From 18374d89e5fe96772102f44f535efb1198d9be08 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Thu, 17 Dec 2009 18:29:46 -0800 Subject: x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system John Blackwood reported: > on an older Dell PowerEdge 6650 system with 8 cpus (4 are hyper-threaded), > and 32 bit (x86) kernel, once you change the irq smp_affinity of an irq > to be less than all cpus in the system, you can never change really the > irq smp_affinity back to be all cpus in the system (0xff) again, > even though no error status is returned on the "/bin/echo ff > > /proc/irq/[n]/smp_affinity" operation. > > This is due to that fact that BAD_APICID has the same value as > all cpus (0xff) on 32bit kernels, and thus the value returned from > set_desc_affinity() via the cpu_mask_to_apicid_and() function is treated > as a failure in set_ioapic_affinity_irq_desc(), and no affinity changes > are made. set_desc_affinity() is already checking if the incoming cpu mask intersects with the cpu online mask or not. So there is no need for the apic op cpu_mask_to_apicid_and() to check again and return BAD_APICID. Remove the BAD_APICID return value from cpu_mask_to_apicid_and() and also fix set_desc_affinity() to return -1 instead of using BAD_APICID to represent error conditions (as cpu_mask_to_apicid_and() can return logical or physical apicid values and BAD_APICID is really to represent bad physical apic id). Reported-by: John Blackwood Root-caused-by: John Blackwood Signed-off-by: Suresh Siddha LKML-Reference: <1261103386.2535.409.camel@sbs-t61> Signed-off-by: H. Peter Anvin --- arch/x86/kernel/apic/apic_flat_64.c | 5 +---- arch/x86/kernel/apic/bigsmp_32.c | 5 +---- arch/x86/kernel/apic/io_apic.c | 32 ++++++++++++++------------------ arch/x86/kernel/apic/x2apic_cluster.c | 5 +---- arch/x86/kernel/apic/x2apic_phys.c | 5 +---- arch/x86/kernel/apic/x2apic_uv_x.c | 5 +---- 6 files changed, 19 insertions(+), 38 deletions(-) (limited to 'arch/x86/kernel/apic') diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c index d0c99abc26c..eacbd2b31d2 100644 --- a/arch/x86/kernel/apic/apic_flat_64.c +++ b/arch/x86/kernel/apic/apic_flat_64.c @@ -306,10 +306,7 @@ physflat_cpu_mask_to_apicid_and(const struct cpumask *cpumask, if (cpumask_test_cpu(cpu, cpu_online_mask)) break; } - if (cpu < nr_cpu_ids) - return per_cpu(x86_cpu_to_apicid, cpu); - - return BAD_APICID; + return per_cpu(x86_cpu_to_apicid, cpu); } struct apic apic_physflat = { diff --git a/arch/x86/kernel/apic/bigsmp_32.c b/arch/x86/kernel/apic/bigsmp_32.c index 38dcecfa581..cb804c5091b 100644 --- a/arch/x86/kernel/apic/bigsmp_32.c +++ b/arch/x86/kernel/apic/bigsmp_32.c @@ -131,10 +131,7 @@ static unsigned int bigsmp_cpu_mask_to_apicid_and(const struct cpumask *cpumask, if (cpumask_test_cpu(cpu, cpu_online_mask)) break; } - if (cpu < nr_cpu_ids) - return bigsmp_cpu_to_logical_apicid(cpu); - - return BAD_APICID; + return bigsmp_cpu_to_logical_apicid(cpu); } static int bigsmp_phys_pkg_id(int cpuid_apic, int index_msb) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index d5d498fbee4..98ced709e82 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -2276,26 +2276,28 @@ static void __target_IO_APIC_irq(unsigned int irq, unsigned int dest, struct irq /* * Either sets desc->affinity to a valid value, and returns - * ->cpu_mask_to_apicid of that, or returns BAD_APICID and + * ->cpu_mask_to_apicid of that in dest_id, or returns -1 and * leaves desc->affinity untouched. */ unsigned int -set_desc_affinity(struct irq_desc *desc, const struct cpumask *mask) +set_desc_affinity(struct irq_desc *desc, const struct cpumask *mask, + unsigned