[PATCH 1/4] irq: correct CPUMASKS_OFFSTACK typo -v2

[PATCH 1/4] irq: correct CPUMASKS_OFFSTACK typo -v2

[Yinghai Lu]

Impact: fix smp_affinity copying when moving irq_desc

CPUMASKS_OFFSTACK is not defined anywhere. it is a typo
and init_allocate_desc_masks called before it set affinity to all cpus...

split init_alloc_desc_masks() into all_desc_masks() and init_desc_masks()
so in the init_copy_desc_masks could use CPUMASK_OFFSTACK there.
aka copy path will not calling init_desc_masks anymore.

also could use that CPUMASK_OFFSTACK in alloc_desc_masks()

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>

---
 include/linux/irq.h       |   27 ++++++++++++++++++---------
 kernel/irq/handle.c       |    9 ++++++---
 kernel/irq/numa_migrate.c |    2 +-
 3 files changed, 25 insertions(+), 13 deletions(-)

Index: linux-2.6/include/linux/irq.h
===================================================================
--- linux-2.6.orig/include/linux/irq.h
+++ linux-2.6/include/linux/irq.h
@@ -424,27 +424,25 @@ extern int set_irq_msi(unsigned int irq,
 
 #ifdef CONFIG_SMP
 /**
- * init_alloc_desc_masks - allocate cpumasks for irq_desc
+ * alloc_desc_masks - allocate cpumasks for irq_desc
  * @desc:	pointer to irq_desc struct
  * @cpu:	cpu which will be handling the cpumasks
  * @boot:	true if need bootmem
  *
  * Allocates affinity and pending_mask cpumask if required.
  * Returns true if successful (or not required).
- * Side effect: affinity has all bits set, pending_mask has all bits clear.
  */
-static inline bool init_alloc_desc_masks(struct irq_desc *desc, int cpu,
+static inline bool alloc_desc_masks(struct irq_desc *desc, int cpu,
 								bool boot)
 {
+#ifdef CONFIG_CPUMASK_OFFSTACK
 	int node;
 
 	if (boot) {
 		alloc_bootmem_cpumask_var(&desc->affinity);
-		cpumask_setall(desc->affinity);
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 		alloc_bootmem_cpumask_var(&desc->pending_mask);
-		cpumask_clear(desc->pending_mask);
 #endif
 		return true;
 	}
@@ -453,18 +451,25 @@ static inline bool init_alloc_desc_masks
 
 	if (!alloc_cpumask_var_node(&desc->affinity, GFP_ATOMIC, node))
 		return false;
-	cpumask_setall(desc->affinity);
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	if (!alloc_cpumask_var_node(&desc->pending_mask, GFP_ATOMIC, node)) {
 		free_cpumask_var(desc->affinity);
 		return false;
 	}
-	cpumask_clear(desc->pending_mask);
+#endif
 #endif
 	return true;
 }
 
+static inline void init_desc_masks(struct irq_desc *desc)
+{
+	cpumask_setall(desc->affinity);
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+	cpumask_clear(desc->pending_mask);
+#endif
+}
+
 /**
  * init_copy_desc_masks - copy cpumasks for irq_desc
  * @old_desc:	pointer to old irq_desc struct
@@ -478,7 +483,7 @@ static inline bool init_alloc_desc_masks
 static inline void init_copy_desc_masks(struct irq_desc *old_desc,
 					struct irq_desc *new_desc)
 {
-#ifdef CONFIG_CPUMASKS_OFFSTACK
+#ifdef CONFIG_CPUMASK_OFFSTACK
 	cpumask_copy(new_desc->affinity, old_desc->affinity);
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
@@ -499,12 +504,16 @@ static inline void free_desc_masks(struc
 
 #else /* !CONFIG_SMP */
 
-static inline bool init_alloc_desc_masks(struct irq_desc *desc, int cpu,
+static inline bool alloc_desc_masks(struct irq_desc *desc, int cpu,
 								bool boot)
 {
 	return true;
 }
 
+static inline void init_desc_masks(struct irq_desc *desc)
+{
+}
+
 static inline void init_copy_desc_masks(struct irq_desc *old_desc,
 					struct irq_desc *new_desc)
 {
Index: linux-2.6/kernel/irq/handle.c
===================================================================
--- linux-2.6.orig/kernel/irq/handle.c
+++ linux-2.6/kernel/irq/handle.c
@@ -115,10 +115,11 @@ static void init_one_irq_desc(int irq, s
 		printk(KERN_ERR "can not alloc kstat_irqs\n");
 		BUG_ON(1);
 	}
-	if (!init_alloc_desc_masks(desc, cpu, false)) {
+	if (!alloc_desc_masks(desc, cpu, false)) {
 		printk(KERN_ERR "can not alloc irq_desc cpumasks\n");
 		BUG_ON(1);
 	}
+	init_desc_masks(desc);
 	arch_init_chip_data(desc, cpu);
 }
 
@@ -169,7 +170,8 @@ int __init early_irq_init(void)
 		desc[i].irq = i;
 		desc[i].kstat_irqs = kstat_irqs_legacy + i * nr_cpu_ids;
 		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
-		init_alloc_desc_masks(&desc[i], 0, true);
+		alloc_desc_masks(&desc[i], 0, true);
+		init_desc_masks(&desc[i]);
 		irq_desc_ptrs[i] = desc + i;
 	}
 
@@ -256,7 +258,8 @@ int __init early_irq_init(void)
 
 	for (i = 0; i < count; i++) {
 		desc[i].irq = i;
-		init_alloc_desc_masks(&desc[i], 0, true);
+		alloc_desc_masks(&desc[i], 0, true);
+		init_desc_masks(&desc[i]);
 		desc[i].kstat_irqs = kstat_irqs_all[i];
 	}
 	return arch_early_irq_init();
Index: linux-2.6/kernel/irq/numa_migrate.c
===================================================================
--- linux-2.6.orig/kernel/irq/numa_migrate.c
+++ linux-2.6/kernel/irq/numa_migrate.c
@@ -37,7 +37,7 @@ static bool init_copy_one_irq_desc(int i
 		 struct irq_desc *desc, int cpu)
 {
 	memcpy(desc, old_desc, sizeof(struct irq_desc));
-	if (!init_alloc_desc_masks(desc, cpu, false)) {
+	if (!alloc_desc_masks(desc, cpu, false)) {
 		printk(KERN_ERR "irq %d: can not get new irq_desc cpumask "
 				"for migration.\n", irq);
 		return false;

[PATCH 2/4] irq: make set_affinity to return status

[Yinghai Lu]

Impact: prepare to use it to keep affinity consistent

according to Ingo, change set_affinity() in irq_chip to return int.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 arch/alpha/kernel/sys_dp264.c         |    8 +++-
 arch/alpha/kernel/sys_titan.c         |    4 +-
 arch/arm/common/gic.c                 |    4 +-
 arch/cris/arch-v32/kernel/irq.c       |    4 +-
 arch/ia64/hp/sim/hpsim_irq.c          |    3 +
 arch/ia64/kernel/iosapic.c            |   10 +++--
 arch/ia64/kernel/msi_ia64.c           |   16 +++++---
 arch/ia64/sn/kernel/irq.c             |    4 +-
 arch/ia64/sn/kernel/msi_sn.c          |    8 ++--
 arch/mips/cavium-octeon/octeon-irq.c  |    8 +++-
 arch/mips/include/asm/irq.h           |    2 -
 arch/mips/kernel/irq-gic.c            |    5 +-
 arch/mips/mti-malta/malta-smtc.c      |    4 +-
 arch/mips/sibyte/bcm1480/irq.c        |    8 ++--
 arch/mips/sibyte/sb1250/irq.c         |    8 ++--
 arch/parisc/kernel/irq.c              |    6 ++-
 arch/powerpc/platforms/pseries/xics.c |   12 +++---
 arch/powerpc/sysdev/mpic.c            |    4 +-
 arch/sparc/kernel/irq_64.c            |   12 ++++--
 arch/x86/kernel/apic/io_apic.c        |   64 +++++++++++++++++++++-------------
 drivers/parisc/iosapic.c              |    6 ++-
 drivers/xen/events.c                  |   12 +++---
 include/linux/irq.h                   |    2 -
 23 files changed, 140 insertions(+), 74 deletions(-)

Index: linux-2.6/arch/alpha/kernel/sys_dp264.c
===================================================================
--- linux-2.6.orig/arch/alpha/kernel/sys_dp264.c
+++ linux-2.6/arch/alpha/kernel/sys_dp264.c
@@ -176,22 +176,26 @@ cpu_set_irq_affinity(unsigned int irq, c
 	}
 }
 
-static void
+static int
 dp264_set_affinity(unsigned int irq, const struct cpumask *affinity)
 { 
 	spin_lock(&dp264_irq_lock);
 	cpu_set_irq_affinity(irq, *affinity);
 	tsunami_update_irq_hw(cached_irq_mask);
 	spin_unlock(&dp264_irq_lock);
+
+	return 0;
 }
 
-static void
+static int
 clipper_set_affinity(unsigned int irq, const struct cpumask *affinity)
 { 
 	spin_lock(&dp264_irq_lock);
 	cpu_set_irq_affinity(irq - 16, *affinity);
 	tsunami_update_irq_hw(cached_irq_mask);
 	spin_unlock(&dp264_irq_lock);
+
+	return 0;
 }
 
 static struct hw_interrupt_type dp264_irq_type = {
Index: linux-2.6/arch/alpha/kernel/sys_titan.c
===================================================================
--- linux-2.6.orig/arch/alpha/kernel/sys_titan.c
+++ linux-2.6/arch/alpha/kernel/sys_titan.c
@@ -157,13 +157,15 @@ titan_cpu_set_irq_affinity(unsigned int
 
 }
 
-static void
+static int
 titan_set_irq_affinity(unsigned int irq, const struct cpumask *affinity)
 { 
 	spin_lock(&titan_irq_lock);
 	titan_cpu_set_irq_affinity(irq - 16, *affinity);
 	titan_update_irq_hw(titan_cached_irq_mask);
 	spin_unlock(&titan_irq_lock);
+
+	return 0;
 }
 
 static void
Index: linux-2.6/arch/arm/common/gic.c
===================================================================
--- linux-2.6.orig/arch/arm/common/gic.c
+++ linux-2.6/arch/arm/common/gic.c
@@ -109,7 +109,7 @@ static void gic_unmask_irq(unsigned int
 }
 
 #ifdef CONFIG_SMP
-static void gic_set_cpu(unsigned int irq, const struct cpumask *mask_val)
+static int gic_set_cpu(unsigned int irq, const struct cpumask *mask_val)
 {
 	void __iomem *reg = gic_dist_base(irq) + GIC_DIST_TARGET + (gic_irq(irq) & ~3);
 	unsigned int shift = (irq % 4) * 8;
@@ -122,6 +122,8 @@ static void gic_set_cpu(unsigned int irq
 	val |= 1 << (cpu + shift);
 	writel(val, reg);
 	spin_unlock(&irq_controller_lock);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/cris/arch-v32/kernel/irq.c
===================================================================
--- linux-2.6.orig/arch/cris/arch-v32/kernel/irq.c
+++ linux-2.6/arch/cris/arch-v32/kernel/irq.c
@@ -325,12 +325,14 @@ static void end_crisv32_irq(unsigned int
 {
 }
 
-void set_affinity_crisv32_irq(unsigned int irq, const struct cpumask *dest)
+int set_affinity_crisv32_irq(unsigned int irq, const struct cpumask *dest)
 {
 	unsigned long flags;
 	spin_lock_irqsave(&irq_lock, flags);
 	irq_allocations[irq - FIRST_IRQ].mask = *dest;
 	spin_unlock_irqrestore(&irq_lock, flags);
+
+	return 0;
 }
 
 static struct irq_chip crisv32_irq_type = {
Index: linux-2.6/arch/ia64/hp/sim/hpsim_irq.c
===================================================================
--- linux-2.6.orig/arch/ia64/hp/sim/hpsim_irq.c
+++ linux-2.6/arch/ia64/hp/sim/hpsim_irq.c
@@ -21,9 +21,10 @@ hpsim_irq_noop (unsigned int irq)
 {
 }
 
