From 2ffc48fc7071da4b2d881b0f21d37ed05feb697b Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Thu, 20 Jan 2022 01:09:17 -0800 Subject: RISC-V: Move spinwait booting method to its own config The spinwait booting method should only be used for platforms with older firmware without SBI HSM extension or M-mode firmware because spinwait method can't support cpu hotplug, kexec or sparse hartid. It is better to move the entire spinwait implementation to its own config which can be disabled if required. It is enabled by default to maintain backward compatibility and M-mode Linux. Reviewed-by: Anup Patel Signed-off-by: Atish Patra Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/Makefile | 3 ++- arch/riscv/kernel/cpu_ops.c | 8 ++++++++ arch/riscv/kernel/head.S | 8 ++++---- arch/riscv/kernel/head.h | 2 ++ 4 files changed, 16 insertions(+), 5 deletions(-) (limited to 'arch/riscv/kernel') diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 3397ddac1a30..612556faa527 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -43,7 +43,8 @@ obj-$(CONFIG_FPU) += fpu.o obj-$(CONFIG_SMP) += smpboot.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_SMP) += cpu_ops.o -obj-$(CONFIG_SMP) += cpu_ops_spinwait.o + +obj-$(CONFIG_RISCV_BOOT_SPINWAIT) += cpu_ops_spinwait.o obj-$(CONFIG_MODULES) += module.o obj-$(CONFIG_MODULE_SECTIONS) += module-sections.o diff --git a/arch/riscv/kernel/cpu_ops.c b/arch/riscv/kernel/cpu_ops.c index c1e30f403c3b..170d07e57721 100644 --- a/arch/riscv/kernel/cpu_ops.c +++ b/arch/riscv/kernel/cpu_ops.c @@ -15,7 +15,15 @@ const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init; extern const struct cpu_operations cpu_ops_sbi; +#ifdef CONFIG_RISCV_BOOT_SPINWAIT extern const struct cpu_operations cpu_ops_spinwait; +#else +const struct cpu_operations cpu_ops_spinwait = { + .name = "", + .cpu_prepare = NULL, + .cpu_start = NULL, +}; +#endif void __init cpu_set_ops(int cpuid) { diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index b0766f62bd73..2363b43312fc 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -259,7 +259,7 @@ pmp_done: li t0, SR_FS csrc CSR_STATUS, t0 -#ifdef CONFIG_SMP +#ifdef CONFIG_RISCV_BOOT_SPINWAIT li t0, CONFIG_NR_CPUS blt a0, t0, .Lgood_cores tail .Lsecondary_park @@ -285,7 +285,7 @@ pmp_done: beq t0, t1, .Lsecondary_start #endif /* CONFIG_XIP */ -#endif /* CONFIG_SMP */ +#endif /* CONFIG_RISCV_BOOT_SPINWAIT */ #ifdef CONFIG_XIP_KERNEL la sp, _end + THREAD_SIZE @@ -344,7 +344,7 @@ clear_bss_done: call soc_early_init tail start_kernel -#ifdef CONFIG_SMP +#if CONFIG_RISCV_BOOT_SPINWAIT .Lsecondary_start: /* Set trap vector to spin forever to help debug */ la a3, .Lsecondary_park @@ -371,7 +371,7 @@ clear_bss_done: fence tail .Lsecondary_start_common -#endif +#endif /* CONFIG_RISCV_BOOT_SPINWAIT */ END(_start_kernel) diff --git a/arch/riscv/kernel/head.h b/arch/riscv/kernel/head.h index 5393cca77790..726731ada534 100644 --- a/arch/riscv/kernel/head.h +++ b/arch/riscv/kernel/head.h @@ -16,7 +16,9 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa); asmlinkage void __init __copy_data(void); #endif +#ifdef CONFIG_RISCV_BOOT_SPINWAIT extern void *__cpu_spinwait_stack_pointer[]; extern void *__cpu_spinwait_task_pointer[]; +#endif #endif /* __ASM_HEAD_H */ -- cgit v1.2.3