kernel.git/arch/riscv/kernel/smpboot.c, branch linux-6.19.y

RISC-V: Enable HOTPLUG_PARALLEL for secondary CPUs

2025-11-19T16:19:27Z

The core kernel already supports parallel bringup of secondary CPUs (aka HOTPLUG_PARALLEL). The x86 and MIPS architectures already use HOTPLUG_PARALLEL and ARM is also moving toward it. On RISC-V, there is no arch specific global data accessed in the RISC-V secondary CPU bringup path so enabling HOTPLUG_PARALLEL for RISC-V would only require: 1) Providing RISC-V specific arch_cpuhp_kick_ap_alive() 2) Calling cpuhp_ap_sync_alive() from smp_callin() This patch is tested natively with OpenSBI on QEMU RV64 virt machine with 64 cores and also tested with KVM RISC-V guest with 32 VCPUs. Signed-off-by: Anup Patel Reviewed-by: Atish Patra Link: https://patch.msgid.link/20250905122512.71684-1-apatel@ventanamicro.com Signed-off-by: Paul Walmsley

riscv: print hartid on bringup

2025-04-01T07:03:03Z

Firmware randomly releases cores, so CPU numbers don't linearly map to hartids. When the system has an exception, we care more about hartids. Adding "dyndbg="file smpboot.c +p" loglevel=8" to the cmdline can output the hartid. Signed-off-by: Yunhui Cui Reviewed-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20250303083424.14309-1-cuiyunhui@bytedance.com Signed-off-by: Alexandre Ghiti

riscv: Call riscv_user_isa_enable() only on the boot hart

2024-10-05T15:51:15Z

Now that the [ms]envcfg CSR value is maintained per thread, not per hart, riscv_user_isa_enable() only needs to be called once during boot, to set the value for the init task. This also allows it to be marked as __init. Reviewed-by: Andrew Jones Reviewed-by: Conor Dooley Reviewed-by: Deepak Gupta Signed-off-by: Samuel Holland Reviewed-by: Charlie Jenkins Link: https://lore.kernel.org/r/20240814081126.956287-4-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt

Merge patch series "Add ACPI NUMA support for RISC-V"

2024-07-22T17:31:51Z

Haibo Xu says: This patch series enable RISC-V ACPI NUMA support which was based on the recently approved ACPI ECR[1]. Patch 1/4 add RISC-V specific acpi_numa.c file to parse NUMA information from SRAT and SLIT ACPI tables. Patch 2/4 add the common SRAT RINTC affinity structure handler. Patch 3/4 change the ACPI_NUMA to a hidden option since it would be selected by default on all supported platform. Patch 4/4 replace pr_info with pr_debug in arch_acpi_numa_init() to avoid potential boot noise on ACPI platforms that are not NUMA. Based-on: https://github.com/linux-riscv/linux-riscv/tree/for-next [1] https://drive.google.com/file/d/1YTdDx2IPm5IeZjAW932EYU-tUtgS08tX/view?usp=sharing Testing: Since the ACPI AIA/PLIC support patch set is still under upstream review, hence it is tested using the poll based HVC SBI console and RAM disk. 1) Build latest Qemu with the following patch backported https://github.com/vlsunil/qemu/commit/42bd4eeefd5d4410a68f02d54fee406d8a1269b0 2) Build latest EDK-II https://github.com/tianocore/edk2/blob/master/OvmfPkg/RiscVVirt/README.md 3) Build Linux with the following configs enabled CONFIG_RISCV_SBI_V01=y CONFIG_SERIAL_EARLYCON_RISCV_SBI=y CONFIG_NONPORTABLE=y CONFIG_HVC_RISCV_SBI=y CONFIG_NUMA=y CONFIG_ACPI_NUMA=y 4) Build buildroot rootfs.cpio 5) Launch the Qemu machine qemu-system-riscv64 -nographic \ -machine virt,pflash0=pflash0,pflash1=pflash1 -smp 4 -m 8G \ -blockdev node-name=pflash0,driver=file,read-only=on,filename=RISCV_VIRT_CODE.fd \ -blockdev node-name=pflash1,driver=file,filename=RISCV_VIRT_VARS.fd \ -object memory-backend-ram,size=4G,id=m0 \ -object memory-backend-ram,size=4G,id=m1 \ -numa node,memdev=m0,cpus=0-1,nodeid=0 \ -numa node,memdev=m1,cpus=2-3,nodeid=1 \ -numa dist,src=0,dst=1,val=30 \ -kernel linux/arch/riscv/boot/Image \ -initrd buildroot/output/images/rootfs.cpio \ -append "root=/dev/ram ro console=hvc0 earlycon=sbi" [ 0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x80000000-0x17fffffff] [ 0.000000] ACPI: SRAT: Node 1 PXM 1 [mem 0x180000000-0x27fffffff] [ 0.000000] NUMA: NODE_DATA [mem 0x17fe3bc40-0x17fe3cfff] [ 0.000000] NUMA: NODE_DATA [mem 0x27fff4c40-0x27fff5fff] ... [ 0.000000] ACPI: NUMA: SRAT: PXM 0 -> HARTID 0x0 -> Node 0 [ 0.000000] ACPI: NUMA: SRAT: PXM 0 -> HARTID 0x1 -> Node 0 [ 0.000000] ACPI: NUMA: SRAT: PXM 1 -> HARTID 0x2 -> Node 1 [ 0.000000] ACPI: NUMA: SRAT: PXM 1 -> HARTID 0x3 -> Node 1 * b4-shazam-merge: ACPI: NUMA: replace pr_info with pr_debug in arch_acpi_numa_init ACPI: NUMA: change the ACPI_NUMA to a hidden option ACPI: NUMA: Add handler for SRAT RINTC affinity structure ACPI: RISCV: Add NUMA support based on SRAT and SLIT Link: https://lore.kernel.org/r/cover.1718268003.git.haibo1.xu@intel.com Signed-off-by: Palmer Dabbelt

