Commit 1dc41e58 authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: Fixup 4K irq stacks. 



There was a clobber issue with the register we were saving
the stack in, so we switch to a register that we handle in
the clobber list properly already.

This also follows the x86 changes for allowing the softirq
checks from hardirq context.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent db9b99d4

arch/sh/kernel/irq.c

+18 −7
Original line number Diff line number Diff line
@@ -78,8 +78,8 @@ union irq_ctx { 
	u32			stack[THREAD_SIZE/sizeof(u32)];

};



static union irq_ctx *hardirq_ctx[NR_CPUS];

static union irq_ctx *softirq_ctx[NR_CPUS];

static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;

static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;

#endif



asmlinkage int do_IRQ(unsigned long r4, unsigned long r5,
@@ -136,17 +136,24 @@ asmlinkage int do_IRQ(unsigned long r4, unsigned long r5, 
		irqctx->tinfo.task = curctx->tinfo.task;

		irqctx->tinfo.previous_sp = current_stack_pointer;



		/*

		 * Copy the softirq bits in preempt_count so that the

		 * softirq checks work in the hardirq context.

		 */

		irqctx->tinfo.preempt_count =

			(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |

			(curctx->tinfo.preempt_count & SOFTIRQ_MASK);



		__asm__ __volatile__ (

			"mov	%0, r4		\n"

			"mov	r15, r9		\n"

			"mov	r15, r8		\n"

			"jsr	@%1		\n"

			/* swith to the irq stack */

			" mov	%2, r15		\n"

			/* restore the stack (ring zero) */

			"mov	r9, r15		\n"

			"mov	r8, r15		\n"

			: /* no outputs */

			: "r" (irq), "r" (generic_handle_irq), "r" (isp)

			/* XXX: A somewhat excessive clobber list? -PFM */

			: "memory", "r0", "r1", "r2", "r3", "r4",

			  "r5", "r6", "r7", "r8", "t", "pr"

		);
@@ -194,7 +201,7 @@ void irq_ctx_init(int cpu) 
	irqctx->tinfo.task		= NULL;

	irqctx->tinfo.exec_domain	= NULL;

	irqctx->tinfo.cpu		= cpu;

	irqctx->tinfo.preempt_count	= SOFTIRQ_OFFSET;

	irqctx->tinfo.preempt_count	= 0;

	irqctx->tinfo.addr_limit	= MAKE_MM_SEG(0);



	softirq_ctx[cpu] = irqctx;
@@ -240,10 +247,14 @@ asmlinkage void do_softirq(void) 
			"mov	r9, r15		\n"

			: /* no outputs */

			: "r" (__do_softirq), "r" (isp)

			/* XXX: A somewhat excessive clobber list? -PFM */

			: "memory", "r0", "r1", "r2", "r3", "r4",

			  "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"

		);



		/*

		 * Shouldnt happen, we returned above if in_interrupt():

		 */

		WARN_ON_ONCE(softirq_count());

	}



	local_irq_restore(flags);

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