kernel-xen/xen3-x86-Unify-fixup_irqs-for-32-bit-and-64-bit-kernels.patch

From: Suresh Siddha <suresh.b.siddha@intel.com>
Subject: x86: Unify fixup_irqs() for 32-bit and 64-bit kernels
References: bnc#558247
Patch-mainline: Yes

Commit 7a7732bc0f7c46f217dbec723f25366b6285cc42 upstream.

There is no reason to have different fixup_irqs() for 32-bit
and 64-bit kernels. Unify by using the superior 64-bit version for
both the kernels.
    
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Rafael J. Wysocki <rjw@suse.de>
Automatically created from "patches.arch/x86-Unify-fixup_irqs-for-32-bit-and-64-bit-kernels.patch" by xen-port-patches.py

--- sle11sp1-2010-01-27.orig/arch/x86/kernel/irq-xen.c	2009-12-18 09:59:05.000000000 +0100
+++ sle11sp1-2010-01-27/arch/x86/kernel/irq-xen.c	2010-01-07 10:30:58.000000000 +0100
@@ -286,3 +286,62 @@ void smp_generic_interrupt(struct pt_reg
 	set_irq_regs(old_regs);
 }
 #endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
+void fixup_irqs(void)
+{
+	unsigned int irq;
+	static int warned;
+	struct irq_desc *desc;
+
+	for_each_irq_desc(irq, desc) {
+		int break_affinity = 0;
+		int set_affinity = 1;
+		const struct cpumask *affinity;
+
+		if (!desc)
+			continue;
+		if (irq == 2)
+			continue;
+
+		/* interrupt's are disabled at this point */
+		spin_lock(&desc->lock);
+
+		affinity = desc->affinity;
+		if (!irq_has_action(irq) ||
+		    cpumask_equal(affinity, cpu_online_mask)) {
+			spin_unlock(&desc->lock);
+			continue;
+		}
+
+		if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
+			break_affinity = 1;
+			affinity = cpu_all_mask;
+		}
+
+		if (desc->chip->mask)
+			desc->chip->mask(irq);
+
+		if (desc->chip->set_affinity)
+			desc->chip->set_affinity(irq, affinity);
+		else if (!(warned++))
+			set_affinity = 0;
+
+		if (desc->chip->unmask)
+			desc->chip->unmask(irq);
+
+		spin_unlock(&desc->lock);
+
+		if (break_affinity && set_affinity)
+			/*printk("Broke affinity for irq %i\n", irq)*/;
+		else if (!set_affinity)
+			printk("Cannot set affinity for irq %i\n", irq);
+	}
+
+	/* That doesn't seem sufficient.  Give it 1ms. */
+	local_irq_enable();
+	mdelay(1);
+	local_irq_disable();
+}
+#endif
--- sle11sp1-2010-01-27.orig/arch/x86/kernel/irq_32-xen.c	2009-11-06 10:52:22.000000000 +0100
+++ /dev/null	1970-01-01 00:00:00.000000000 +0000
@@ -1,258 +0,0 @@
-/*
- *	Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
- *
- * This file contains the lowest level x86-specific interrupt
- * entry, irq-stacks and irq statistics code. All the remaining
- * irq logic is done by the generic kernel/irq/ code and
- * by the x86-specific irq controller code. (e.g. i8259.c and
- * io_apic.c.)
