947] t1 : 0000003fffc9fdf0 t2 : 0000000000000000 s0 : 0000000000000000 [ 0.843434] s1 : 0000000000000000 a0 : 0000003fffca0190 a1 : 0000003fffcafe18 [ 0.843891] a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000 [ 0.844357] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000 [ 0.844803] s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000 [ 0.845253] s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000 [ 0.845722] s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000 [ 0.846180] s11: 0000000000d144e0 t3 : 0000000000000000 t4 : 0000000000000000 [ 0.846616] t5 : 0000000000000000 t6 : 0000000000000000 [ 0.847204] status: 0000000200000020 badaddr: 00000000f0028053 cause: 0000000000000002 [ 0.848219] Code: f06f ff5f 3823 fa11 0113 fb01 2e23 0201 0293 0000 (8053) f002 [ 0.851016] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004 Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230912021349.28302-1-cuiyunhui@bytedance.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Nam Cao authored
Instructions can write to x0, so we should simulate these instructions normally. Currently, the kernel hangs if an instruction who writes to x0 is simulated. Fixes: c22b0bcb ("riscv: Add kprobes supported") Cc: stable@vger.kernel.org Signed-off-by: Nam Cao <namcaov@gmail.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Acked-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230829182500.61875-1-namcaov@gmail.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Nam Cao authored
uprobes expects is_trap_insn() to return true for any trap instructions, not just the one used for installing uprobe. The current default implementation only returns true for 16-bit c.ebreak if C extension is enabled. This can confuse uprobes if a 32-bit ebreak generates a trap exception from userspace: uprobes asks is_trap_insn() who says there is no trap, so uprobes assume a probe was there before but has been removed, and return to the trap instruction. This causes an infinite loop of entering and exiting trap handler. Instead of using the default implementation, implement this function speficially for riscv with checks for both ebreak and c.ebreak. Fixes: 74784081 ("riscv: Add uprobes supported") Signed-off-by: Nam Cao <namcaov@gmail.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230829083614.117748-1-namcaov@gmail.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Yu Chien Peter Lin <peterlin@andestech.com> says: This patchset enhances PTDUMP by providing additional information from pagetable entries. The first patch fixes the RSW field, while the second and third patches introduce the PBMT and NAPOT fields, respectively, for RV64 systems. * b4-shazam-merge: riscv: Introduce NAPOT field to PTDUMP riscv: Introduce PBMT field to PTDUMP riscv: Improve PTDUMP to show RSW with non-zero value Link: https://lore.kernel.org/r/20230921025022.3989723-1-peterlin@andestech.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Yu Chien Peter Lin authored
This patch introduces the NAPOT field to PTDUMP, allowing it to display the letter "N" for pages that have the 63rd bit set. Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230921025022.3989723-4-peterlin@andestech.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Yu Chien Peter Lin authored
This patch introduces the PBMT field to the PTDUMP, so it can display the memory attributes for NC or IO. Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230921025022.3989723-3-peterlin@andestech.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Yu Chien Peter Lin authored
RSW field can be used to encode 2 bits of software defined information. Currently, PTDUMP only prints "RSW" when its value is 1 or 3. To fix this issue and improve the debugging experience with PTDUMP, we redefine _PAGE_SPECIAL to its original value and use _PAGE_SOFT as the RSW mask, allow it to print the RSW with any non-zero value. This patch also removes the val from the struct prot_bits as it is no longer needed. Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230921025022.3989723-2-peterlin@andestech.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Conor Dooley authored
The CMO op macros initially used lower case, as the original iteration of the ALT_CMO_OP alternative stringified the first parameter to finalise the assembly for the standard variant. As a knock-on, the T-Head versions of these CMOs had to use mixed case defines. Commit dd23e953 ("RISC-V: replace cbom instructions with an insn-def") removed the asm construction with stringify, replacing it an insn-def macro, rending the lower-case surplus to requirements. As far as I can tell from a brief check, CBO_zero does not see similar use and didn't require the mixed case define in the first place. Replace the lower case characters now for consistency with other insn-def macros in the standard and T-Head forms, and adjust the callsites. Suggested-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230915-aloe-dollar-994937477776@spudSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jisheng Zhang authored
