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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 3d0cc6f..496f0a0 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -881,7 +881,13 @@
#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 @@
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);
}