-static void
+static int
 hpsim_set_affinity_noop(unsigned int a, const struct cpumask *b)
 {
+	return 0;
 }
 
 static struct hw_interrupt_type irq_type_hp_sim = {
Index: linux-2.6/arch/ia64/kernel/iosapic.c
===================================================================
--- linux-2.6.orig/arch/ia64/kernel/iosapic.c
+++ linux-2.6/arch/ia64/kernel/iosapic.c
@@ -329,7 +329,7 @@ unmask_irq (unsigned int irq)
 }
 
 
-static void
+static int
 iosapic_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 #ifdef CONFIG_SMP
@@ -343,15 +343,15 @@ iosapic_set_affinity(unsigned int irq, c
 
 	cpu = cpumask_first_and(cpu_online_mask, mask);
 	if (cpu >= nr_cpu_ids)
-		return;
+		return -1;
 
 	if (irq_prepare_move(irq, cpu))
-		return;
+		return -1;
 
 	dest = cpu_physical_id(cpu);
 
 	if (!iosapic_intr_info[irq].count)
-		return;			/* not an IOSAPIC interrupt */
+		return -1;			/* not an IOSAPIC interrupt */
 
 	set_irq_affinity_info(irq, dest, redir);
 
@@ -376,7 +376,9 @@ iosapic_set_affinity(unsigned int irq, c
 		iosapic_write(iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
 		iosapic_write(iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 	}
+
 #endif
+	return 0;
 }
 
 /*
Index: linux-2.6/arch/ia64/kernel/msi_ia64.c
===================================================================
--- linux-2.6.orig/arch/ia64/kernel/msi_ia64.c
+++ linux-2.6/arch/ia64/kernel/msi_ia64.c
@@ -12,7 +12,7 @@
 static struct irq_chip	ia64_msi_chip;
 
 #ifdef CONFIG_SMP
-static void ia64_set_msi_irq_affinity(unsigned int irq,
+static int ia64_set_msi_irq_affinity(unsigned int irq,
 				      const cpumask_t *cpu_mask)
 {
 	struct msi_msg msg;
@@ -20,10 +20,10 @@ static void ia64_set_msi_irq_affinity(un
 	int cpu = first_cpu(*cpu_mask);
 
 	if (!cpu_online(cpu))
-		return;
+		return -1;
 
 	if (irq_prepare_move(irq, cpu))
-		return;
+		return -1;
 
 	read_msi_msg(irq, &msg);
 
@@ -39,6 +39,8 @@ static void ia64_set_msi_irq_affinity(un
 
 	write_msi_msg(irq, &msg);
 	cpumask_copy(irq_desc[irq].affinity, cpumask_of(cpu));
+
+	return 0;
 }
 #endif /* CONFIG_SMP */
 
@@ -130,17 +132,17 @@ void arch_teardown_msi_irq(unsigned int
 
 #ifdef CONFIG_DMAR
 #ifdef CONFIG_SMP
-static void dmar_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int dmar_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_cfg *cfg = irq_cfg + irq;
 	struct msi_msg msg;
 	int cpu = cpumask_first(mask);
 
 	if (!cpu_online(cpu))
-		return;
+		return -1;
 
 	if (irq_prepare_move(irq, cpu))
-		return;
+		return -1;
 
 	dmar_msi_read(irq, &msg);
 
@@ -151,6 +153,8 @@ static void dmar_msi_set_affinity(unsign
 
 	dmar_msi_write(irq, &msg);
 	cpumask_copy(irq_desc[irq].affinity, mask);
+
+	return 0;
 }
 #endif /* CONFIG_SMP */
 
Index: linux-2.6/arch/ia64/sn/kernel/irq.c
===================================================================
--- linux-2.6.orig/arch/ia64/sn/kernel/irq.c
+++ linux-2.6/arch/ia64/sn/kernel/irq.c
@@ -227,7 +227,7 @@ finish_up:
 	return new_irq_info;
 }
 
-static void sn_set_affinity_irq(unsigned int irq, const struct cpumask *mask)
+static int sn_set_affinity_irq(unsigned int irq, const struct cpumask *mask)
 {
 	struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 	nasid_t nasid;
@@ -239,6 +239,8 @@ static void sn_set_affinity_irq(unsigned
 	list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 				 sn_irq_lh[irq], list)
 		(void)sn_retarget_vector(sn_irq_info, nasid, slice);
+
+	return 0;
 }
 
 #ifdef CONFIG_SMP
Index: linux-2.6/arch/ia64/sn/kernel/msi_sn.c
===================================================================
--- linux-2.6.orig/arch/ia64/sn/kernel/msi_sn.c
+++ linux-2.6/arch/ia64/sn/kernel/msi_sn.c
@@ -151,7 +151,7 @@ int sn_setup_msi_irq(struct pci_dev *pde
 }
 
 #ifdef CONFIG_SMP
-static void sn_set_msi_irq_affinity(unsigned int irq,
+static int sn_set_msi_irq_affinity(unsigned int irq,
 				    const struct cpumask *cpu_mask)
 {
 	struct msi_msg msg;
@@ -168,7 +168,7 @@ static void sn_set_msi_irq_affinity(unsi
 	cpu = cpumask_first(cpu_mask);
 	sn_irq_info = sn_msi_info[irq].sn_irq_info;
 	if (sn_irq_info == NULL || sn_irq_info->irq_int_bit >= 0)
-		return;
+		return -1;
 
 	/*
 	 * Release XIO resources for the old MSI PCI address
@@ -189,7 +189,7 @@ static void sn_set_msi_irq_affinity(unsi
 	new_irq_info = sn_retarget_vector(sn_irq_info, nasid, slice);
 	sn_msi_info[irq].sn_irq_info = new_irq_info;
 	if (new_irq_info == NULL)
-		return;
+		return -1;
 
 	/*
 	 * Map the xio address into bus space
@@ -206,6 +206,8 @@ static void sn_set_msi_irq_affinity(unsi
 
 	write_msi_msg(irq, &msg);
 	cpumask_copy(irq_desc[irq].affinity, cpu_mask);
+
+	return 0;
 }
 #endif /* CONFIG_SMP */
 
Index: linux-2.6/arch/mips/cavium-octeon/octeon-irq.c
===================================================================
--- linux-2.6.orig/arch/mips/cavium-octeon/octeon-irq.c
+++ linux-2.6/arch/mips/cavium-octeon/octeon-irq.c
@@ -177,7 +177,7 @@ static void octeon_irq_ciu0_disable(unsi
 }
 
 #ifdef CONFIG_SMP
-static void octeon_irq_ciu0_set_affinity(unsigned int irq, const struct cpumask *dest)
+static int octeon_irq_ciu0_set_affinity(unsigned int irq, const struct cpumask *dest)
 {
 	int cpu;
 	int bit = irq - OCTEON_IRQ_WORKQ0;	/* Bit 0-63 of EN0 */
@@ -199,6 +199,8 @@ static void octeon_irq_ciu0_set_affinity
 	 */
 	cvmx_read_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2));
 	write_unlock(&octeon_irq_ciu0_rwlock);
+
+	reutrn 0;
 }
 #endif
 
@@ -292,7 +294,7 @@ static void octeon_irq_ciu1_disable(unsi
 }
 
 #ifdef CONFIG_SMP
-static void octeon_irq_ciu1_set_affinity(unsigned int irq, const struct cpumask *dest)
+static int octeon_irq_ciu1_set_affinity(unsigned int irq, const struct cpumask *dest)
 {
 	int cpu;
 	int bit = irq - OCTEON_IRQ_WDOG0;	/* Bit 0-63 of EN1 */
@@ -315,6 +317,8 @@ static void octeon_irq_ciu1_set_affinity
 	 */
 	cvmx_read_csr(CVMX_CIU_INTX_EN1(cvmx_get_core_num() * 2 + 1));
 	write_unlock(&octeon_irq_ciu1_rwlock);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/mips/kernel/irq-gic.c
===================================================================
--- linux-2.6.orig/arch/mips/kernel/irq-gic.c
+++ linux-2.6/arch/mips/kernel/irq-gic.c
@@ -155,7 +155,7 @@ static void gic_unmask_irq(unsigned int
 
 static DEFINE_SPINLOCK(gic_lock);
 
-static void gic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
+static int gic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 {
 	cpumask_t	tmp = CPU_MASK_NONE;
 	unsigned long	flags;
@@ -166,7 +166,7 @@ static void gic_set_affinity(unsigned in
 
 	cpumask_and(&tmp, cpumask, cpu_online_mask);
 	if (cpus_empty(tmp))
-		return;
+		return -1;
 
 	/* Assumption : cpumask refers to a single CPU */
 	spin_lock_irqsave(&gic_lock, flags);
@@ -190,6 +190,7 @@ static void gic_set_affinity(unsigned in
 	cpumask_copy(irq_desc[irq].affinity, cpumask);
 	spin_unlock_irqrestore(&gic_lock, flags);
 
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/mips/sibyte/bcm1480/irq.c
===================================================================
--- linux-2.6.orig/arch/mips/sibyte/bcm1480/irq.c
+++ linux-2.6/arch/mips/sibyte/bcm1480/irq.c
@@ -50,7 +50,7 @@ static void enable_bcm1480_irq(unsigned
 static void disable_bcm1480_irq(unsigned int irq);
 static void ack_bcm1480_irq(unsigned int irq);
 #ifdef CONFIG_SMP
-static void bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask);
+static int bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask);
 #endif
 
 #ifdef CONFIG_PCI
@@ -109,7 +109,7 @@ void bcm1480_unmask_irq(int cpu, int irq
 }
 
 #ifdef CONFIG_SMP
-static void bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	int i = 0, old_cpu, cpu, int_on, k;
 	u64 cur_ints;
@@ -119,7 +119,7 @@ static void bcm1480_set_affinity(unsigne
 
 	if (cpumask_weight(mask) != 1) {
 		printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
-		return;
+		return -1;
 	}
 	i = cpumask_first(mask);
 
@@ -155,6 +155,8 @@ static void bcm1480_set_affinity(unsigne
 	}
 	spin_unlock(&bcm1480_imr_lock);
 	spin_unlock_irqrestore(&desc->lock, flags);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/mips/sibyte/sb1250/irq.c
===================================================================
--- linux-2.6.orig/arch/mips/sibyte/sb1250/irq.c
+++ linux-2.6/arch/mips/sibyte/sb1250/irq.c
@@ -50,7 +50,7 @@ static void enable_sb1250_irq(unsigned i
 static void disable_sb1250_irq(unsigned int irq);
 static void ack_sb1250_irq(unsigned int irq);
 #ifdef CONFIG_SMP
-static void sb1250_set_affinity(unsigned int irq, const struct cpumask *mask);
+static int sb1250_set_affinity(unsigned int irq, const struct cpumask *mask);
 #endif
 
 #ifdef CONFIG_SIBYTE_HAS_LDT
@@ -103,7 +103,7 @@ void sb1250_unmask_irq(int cpu, int irq)
 }
 
 #ifdef CONFIG_SMP
-static void sb1250_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int sb1250_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	int i = 0, old_cpu, cpu, int_on;
 	u64 cur_ints;
@@ -114,7 +114,7 @@ static void sb1250_set_affinity(unsigned
 
 	if (cpumask_weight(mask) > 1) {
 		printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
-		return;
+		return -1;
 	}
 