If misaligned_access_speed percpu var isn't so called "HWPROBE MISALIGNED UNKNOWN", it means the probe has happened(this is possible for example, hotplug off then hotplug on one cpu), and the percpu var has been set, don't probe again in this case. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Fixes: 584ea656 ("RISC-V: Probe for unaligned access speed") Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230912154040.3306-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jinyu Tang authored
If these config not set, mmc can't run for jh7110, rootfs can't be found when using SD card. So set CONFIG_MMC_DW=y like arm64 defconfig, and set CONFIG_MMC_DW_STARFIVE=y for starfive. Then starfive vf2 board can start SD card rootfs with mainline defconfig and dtb. Signed-off-by: Jinyu Tang <tangjinyu@tinylab.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230912133128.5247-1-tangjinyu@tinylab.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Haorong Lu authored
In the current riscv implementation, blocking syscalls like read() may not correctly restart after being interrupted by ptrace. This problem arises when the syscall restart process in arch_do_signal_or_restart() is bypassed due to changes to the regs->cause register, such as an ebreak instruction. Steps to reproduce: 1. Interrupt the tracee process with PTRACE_SEIZE & PTRACE_INTERRUPT. 2. Backup original registers and instruction at new_pc. 3. Change pc to new_pc, and inject an instruction (like ebreak) to this address. 4. Resume with PTRACE_CONT and wait for the process to stop again after executing ebreak. 5. Restore original registers and instructions, and detach from the tracee process. 6. Now the read() syscall in tracee will return -1 with errno set to ERESTARTSYS. Specifically, during an interrupt, the regs->cause changes from EXC_SYSCALL to EXC_BREAKPOINT due to the injected ebreak, which is inaccessible via ptrace so we cannot restore it. This alteration breaks the syscall restart condition and ends the read() syscall with an ERESTARTSYS error. According to include/linux/errno.h, it should never be seen by user programs. X86 can avoid this issue as it checks the syscall condition using a register (orig_ax) exposed to user space. Arm64 handles syscall restart before calling get_signal, where it could be paused and inspected by ptrace/debugger. This patch adjusts the riscv implementation to arm64 style, which also checks syscall using a kernel register (syscallno). It ensures the syscall restart process is not bypassed when changes to the cause register occur, providing more consistent behavior across various architectures. For a simplified reproduction program, feel free to visit: https://github.com/ancientmodern/riscv-ptrace-bug-demo. Signed-off-by: Haorong Lu <ancientmodern4@gmail.com> Link: https://lore.kernel.org/r/20230803224458.4156006-1-ancientmodern4@gmail.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Clément Léger <cleger@rivosinc.com> says: Since commit 61cadb9 ("Provide new description of misaligned load/store behavior compatible with privileged architecture.") in the RISC-V ISA manual, it is stated that misaligned load/store might not be supported. However, the RISC-V kernel uABI describes that misaligned accesses are supported. In order to support that, this series adds support for S-mode handling of misaligned accesses as well support for prctl(PR_UNALIGN). Handling misaligned access in kernel allows for a finer grain control of the misaligned accesses behavior, and thanks to the prctl() call, can allow disabling misaligned access emulation to generate SIGBUS. User space can then optimize its software by removing such access based on SIGBUS generation. This series is useful when using a SBI implementation that does not handle misaligned traps as well as detecting misaligned accesses generated by userspace application using the prctrl(PR_SET_UNALIGN) feature. This series can be tested using the spike simulator[1] and a modified openSBI version[2] which allows to always delegate misaligned load/store to S-mode. A test[3] that exercise various instructions/registers can be executed to verify the unaligned access support. [1] https://github.com/riscv-software-src/riscv-isa-sim [2] https://github.com/rivosinc/opensbi/tree/dev/cleger/no_misaligned [3] https://github.com/clementleger/unaligned_test * b4-shazam-merge: riscv: add support for PR_SET_UNALIGN and PR_GET_UNALIGN riscv: report misaligned accesses emulation to hwprobe riscv: annotate check_unaligned_access_boot_cpu() with __init riscv: add support for sysctl unaligned_enabled control riscv: add floating point insn support to misaligned access emulation riscv: report perf event for misaligned fault riscv: add support for misaligned trap handling in S-mode riscv: remove unused functions in traps_misaligned.c Link: https://lore.kernel.org/r/20231004151405.521596-1-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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- 02 Nov, 2023 5 commits
