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

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
......@@ -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
......
......@@ -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;
......
......@@ -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 *);
......
......@@ -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
......
......@@ -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);
}
......
......@@ -106,7 +106,8 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
const struct stacktrace_ops *ops, void *data)
{
const unsigned cpu = get_cpu();
unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
unsigned long *irq_stack_end =
(unsigned long *)per_cpu(irq_stack_ptr, cpu);
unsigned used = 0;
struct thread_info *tinfo;
int graph = 0;
......@@ -160,23 +161,23 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
stack = (unsigned long *) estack_end[-2];
continue;
}
if (irqstack_end) {
unsigned long *irqstack;
irqstack = irqstack_end -
(IRQSTACKSIZE - 64) / sizeof(*irqstack);
if (irq_stack_end) {
unsigned long *irq_stack;
irq_stack = irq_stack_end -
(IRQ_STACK_SIZE - 64) / sizeof(*irq_stack);
if (stack >= irqstack && stack < irqstack_end) {
if (stack >= irq_stack && stack < irq_stack_end) {
if (ops->stack(data, "IRQ") < 0)
break;
bp = print_context_stack(tinfo, stack, bp,
ops, data, irqstack_end, &graph);
ops, data, irq_stack_end, &graph);
/*
* We link to the next stack (which would be
* the process stack normally) the last
* pointer (index -1 to end) in the IRQ stack:
*/
stack = (unsigned long *) (irqstack_end[-1]);
irqstack_end = NULL;
stack = (unsigned long *) (irq_stack_end[-1]);
irq_stack_end = NULL;
ops->stack(data, "EOI");
continue;
}
......@@ -199,10 +200,10 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *stack;
int i;
const int cpu = smp_processor_id();
unsigned long *irqstack_end =
(unsigned long *) (cpu_pda(cpu)->irqstackptr);
unsigned long *irqstack =
(unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
unsigned long *irq_stack_end =
(unsigned long *)(per_cpu(irq_stack_ptr, cpu));
unsigned long *irq_stack =
(unsigned long *)(per_cpu(irq_stack_ptr, cpu) - IRQ_STACK_SIZE);
/*
* debugging aid: "show_stack(NULL, NULL);" prints the
......@@ -218,9 +219,9 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
if (stack >= irqstack && stack <= irqstack_end) {
if (stack == irqstack_end) {
stack = (unsigned long *) (irqstack_end[-1]);
if (stack >= irq_stack && stack <= irq_stack_end) {
if (stack == irq_stack_end) {
stack = (unsigned long *) (irq_stack_end[-1]);
printk(" <EOI> ");
}
} else {
......
......@@ -345,7 +345,7 @@ ENTRY(save_args)
1: incl %gs:pda_irqcount
jne 2f
popq_cfi %rax /* move return address... */
mov %gs:pda_irqstackptr,%rsp
mov PER_CPU_VAR(irq_stack_ptr),%rsp
EMPTY_FRAME 0
pushq_cfi %rax /* ... to the new stack */
/*
......@@ -1261,7 +1261,7 @@ ENTRY(call_softirq)
mov %rsp,%rbp
CFI_DEF_CFA_REGISTER rbp
incl %gs:pda_irqcount
cmove %gs:pda_irqstackptr,%rsp
cmove PER_CPU_VAR(irq_stack_ptr),%rsp
push %rbp # backlink for old unwinder
call __do_softirq
leaveq
......@@ -1300,7 +1300,7 @@ ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
11: incl %gs:pda_irqcount
movq %rsp,%rbp
CFI_DEF_CFA_REGISTER rbp
cmovzq %gs:pda_irqstackptr,%rsp
cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp
pushq %rbp # backlink for old unwinder
call xen_evtchn_do_upcall
popq %rsp
......
......@@ -192,7 +192,10 @@ void __init setup_per_cpu_areas(void)
memcpy(ptr, __per_cpu_load, __per_cpu_end - __per_cpu_start);
per_cpu_offset(cpu) = ptr - __per_cpu_start;
per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
#ifdef CONFIG_X86_64
per_cpu(irq_stack_ptr, cpu) =
(char *)per_cpu(irq_stack, cpu) + IRQ_STACK_SIZE - 64;
/*
* CPU0 modified pda in the init data area, reload pda
* offset for CPU0 and clear the area for others.
......@@ -202,7 +205,6 @@ void __init setup_per_cpu_areas(void)
else
memset(cpu_pda(cpu), 0, sizeof(*cpu_pda(cpu)));
#endif
per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
DBG("PERCPU: cpu %4d %p\n", cpu, ptr);
}
......
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