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x86-64: Move irqcount from PDA to per-cpu. 

tj: s/irqcount/irq_count/

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Brian Gerst 2009-01-19 00:38:58 +09:00 committed by Tejun Heo
parent 3d1e42a7cf
commit 5689553076
4 changed files with 10 additions and 11 deletions
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2
arch/x86/include/asm/pda.h
View File

@ -15,7 +15,7 @@ struct x8664_pda {
unsigned long unused2;
unsigned long unused3;
unsigned long unused4;
int irqcount; /* 32 Irq nesting counter. Starts -1 */
int unused5;
unsigned int unused6; /* 36 was cpunumber */
#ifdef CONFIG_CC_STACKPROTECTOR
unsigned long stack_canary; /* 40 stack canary value */

1
arch/x86/kernel/asm-offsets_64.c
View File

@ -49,7 +49,6 @@ int main(void)
BLANK();
#undef ENTRY
#define ENTRY(entry) DEFINE(pda_ ## entry, offsetof(struct x8664_pda, entry))
ENTRY(irqcount);
DEFINE(pda_size, sizeof(struct x8664_pda));
BLANK();
#undef ENTRY

4
arch/x86/kernel/cpu/common.c
View File

@ -893,6 +893,8 @@ DEFINE_PER_CPU(unsigned long, kernel_stack) =
(unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
EXPORT_PER_CPU_SYMBOL(kernel_stack);
DEFINE_PER_CPU(unsigned int, irq_count) = -1;
void __cpuinit pda_init(int cpu)
{
struct x8664_pda *pda = cpu_pda(cpu);
@ -903,8 +905,6 @@ void __cpuinit pda_init(int cpu)
load_pda_offset(cpu);
pda->irqcount = -1;
if (cpu != 0) {
if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
pda->nodenumber = cpu_to_node(cpu);

14
arch/x86/kernel/entry_64.S
View File

@ -337,12 +337,12 @@ ENTRY(save_args)
je 1f
SWAPGS
/*
* irqcount is used to check if a CPU is already on an interrupt stack
* irq_count is used to check if a CPU is already on an interrupt stack
* or not. While this is essentially redundant with preempt_count it is
* a little cheaper to use a separate counter in the PDA (short of
* moving irq_enter into assembly, which would be too much work)
*/
1: incl %gs:pda_irqcount
1: incl PER_CPU_VAR(irq_count)
jne 2f
popq_cfi %rax /* move return address... */
mov PER_CPU_VAR(irq_stack_ptr),%rsp
@ -837,7 +837,7 @@ common_interrupt:
ret_from_intr:
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
decl %gs:pda_irqcount
decl PER_CPU_VAR(irq_count)
leaveq
CFI_DEF_CFA_REGISTER rsp
CFI_ADJUST_CFA_OFFSET -8
@ -1260,14 +1260,14 @@ ENTRY(call_softirq)
CFI_REL_OFFSET rbp,0
mov %rsp,%rbp
CFI_DEF_CFA_REGISTER rbp
incl %gs:pda_irqcount
incl PER_CPU_VAR(irq_count)
cmove PER_CPU_VAR(irq_stack_ptr),%rsp
push %rbp # backlink for old unwinder
call __do_softirq
leaveq
CFI_DEF_CFA_REGISTER rsp
CFI_ADJUST_CFA_OFFSET -8
decl %gs:pda_irqcount
decl PER_CPU_VAR(irq_count)
ret
CFI_ENDPROC
END(call_softirq)
@ -1297,7 +1297,7 @@ ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
movq %rdi, %rsp # we don't return, adjust the stack frame
CFI_ENDPROC
DEFAULT_FRAME
11: incl %gs:pda_irqcount
11: incl PER_CPU_VAR(irq_count)
movq %rsp,%rbp
CFI_DEF_CFA_REGISTER rbp
cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp
@ -1305,7 +1305,7 @@ ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
call xen_evtchn_do_upcall
popq %rsp
CFI_DEF_CFA_REGISTER rsp
decl %gs:pda_irqcount
decl PER_CPU_VAR(irq_count)
jmp error_exit
CFI_ENDPROC
END(do_hypervisor_callback)