ACPI: RISCV: Add NUMA support based on SRAT and SLIT

2024-07-22T14:13:06Z

Add acpi_numa.c file to enable parse NUMA information from ACPI SRAT and SLIT tables. SRAT table provide CPUs(Hart) and memory nodes to proximity domain mapping, while SLIT table provide the distance metrics between proximity domains. Signed-off-by: Haibo Xu Reviewed-by: Sunil V L Reviewed-by: Hanjun Guo Link: https://lore.kernel.org/r/65dbad1fda08a32922c44886e4581e49b4a2fecc.1718268003.git.haibo1.xu@intel.com Signed-off-by: Palmer Dabbelt

riscv: smp: fail booting up smp if inconsistent vlen is detected

2024-05-30T21:33:05Z

Currently we only support Vector for SMP platforms, that is, all SMP cores have the same vlenb. If we happen to detect a mismatching vlen, it is better to just fail bootting it up to prevent further race/scheduling issues. Also, move .Lsecondary_park forward and chage `tail smp_callin` into a regular call in the early assembly. So a core would be parked right after a return from smp_callin. Note that a successful smp_callin does not return. Fixes: 7017858eb2d7 ("riscv: Introduce riscv_v_vsize to record size of Vector context") Reported-by: Conor Dooley Closes: https://lore.kernel.org/linux-riscv/20240228-vicinity-cornstalk-4b8eb5fe5730@spud/ Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Yunhui Cui Link: https://lore.kernel.org/r/20240510-zve-detection-v5-2-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt

Use bool value in set_cpu_online()

2024-05-22T23:12:52Z

The declaration of set_cpu_online() takes a bool value. So replace int here to make it consistent with the declaration. Signed-off-by: Zhao Ke Reviewed-by: Charlie Jenkins Link: https://lore.kernel.org/r/20240318065404.123668-1-ke.zhao@shingroup.cn Signed-off-by: Palmer Dabbelt

riscv: Flush the instruction cache during SMP bringup

2024-04-29T17:49:24Z

Instruction cache flush IPIs are sent only to CPUs in cpu_online_mask, so they will not target a CPU until it calls set_cpu_online() earlier in smp_callin(). As a result, if instruction memory is modified between the CPU coming out of reset and that point, then its instruction cache may contain stale data. Therefore, the instruction cache must be flushed after the set_cpu_online() synchronization point. Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable") Reviewed-by: Alexandre Ghiti Signed-off-by: Samuel Holland Link: https://lore.kernel.org/r/20240327045035.368512-2-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt

Merge tag 'riscv-for-linus-6.9-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2024-03-22T17:41:13Z

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 ...

smp: Consolidate smp_prepare_boot_cpu()

2024-03-04T11:01:54Z

There is no point in having seven architectures implementing the same empty stub. Provide a weak function in the init code and remove the stubs. This also allows to utilize the function on UP which is required to sanitize the per CPU handling on X86 UP. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20240304005104.567671691@linutronix.de