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authorKumar Gala <galak@kernel.crashing.org>2008-04-28 16:21:22 +1000
committerPaul Mackerras <paulus@samba.org>2008-04-29 15:57:34 +1000
commit85218827cc4ca900867807f19345418164ffc108 (patch)
tree1813b7fadb7c077acd0ef62f57385b7424ca0121 /arch/powerpc/kernel/irq.c
parentdd18434ff0b7d9b9ad3d596985fc84b329d2f9a8 (diff)
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[POWERPC] Add IRQSTACKS support on ppc32
This makes it possible to use separate stacks for hard and soft IRQs on 32-bit powerpc as well as on 64-bit. The code for 32-bit is just the 32-bit analog of the 64-bit code. * Added allocation and initialization of the irq stacks. We limit the stacks to be in lowmem for ppc32. * Implemented ppc32 versions of call_do_softirq() and call_handle_irq() to switch the stack pointers * Reworked how we do stack overflow detection. We now keep around the limit of the stack in the thread_struct and compare against the limit to see if we've overflowed. We can now use this on ppc64 if desired. [ paulus@samba.org: Fixed bug on 6xx where we need to reload r9 with the thread_info pointer. ] Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/irq.c')
-rw-r--r--arch/powerpc/kernel/irq.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 425616f..2f73f70 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -307,6 +307,7 @@ void do_IRQ(struct pt_regs *regs)
if (curtp != irqtp) {
struct irq_desc *desc = irq_desc + irq;
void *handler = desc->handle_irq;
+ unsigned long saved_sp_limit = current->thread.ksp_limit;
if (handler == NULL)
handler = &__do_IRQ;
irqtp->task = curtp->task;
@@ -319,7 +320,10 @@ void do_IRQ(struct pt_regs *regs)
(irqtp->preempt_count & ~SOFTIRQ_MASK) |
(curtp->preempt_count & SOFTIRQ_MASK);
+ current->thread.ksp_limit = (unsigned long)irqtp +
+ _ALIGN_UP(sizeof(struct thread_info), 16);
call_handle_irq(irq, desc, irqtp, handler);
+ current->thread.ksp_limit = saved_sp_limit;
irqtp->task = NULL;
@@ -352,9 +356,7 @@ void __init init_IRQ(void)
{
if (ppc_md.init_IRQ)
ppc_md.init_IRQ();
-#ifdef CONFIG_PPC64
irq_ctx_init();
-#endif
}
@@ -383,11 +385,15 @@ void irq_ctx_init(void)
static inline void do_softirq_onstack(void)
{
struct thread_info *curtp, *irqtp;
+ unsigned long saved_sp_limit = current->thread.ksp_limit;
curtp = current_thread_info();
irqtp = softirq_ctx[smp_processor_id()];
irqtp->task = curtp->task;
+ current->thread.ksp_limit = (unsigned long)irqtp +
+ _ALIGN_UP(sizeof(struct thread_info), 16);
call_do_softirq(irqtp);
+ current->thread.ksp_limit = saved_sp_limit;
irqtp->task = NULL;
}