int *dest_id) { struct irq_cfg *cfg; unsigned int irq; if (!cpumask_intersects(mask, cpu_online_mask)) - return BAD_APICID; + return -1; irq = desc->irq; cfg = desc->chip_data; if (assign_irq_vector(irq, cfg, mask)) - return BAD_APICID; + return -1; cpumask_copy(desc->affinity, mask); - return apic->cpu_mask_to_apicid_and(desc->affinity, cfg->domain); + *dest_id = apic->cpu_mask_to_apicid_and(desc->affinity, cfg->domain); + return 0; } static int @@ -2311,12 +2313,11 @@ set_ioapic_affinity_irq_desc(struct irq_desc *desc, const struct cpumask *mask) cfg = desc->chip_data; spin_lock_irqsave(&ioapic_lock, flags); - dest = set_desc_affinity(desc, mask); - if (dest != BAD_APICID) { + ret = set_desc_affinity(desc, mask, &dest); + if (!ret) { /* 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); @@ -3351,8 +3352,7 @@ static int set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask) struct msi_msg msg; unsigned int dest; - dest = set_desc_affinity(desc, mask); - if (dest == BAD_APICID) + if (set_desc_affinity(desc, mask, &dest)) return -1; cfg = desc->chip_data; @@ -3384,8 +3384,7 @@ ir_set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask) if (get_irte(irq, &irte)) return -1; - dest = set_desc_affinity(desc, mask); - if (dest == BAD_APICID) + if (set_desc_affinity(desc, mask, &dest)) return -1; irte.vector = cfg->vector; @@ -3567,8 +3566,7 @@ static int dmar_msi_set_affinity(unsigned int irq, const struct cpumask *mask) struct msi_msg msg; unsigned int dest; - dest = set_desc_affinity(desc, mask); - if (dest == BAD_APICID) + if (set_desc_affinity(desc, mask, &dest)) return -1; cfg = desc->chip_data; @@ -3623,8 +3621,7 @@ static int hpet_msi_set_affinity(unsigned int irq, const struct cpumask *mask) struct msi_msg msg; unsigned int dest; - dest = set_desc_affinity(desc, mask); - if (dest == BAD_APICID) + if (set_desc_affinity(desc, mask, &dest)) return -1; cfg = desc->chip_data; @@ -3730,8 +3727,7 @@ static int set_ht_irq_affinity(unsigned int irq, const struct cpumask *mask) struct irq_cfg *cfg; unsigned int dest; - dest = set_desc_affinity(desc, mask); - if (dest == BAD_APICID) + if (set_desc_affinity(desc, mask, &dest)) return -1; cfg = desc->chip_data; diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c index a5371ec3677..cf69c59f491 100644 --- a/arch/x86/kernel/apic/x2apic_cluster.c +++ b/arch/x86/kernel/apic/x2apic_cluster.c @@ -148,10 +148,7 @@ x2apic_cpu_mask_to_apicid_and(const struct cpumask *cpumask, break; } - if (cpu < nr_cpu_ids) - return per_cpu(x86_cpu_to_logical_apicid, cpu); - - return BAD_APICID; + return per_cpu(x86_cpu_to_logical_apicid, cpu); } static unsigned int x2apic_cluster_phys_get_apic_id(unsigned long x) diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c index a8989aadc99..8972f38c5ce 100644 --- a/arch/x86/kernel/apic/x2apic_phys.c +++ b/arch/x86/kernel/apic/x2apic_phys.c @@ -146,10 +146,7 @@ x2apic_cpu_mask_to_apicid_and(const struct cpumask *cpumask, break; } - if (cpu < nr_cpu_ids) - return per_cpu(x86_cpu_to_apicid, cpu); - - return BAD_APICID; + return per_cpu(x86_cpu_to_apicid, cpu); } static unsigned int x2apic_phys_get_apic_id(unsigned long x) diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index b684bb303cb..d56b0efb205 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c @@ -225,10 +225,7 @@ uv_cpu_mask_to_apicid_and(const struct cpumask *cpumask, if (cpumask_test_cpu(cpu, cpu_online_mask)) break; } - if (cpu < nr_cpu_ids) - return per_cpu(x86_cpu_to_apicid, cpu); - - return BAD_APICID; + return per_cpu(x86_cpu_to_apicid, cpu); } static unsigned int x2apic_get_apic_id(unsigned long x) -- cgit v1.2.3