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Andrew Jones authored
A hwprobe pair key is signed, but the hwprobe vDSO function was only checking that the upper bound was valid. In order to help avoid this type of problem in the future, and in anticipation of this check becoming more complicated with sparse keys, introduce and use a "key is valid" predicate function for the check. Fixes: aa5af0aa ("RISC-V: Add hwprobe vDSO function and data") Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20231010165101.14942-2-ajones@ventanamicro.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Lad Prabhakar authored
Enable the configs required by the below IP blocks which are present on RZ/Five SoC: * ADC * CANFD * DMAC * eMMC/SDHI * OSTM * RAVB (+ Micrel PHY) * RIIC * RSPI * SSI (Sound+WM8978 codec) * Thermal * USB (PHY/RESET/OTG) Along with the above some core configs are enabled too, -> CPU frequency scaling as RZ/Five does support this. -> MTD is enabled as RSPI can be connected to flash chips -> Enabled I2C chardev so that it enables userspace to read/write i2c devices (similar to arm64) -> Thermal configs as RZ/Five SoC does have thermal unit -> GPIO regulator as we might have IP blocks for which voltage levels are controlled by GPIOs -> OTG configs as RZ/Five USB can support host/function -> Gadget configs so that we can test USB function (as done in arm64 all the gadget configs are enabled) Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20230929000704.53217-6-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Sami Tolvanen <samitolvanen@google.com> says: This series adds Shadow Call Stack (SCS) support for RISC-V. SCS uses compiler instrumentation to store return addresses in a separate shadow stack to protect them against accidental or malicious overwrites. More information about SCS can be found here: https://clang.llvm.org/docs/ShadowCallStack.html Patch 1 is from Deepak, and it simplifies VMAP_STACK overflow handling by adding support for accessing per-CPU variables directly in assembly. The patch is included in this series to make IRQ stack switching cleaner with SCS, and I've simply rebased it and fixed a couple of minor issues. Patch 2 uses this functionality to clean up the stack switching by moving duplicate code into a single function. On RISC-V, the compiler uses the gp register for storing the current shadow call stack pointer, which is incompatible with global pointer relaxation. Patch 3 moves global pointer loading into a macro that can be easily disabled with SCS. Patch 4 implements SCS register loading and switching, and allows the feature to be enabled, and patch 5 adds separate per-CPU IRQ shadow call stacks when CONFIG_IRQ_STACKS is enabled. Patch 6 fixes the backward-edge CFI test in lkdtm for RISC-V. Note that this series requires Clang 17. Earlier Clang versions support SCS on RISC-V, but use the x18 register instead of gp, which isn't ideal. gcc has SCS support for arm64, but I'm not aware of plans to support RISC-V. Once the Zicfiss extension is ratified, it's probably preferable to use hardware-backed shadow stacks instead of SCS on hardware that supports the extension, and we may want to consider implementing CONFIG_DYNAMIC_SCS to patch between the implementation at runtime (similarly to the arm64 implementation, which switches to SCS when hardware PAC support isn't available). * b4-shazam-merge: lkdtm: Fix CFI_BACKWARD on RISC-V riscv: Use separate IRQ shadow call stacks riscv: Implement Shadow Call Stack riscv: Move global pointer loading to a macro riscv: Deduplicate IRQ stack switching riscv: VMAP_STACK overflow detection thread-safe Link: https://lore.kernel.org/r/20230927224757.1154247-8-samitolvanen@google.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
This fixes an encoding issue with T-Head's dcache.cva and fixes the comment about the T-Head encodings. The first of these was a fix and got picked up earlier, I'm merging the second on top of it as they touch the same comment. * b4-shazam-merge: riscv: errata: prefix T-Head mnemonics with th. riscv: errata: fix T-Head dcache.cva encoding Link: https://lore.kernel.org/r/20230827090813.1353-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Icenowy Zheng authored
