From 5689553076c4a67b83426b076082c63085b7567a Mon Sep 17 00:00:00 2001
From: Brian Gerst <brgerst@gmail.com>
Date: Mon, 19 Jan 2009 00:38:58 +0900
Subject: [PATCH] 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>
---
arch/x86/include/asm/pda.h | 2 +-
arch/x86/kernel/asm-offsets_64.c | 1 -
arch/x86/kernel/cpu/common.c | 4 ++--
arch/x86/kernel/entry_64.S | 14 +++++++-------
4 files changed, 10 insertions(+), 11 deletions(-)
diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h
index ae23deb99559..4527d70314d4 100644
--- a/arch/x86/include/asm/pda.h
+++ b/arch/x86/include/asm/pda.h
@@ -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 */
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index afda6deb8515..64c834a39aa8 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -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
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 06b6290088f4..e2323ecce1d3 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -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);
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 7c27da407da7..c52b60919163 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -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)