From ff164324123c0fe181d8de7dadcc7b3fbe25f2cf Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Thu, 7 Jun 2012 15:15:59 +0200 Subject: x86/apic: Make cpu_mask_to_apicid() operations return error code Current cpu_mask_to_apicid() and cpu_mask_to_apicid_and() implementations have few shortcomings: 1. A value returned by cpu_mask_to_apicid() is written to hardware registers unconditionally. Should BAD_APICID get ever returned it will be written to a hardware too. But the value of BAD_APICID is not universal across all hardware in all modes and might cause unexpected results, i.e. interrupts might get routed to CPUs that are not configured to receive it. 2. Because the value of BAD_APICID is not universal it is counter- intuitive to return it for a hardware where it does not make sense (i.e. x2apic). 3. cpu_mask_to_apicid_and() operation is thought as an complement to cpu_mask_to_apicid() that only applies a AND mask on top of a cpumask being passed. Yet, as consequence of 18374d8 commit the two operations are inconsistent in that of: cpu_mask_to_apicid() should not get a offline CPU with the cpumask cpu_mask_to_apicid_and() should not fail and return BAD_APICID These limitations are impossible to realize just from looking at the operations prototypes. Most of these shortcomings are resolved by returning a error code instead of BAD_APICID. As the result, faults are reported back early rather than possibilities to cause a unexpected behaviour exist (in case of [1]). The only exception is setup_timer_IRQ0_pin() routine. Although obviously controversial to this fix, its existing behaviour is preserved to not break the fragile check_timer() and would better addressed in a separate fix. Signed-off-by: Alexander Gordeev Acked-by: Suresh Siddha Cc: Yinghai Lu Link: http://lkml.kernel.org/r/20120607131559.GF4759@dhcp-26-207.brq.redhat.com Signed-off-by: Ingo Molnar --- drivers/iommu/intel_irq_remapping.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index 6d34706..dafbad0 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -924,6 +924,7 @@ intel_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask, struct irq_cfg *cfg = data->chip_data; unsigned int dest, irq = data->irq; struct irte irte; + int err; if (!cpumask_intersects(mask, cpu_online_mask)) return -EINVAL; @@ -931,10 +932,16 @@ intel_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask, if (get_irte(irq, &irte)) return -EBUSY; - if (assign_irq_vector(irq, cfg, mask)) - return -EBUSY; + err = assign_irq_vector(irq, cfg, mask); + if (err) + return err; - dest = apic->cpu_mask_to_apicid_and(cfg->domain, mask); + err = apic->cpu_mask_to_apicid_and(cfg->domain, mask, &dest); + if (err) { + if (assign_irq_vector(irq, cfg, data->affinity)); + pr_err("Failed to recover vector for irq %d\n", irq); + return err; + } irte.vector = cfg->vector; irte.dest_id = IRTE_DEST(dest); -- cgit v1.1 From ed88bed881c9948c4035828c5d63f60c7b015f86 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 12 Jun 2012 19:26:33 +0300 Subject: x86/apic/irq_remap: Silence a bogus pr_err() There is an extra semicolon here so the pr_err() message is printed when it is not intended. Signed-off-by: Dan Carpenter Acked-by: Yinghai Lu Cc: Alexander Gordeev Cc: Suresh Siddha Cc: Joerg Roedel Link: http://lkml.kernel.org/r/20120612162633.GA11077@elgon.mountain Signed-off-by: Ingo Molnar --- drivers/iommu/intel_irq_remapping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index dafbad0..853902a 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -938,7 +938,7 @@ intel_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask, err = apic->cpu_mask_to_apicid_and(cfg->domain, mask, &dest); if (err) { - if (assign_irq_vector(irq, cfg, data->affinity)); + if (assign_irq_vector(irq, cfg, data->affinity)) pr_err("Failed to recover vector for irq %d\n", irq); return err; } -- cgit v1.1 From 7eb9ae0799b1e9f0b77733b432bc5f6f055b020b Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Thu, 14 Jun 2012 18:28:49 -0700 Subject: irq/apic: Use config_enabled(CONFIG_SMP) checks to clean up irq_set_affinity() for UP Move the ->irq_set_affinity() routines out of the #ifdef CONFIG_SMP sections and use config_enabled(CONFIG_SMP) checks inside those routines. Thus making those routines simple null stubs for !CONFIG_SMP and retaining those routines with no additional runtime overhead for CONFIG_SMP kernels. Cleans up the ifdef CONFIG_SMP in and around routines related to irq_set_affinity in io_apic and irq_remapping subsystems. Signed-off-by: Suresh Siddha Cc: torvalds@linux-foundation.org Cc: joerg.roedel@amd.com Cc: Sam Ravnborg Cc: Paul Gortmaker Link: http://lkml.kernel.org/r/1339723729.3475.63.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar --- drivers/iommu/intel_irq_remapping.c | 7 +++---- drivers/iommu/irq_remapping.c | 5 ++--- drivers/iommu/irq_remapping.h | 2 -- 3 files changed, 5 insertions(+), 9 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index 853902a..e0b18f3 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -902,7 +902,6 @@ static int intel_setup_ioapic_entry(int irq, return 0; } -#ifdef CONFIG_SMP /* * Migrate the IO-APIC irq in the presence of intr-remapping. * @@ -926,6 +925,9 @@ intel_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask, struct irte irte; int err; + if (!config_enabled(CONFIG_SMP)) + return -EINVAL; + if (!cpumask_intersects(mask, cpu_online_mask)) return -EINVAL; @@ -963,7 +965,6 @@ intel_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask, cpumask_copy(data->affinity, mask); return 0; } -#endif static void intel_compose_msi_msg(struct pci_dev *pdev, unsigned int irq, unsigned int dest, @@ -1065,9 +1066,7 @@ struct irq_remap_ops intel_irq_remap_ops = { .reenable = reenable_irq_remapping, .enable_faulting = enable_drhd_fault_handling, .setup_ioapic_entry = intel_setup_ioapic_entry, -#ifdef CONFIG_SMP .set_affinity = intel_ioapic_set_affinity, -#endif .free_irq = free_irte, .compose_msi_msg = intel_compose_msi_msg, .msi_alloc_irq = intel_msi_alloc_irq, diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c index 40cda8e..1d29b1c 100644 --- a/drivers/iommu/irq_remapping.c +++ b/drivers/iommu/irq_remapping.c @@ -111,16 +111,15 @@ int setup_ioapic_remapped_entry(int irq, vector, attr); } -#ifdef CONFIG_SMP int set_remapped_irq_affinity(struct irq_data *data, const struct cpumask *mask, bool force) { - if (!remap_ops || !remap_ops->set_affinity) + if (!config_enabled(CONFIG_SMP) || !remap_ops || + !remap_ops->set_affinity) return 0; return remap_ops->set_affinity(data, mask, force); } -#endif void free_remapped_irq(int irq) { diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h index be9d729..b12974c 100644 --- a/drivers/iommu/irq_remapping.h +++ b/drivers/iommu/irq_remapping.h @@ -59,11 +59,9 @@ struct irq_remap_ops { unsigned int, int, struct io_apic_irq_attr *); -#ifdef CONFIG_SMP /* Set the CPU affinity of a remapped interrupt */ int (*set_affinity)(struct irq_data *data, const struct cpumask *mask, bool force); -#endif /* Free an IRQ */ int (*free_irq)(int); -- cgit v1.1