Commit 92d65b23 authored by Brian Gerst's avatar Brian Gerst Committed by Tejun Heo
Browse files

x86-64: Convert exception stacks to per-cpu 



Move the exception stacks to per-cpu, removing specific allocation code.

Signed-off-by: default avatarBrian Gerst <brgerst@gmail.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 26f80bd6

arch/x86/kernel/cpu/common.c

+8 −15
Original line number Diff line number Diff line
@@ -913,8 +913,9 @@ void __cpuinit pda_init(int cpu) 
	}

}



static char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +

				  DEBUG_STKSZ] __page_aligned_bss;

static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks

	[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ])

	__aligned(PAGE_SIZE);



extern asmlinkage void ignore_sysret(void);
@@ -972,15 +973,12 @@ void __cpuinit cpu_init(void) 
	struct tss_struct *t = &per_cpu(init_tss, cpu);

	struct orig_ist *orig_ist = &per_cpu(orig_ist, cpu);

	unsigned long v;

	char *estacks = NULL;

	struct task_struct *me;

	int i;



	/* CPU 0 is initialised in head64.c */

	if (cpu != 0)

		pda_init(cpu);

	else

		estacks = boot_exception_stacks;



	me = current;
@@ -1014,18 +1012,13 @@ void __cpuinit cpu_init(void) 
	 * set up and load the per-CPU TSS

	 */

	if (!orig_ist->ist[0]) {

		static const unsigned int order[N_EXCEPTION_STACKS] = {

		  [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,

		  [DEBUG_STACK - 1] = DEBUG_STACK_ORDER

		static const unsigned int sizes[N_EXCEPTION_STACKS] = {

		  [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,

		  [DEBUG_STACK - 1] = DEBUG_STKSZ

		};

		char *estacks = per_cpu(exception_stacks, cpu);

		for (v = 0; v < N_EXCEPTION_STACKS; v++) {

			if (cpu) {

				estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);

				if (!estacks)

					panic("Cannot allocate exception "

					      "stack %ld %d\n", v, cpu);

			}

			estacks += PAGE_SIZE << order[v];

			estacks += sizes[v];

			orig_ist->ist[v] = t->x86_tss.ist[v] =

					(unsigned long)estacks;

		}