 	/* Convert logical CPU to physical CPU */
@@ -146,6 +146,8 @@ static void sb1250_set_affinity(unsigned
 	}
 	spin_unlock(&sb1250_imr_lock);
 	spin_unlock_irqrestore(&desc->lock, flags);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/parisc/kernel/irq.c
===================================================================
--- linux-2.6.orig/arch/parisc/kernel/irq.c
+++ linux-2.6/arch/parisc/kernel/irq.c
@@ -130,15 +130,17 @@ int cpu_check_affinity(unsigned int irq,
 	return cpu_dest;
 }
 
-static void cpu_set_affinity_irq(unsigned int irq, const struct cpumask *dest)
+static int cpu_set_affinity_irq(unsigned int irq, const struct cpumask *dest)
 {
 	int cpu_dest;
 
 	cpu_dest = cpu_check_affinity(irq, dest);
 	if (cpu_dest < 0)
-		return;
+		return -1;
 
 	cpumask_copy(&irq_desc[irq].affinity, dest);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/powerpc/platforms/pseries/xics.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/pseries/xics.c
+++ linux-2.6/arch/powerpc/platforms/pseries/xics.c
@@ -333,7 +333,7 @@ static void xics_eoi_lpar(unsigned int v
 	lpar_xirr_info_set((0xff << 24) | irq);
 }
 
-static void xics_set_affinity(unsigned int virq, const struct cpumask *cpumask)
+static int xics_set_affinity(unsigned int virq, const struct cpumask *cpumask)
 {
 	unsigned int irq;
 	int status;
@@ -342,14 +342,14 @@ static void xics_set_affinity(unsigned i
 
 	irq = (unsigned int)irq_map[virq].hwirq;
 	if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
-		return;
+		return -1;
 
 	status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
 
 	if (status) {
 		printk(KERN_ERR "%s: ibm,get-xive irq=%u returns %d\n",
 			__func__, irq, status);
-		return;
+		return -1;
 	}
 
 	/*
@@ -363,7 +363,7 @@ static void xics_set_affinity(unsigned i
 		printk(KERN_WARNING
 			"%s: No online cpus in the mask %s for irq %d\n",
 			__func__, cpulist, virq);
-		return;
+		return -1;
 	}
 
 	status = rtas_call(ibm_set_xive, 3, 1, NULL,
@@ -372,8 +372,10 @@ static void xics_set_affinity(unsigned i
 	if (status) {
 		printk(KERN_ERR "%s: ibm,set-xive irq=%u returns %d\n",
 			__func__, irq, status);
-		return;
+		return -1;
 	}
+
+	return 0;
 }
 
 static struct irq_chip xics_pic_direct = {
Index: linux-2.6/arch/powerpc/sysdev/mpic.c
===================================================================
--- linux-2.6.orig/arch/powerpc/sysdev/mpic.c
+++ linux-2.6/arch/powerpc/sysdev/mpic.c
@@ -807,7 +807,7 @@ static void mpic_end_ipi(unsigned int ir
 
 #endif /* CONFIG_SMP */
 
-void mpic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
+int mpic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 {
 	struct mpic *mpic = mpic_from_irq(irq);
 	unsigned int src = mpic_irq_to_hw(irq);
@@ -824,6 +824,8 @@ void mpic_set_affinity(unsigned int irq,
 		mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION),
 			       mpic_physmask(cpus_addr(tmp)[0]));
 	}
+
+	return 0;
 }
 
 static unsigned int mpic_type_to_vecpri(struct mpic *mpic, unsigned int type)
Index: linux-2.6/arch/sparc/kernel/irq_64.c
===================================================================
--- linux-2.6.orig/arch/sparc/kernel/irq_64.c
+++ linux-2.6/arch/sparc/kernel/irq_64.c
@@ -318,10 +318,12 @@ static void sun4u_irq_enable(unsigned in
 	}
 }
 
-static void sun4u_set_affinity(unsigned int virt_irq,
+static int sun4u_set_affinity(unsigned int virt_irq,
 			       const struct cpumask *mask)
 {
 	sun4u_irq_enable(virt_irq);
+
+	return 0;
 }
 
 /* Don't do anything.  The desc->status check for IRQ_DISABLED in
@@ -377,7 +379,7 @@ static void sun4v_irq_enable(unsigned in
 		       ino, err);
 }
 
-static void sun4v_set_affinity(unsigned int virt_irq,
+static int sun4v_set_affinity(unsigned int virt_irq,
 			       const struct cpumask *mask)
 {
 	unsigned int ino = virt_irq_table[virt_irq].dev_ino;
@@ -388,6 +390,8 @@ static void sun4v_set_affinity(unsigned
 	if (err != HV_EOK)
 		printk(KERN_ERR "sun4v_intr_settarget(%x,%lu): "
 		       "err(%d)\n", ino, cpuid, err);
+
+	return 0;
 }
 
 static void sun4v_irq_disable(unsigned int virt_irq)
@@ -445,7 +449,7 @@ static void sun4v_virq_enable(unsigned i
 		       dev_handle, dev_ino, err);
 }
 
-static void sun4v_virt_set_affinity(unsigned int virt_irq,
+static int sun4v_virt_set_affinity(unsigned int virt_irq,
 				    const struct cpumask *mask)
 {
 	unsigned long cpuid, dev_handle, dev_ino;
@@ -461,6 +465,8 @@ static void sun4v_virt_set_affinity(unsi
 		printk(KERN_ERR "sun4v_vintr_set_target(%lx,%lx,%lu): "
 		       "err(%d)\n",
 		       dev_handle, dev_ino, cpuid, err);
+
+	return 0;
 }
 
 static void sun4v_virq_disable(unsigned int virt_irq)
Index: linux-2.6/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6/arch/x86/kernel/apic/io_apic.c
@@ -2326,13 +2326,14 @@ set_desc_affinity(struct irq_desc *desc,
 	return apic->cpu_mask_to_apicid_and(desc->affinity, cfg->domain);
 }
 
-static void
+static int
 set_ioapic_affinity_irq_desc(struct irq_desc *desc, const struct cpumask *mask)
 {
 	struct irq_cfg *cfg;
 	unsigned long flags;
 	unsigned int dest;
 	unsigned int irq;
+	int ret = -1;
 
 	irq = desc->irq;
 	cfg = desc->chip_data;
@@ -2343,18 +2344,21 @@ set_ioapic_affinity_irq_desc(struct irq_
 		/* Only the high 8 bits are valid. */
 		dest = SET_APIC_LOGICAL_ID(dest);
 		__target_IO_APIC_irq(irq, dest, cfg);
+		ret = 0;
 	}
 	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return ret;
 }
 
-static void
+static int
 set_ioapic_affinity_irq(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc;
 
 	desc = irq_to_desc(irq);
 
-	set_ioapic_affinity_irq_desc(desc, mask);
+	return set_ioapic_affinity_irq_desc(desc, mask);
 }
 
 #ifdef CONFIG_INTR_REMAP
@@ -2370,24 +2374,25 @@ set_ioapic_affinity_irq(unsigned int irq
  * Real vector that is used for interrupting cpu will be coming from
  * the interrupt-remapping table entry.
  */
-static void
+static int
 migrate_ioapic_irq_desc(struct irq_desc *desc, const struct cpumask *mask)
 {
 	struct irq_cfg *cfg;
 	struct irte irte;
 	unsigned int dest;
 	unsigned int irq;
+	int ret = -1;
 
 	if (!cpumask_intersects(mask, cpu_online_mask))
-		return;
+		return ret;
 
 	irq = desc->irq;
 	if (get_irte(irq, &irte))
-		return;
+		return ret;
 
 	cfg = desc->chip_data;
 	if (assign_irq_vector(irq, cfg, mask))
-		return;
+		return ret;
 
 	set_extra_move_desc(desc, mask);
 
@@ -2405,27 +2410,30 @@ migrate_ioapic_irq_desc(struct irq_desc
 		send_cleanup_vector(cfg);
 
 	cpumask_copy(desc->affinity, mask);
+
+	return 0;
 }
 
 /*
  * Migrates the IRQ destination in the process context.
  */
-static void set_ir_ioapic_affinity_irq_desc(struct irq_desc *desc,
+static int set_ir_ioapic_affinity_irq_desc(struct irq_desc *desc,
 					    const struct cpumask *mask)
 {
-	migrate_ioapic_irq_desc(desc, mask);
+	return migrate_ioapic_irq_desc(desc, mask);
 }
-static void set_ir_ioapic_affinity_irq(unsigned int irq,
+static int set_ir_ioapic_affinity_irq(unsigned int irq,
 				       const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
-	set_ir_ioapic_affinity_irq_desc(desc, mask);
+	return set_ir_ioapic_affinity_irq_desc(desc, mask);
 }
 #else
-static inline void set_ir_ioapic_affinity_irq_desc(struct irq_desc *desc,
+static inline int set_ir_ioapic_affinity_irq_desc(struct irq_desc *desc,
 						   const struct cpumask *mask)
 {
+	return 0;
 }
 #endif
 
@@ -3362,7 +3370,7 @@ static int msi_compose_msg(struct pci_de
 }
 
 #ifdef CONFIG_SMP
-static void set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask)
+static int set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	struct irq_cfg *cfg;
@@ -3371,7 +3379,7 @@ static void set_msi_irq_affinity(unsigne
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	cfg = desc->chip_data;
 
@@ -3383,13 +3391,15 @@ static void set_msi_irq_affinity(unsigne
 	msg.address_lo |= MSI_ADDR_DEST_ID(dest);
 
 	write_msi_msg_desc(desc, &msg);
+
+	return 0;
 }
 #ifdef CONFIG_INTR_REMAP
 /*
  * Migrate the MSI irq to another cpumask. This migration is
  * done in the process context using interrupt-remapping hardware.
  */
-static void
+static int
 ir_set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
@@ -3398,11 +3408,11 @@ ir_set_msi_irq_affinity(unsigned int irq
 	struct irte irte;
 
 	if (get_irte(irq, &irte))
-		return;
+		return -1;
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	irte.vector = cfg->vector;
 	irte.dest_id = IRTE_DEST(dest);
@@ -3419,6 +3429,8 @@ ir_set_msi_irq_affinity(unsigned int irq
 	 */
 	if (cfg->move_in_progress)
 		send_cleanup_vector(cfg);
+
+	return 0;
 }
 
 #endif
@@ -3572,7 +3584,7 @@ void arch_teardown_msi_irq(unsigned int
 
 #if defined (CONFIG_DMAR) || defined (CONFIG_INTR_REMAP)
 #ifdef CONFIG_SMP
-static void dmar_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int dmar_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	struct irq_cfg *cfg;
@@ -3581,7 +3593,7 @@ static void dmar_msi_set_affinity(unsign
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	cfg = desc->chip_data;
 
@@ -3593,6 +3605,8 @@ static void dmar_msi_set_affinity(unsign
 	msg.address_lo |= MSI_ADDR_DEST_ID(dest);
 
 	dmar_msi_write(irq, &msg);
+
+	return 0;
 }
 
 #endif /* CONFIG_SMP */
@@ -3626,7 +3640,7 @@ int arch_setup_dmar_msi(unsigned int irq
 #ifdef CONFIG_HPET_TIMER
 
 #ifdef CONFIG_SMP
-static void hpet_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int hpet_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	struct irq_cfg *cfg;
@@ -3635,7 +3649,7 @@ static void hpet_msi_set_affinity(unsign
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	cfg = desc->chip_data;
 
@@ -3647,6 +3661,8 @@ static void hpet_msi_set_affinity(unsign
 	msg.address_lo |= MSI_ADDR_DEST_ID(dest);
 
 	hpet_msi_write(irq, &msg);
+
+	return 0;
 }
 
 #endif /* CONFIG_SMP */
@@ -3703,7 +3719,7 @@ static void target_ht_irq(unsigned int i
 	write_ht_irq_msg(irq, &msg);
 }
 
