Commit 26f80bd6 authored by Brian Gerst's avatar Brian Gerst Committed by Tejun Heo
Browse files

x86-64: Convert irqstacks to per-cpu 



Move the irqstackptr variable from the PDA to per-cpu.  Make the
stacks themselves per-cpu, removing some specific allocation code.
Add a seperate flag (is_boot_cpu) to simplify the per-cpu boot
adjustments.

tj: * sprinkle some underbars around.

    * irq_stack_ptr is not used till traps_init(), no reason to
      initialize it early.  On SMP, just leaving it NULL till proper
      initialization in setup_per_cpu_areas() works.  Dropped
      is_boot_cpu and early irq_stack_ptr initialization.

    * do DECLARE/DEFINE_PER_CPU(char[IRQ_STACK_SIZE], irq_stack)
      instead of (char, irq_stack[IRQ_STACK_SIZE]).

Signed-off-by: default avatarBrian Gerst <brgerst@gmail.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 9eb912d1

arch/x86/include/asm/page_64.h

+2 −2
Original line number Diff line number Diff line
@@ -13,8 +13,8 @@ 
#define DEBUG_STACK_ORDER (EXCEPTION_STACK_ORDER + 1)

#define DEBUG_STKSZ (PAGE_SIZE << DEBUG_STACK_ORDER)



#define IRQSTACK_ORDER 2

#define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER)

#define IRQ_STACK_ORDER 2

#define IRQ_STACK_SIZE (PAGE_SIZE << IRQ_STACK_ORDER)



#define STACKFAULT_STACK 1

#define DOUBLEFAULT_STACK 2

arch/x86/include/asm/pda.h

+0 −1
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ struct x8664_pda { 
					/* gcc-ABI: this canary MUST be at

					   offset 40!!! */

#endif

	char *irqstackptr;

	short nodenumber;		/* number of current node (32k max) */

	short in_bootmem;		/* pda lives in bootmem */

	short isidle;

arch/x86/include/asm/processor.h

+3 −0
Original line number Diff line number Diff line
@@ -378,6 +378,9 @@ union thread_xstate { 


#ifdef CONFIG_X86_64

DECLARE_PER_CPU(struct orig_ist, orig_ist);



DECLARE_PER_CPU(char[IRQ_STACK_SIZE], irq_stack);

DECLARE_PER_CPU(char *, irq_stack_ptr);

#endif



extern void print_cpu_info(struct cpuinfo_x86 *);

arch/x86/kernel/asm-offsets_64.c

+0 −1
Original line number Diff line number Diff line
@@ -54,7 +54,6 @@ int main(void) 
	ENTRY(pcurrent); 

	ENTRY(irqcount);

	ENTRY(cpunumber);

	ENTRY(irqstackptr);

	DEFINE(pda_size, sizeof(struct x8664_pda));

	BLANK();

#undef ENTRY

arch/x86/kernel/cpu/common.c

+7 −12
Original line number Diff line number Diff line
@@ -881,7 +881,13 @@ __setup("clearcpuid=", setup_disablecpuid); 
#ifdef CONFIG_X86_64

struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };



static char boot_cpu_stack[IRQSTACKSIZE] __page_aligned_bss;

DEFINE_PER_CPU_PAGE_ALIGNED(char[IRQ_STACK_SIZE], irq_stack);

#ifdef CONFIG_SMP

DEFINE_PER_CPU(char *, irq_stack_ptr);	/* will be set during per cpu init */

#else

DEFINE_PER_CPU(char *, irq_stack_ptr) =

	per_cpu_var(irq_stack) + IRQ_STACK_SIZE - 64;

#endif



void __cpuinit pda_init(int cpu)

{
@@ -901,18 +907,7 @@ void __cpuinit pda_init(int cpu) 
	if (cpu == 0) {

		/* others are initialized in smpboot.c */

		pda->pcurrent = &init_task;

		pda->irqstackptr = boot_cpu_stack;

		pda->irqstackptr += IRQSTACKSIZE - 64;

	} else {

		if (!pda->irqstackptr) {

			pda->irqstackptr = (char *)

				__get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);

			if (!pda->irqstackptr)

				panic("cannot allocate irqstack for cpu %d",

				      cpu);

			pda->irqstackptr += IRQSTACKSIZE - 64;

		}



		if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)

			pda->nodenumber = cpu_to_node(cpu);

	}

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