- */
-
-#include <linux/module.h>
-#include <linux/seq_file.h>
-#include <linux/interrupt.h>
-#include <linux/kernel_stat.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <linux/delay.h>
-#include <linux/uaccess.h>
-#include <linux/percpu.h>
-
-#include <asm/apic.h>
-
-DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
-EXPORT_PER_CPU_SYMBOL(irq_stat);
-
-DEFINE_PER_CPU(struct pt_regs *, irq_regs);
-EXPORT_PER_CPU_SYMBOL(irq_regs);
-
-#ifdef CONFIG_DEBUG_STACKOVERFLOW
-/* Debugging check for stack overflow: is there less than 1KB free? */
-static int check_stack_overflow(void)
-{
-	long sp;
-
-	__asm__ __volatile__("andl %%esp,%0" :
-			     "=r" (sp) : "0" (THREAD_SIZE - 1));
-
-	return sp < (sizeof(struct thread_info) + STACK_WARN);
-}
-
-static void print_stack_overflow(void)
-{
-	printk(KERN_WARNING "low stack detected by irq handler\n");
-	dump_stack();
-}
-
-#else
-static inline int check_stack_overflow(void) { return 0; }
-static inline void print_stack_overflow(void) { }
-#endif
-
-#ifdef CONFIG_4KSTACKS
-/*
- * per-CPU IRQ handling contexts (thread information and stack)
- */
-union irq_ctx {
-	struct thread_info      tinfo;
-	u32                     stack[THREAD_SIZE/sizeof(u32)];
-} __attribute__((aligned(PAGE_SIZE)));
-
-static DEFINE_PER_CPU(union irq_ctx *, hardirq_ctx);
-static DEFINE_PER_CPU(union irq_ctx *, softirq_ctx);
-
-static DEFINE_PER_CPU_PAGE_ALIGNED(union irq_ctx, hardirq_stack);
-static DEFINE_PER_CPU_PAGE_ALIGNED(union irq_ctx, softirq_stack);
-
-static void call_on_stack(void *func, void *stack)
-{
-	asm volatile("xchgl	%%ebx,%%esp	\n"
-		     "call	*%%edi		\n"
-		     "movl	%%ebx,%%esp	\n"
-		     : "=b" (stack)
-		     : "0" (stack),
-		       "D"(func)
-		     : "memory", "cc", "edx", "ecx", "eax");
-}
-
-static inline int
-execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq)
-{
-	union irq_ctx *curctx, *irqctx;
-	u32 *isp, arg1, arg2;
-
-	curctx = (union irq_ctx *) current_thread_info();
-	irqctx = __get_cpu_var(hardirq_ctx);
-
-	/*
-	 * this is where we switch to the IRQ stack. However, if we are
-	 * already using the IRQ stack (because we interrupted a hardirq
-	 * handler) we can't do that and just have to keep using the
-	 * current stack (which is the irq stack already after all)
-	 */
-	if (unlikely(curctx == irqctx))
-		return 0;
-
-	/* build the stack frame on the IRQ stack */
-	isp = (u32 *) ((char *)irqctx + sizeof(*irqctx));
-	irqctx->tinfo.task = curctx->tinfo.task;
-	irqctx->tinfo.previous_esp = 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);
-
-	if (unlikely(overflow))
-		call_on_stack(print_stack_overflow, isp);
-
-	asm volatile("xchgl	%%ebx,%%esp	\n"
-		     "call	*%%edi		\n"
-		     "movl	%%ebx,%%esp	\n"
-		     : "=a" (arg1), "=d" (arg2), "=b" (isp)
-		     :  "0" (irq),   "1" (desc),  "2" (isp),
-			"D" (desc->handle_irq)
-		     : "memory", "cc", "ecx");
-	return 1;
-}
-
-/*
- * allocate per-cpu stacks for hardirq and for softirq processing
- */
-void __cpuinit irq_ctx_init(int cpu)
-{
-	union irq_ctx *irqctx;
-
-	if (per_cpu(hardirq_ctx, cpu))
-		return;
-
-	irqctx = &per_cpu(hardirq_stack, cpu);
-	irqctx->tinfo.task		= NULL;
-	irqctx->tinfo.exec_domain	= NULL;
-	irqctx->tinfo.cpu		= cpu;
-	irqctx->tinfo.preempt_count	= HARDIRQ_OFFSET;