-static void set_ht_irq_affinity(unsigned int irq, const struct cpumask *mask)
+static int set_ht_irq_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	struct irq_cfg *cfg;
@@ -3711,11 +3727,13 @@ static void set_ht_irq_affinity(unsigned
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	cfg = desc->chip_data;
 
 	target_ht_irq(irq, dest, cfg->vector);
+
+	return 0;
 }
 
 #endif
Index: linux-2.6/drivers/parisc/iosapic.c
===================================================================
--- linux-2.6.orig/drivers/parisc/iosapic.c
+++ linux-2.6/drivers/parisc/iosapic.c
@@ -702,7 +702,7 @@ static unsigned int iosapic_startup_irq(
 }
 
 #ifdef CONFIG_SMP
-static void iosapic_set_affinity_irq(unsigned int irq,
+static int iosapic_set_affinity_irq(unsigned int irq,
 				     const struct cpumask *dest)
 {
 	struct vector_info *vi = iosapic_get_vector(irq);
@@ -712,7 +712,7 @@ static void iosapic_set_affinity_irq(uns
 
 	dest_cpu = cpu_check_affinity(irq, dest);
 	if (dest_cpu < 0)
-		return;
+		return -1;
 
 	cpumask_copy(irq_desc[irq].affinity, cpumask_of(dest_cpu));
 	vi->txn_addr = txn_affinity_addr(irq, dest_cpu);
@@ -724,6 +724,8 @@ static void iosapic_set_affinity_irq(uns
 	iosapic_set_irt_data(vi, &dummy_d0, &d1);
 	iosapic_wr_irt_entry(vi, d0, d1);
 	spin_unlock_irqrestore(&iosapic_lock, flags);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/drivers/xen/events.c
===================================================================
--- linux-2.6.orig/drivers/xen/events.c
+++ linux-2.6/drivers/xen/events.c
@@ -694,13 +694,13 @@ void rebind_evtchn_irq(int evtchn, int i
 }
 
 /* Rebind an evtchn so that it gets delivered to a specific cpu */
-static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
+static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
 {
 	struct evtchn_bind_vcpu bind_vcpu;
 	int evtchn = evtchn_from_irq(irq);
 
 	if (!VALID_EVTCHN(evtchn))
-		return;
+		returni -1;
 
 	/* Send future instances of this interrupt to other vcpu. */
 	bind_vcpu.port = evtchn;
@@ -713,13 +713,15 @@ static void rebind_irq_to_cpu(unsigned i
 	 */
 	if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
 		bind_evtchn_to_cpu(evtchn, tcpu);
-}
 
+	return 0;
+}
 
-static void set_affinity_irq(unsigned irq, const struct cpumask *dest)
+static int set_affinity_irq(unsigned irq, const struct cpumask *dest)
 {
 	unsigned tcpu = cpumask_first(dest);
-	rebind_irq_to_cpu(irq, tcpu);
+
+	return rebind_irq_to_cpu(irq, tcpu);
 }
 
 int resend_irq_on_evtchn(unsigned int irq)
Index: linux-2.6/include/linux/irq.h
===================================================================
--- linux-2.6.orig/include/linux/irq.h
+++ linux-2.6/include/linux/irq.h
@@ -117,7 +117,7 @@ struct irq_chip {
 	void		(*eoi)(unsigned int irq);
 
 	void		(*end)(unsigned int irq);
-	void		(*set_affinity)(unsigned int irq,
+	int		(*set_affinity)(unsigned int irq,
 					const struct cpumask *dest);
 	int		(*retrigger)(unsigned int irq);
 	int		(*set_type)(unsigned int irq, unsigned int flow_type);
Index: linux-2.6/arch/mips/include/asm/irq.h
===================================================================
--- linux-2.6.orig/arch/mips/include/asm/irq.h
+++ linux-2.6/arch/mips/include/asm/irq.h
@@ -49,7 +49,7 @@ static inline void smtc_im_ack_irq(unsig
 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
 #include <linux/cpumask.h>
 
-extern void plat_set_irq_affinity(unsigned int irq,
+extern int plat_set_irq_affinity(unsigned int irq,
 				  const struct cpumask *affinity);
 extern void smtc_forward_irq(unsigned int irq);
 
Index: linux-2.6/arch/mips/mti-malta/malta-smtc.c
===================================================================
--- linux-2.6.orig/arch/mips/mti-malta/malta-smtc.c
+++ linux-2.6/arch/mips/mti-malta/malta-smtc.c
@@ -114,7 +114,7 @@ struct plat_smp_ops msmtc_smp_ops = {
  */
 
 
-void plat_set_irq_affinity(unsigned int irq, const struct cpumask *affinity)
+int plat_set_irq_affinity(unsigned int irq, const struct cpumask *affinity)
 {
 	cpumask_t tmask;
 	int cpu = 0;
@@ -156,5 +156,7 @@ void plat_set_irq_affinity(unsigned int
 
 	/* Do any generic SMTC IRQ affinity setup */
 	smtc_set_irq_affinity(irq, tmask);
+
+	return 0;
 }
 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */

[PATCH 3/4] irq: only update affinity in chip set_affinity() -v3

[Yinghai Lu]

Impact: keep affinity consistent

irq_set_affinity() and move_masked_irq() try to assign affinity
before calling chip set_affinity(). some archs are assigning again in set_affinity
again.

something like:
cpumask_cpy(desc->affinity, mask);
desc->chip->set_affinity(mask);

in the failing path, affinity should not be touched.

also set_extra_move_desc() ( called by set_affinity)  will rely on the old
affinity to decide if need to move irq_desc to different node when logical
flat apic mode is used.

So try remove those assignment, and make some missed arch to assign affinity
in their set_affinity.

v2: update after "irq, x86: Remove IRQ_DISABLED check in process context IRQ move"
v3: according to Ingo, change set_affinity() in irq_chip to return int.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>


---
 kernel/irq/internals.h |    3 +++
 kernel/irq/manage.c    |   17 +++++++++++------
 kernel/irq/migration.c |   14 +++++++++-----
 3 files changed, 23 insertions(+), 11 deletions(-)

Index: linux-2.6/kernel/irq/internals.h
===================================================================
--- linux-2.6.orig/kernel/irq/internals.h
+++ linux-2.6/kernel/irq/internals.h
@@ -42,6 +42,9 @@ static inline void unregister_handler_pr
 
 extern int irq_select_affinity_usr(unsigned int irq);
 
+extern void
+irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask);
+
 /*
  * Debugging printout:
  */
Index: linux-2.6/kernel/irq/manage.c
===================================================================
--- linux-2.6.orig/kernel/irq/manage.c
+++ linux-2.6/kernel/irq/manage.c
@@ -80,7 +80,7 @@ int irq_can_set_affinity(unsigned int ir
 	return 1;
 }
 
-static void
+void
 irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask)
 {
 	struct irqaction *action = desc->action;
@@ -109,17 +109,22 @@ int irq_set_affinity(unsigned int irq, c
 	spin_lock_irqsave(&desc->lock, flags);
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
-	if (desc->status & IRQ_MOVE_PCNTXT)
-		desc->chip->set_affinity(irq, cpumask);
+	if (desc->status & IRQ_MOVE_PCNTXT) {
+		if (!desc->chip->set_affinity(irq, cpumask)) {
+			cpumask_copy(desc->affinity, cpumask);
+			irq_set_thread_affinity(desc, cpumask);
+		}
+	}
 	else {
 		desc->status |= IRQ_MOVE_PENDING;
 		cpumask_copy(desc->pending_mask, cpumask);
 	}
 #else
-	cpumask_copy(desc->affinity, cpumask);
-	desc->chip->set_affinity(irq, cpumask);
+	if (!desc->chip->set_affinity(irq, cpumask)) {
+		cpumask_copy(desc->affinity, cpumask);
+		irq_set_thread_affinity(desc, cpumask);
+	}
 #endif
-	irq_set_thread_affinity(desc, cpumask);
 	desc->status |= IRQ_AFFINITY_SET;
 	spin_unlock_irqrestore(&desc->lock, flags);
 	return 0;
Index: linux-2.6/kernel/irq/migration.c
===================================================================
--- linux-2.6.orig/kernel/irq/migration.c
+++ linux-2.6/kernel/irq/migration.c
@@ -1,5 +1,8 @@
 
 #include <linux/irq.h>
+#include <linux/interrupt.h>
+
+#include "internals.h"
 
 void move_masked_irq(int irq)
 {
@@ -39,11 +42,12 @@ void move_masked_irq(int irq)
 	 * masking the irqs.
 	 */
 	if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
-		   < nr_cpu_ids)) {
-		cpumask_and(desc->affinity,
-			    desc->pending_mask, cpu_online_mask);
-		desc->chip->set_affinity(irq, desc->affinity);
-	}
+		   < nr_cpu_ids))
+		if (!desc->chip->set_affinity(irq, desc->pending_mask)) {
+			cpumask_copy(desc->affinity, desc->pending_mask);
+			irq_set_thread_affinity(desc, desc->pending_mask);
+		}
+
 	cpumask_clear(desc->pending_mask);
 }
 

[PATCH 4/4] irq: move move_irq_desc calling to set_affinity directly -v4

[Yinghai Lu]

Impact: fix panic

so could move_masked_irq call move_irq_desc directly.
also we still don't support IRQ_MOVE_PCNTXT aka intr_remapped path

v3: update after "irq, x86: Remove IRQ_DISABLED check in process context IRQ move"
v4: update after "irq: make set_affinity to return status"

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 arch/x86/kernel/apic/io_apic.c |  108 +++++++++++++++++++++++++++--------------
 kernel/irq/migration.c         |   10 +++
 2 files changed, 80 insertions(+), 38 deletions(-)

Index: linux-2.6/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6/arch/x86/kernel/apic/io_apic.c
@@ -361,8 +361,12 @@ void arch_free_chip_data(struct irq_desc
 static void
 set_extra_move_desc(struct irq_desc *desc, const struct cpumask *mask)
 {
-	struct irq_cfg *cfg = desc->chip_data;
+	struct irq_cfg *cfg;
+
+	if (desc->status & IRQ_MOVE_PCNTXT)
+		return;
 
+	cfg = desc->chip_data;
 	if (!cfg->move_in_progress) {
 		/* it means that domain is not changed */
 		if (!cpumask_intersects(desc->affinity, mask))
@@ -2299,14 +2303,53 @@ __target_IO_APIC_irq(unsigned int irq, u
 	}
 }
 
+#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
+static struct irq_desc *masked_move_desc(struct irq_desc *desc,
+					 const struct cpumask *mask)
+{
+	struct irq_cfg *cfg;
+	int cpu;
+
+	/*
+	 * can not moved via set_affinity from irq_set_affinity when
+	 * intr_remapped aka IRQ_MOVE_PCNTXT is set
+	 */
+	if (desc->status & IRQ_MOVE_PCNTXT)
+		return desc;
+
+	cfg = desc->chip_data;
+	if (likely(!cfg->move_in_progress))
+		if (likely(!cfg->move_desc_pending))
+			return desc;
+
+	for_each_cpu_and(cpu, mask, cfg->domain) {
+		if (cpumask_test_cpu(cpu, cpu_online_mask))
+			break;
+	}
+
+	desc = move_irq_desc(desc, cpu);
+	cfg = desc->chip_data;
+	cfg->move_desc_pending = 0;
+
+	return desc;
+}
+#else
+static inline struct irq_desc *masked_move_desc(struct irq_desc *desc,
+						const struct cpumask *mask)
+{
+	return desc;
+}
+#endif
+
 /*
  * Either sets desc->affinity to a valid value, and returns
  * ->cpu_mask_to_apicid of that, or returns BAD_APICID and
  * leaves desc->affinity untouched.
  */
 static unsigned int
-set_desc_affinity(struct irq_desc *desc, const struct cpumask *mask)
+set_desc_affinity(struct irq_desc **descp, const struct cpumask *mask)
 {
+	struct irq_desc *desc = *descp;
 	struct irq_cfg *cfg;
 	unsigned int irq;
 
