From 19f29aebd929c31c5cc901f38a9295617b602c38 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Sat, 18 Sep 2021 10:44:35 +0200 Subject: ARM: smp: Pass task to secondary_start_kernel This avoids needing to compute the task pointer in this function, which will no longer be possible once we move thread_info off the stack. Signed-off-by: Keith Packard Signed-off-by: Ard Biesheuvel Reviewed-by: Linus Walleij Tested-by: Amit Daniel Kachhap --- arch/arm/include/asm/smp.h | 3 ++- arch/arm/kernel/head-nommu.S | 1 + arch/arm/kernel/head.S | 5 +++-- arch/arm/kernel/smp.c | 8 ++++++-- 4 files changed, 12 insertions(+), 5 deletions(-) diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index 5d508f5d56c4..f16cbbd5cda4 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -48,7 +48,7 @@ extern void set_smp_ipi_range(int ipi_base, int nr_ipi); * Called from platform specific assembly code, this is the * secondary CPU entry point. */ -asmlinkage void secondary_start_kernel(void); +asmlinkage void secondary_start_kernel(struct task_struct *task); /* @@ -61,6 +61,7 @@ struct secondary_data { }; unsigned long swapper_pg_dir; void *stack; + struct task_struct *task; }; extern struct secondary_data secondary_data; extern void secondary_startup(void); diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S index 0fc814bbc34b..fadfee9e2b45 100644 --- a/arch/arm/kernel/head-nommu.S +++ b/arch/arm/kernel/head-nommu.S @@ -115,6 +115,7 @@ ENTRY(secondary_startup) ret r12 1: bl __after_proc_init ldr sp, [r7, #12] @ set up the stack pointer + ldr r0, [r7, #16] @ set up task pointer mov fp, #0 b secondary_start_kernel ENDPROC(secondary_startup) diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 29070eb8df7d..fa44e2d9f0b0 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -424,8 +424,9 @@ ENDPROC(secondary_startup) ENDPROC(secondary_startup_arm) ENTRY(__secondary_switched) - ldr_l r7, secondary_data + 12 @ get secondary_data.stack - mov sp, r7 + adr_l r7, secondary_data + 12 @ get secondary_data.stack + ldr sp, [r7] + ldr r0, [r7, #4] @ get secondary_data.task mov fp, #0 b secondary_start_kernel ENDPROC(__secondary_switched) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 842427ff2b3c..8979d548ec17 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -153,6 +153,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) secondary_data.pgdir = virt_to_phys(idmap_pgd); secondary_data.swapper_pg_dir = get_arch_pgd(swapper_pg_dir); #endif + secondary_data.task = idle; sync_cache_w(&secondary_data); /* @@ -375,9 +376,12 @@ void arch_cpu_idle_dead(void) */ __asm__("mov sp, %0\n" " mov fp, #0\n" + " mov r0, %1\n" " b secondary_start_kernel" : - : "r" (task_stack_page(current) + THREAD_SIZE - 8)); + : "r" (task_stack_page(current) + THREAD_SIZE - 8), + "r" (current) + : "r0"); } #endif /* CONFIG_HOTPLUG_CPU */ @@ -400,7 +404,7 @@ static void smp_store_cpu_info(unsigned int cpuid) * This is the secondary CPU boot entry. We're using this CPUs * idle thread stack, but a set of temporary page tables. */ -asmlinkage void secondary_start_kernel(void) +asmlinkage void secondary_start_kernel(struct task_struct *task) { struct mm_struct *mm = &init_mm; unsigned int cpu; -- cgit