Messages in this thread Patch in this message | | | From | Mark Rutland <> | Subject | [RFC PATCH 4/6] arm64: pass stack base to secondary_start_kernel | Date | Wed, 12 Jul 2017 23:33:01 +0100 |
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In subsequent patches, we'll want the base of the secondary stack in secondary_start_kernel.
Pass the stack base down, as we do in the primary path, and add the offset in secondary_start_kernel. Unfortunately, we can't encode STACK_START_SP in an add immediate, so use a mov immedaite, which has greater range.
This is far from a hot path, so the overhead shouldn't matter.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> --- arch/arm64/kernel/head.S | 3 ++- arch/arm64/kernel/smp.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index a58ecda..db77cac 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -613,7 +613,8 @@ __secondary_switched: adr_l x0, secondary_data ldr x1, [x0, #CPU_BOOT_STACK] // get secondary_data.stack - mov sp, x1 + mov x3, #THREAD_START_SP + add sp, x1, x3 ldr x2, [x0, #CPU_BOOT_TASK] msr tpidr_el1, x2 mov x29, #0 diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 6e0e16a..269c957 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -154,7 +154,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) * page tables. */ secondary_data.task = idle; - secondary_data.stack = task_stack_page(idle) + THREAD_START_SP; + secondary_data.stack = task_stack_page(idle); update_cpu_boot_status(CPU_MMU_OFF); __flush_dcache_area(&secondary_data, sizeof(secondary_data)); -- 1.9.1
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