Commit 19f29aeb authored by Keith Packard's avatar Keith Packard Committed by Ard Biesheuvel
Browse files

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: default avatarKeith Packard <keithpac@amazon.com>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Tested-by: default avatarAmit Daniel Kachhap <amit.kachhap@arm.com>
parent dfbdcda2

arch/arm/include/asm/smp.h

+2 −1
Original line number Diff line number Diff line
@@ -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);

arch/arm/kernel/head-nommu.S

+1 −0
Original line number Diff line number Diff line
@@ -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)

arch/arm/kernel/head.S

+3 −2
Original line number Diff line number Diff line
@@ -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)

arch/arm/kernel/smp.c

+6 −2
Original line number Diff line number Diff line
@@ -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;