-	irqctx->tinfo.addr_limit	= MAKE_MM_SEG(0);
-
-	per_cpu(hardirq_ctx, cpu) = irqctx;
-
-	irqctx = &per_cpu(softirq_stack, cpu);
-	irqctx->tinfo.task		= NULL;
-	irqctx->tinfo.exec_domain	= NULL;
-	irqctx->tinfo.cpu		= cpu;
-	irqctx->tinfo.preempt_count	= 0;
-	irqctx->tinfo.addr_limit	= MAKE_MM_SEG(0);
-
-	per_cpu(softirq_ctx, cpu) = irqctx;
-
-	printk(KERN_DEBUG "CPU %u irqstacks, hard=%p soft=%p\n",
-	       cpu, per_cpu(hardirq_ctx, cpu),  per_cpu(softirq_ctx, cpu));
-}
-
-void irq_ctx_exit(int cpu)
-{
-	per_cpu(hardirq_ctx, cpu) = NULL;
-}
-
-asmlinkage void do_softirq(void)
-{
-	unsigned long flags;
-	struct thread_info *curctx;
-	union irq_ctx *irqctx;
-	u32 *isp;
-
-	if (in_interrupt())
-		return;
-
-	local_irq_save(flags);
-
-	if (local_softirq_pending()) {
-		curctx = current_thread_info();
-		irqctx = __get_cpu_var(softirq_ctx);
-		irqctx->tinfo.task = curctx->task;
-		irqctx->tinfo.previous_esp = current_stack_pointer;
-
-		/* build the stack frame on the softirq stack */
-		isp = (u32 *) ((char *)irqctx + sizeof(*irqctx));
-
-		call_on_stack(__do_softirq, isp);
-		/*
-		 * Shouldnt happen, we returned above if in_interrupt():
-		 */
-		WARN_ON_ONCE(softirq_count());
-	}
-
-	local_irq_restore(flags);
-}
-
-#else
-static inline int
-execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) { return 0; }
-#endif
-
-bool handle_irq(unsigned irq, struct pt_regs *regs)
-{
-	struct irq_desc *desc;
-	int overflow;
-
-	overflow = check_stack_overflow();
-
-	desc = irq_to_desc(irq);
-	if (unlikely(!desc))
-		return false;
-
-	if (!execute_on_irq_stack(overflow, desc, irq)) {
-		if (unlikely(overflow))
-			print_stack_overflow();
-		desc->handle_irq(irq, desc);
-	}
-
-	return true;
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
-void fixup_irqs(void)
-{
-	unsigned int irq;
-	struct irq_desc *desc;
-
-	for_each_irq_desc(irq, desc) {
-		const struct cpumask *affinity;
-
-		if (!desc)
-			continue;
-		if (irq == 2)
-			continue;
-
-		affinity = desc->affinity;
-		if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
-			/*printk("Breaking affinity for irq %i\n", irq);*/
-			affinity = cpu_all_mask;
-		}
-		if (desc->chip->set_affinity)
-			desc->chip->set_affinity(irq, affinity);
-		else if (desc->action)
-			printk_once("Cannot set affinity for irq %i\n", irq);
-	}
-
-#if 0
-	barrier();
-	/* Ingo Molnar says: "after the IO-APIC masks have been redirected
-	   [note the nop - the interrupt-enable boundary on x86 is two
-	   instructions from sti] - to flush out pending hardirqs and
-	   IPIs. After this point nothing is supposed to reach this CPU." */
-	__asm__ __volatile__("sti; nop; cli");
-	barrier();
-#else
-	/* That doesn't seem sufficient.  Give it 1ms. */
-	local_irq_enable();
-	mdelay(1);
-	local_irq_disable();
-#endif
-}
-#endif
-
--- sle11sp1-2010-01-27.orig/arch/x86/kernel/irq_64-xen.c	2009-11-06 10:52:02.000000000 +0100
+++ /dev/null	1970-01-01 00:00:00.000000000 +0000
@@ -1,142 +0,0 @@
-/*
- *	Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
- *
- * This file contains the lowest level x86_64-specific interrupt
- * entry and irq statistics code. All the remaining irq logic is
- * done by the generic kernel/irq/ code and in the
- * x86_64-specific irq controller code. (e.g. i8259.c and
- * io_apic.c.)