@@ -2323,6 +2366,9 @@ set_desc_affinity(struct irq_desc *desc,
 
 	cpumask_copy(desc->affinity, mask);
 
+	*descp = desc = masked_move_desc(desc, mask);
+	cfg = desc->chip_data;
+
 	return apic->cpu_mask_to_apicid_and(desc->affinity, cfg->domain);
 }
 
@@ -2339,7 +2385,7 @@ set_ioapic_affinity_irq_desc(struct irq_
 	cfg = desc->chip_data;
 
 	spin_lock_irqsave(&ioapic_lock, flags);
-	dest = set_desc_affinity(desc, mask);
+	dest = set_desc_affinity(&desc, mask);
 	if (dest != BAD_APICID) {
 		/* Only the high 8 bits are valid. */
 		dest = SET_APIC_LOGICAL_ID(dest);
@@ -2394,6 +2440,12 @@ migrate_ioapic_irq_desc(struct irq_desc
 	if (assign_irq_vector(irq, cfg, mask))
 		return ret;
 
+	/*
+	 * when intr_remap is used, IRQ_MOVE_PCNTXT is set,
+	 * set_affinity will be called directly by irq_set_affinity
+	 * Can we to make intr could be go through move_masked_irq/
+	 *	 move_native_irq path ?
+	 */
 	set_extra_move_desc(desc, mask);
 
 	dest = apic->cpu_mask_to_apicid_and(cfg->domain, mask);
@@ -2411,6 +2463,8 @@ migrate_ioapic_irq_desc(struct irq_desc
 
 	cpumask_copy(desc->affinity, mask);
 
+	desc = masked_move_desc(desc, mask);
+
 	return 0;
 }
 
@@ -2489,43 +2543,22 @@ unlock:
 	irq_exit();
 }
 
-static void irq_complete_move(struct irq_desc **descp)
+static void irq_complete_move(struct irq_desc *desc)
 {
-	struct irq_desc *desc = *descp;
 	struct irq_cfg *cfg = desc->chip_data;
 	unsigned vector, me;
 
-	if (likely(!cfg->move_in_progress)) {
-#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
-		if (likely(!cfg->move_desc_pending))
-			return;
-
-		/* domain has not changed, but affinity did */
-		me = smp_processor_id();
-		if (cpumask_test_cpu(me, desc->affinity)) {
-			*descp = desc = move_irq_desc(desc, me);
-			/* get the new one */
-			cfg = desc->chip_data;
-			cfg->move_desc_pending = 0;
-		}
-#endif
+	if (likely(!cfg->move_in_progress))
 		return;
-	}
 
 	vector = ~get_irq_regs()->orig_ax;
 	me = smp_processor_id();
 
-	if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain)) {
-#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
-		*descp = desc = move_irq_desc(desc, me);
-		/* get the new one */
-		cfg = desc->chip_data;
-#endif
+	if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain))
 		send_cleanup_vector(cfg);
-	}
 }
 #else
-static inline void irq_complete_move(struct irq_desc **descp) {}
+static inline void irq_complete_move(struct irq_desc *desc) {}
 #endif
 
 static void __eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg)
@@ -2579,7 +2612,7 @@ static void ack_apic_edge(unsigned int i
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
-	irq_complete_move(&desc);
+	irq_complete_move(desc);
 	move_native_irq(irq);
 	ack_APIC_irq();
 }
@@ -2597,7 +2630,7 @@ static void ack_apic_level(unsigned int
 	struct irq_cfg *cfg;
 	int do_unmask_irq = 0;
 
-	irq_complete_move(&desc);
+	irq_complete_move(desc);
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	/* If we are moving the irq we need to mask it */
 	if (unlikely(desc->status & IRQ_MOVE_PENDING)) {
@@ -2670,8 +2703,11 @@ static void ack_apic_level(unsigned int
 		 * and you can go talk to the chipset vendor about it.
 		 */
 		cfg = desc->chip_data;
-		if (!io_apic_level_ack_pending(cfg))
+		if (!io_apic_level_ack_pending(cfg)) {
 			move_masked_irq(irq);
+			desc = irq_remap_to_desc(irq, desc);
+			cfg = desc->chip_data;
+		}
 		unmask_IO_APIC_irq_desc(desc);
 	}
 
@@ -3377,7 +3413,7 @@ static int set_msi_irq_affinity(unsigned
 	struct msi_msg msg;
 	unsigned int dest;
 
-	dest = set_desc_affinity(desc, mask);
+	dest = set_desc_affinity(&desc, mask);
 	if (dest == BAD_APICID)
 		return -1;
 
@@ -3410,7 +3446,7 @@ ir_set_msi_irq_affinity(unsigned int irq
 	if (get_irte(irq, &irte))
 		return -1;
 
-	dest = set_desc_affinity(desc, mask);
+	dest = set_desc_affinity(&desc, mask);
 	if (dest == BAD_APICID)
 		return -1;
 
@@ -3591,7 +3627,7 @@ static int dmar_msi_set_affinity(unsigne
 	struct msi_msg msg;
 	unsigned int dest;
 
-	dest = set_desc_affinity(desc, mask);
+	dest = set_desc_affinity(&desc, mask);
 	if (dest == BAD_APICID)
 		return -1;
 
@@ -3647,7 +3683,7 @@ static int hpet_msi_set_affinity(unsigne
 	struct msi_msg msg;
 	unsigned int dest;
 
-	dest = set_desc_affinity(desc, mask);
+	dest = set_desc_affinity(&desc, mask);
 	if (dest == BAD_APICID)
 		return -1;
 
@@ -3725,7 +3761,7 @@ static int set_ht_irq_affinity(unsigned
 	struct irq_cfg *cfg;
 	unsigned int dest;
 
-	dest = set_desc_affinity(desc, mask);
+	dest = set_desc_affinity(&desc, mask);
 	if (dest == BAD_APICID)
 		return -1;
 
Index: linux-2.6/kernel/irq/migration.c
===================================================================
--- linux-2.6.orig/kernel/irq/migration.c
+++ linux-2.6/kernel/irq/migration.c
@@ -42,11 +42,16 @@ void move_masked_irq(int irq)
 	 * masking the irqs.
 	 */
 	if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
-		   < nr_cpu_ids))
-		if (!desc->chip->set_affinity(irq, desc->pending_mask)) {
+		   < nr_cpu_ids)) {
+		int ret;
+
+		ret = desc->chip->set_affinity(irq, desc->pending_mask);
+		desc = irq_remap_to_desc(irq, desc);
+		if (!ret) {
 			cpumask_copy(desc->affinity, desc->pending_mask);
 			irq_set_thread_affinity(desc, desc->pending_mask);
 		}
+	}
 
 	cpumask_clear(desc->pending_mask);
 }
@@ -63,6 +68,7 @@ void move_native_irq(int irq)
 
 	desc->chip->mask(irq);
 	move_masked_irq(irq);
+	desc = irq_remap_to_desc(irq, desc);
 	desc->chip->unmask(irq);
 }
 

Re: [PATCH 1/4] irq: correct CPUMASKS_OFFSTACK typo -v2

[Andrew Morton]

On Tue, 14 Apr 2009 13:41:55 -0700
Yinghai Lu <yinghai@kernel.org> wrote:

> irq

Speaking of which, could someone please take a look at
http://www.gossamer-threads.com/lists/linux/kernel/1060580?do=post_view_threaded#1060580
?

Thanks.

Re: [PATCH 4/4] irq: move move_irq_desc calling to set_affinity directly -v4

[Suresh Siddha]

Nack.

This patch and the existing code in Linus's git is wrong.

In mainline:

static void ack_apic_edge(unsigned int irq)
{
        struct irq_desc *desc = irq_to_desc(irq);

        irq_complete_move(&desc);
...

And

static void irq_complete_move(struct irq_desc **descp)
{
...
	*descp = desc = move_irq_desc(desc, me);
...
}

So, we end up modifying the stack pointer in the stack frame of
ack_apic_edge() but not really achieving the actual irq desc migration.

hmm.. We should be seeing crashes/memory leaks etc when this code is
turned on with the appropriate config options (apart from the code not
achieving its actual intentions).

As far as I can see, this patch also has the same issue.
Please fix both mainline and this patch.

And also, please see below:

On Tue, 2009-04-14 at 13:44 -0700, Yinghai Lu wrote:
> Impact: fix panic
> 
> so could move_masked_irq call move_irq_desc directly.
> also we still don't support IRQ_MOVE_PCNTXT aka intr_remapped path

As you added the original bits and also modifying these bits now, it
will be good if you can post a patch for this too. And if you can't test
particular paths, please copy the interested folks and get an ack from
their test results, before pushing the patch to upstream.

thanks,
suresh

Re: [PATCH 2/4] irq: make set_affinity to return status

[Rusty Russell]

On Wed, 15 Apr 2009 06:12:52 am Yinghai Lu wrote:
> 
> Impact: prepare to use it to keep affinity consistent
> 
> according to Ingo, change set_affinity() in irq_chip to return int.

I prefer a bool, or an actual -errno rather than -1.  Maybe Ingo feels
differently?

Plus:

> @@ -199,6 +199,8 @@ static void octeon_irq_ciu0_set_affinity
>  	 */
>  	cvmx_read_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2));
>  	write_unlock(&octeon_irq_ciu0_rwlock);
> +
> +	reutrn 0;
>  }

Typo.

Thanks,
Rusty.

[PATCH 2/4] irq: make set_affinity to return status -v2

[Yinghai Lu]

Impact: prepare to use it to keep affinity consistent

according to Ingo, change set_affinity() in irq_chip to return int.

v2: fix two typo that pointed by Rusty

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 arch/alpha/kernel/sys_dp264.c         |    8 +++-
 arch/alpha/kernel/sys_titan.c         |    4 +-
 arch/arm/common/gic.c                 |    4 +-
 arch/cris/arch-v32/kernel/irq.c       |    4 +-
 arch/ia64/hp/sim/hpsim_irq.c          |    3 +
 arch/ia64/kernel/iosapic.c            |   10 +++--
 arch/ia64/kernel/msi_ia64.c           |   16 +++++---
 arch/ia64/sn/kernel/irq.c             |    4 +-
 arch/ia64/sn/kernel/msi_sn.c          |    8 ++--
 arch/mips/cavium-octeon/octeon-irq.c  |    8 +++-
 arch/mips/include/asm/irq.h           |    2 -
 arch/mips/kernel/irq-gic.c            |    5 +-
 arch/mips/mti-malta/malta-smtc.c      |    4 +-
 arch/mips/sibyte/bcm1480/irq.c        |    8 ++--
 arch/mips/sibyte/sb1250/irq.c         |    8 ++--
 arch/parisc/kernel/irq.c              |    6 ++-
 arch/powerpc/platforms/pseries/xics.c |   12 +++---
 arch/powerpc/sysdev/mpic.c            |    4 +-
 arch/sparc/kernel/irq_64.c            |   12 ++++--
 arch/x86/kernel/apic/io_apic.c        |   64 +++++++++++++++++++++-------------
 drivers/parisc/iosapic.c              |    6 ++-
 drivers/xen/events.c                  |   12 +++---
 include/linux/irq.h                   |    2 -
 23 files changed, 140 insertions(+), 74 deletions(-)

Index: linux-2.6/arch/alpha/kernel/sys_dp264.c
===================================================================
--- linux-2.6.orig/arch/alpha/kernel/sys_dp264.c
+++ linux-2.6/arch/alpha/kernel/sys_dp264.c
@@ -176,22 +176,26 @@ cpu_set_irq_affinity(unsigned int irq, c
 	}
 }
 
