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>

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)