- */
-
-#include <linux/kernel_stat.h>
-#include <linux/interrupt.h>
-#include <linux/seq_file.h>
-#include <linux/module.h>
-#include <linux/delay.h>
-#include <linux/ftrace.h>
-#include <linux/uaccess.h>
-#include <linux/smp.h>
-#include <asm/io_apic.h>
-#include <asm/idle.h>
-#include <asm/apic.h>
-
-DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
-EXPORT_PER_CPU_SYMBOL(irq_stat);
-
-DEFINE_PER_CPU(struct pt_regs *, irq_regs);
-EXPORT_PER_CPU_SYMBOL(irq_regs);
-
-/*
- * Probabilistic stack overflow check:
- *
- * Only check the stack in process context, because everything else
- * runs on the big interrupt stacks. Checking reliably is too expensive,
- * so we just check from interrupts.
- */
-static inline void stack_overflow_check(struct pt_regs *regs)
-{
-#ifdef CONFIG_DEBUG_STACKOVERFLOW
-	u64 curbase = (u64)task_stack_page(current);
-
-	WARN_ONCE(regs->sp >= curbase &&
-		  regs->sp <= curbase + THREAD_SIZE &&
-		  regs->sp <  curbase + sizeof(struct thread_info) +
-					sizeof(struct pt_regs) + 128,
-
-		  "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
-			current->comm, curbase, regs->sp);
-#endif
-}
-
-bool handle_irq(unsigned irq, struct pt_regs *regs)
-{
-	struct irq_desc *desc;
-
-	stack_overflow_check(regs);
-
-	desc = irq_to_desc(irq);
-	if (unlikely(!desc))
-		return false;
-
-	generic_handle_irq_desc(irq, desc);
-	return true;
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
-void fixup_irqs(void)
-{
-	unsigned int irq;
-	static int warned;
-	struct irq_desc *desc;
-
-	for_each_irq_desc(irq, desc) {
-		int break_affinity = 0;
-		int set_affinity = 1;
-		const struct cpumask *affinity;
-
-		if (!desc)
-			continue;
-		if (irq == 2)
-			continue;
-
-		/* interrupt's are disabled at this point */
-		spin_lock(&desc->lock);
-
-		affinity = desc->affinity;
-		if (!irq_has_action(irq) ||
-		    cpumask_equal(affinity, cpu_online_mask)) {
-			spin_unlock(&desc->lock);
-			continue;
-		}
-
-		if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
-			break_affinity = 1;
-			affinity = cpu_all_mask;
-		}
-
-		if (desc->chip->mask)
-			desc->chip->mask(irq);
-
-		if (desc->chip->set_affinity)
-			desc->chip->set_affinity(irq, affinity);
-		else if (!(warned++))
-			set_affinity = 0;
-
-		if (desc->chip->unmask)
-			desc->chip->unmask(irq);
-
-		spin_unlock(&desc->lock);
-
-		if (break_affinity && set_affinity)
-			/*printk("Broke affinity for irq %i\n", irq)*/;
-		else if (!set_affinity)
-			printk("Cannot set affinity for irq %i\n", irq);
-	}
-
-	/* That doesn't seem sufficient.  Give it 1ms. */
-	local_irq_enable();
-	mdelay(1);
-	local_irq_disable();
-}
-#endif
-
-extern void call_softirq(void);
-
-asmlinkage void do_softirq(void)
-{
-	__u32 pending;
-	unsigned long flags;
-
-	if (in_interrupt())
-		return;
-
-	local_irq_save(flags);
-	pending = local_softirq_pending();
-	/* Switch to interrupt stack */
-	if (pending) {
-		call_softirq();
-		WARN_ON_ONCE(softirq_count());
-	}
-	local_irq_restore(flags);
-}