-static void
+static int
 dp264_set_affinity(unsigned int irq, const struct cpumask *affinity)
 { 
 	spin_lock(&dp264_irq_lock);
 	cpu_set_irq_affinity(irq, *affinity);
 	tsunami_update_irq_hw(cached_irq_mask);
 	spin_unlock(&dp264_irq_lock);
+
+	return 0;
 }
 
-static void
+static int
 clipper_set_affinity(unsigned int irq, const struct cpumask *affinity)
 { 
 	spin_lock(&dp264_irq_lock);
 	cpu_set_irq_affinity(irq - 16, *affinity);
 	tsunami_update_irq_hw(cached_irq_mask);
 	spin_unlock(&dp264_irq_lock);
+
+	return 0;
 }
 
 static struct hw_interrupt_type dp264_irq_type = {
Index: linux-2.6/arch/alpha/kernel/sys_titan.c
===================================================================
--- linux-2.6.orig/arch/alpha/kernel/sys_titan.c
+++ linux-2.6/arch/alpha/kernel/sys_titan.c
@@ -157,13 +157,15 @@ titan_cpu_set_irq_affinity(unsigned int
 
 }
 
-static void
+static int
 titan_set_irq_affinity(unsigned int irq, const struct cpumask *affinity)
 { 
 	spin_lock(&titan_irq_lock);
 	titan_cpu_set_irq_affinity(irq - 16, *affinity);
 	titan_update_irq_hw(titan_cached_irq_mask);
 	spin_unlock(&titan_irq_lock);
+
+	return 0;
 }
 
 static void
Index: linux-2.6/arch/arm/common/gic.c
===================================================================
--- linux-2.6.orig/arch/arm/common/gic.c
+++ linux-2.6/arch/arm/common/gic.c
@@ -109,7 +109,7 @@ static void gic_unmask_irq(unsigned int
 }
 
 #ifdef CONFIG_SMP
-static void gic_set_cpu(unsigned int irq, const struct cpumask *mask_val)
+static int gic_set_cpu(unsigned int irq, const struct cpumask *mask_val)
 {
 	void __iomem *reg = gic_dist_base(irq) + GIC_DIST_TARGET + (gic_irq(irq) & ~3);
 	unsigned int shift = (irq % 4) * 8;
@@ -122,6 +122,8 @@ static void gic_set_cpu(unsigned int irq
 	val |= 1 << (cpu + shift);
 	writel(val, reg);
 	spin_unlock(&irq_controller_lock);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/cris/arch-v32/kernel/irq.c
===================================================================
--- linux-2.6.orig/arch/cris/arch-v32/kernel/irq.c
+++ linux-2.6/arch/cris/arch-v32/kernel/irq.c
@@ -325,12 +325,14 @@ static void end_crisv32_irq(unsigned int
 {
 }
 
-void set_affinity_crisv32_irq(unsigned int irq, const struct cpumask *dest)
+int set_affinity_crisv32_irq(unsigned int irq, const struct cpumask *dest)
 {
 	unsigned long flags;
 	spin_lock_irqsave(&irq_lock, flags);
 	irq_allocations[irq - FIRST_IRQ].mask = *dest;
 	spin_unlock_irqrestore(&irq_lock, flags);
+
+	return 0;
 }
 
 static struct irq_chip crisv32_irq_type = {
Index: linux-2.6/arch/ia64/hp/sim/hpsim_irq.c
===================================================================
--- linux-2.6.orig/arch/ia64/hp/sim/hpsim_irq.c
+++ linux-2.6/arch/ia64/hp/sim/hpsim_irq.c
@@ -21,9 +21,10 @@ hpsim_irq_noop (unsigned int irq)
 {
 }
 
-static void
+static int
 hpsim_set_affinity_noop(unsigned int a, const struct cpumask *b)
 {
+	return 0;
 }
 
 static struct hw_interrupt_type irq_type_hp_sim = {
Index: linux-2.6/arch/ia64/kernel/iosapic.c
===================================================================
--- linux-2.6.orig/arch/ia64/kernel/iosapic.c
+++ linux-2.6/arch/ia64/kernel/iosapic.c
@@ -329,7 +329,7 @@ unmask_irq (unsigned int irq)
 }
 
 
-static void
+static int
 iosapic_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 #ifdef CONFIG_SMP
@@ -343,15 +343,15 @@ iosapic_set_affinity(unsigned int irq, c
 
 	cpu = cpumask_first_and(cpu_online_mask, mask);
 	if (cpu >= nr_cpu_ids)
-		return;
+		return -1;
 
 	if (irq_prepare_move(irq, cpu))
-		return;
+		return -1;
 
 	dest = cpu_physical_id(cpu);
 
 	if (!iosapic_intr_info[irq].count)
-		return;			/* not an IOSAPIC interrupt */
+		return -1;			/* not an IOSAPIC interrupt */
 
 	set_irq_affinity_info(irq, dest, redir);
 
@@ -376,7 +376,9 @@ iosapic_set_affinity(unsigned int irq, c
 		iosapic_write(iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
 		iosapic_write(iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
 	}
+
 #endif
+	return 0;
 }
 
 /*
Index: linux-2.6/arch/ia64/kernel/msi_ia64.c
===================================================================
--- linux-2.6.orig/arch/ia64/kernel/msi_ia64.c
+++ linux-2.6/arch/ia64/kernel/msi_ia64.c
@@ -12,7 +12,7 @@
 static struct irq_chip	ia64_msi_chip;
 
 #ifdef CONFIG_SMP
-static void ia64_set_msi_irq_affinity(unsigned int irq,
+static int ia64_set_msi_irq_affinity(unsigned int irq,
 				      const cpumask_t *cpu_mask)
 {
 	struct msi_msg msg;
@@ -20,10 +20,10 @@ static void ia64_set_msi_irq_affinity(un
 	int cpu = first_cpu(*cpu_mask);
 
 	if (!cpu_online(cpu))
-		return;
+		return -1;
 
 	if (irq_prepare_move(irq, cpu))
-		return;
+		return -1;
 
 	read_msi_msg(irq, &msg);
 
@@ -39,6 +39,8 @@ static void ia64_set_msi_irq_affinity(un
 
 	write_msi_msg(irq, &msg);
 	cpumask_copy(irq_desc[irq].affinity, cpumask_of(cpu));
+
+	return 0;
 }
 #endif /* CONFIG_SMP */
 
@@ -130,17 +132,17 @@ void arch_teardown_msi_irq(unsigned int
 
 #ifdef CONFIG_DMAR
 #ifdef CONFIG_SMP
-static void dmar_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int dmar_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_cfg *cfg = irq_cfg + irq;
 	struct msi_msg msg;
 	int cpu = cpumask_first(mask);
 
 	if (!cpu_online(cpu))
-		return;
+		return -1;
 
 	if (irq_prepare_move(irq, cpu))
-		return;
+		return -1;
 
 	dmar_msi_read(irq, &msg);
 
@@ -151,6 +153,8 @@ static void dmar_msi_set_affinity(unsign
 
 	dmar_msi_write(irq, &msg);
 	cpumask_copy(irq_desc[irq].affinity, mask);
+
+	return 0;
 }
 #endif /* CONFIG_SMP */
 
Index: linux-2.6/arch/ia64/sn/kernel/irq.c
===================================================================
--- linux-2.6.orig/arch/ia64/sn/kernel/irq.c
+++ linux-2.6/arch/ia64/sn/kernel/irq.c
@@ -227,7 +227,7 @@ finish_up:
 	return new_irq_info;
 }
 
-static void sn_set_affinity_irq(unsigned int irq, const struct cpumask *mask)
+static int sn_set_affinity_irq(unsigned int irq, const struct cpumask *mask)
 {
 	struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
 	nasid_t nasid;
@@ -239,6 +239,8 @@ static void sn_set_affinity_irq(unsigned
 	list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
 				 sn_irq_lh[irq], list)
 		(void)sn_retarget_vector(sn_irq_info, nasid, slice);
+
+	return 0;
 }
 
 #ifdef CONFIG_SMP
Index: linux-2.6/arch/ia64/sn/kernel/msi_sn.c
===================================================================
--- linux-2.6.orig/arch/ia64/sn/kernel/msi_sn.c
+++ linux-2.6/arch/ia64/sn/kernel/msi_sn.c
@@ -151,7 +151,7 @@ int sn_setup_msi_irq(struct pci_dev *pde
 }
 
 #ifdef CONFIG_SMP
-static void sn_set_msi_irq_affinity(unsigned int irq,
+static int sn_set_msi_irq_affinity(unsigned int irq,
 				    const struct cpumask *cpu_mask)
 {
 	struct msi_msg msg;
@@ -168,7 +168,7 @@ static void sn_set_msi_irq_affinity(unsi
 	cpu = cpumask_first(cpu_mask);
 	sn_irq_info = sn_msi_info[irq].sn_irq_info;
 	if (sn_irq_info == NULL || sn_irq_info->irq_int_bit >= 0)
-		return;
+		return -1;
 
 	/*
 	 * Release XIO resources for the old MSI PCI address
@@ -189,7 +189,7 @@ static void sn_set_msi_irq_affinity(unsi
 	new_irq_info = sn_retarget_vector(sn_irq_info, nasid, slice);
 	sn_msi_info[irq].sn_irq_info = new_irq_info;
 	if (new_irq_info == NULL)
-		return;
+		return -1;
 
 	/*
 	 * Map the xio address into bus space
@@ -206,6 +206,8 @@ static void sn_set_msi_irq_affinity(unsi
 
 	write_msi_msg(irq, &msg);
 	cpumask_copy(irq_desc[irq].affinity, cpu_mask);
+
+	return 0;
 }
 #endif /* CONFIG_SMP */
 
Index: linux-2.6/arch/mips/cavium-octeon/octeon-irq.c
===================================================================
--- linux-2.6.orig/arch/mips/cavium-octeon/octeon-irq.c
+++ linux-2.6/arch/mips/cavium-octeon/octeon-irq.c
@@ -177,7 +177,7 @@ static void octeon_irq_ciu0_disable(unsi
 }
 
 #ifdef CONFIG_SMP
-static void octeon_irq_ciu0_set_affinity(unsigned int irq, const struct cpumask *dest)
+static int octeon_irq_ciu0_set_affinity(unsigned int irq, const struct cpumask *dest)
 {
 	int cpu;
 	int bit = irq - OCTEON_IRQ_WORKQ0;	/* Bit 0-63 of EN0 */
@@ -199,6 +199,8 @@ static void octeon_irq_ciu0_set_affinity
 	 */
 	cvmx_read_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2));
 	write_unlock(&octeon_irq_ciu0_rwlock);
+
+	return 0;
 }
 #endif
 
@@ -292,7 +294,7 @@ static void octeon_irq_ciu1_disable(unsi
 }
 
 #ifdef CONFIG_SMP
-static void octeon_irq_ciu1_set_affinity(unsigned int irq, const struct cpumask *dest)
+static int octeon_irq_ciu1_set_affinity(unsigned int irq, const struct cpumask *dest)
 {
 	int cpu;
 	int bit = irq - OCTEON_IRQ_WDOG0;	/* Bit 0-63 of EN1 */
@@ -315,6 +317,8 @@ static void octeon_irq_ciu1_set_affinity
 	 */
 	cvmx_read_csr(CVMX_CIU_INTX_EN1(cvmx_get_core_num() * 2 + 1));
 	write_unlock(&octeon_irq_ciu1_rwlock);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/mips/kernel/irq-gic.c
===================================================================
--- linux-2.6.orig/arch/mips/kernel/irq-gic.c
+++ linux-2.6/arch/mips/kernel/irq-gic.c
@@ -155,7 +155,7 @@ static void gic_unmask_irq(unsigned int
 
 static DEFINE_SPINLOCK(gic_lock);
 