T-Head now maintains some specification for their extended instructions at [1], in which all instructions are prefixed "th.". Follow this practice in the kernel comments. Link: https://github.com/T-head-Semi/thead-extension-spec [1] Signed-off-by: Icenowy Zheng <uwu@icenowy.me> Reviewed-by: Guo Ren <guoren@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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- 01 Nov, 2023 10 commits
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Clément Léger authored
Now that trap support is ready to handle misalignment errors in S-mode, allow the user to control the behavior of misaligned accesses using prctl(PR_SET_UNALIGN). Add an align_ctl flag in thread_struct which will be used to determine if we should SIGBUS the process or not on such fault. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-9-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Clément Léger authored
hwprobe provides a way to report if misaligned access are emulated. In order to correctly populate that feature, we can check if it actually traps when doing a misaligned access. This can be checked using an exception table entry which will actually be used when a misaligned access is done from kernel mode. Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-8-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Clément Léger authored
This function is solely called as an initcall, thus annotate it with __init. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-7-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Clément Léger authored
This sysctl tuning option allows the user to disable misaligned access handling globally on the system. This will also be used by misaligned detection code to temporarily disable misaligned access handling. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-6-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Clément Léger authored
This support is partially based of openSBI misaligned emulation floating point instruction support. It provides support for the existing floating point instructions (both for 32/64 bits as well as compressed ones). Since floating point registers are not part of the pt_regs struct, we need to modify them directly using some assembly. We also dirty the pt_regs status in case we modify them to be sure context switch will save FP state. With this support, Linux is on par with openSBI support. Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-5-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Clément Léger authored
Add missing calls to account for misaligned fault event using perf_sw_event(). Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-4-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Clément Léger authored
Misalignment trap handling is only supported for M-mode and uses direct accesses to user memory. In S-mode, when handling usermode fault, this requires to use the get_user()/put_user() accessors. Implement load_u8(), store_u8() and get_insn() using these accessors for userspace and direct text access for kernel. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-3-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Clément Léger authored
Replace macros by the only two function calls that are done from this file, store_u8() and load_u8(). Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-2-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Sunil V L <sunilvl@ventanamicro.com> says: This series is a set of patches which were originally part of RFC v1 series [1] to add ACPI support in RISC-V interrupt controllers. Since these patches are independent of the interrupt controllers, creating this new series which helps to merge instead of waiting for big series. This set of patches primarily adds support below ECR [2] which is approved by the ASWG and adds below features. - Get CBO block sizes from RHCT on ACPI based systems. Additionally, the series contains a patch to improve acpi_os_ioremap(). [1] - https://lore.kernel.org/lkml/20230803175202.3173957-1-sunilvl@ventanamicro.com/ [2] - https://drive.google.com/file/d/1sKbOa8m1UZw1JkquZYe3F1zQBN1xXsaf/view?usp=sharing * b4-shazam-merge: RISC-V: cacheflush: Initialize CBO variables on ACPI systems RISC-V: ACPI: RHCT: Add function to get CBO block sizes RISC-V: ACPI: Update the return value of acpi_get_rhct() RISC-V: ACPI: Enhance acpi_os_ioremap with MMIO remapping Link: https://lore.kernel.org/r/20231018124007.1306159-1-sunilvl@ventanamicro.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Nam Cao authored
The interrupt entries are expected to be in the .irqentry.text section. For example, for kprobes to work properly, exception code cannot be probed; this is ensured by blacklisting addresses in the .irqentry.text section. Fixes: 7db91e57 ("RISC-V: Task implementation") Signed-off-by: Nam Cao <namcaov@gmail.com> Link: https://lore.kernel.org/r/20230821145708.21270-1-namcaov@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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