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2025-03-18riscv: Add stimecmp save and restoreNick Hu
If the HW support the SSTC extension, we should save and restore the stimecmp register while cpu non retention suspend. Signed-off-by: Nick Hu <nick.hu@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20250219114135.27764-2-nick.hu@sifive.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2024-10-05riscv: Enable cbo.zero only when all harts support ZicbozSamuel Holland
Currently, we enable cbo.zero for usermode on each hart that supports the Zicboz extension. This means that the [ms]envcfg CSR value may differ between harts. Other features, such as pointer masking and CFI, require setting [ms]envcfg bits on a per-thread basis. The combination of these two adds quite some complexity and overhead to context switching, as we would need to maintain two separate masks for the per-hart and per-thread bits. Andrew Jones, who originally added Zicboz support, writes[1][2]: I've approached Zicboz the same way I would approach all extensions, which is to be per-hart. I'm not currently aware of a platform that is / will be composed of harts where some have Zicboz and others don't, but there's nothing stopping a platform like that from being built. So, how about we add code that confirms Zicboz is on all harts. If any hart does not have it, then we complain loudly and disable it on all the other harts. If it was just a hardware description bug, then it'll get fixed. If there's actually a platform which doesn't have Zicboz on all harts, then, when the issue is reported, we can decide to not support it, support it with defconfig, or support it under a Kconfig guard which must be enabled by the user. Let's follow his suggested solution and require the extension to be available on all harts, so the envcfg CSR value does not need to change when a thread migrates between harts. Since we are doing this for all extensions with fields in envcfg, the CSR itself only needs to be saved/ restored when it is present on all harts. This should not be a regression as no known hardware has asymmetric Zicboz support, but if anyone reports seeing the warning, we will re-evaluate our solution. Link: https://lore.kernel.org/linux-riscv/20240322-168f191eeb8479b2ea169a5e@orel/ [1] Link: https://lore.kernel.org/linux-riscv/20240323-28943722feb57a41fb0ff488@orel/ [2] Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Deepak Gupta <debug@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240814081126.956287-2-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-28riscv: Do not save the scratch CSR during suspendSamuel Holland
While the processor is executing kernel code, the value of the scratch CSR is always zero, so there is no need to save the value. Continue to write the CSR during the resume flow, so we do not rely on firmware to initialize it. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20240312195641.1830521-1-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-22Merge tag 'riscv-for-linus-6.9-mw2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for various vector-accelerated crypto routines - Hibernation is now enabled for portable kernel builds - mmap_rnd_bits_max is larger on systems with larger VAs - Support for fast GUP - Support for membarrier-based instruction cache synchronization - Support for the Andes hart-level interrupt controller and PMU - Some cleanups around unaligned access speed probing and Kconfig settings - Support for ACPI LPI and CPPC - Various cleanus related to barriers - A handful of fixes * tag 'riscv-for-linus-6.9-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (66 commits) riscv: Fix syscall wrapper for >word-size arguments crypto: riscv - add vector crypto accelerated AES-CBC-CTS crypto: riscv - parallelize AES-CBC decryption riscv: Only flush the mm icache when setting an exec pte riscv: Use kcalloc() instead of kzalloc() riscv/barrier: Add missing space after ',' riscv/barrier: Consolidate fence definitions riscv/barrier: Define RISCV_FULL_BARRIER riscv/barrier: Define __{mb,rmb,wmb} RISC-V: defconfig: Enable CONFIG_ACPI_CPPC_CPUFREQ cpufreq: Move CPPC configs to common Kconfig and add RISC-V ACPI: RISC-V: Add CPPC driver ACPI: Enable ACPI_PROCESSOR for RISC-V ACPI: RISC-V: Add LPI driver cpuidle: RISC-V: Move few functions to arch/riscv riscv: Introduce set_compat_task() in asm/compat.h riscv: Introduce is_compat_thread() into compat.h riscv: add compile-time test into is_compat_task() riscv: Replace direct thread flag check with is_compat_task() riscv: Improve arch_get_mmap_end() macro ...
2024-03-19cpuidle: RISC-V: Move few functions to arch/riscvSunil V L
To support ACPI Low Power Idle (LPI), few functions are required which are currently static functions in the DT based cpuidle driver. Hence, move them under arch/riscv so that ACPI driver also can use them. Since they are no longer static functions, append "riscv_" prefix to the function name. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20240118062930.245937-2-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-02-29riscv: Save/restore envcfg CSR during CPU suspendSamuel Holland
The value of the [ms]envcfg CSR is lost when entering a nonretentive idle state, so the CSR must be rewritten when resuming the CPU. Cc: <stable@vger.kernel.org> # v6.7+ Fixes: 43c16d51a19b ("RISC-V: Enable cbo.zero in usermode") Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20240228065559.3434837-4-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-11riscv: sbi: Introduce system suspend supportAndrew Jones
When the SUSP SBI extension is present it implies that the standard "suspend to RAM" type is available. Wire it up to the generic platform suspend support, also applying the already present support for non-retentive CPU suspend. When the kernel is built with CONFIG_SUSPEND, one can do 'echo mem > /sys/power/state' to suspend. Resumption will occur when a platform-specific wake-up event arrives. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Tested-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20231206110807.35882-4-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-29RISC-V: Change suspend_save_csrs and suspend_restore_csrs to public functionSia Jee Heng
Currently suspend_save_csrs() and suspend_restore_csrs() functions are statically defined in the suspend.c. Change the function's attribute to public so that the functions can be used by hibernation as well. Signed-off-by: Sia Jee Heng <jeeheng.sia@starfivetech.com> Reviewed-by: Ley Foon Tan <leyfoon.tan@starfivetech.com> Reviewed-by: Mason Huo <mason.huo@starfivetech.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230330064321.1008373-2-jeeheng.sia@starfivetech.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-10RISC-V: Add arch functions for non-retentive suspend entry/exitAnup Patel
The hart registers and CSRs are not preserved in non-retentative suspend state so we provide arch specific helper functions which will save/restore hart context upon entry/exit to non-retentive suspend state. These helper functions can be used by cpuidle drivers for non-retentive suspend entry/exit. Signed-off-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Guo Ren <guoren@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>