-static void gic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
+static int gic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 {
 	cpumask_t	tmp = CPU_MASK_NONE;
 	unsigned long	flags;
@@ -166,7 +166,7 @@ static void gic_set_affinity(unsigned in
 
 	cpumask_and(&tmp, cpumask, cpu_online_mask);
 	if (cpus_empty(tmp))
-		return;
+		return -1;
 
 	/* Assumption : cpumask refers to a single CPU */
 	spin_lock_irqsave(&gic_lock, flags);
@@ -190,6 +190,7 @@ static void gic_set_affinity(unsigned in
 	cpumask_copy(irq_desc[irq].affinity, cpumask);
 	spin_unlock_irqrestore(&gic_lock, flags);
 
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/mips/sibyte/bcm1480/irq.c
===================================================================
--- linux-2.6.orig/arch/mips/sibyte/bcm1480/irq.c
+++ linux-2.6/arch/mips/sibyte/bcm1480/irq.c
@@ -50,7 +50,7 @@ static void enable_bcm1480_irq(unsigned
 static void disable_bcm1480_irq(unsigned int irq);
 static void ack_bcm1480_irq(unsigned int irq);
 #ifdef CONFIG_SMP
-static void bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask);
+static int bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask);
 #endif
 
 #ifdef CONFIG_PCI
@@ -109,7 +109,7 @@ void bcm1480_unmask_irq(int cpu, int irq
 }
 
 #ifdef CONFIG_SMP
-static void bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	int i = 0, old_cpu, cpu, int_on, k;
 	u64 cur_ints;
@@ -119,7 +119,7 @@ static void bcm1480_set_affinity(unsigne
 
 	if (cpumask_weight(mask) != 1) {
 		printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
-		return;
+		return -1;
 	}
 	i = cpumask_first(mask);
 
@@ -155,6 +155,8 @@ static void bcm1480_set_affinity(unsigne
 	}
 	spin_unlock(&bcm1480_imr_lock);
 	spin_unlock_irqrestore(&desc->lock, flags);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/mips/sibyte/sb1250/irq.c
===================================================================
--- linux-2.6.orig/arch/mips/sibyte/sb1250/irq.c
+++ linux-2.6/arch/mips/sibyte/sb1250/irq.c
@@ -50,7 +50,7 @@ static void enable_sb1250_irq(unsigned i
 static void disable_sb1250_irq(unsigned int irq);
 static void ack_sb1250_irq(unsigned int irq);
 #ifdef CONFIG_SMP
-static void sb1250_set_affinity(unsigned int irq, const struct cpumask *mask);
+static int sb1250_set_affinity(unsigned int irq, const struct cpumask *mask);
 #endif
 
 #ifdef CONFIG_SIBYTE_HAS_LDT
@@ -103,7 +103,7 @@ void sb1250_unmask_irq(int cpu, int irq)
 }
 
 #ifdef CONFIG_SMP
-static void sb1250_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int sb1250_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	int i = 0, old_cpu, cpu, int_on;
 	u64 cur_ints;
@@ -114,7 +114,7 @@ static void sb1250_set_affinity(unsigned
 
 	if (cpumask_weight(mask) > 1) {
 		printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
-		return;
+		return -1;
 	}
 
 	/* Convert logical CPU to physical CPU */
@@ -146,6 +146,8 @@ static void sb1250_set_affinity(unsigned
 	}
 	spin_unlock(&sb1250_imr_lock);
 	spin_unlock_irqrestore(&desc->lock, flags);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/parisc/kernel/irq.c
===================================================================
--- linux-2.6.orig/arch/parisc/kernel/irq.c
+++ linux-2.6/arch/parisc/kernel/irq.c
@@ -130,15 +130,17 @@ int cpu_check_affinity(unsigned int irq,
 	return cpu_dest;
 }
 
-static void cpu_set_affinity_irq(unsigned int irq, const struct cpumask *dest)
+static int cpu_set_affinity_irq(unsigned int irq, const struct cpumask *dest)
 {
 	int cpu_dest;
 
 	cpu_dest = cpu_check_affinity(irq, dest);
 	if (cpu_dest < 0)
-		return;
+		return -1;
 
 	cpumask_copy(&irq_desc[irq].affinity, dest);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/arch/powerpc/platforms/pseries/xics.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/pseries/xics.c
+++ linux-2.6/arch/powerpc/platforms/pseries/xics.c
@@ -333,7 +333,7 @@ static void xics_eoi_lpar(unsigned int v
 	lpar_xirr_info_set((0xff << 24) | irq);
 }
 
-static void xics_set_affinity(unsigned int virq, const struct cpumask *cpumask)
+static int xics_set_affinity(unsigned int virq, const struct cpumask *cpumask)
 {
 	unsigned int irq;
 	int status;
@@ -342,14 +342,14 @@ static void xics_set_affinity(unsigned i
 
 	irq = (unsigned int)irq_map[virq].hwirq;
 	if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
-		return;
+		return -1;
 
 	status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
 
 	if (status) {
 		printk(KERN_ERR "%s: ibm,get-xive irq=%u returns %d\n",
 			__func__, irq, status);
-		return;
+		return -1;
 	}
 
 	/*
@@ -363,7 +363,7 @@ static void xics_set_affinity(unsigned i
 		printk(KERN_WARNING
 			"%s: No online cpus in the mask %s for irq %d\n",
 			__func__, cpulist, virq);
-		return;
+		return -1;
 	}
 
 	status = rtas_call(ibm_set_xive, 3, 1, NULL,
@@ -372,8 +372,10 @@ static void xics_set_affinity(unsigned i
 	if (status) {
 		printk(KERN_ERR "%s: ibm,set-xive irq=%u returns %d\n",
 			__func__, irq, status);
-		return;
+		return -1;
 	}
+
+	return 0;
 }
 
 static struct irq_chip xics_pic_direct = {
Index: linux-2.6/arch/powerpc/sysdev/mpic.c
===================================================================
--- linux-2.6.orig/arch/powerpc/sysdev/mpic.c
+++ linux-2.6/arch/powerpc/sysdev/mpic.c
@@ -807,7 +807,7 @@ static void mpic_end_ipi(unsigned int ir
 
 #endif /* CONFIG_SMP */
 
-void mpic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
+int mpic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 {
 	struct mpic *mpic = mpic_from_irq(irq);
 	unsigned int src = mpic_irq_to_hw(irq);
@@ -824,6 +824,8 @@ void mpic_set_affinity(unsigned int irq,
 		mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION),
 			       mpic_physmask(cpus_addr(tmp)[0]));
 	}
+
+	return 0;
 }
 
 static unsigned int mpic_type_to_vecpri(struct mpic *mpic, unsigned int type)
Index: linux-2.6/arch/sparc/kernel/irq_64.c
===================================================================
--- linux-2.6.orig/arch/sparc/kernel/irq_64.c
+++ linux-2.6/arch/sparc/kernel/irq_64.c
@@ -318,10 +318,12 @@ static void sun4u_irq_enable(unsigned in
 	}
 }
 
-static void sun4u_set_affinity(unsigned int virt_irq,
+static int sun4u_set_affinity(unsigned int virt_irq,
 			       const struct cpumask *mask)
 {
 	sun4u_irq_enable(virt_irq);
+
+	return 0;
 }
 
 /* Don't do anything.  The desc->status check for IRQ_DISABLED in
@@ -377,7 +379,7 @@ static void sun4v_irq_enable(unsigned in
 		       ino, err);
 }
 
-static void sun4v_set_affinity(unsigned int virt_irq,
+static int sun4v_set_affinity(unsigned int virt_irq,
 			       const struct cpumask *mask)
 {
 	unsigned int ino = virt_irq_table[virt_irq].dev_ino;
@@ -388,6 +390,8 @@ static void sun4v_set_affinity(unsigned
 	if (err != HV_EOK)
 		printk(KERN_ERR "sun4v_intr_settarget(%x,%lu): "
 		       "err(%d)\n", ino, cpuid, err);
+
+	return 0;
 }
 
 static void sun4v_irq_disable(unsigned int virt_irq)
@@ -445,7 +449,7 @@ static void sun4v_virq_enable(unsigned i
 		       dev_handle, dev_ino, err);
 }
 
-static void sun4v_virt_set_affinity(unsigned int virt_irq,
+static int sun4v_virt_set_affinity(unsigned int virt_irq,
 				    const struct cpumask *mask)
 {
 	unsigned long cpuid, dev_handle, dev_ino;
@@ -461,6 +465,8 @@ static void sun4v_virt_set_affinity(unsi
 		printk(KERN_ERR "sun4v_vintr_set_target(%lx,%lx,%lu): "
 		       "err(%d)\n",
 		       dev_handle, dev_ino, cpuid, err);
+
+	return 0;
 }
 
 static void sun4v_virq_disable(unsigned int virt_irq)
Index: linux-2.6/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6/arch/x86/kernel/apic/io_apic.c
@@ -2326,13 +2326,14 @@ set_desc_affinity(struct irq_desc *desc,
 	return apic->cpu_mask_to_apicid_and(desc->affinity, cfg->domain);
 }
 
-static void
+static int
 set_ioapic_affinity_irq_desc(struct irq_desc *desc, const struct cpumask *mask)
 {
 	struct irq_cfg *cfg;
 	unsigned long flags;
 	unsigned int dest;
 	unsigned int irq;
+	int ret = -1;
 
 	irq = desc->irq;
 	cfg = desc->chip_data;
@@ -2343,18 +2344,21 @@ set_ioapic_affinity_irq_desc(struct irq_
 		/* Only the high 8 bits are valid. */
 		dest = SET_APIC_LOGICAL_ID(dest);
 		__target_IO_APIC_irq(irq, dest, cfg);
+		ret = 0;
 	}
 	spin_unlock_irqrestore(&ioapic_lock, flags);
+
+	return ret;
 }
 
-static void
+static int
 set_ioapic_affinity_irq(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc;
 
 	desc = irq_to_desc(irq);
 
-	set_ioapic_affinity_irq_desc(desc, mask);
+	return set_ioapic_affinity_irq_desc(desc, mask);
 }
 
 #ifdef CONFIG_INTR_REMAP
@@ -2370,24 +2374,25 @@ set_ioapic_affinity_irq(unsigned int irq
  * Real vector that is used for interrupting cpu will be coming from
  * the interrupt-remapping table entry.
  */
-static void
+static int
 migrate_ioapic_irq_desc(struct irq_desc *desc, const struct cpumask *mask)
 {
 	struct irq_cfg *cfg;
 	struct irte irte;
 	unsigned int dest;
 	unsigned int irq;
+	int ret = -1;
 
 	if (!cpumask_intersects(mask, cpu_online_mask))
-		return;
+		return ret;
 
 	irq = desc->irq;
 	if (get_irte(irq, &irte))
-		return;
+		return ret;
 
 	cfg = desc->chip_data;
 	if (assign_irq_vector(irq, cfg, mask))
-		return;
+		return ret;
 
 	set_extra_move_desc(desc, mask);
 
@@ -2405,27 +2410,30 @@ migrate_ioapic_irq_desc(struct irq_desc
 		send_cleanup_vector(cfg);
 
 	cpumask_copy(desc->affinity, mask);
+
+	return 0;
 }
 
 /*
  * Migrates the IRQ destination in the process context.
  */
-static void set_ir_ioapic_affinity_irq_desc(struct irq_desc *desc,
+static int set_ir_ioapic_affinity_irq_desc(struct irq_desc *desc,
 					    const struct cpumask *mask)
 {
-	migrate_ioapic_irq_desc(desc, mask);
+	return migrate_ioapic_irq_desc(desc, mask);
 }
-static void set_ir_ioapic_affinity_irq(unsigned int irq,
+static int set_ir_ioapic_affinity_irq(unsigned int irq,
 				       const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
-	set_ir_ioapic_affinity_irq_desc(desc, mask);
+	return set_ir_ioapic_affinity_irq_desc(desc, mask);
 }
 #else
-static inline void set_ir_ioapic_affinity_irq_desc(struct irq_desc *desc,
+static inline int set_ir_ioapic_affinity_irq_desc(struct irq_desc *desc,
 						   const struct cpumask *mask)
 {
+	return 0;
 }
 #endif
 
@@ -3362,7 +3370,7 @@ static int msi_compose_msg(struct pci_de
 }
 
 #ifdef CONFIG_SMP
-static void set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask)
+static int set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	struct irq_cfg *cfg;
@@ -3371,7 +3379,7 @@ static void set_msi_irq_affinity(unsigne
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	cfg = desc->chip_data;
 
@@ -3383,13 +3391,15 @@ static void set_msi_irq_affinity(unsigne
 	msg.address_lo |= MSI_ADDR_DEST_ID(dest);
 
 	write_msi_msg_desc(desc, &msg);
+
+	return 0;
 }
 #ifdef CONFIG_INTR_REMAP
 /*
  * Migrate the MSI irq to another cpumask. This migration is
  * done in the process context using interrupt-remapping hardware.
  */
-static void
+static int
 ir_set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
@@ -3398,11 +3408,11 @@ ir_set_msi_irq_affinity(unsigned int irq
 	struct irte irte;
 
 	if (get_irte(irq, &irte))
-		return;
+		return -1;
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	irte.vector = cfg->vector;
 	irte.dest_id = IRTE_DEST(dest);
@@ -3419,6 +3429,8 @@ ir_set_msi_irq_affinity(unsigned int irq
 	 */
 	if (cfg->move_in_progress)
 		send_cleanup_vector(cfg);
+
+	return 0;
 }
 
 #endif
@@ -3572,7 +3584,7 @@ void arch_teardown_msi_irq(unsigned int
 
 #if defined (CONFIG_DMAR) || defined (CONFIG_INTR_REMAP)
 #ifdef CONFIG_SMP
-static void dmar_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int dmar_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	struct irq_cfg *cfg;
@@ -3581,7 +3593,7 @@ static void dmar_msi_set_affinity(unsign
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	cfg = desc->chip_data;
 
@@ -3593,6 +3605,8 @@ static void dmar_msi_set_affinity(unsign
 	msg.address_lo |= MSI_ADDR_DEST_ID(dest);
 
 	dmar_msi_write(irq, &msg);
+
+	return 0;
 }
 
 #endif /* CONFIG_SMP */
@@ -3626,7 +3640,7 @@ int arch_setup_dmar_msi(unsigned int irq
 #ifdef CONFIG_HPET_TIMER
 
 #ifdef CONFIG_SMP
-static void hpet_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
+static int hpet_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	struct irq_cfg *cfg;
@@ -3635,7 +3649,7 @@ static void hpet_msi_set_affinity(unsign
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	cfg = desc->chip_data;
 
@@ -3647,6 +3661,8 @@ static void hpet_msi_set_affinity(unsign
 	msg.address_lo |= MSI_ADDR_DEST_ID(dest);
 
 	hpet_msi_write(irq, &msg);
+
+	return 0;
 }
 
 #endif /* CONFIG_SMP */
@@ -3703,7 +3719,7 @@ static void target_ht_irq(unsigned int i
 	write_ht_irq_msg(irq, &msg);
 }
 
-static void set_ht_irq_affinity(unsigned int irq, const struct cpumask *mask)
+static int set_ht_irq_affinity(unsigned int irq, const struct cpumask *mask)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	struct irq_cfg *cfg;
@@ -3711,11 +3727,13 @@ static void set_ht_irq_affinity(unsigned
 
 	dest = set_desc_affinity(desc, mask);
 	if (dest == BAD_APICID)
-		return;
+		return -1;
 
 	cfg = desc->chip_data;
 
 	target_ht_irq(irq, dest, cfg->vector);
+
+	return 0;
 }
 
 #endif
Index: linux-2.6/drivers/parisc/iosapic.c
===================================================================
--- linux-2.6.orig/drivers/parisc/iosapic.c
+++ linux-2.6/drivers/parisc/iosapic.c
@@ -702,7 +702,7 @@ static unsigned int iosapic_startup_irq(
 }
 
 #ifdef CONFIG_SMP
-static void iosapic_set_affinity_irq(unsigned int irq,
+static int iosapic_set_affinity_irq(unsigned int irq,
 				     const struct cpumask *dest)
 {
 	struct vector_info *vi = iosapic_get_vector(irq);
@@ -712,7 +712,7 @@ static void iosapic_set_affinity_irq(uns
 
 	dest_cpu = cpu_check_affinity(irq, dest);
 	if (dest_cpu < 0)
-		return;
+		return -1;
 
 	cpumask_copy(irq_desc[irq].affinity, cpumask_of(dest_cpu));
 	vi->txn_addr = txn_affinity_addr(irq, dest_cpu);
@@ -724,6 +724,8 @@ static void iosapic_set_affinity_irq(uns
 	iosapic_set_irt_data(vi, &dummy_d0, &d1);
 	iosapic_wr_irt_entry(vi, d0, d1);
 	spin_unlock_irqrestore(&iosapic_lock, flags);
+
+	return 0;
 }
 #endif
 
Index: linux-2.6/drivers/xen/events.c
===================================================================
--- linux-2.6.orig/drivers/xen/events.c
+++ linux-2.6/drivers/xen/events.c
@@ -694,13 +694,13 @@ void rebind_evtchn_irq(int evtchn, int i
 }
 
 /* Rebind an evtchn so that it gets delivered to a specific cpu */
-static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
+static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
 {
 	struct evtchn_bind_vcpu bind_vcpu;
 	int evtchn = evtchn_from_irq(irq);
 
 	if (!VALID_EVTCHN(evtchn))
-		return;
+		return -1;
 
 	/* Send future instances of this interrupt to other vcpu. */
 	bind_vcpu.port = evtchn;
@@ -713,13 +713,15 @@ static void rebind_irq_to_cpu(unsigned i
 	 */
 	if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
 		bind_evtchn_to_cpu(evtchn, tcpu);
-}
 
+	return 0;
+}
 
-static void set_affinity_irq(unsigned irq, const struct cpumask *dest)
+static int set_affinity_irq(unsigned irq, const struct cpumask *dest)
 {
 	unsigned tcpu = cpumask_first(dest);
-	rebind_irq_to_cpu(irq, tcpu);
+
+	return rebind_irq_to_cpu(irq, tcpu);
 }
 
 int resend_irq_on_evtchn(unsigned int irq)
Index: linux-2.6/include/linux/irq.h
===================================================================
--- linux-2.6.orig/include/linux/irq.h
+++ linux-2.6/include/linux/irq.h
@@ -117,7 +117,7 @@ struct irq_chip {
 	void		(*eoi)(unsigned int irq);
 
 	void		(*end)(unsigned int irq);
-	void		(*set_affinity)(unsigned int irq,
+	int		(*set_affinity)(unsigned int irq,
 					const struct cpumask *dest);
 	int		(*retrigger)(unsigned int irq);
 	int		(*set_type)(unsigned int irq, unsigned int flow_type);
Index: linux-2.6/arch/mips/include/asm/irq.h
===================================================================
--- linux-2.6.orig/arch/mips/include/asm/irq.h
+++ linux-2.6/arch/mips/include/asm/irq.h
@@ -49,7 +49,7 @@ static inline void smtc_im_ack_irq(unsig
 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
 #include <linux/cpumask.h>
 
-extern void plat_set_irq_affinity(unsigned int irq,
+extern int plat_set_irq_affinity(unsigned int irq,
 				  const struct cpumask *affinity);
 extern void smtc_forward_irq(unsigned int irq);
 
Index: linux-2.6/arch/mips/mti-malta/malta-smtc.c
===================================================================
--- linux-2.6.orig/arch/mips/mti-malta/malta-smtc.c
+++ linux-2.6/arch/mips/mti-malta/malta-smtc.c
@@ -114,7 +114,7 @@ struct plat_smp_ops msmtc_smp_ops = {
  */
 
 
-void plat_set_irq_affinity(unsigned int irq, const struct cpumask *affinity)
+int plat_set_irq_affinity(unsigned int irq, const struct cpumask *affinity)
 {
 	cpumask_t tmask;
 	int cpu = 0;
@@ -156,5 +156,7 @@ void plat_set_irq_affinity(unsigned int
 
 	/* Do any generic SMTC IRQ affinity setup */
 	smtc_set_irq_affinity(irq, tmask);
+
+	return 0;
 }
 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */

Re: [PATCH 1/4] irq: correct CPUMASKS_OFFSTACK typo -v2

[Ingo Molnar]

* Andrew Morton <akpm@linux-foundation.org> wrote:

> On Tue, 14 Apr 2009 13:41:55 -0700
> Yinghai Lu <yinghai@kernel.org> wrote:
> 
> > irq
> 
> Speaking of which, could someone please take a look at
> http://www.gossamer-threads.com/lists/linux/kernel/1060580?do=post_view_threaded#1060580
> ?
[...]

> But try_one_irq() is running tifm_7xx1_isr() with local interrupts 
> enabled, which upsets lockdep.

It doesnt just upset lockdep, it could also cause real lockups. 
Lockdep is just the canary, the lockup is the methane explosion.

> But I suspect that the code as it stands is non-buggy. Unless the 
> interrupt can magically come back to life. In which case any 
> change we make is purely a make-lockdep-shut-up thing.

Hm, i'd suggest we go for the methane leak instead of squashing the 
canary. Which in this case would be try_one_irq() ignoring 
IRQF_DISABLED or so? Affecting (much) more ISRs than just 
tifm_7xx1_isr()?

Thomas?

	Ingo

Re: [PATCH 1/4] irq: correct CPUMASKS_OFFSTACK typo -v2

[Andrew Morton]

On Wed, 15 Apr 2009 12:01:05 +0200
Ingo Molnar <mingo@elte.hu> wrote:

> 
> * Andrew Morton <akpm@linux-foundation.org> wrote:
> 
> > On Tue, 14 Apr 2009 13:41:55 -0700
> > Yinghai Lu <yinghai@kernel.org> wrote:
> > 
> > > irq
> > 
> > Speaking of which, could someone please take a look at
> > http://www.gossamer-threads.com/lists/linux/kernel/1060580?do=post_view_threaded#1060580
> > ?
> [...]
> 
> > But try_one_irq() is running tifm_7xx1_isr() with local interrupts 
> > enabled, which upsets lockdep.
> 
> It doesnt just upset lockdep, it could also cause real lockups. 

Only if the interrupt were to magically come back to life, then
trigger.  I think.  Possibly in the case of shared interrupts we'd lock
up because of an interrupt from another device.

> Lockdep is just the canary, the lockup is the methane explosion.
> 
> > But I suspect that the code as it stands is non-buggy. Unless the 
> > interrupt can magically come back to life. In which case any 
> > change we make is purely a make-lockdep-shut-up thing.
> 
> Hm, i'd suggest we go for the methane leak instead of squashing the 
> canary. Which in this case would be try_one_irq() ignoring 
> IRQF_DISABLED or so? Affecting (much) more ISRs than just 
> tifm_7xx1_isr()?

tifm_7xx1_isr() is requested with bare IRQF_SHARED, so that function is
supposed to be called with local interrupts enabled.

And indeed, try_one_irq() is calling it with local interrupts enabled. 
That gets lockdep upset.  I assume there's magic in lockdep somewhere
which recognises the case where a function is called in hard irq
context with local interrupts enabled and, knowing that the controller
won't generate another interrupt, treats this as
local-interrupt-disabled.  Or something.

I don't know how to fix this really.  We _could_ fudge it by disabling
local interrupts in try_one_irq().  But the ISR could legitimately do
(say) spin_unlock_irq() and muck everything up.