Merge branch irq/affinity-nosmp into irq/plic-masking

* irq/affinity-nosmp:
  : .
  : non-SMP IRQ affinity fixes courtesy of Samuel Holland:
  :
  : "This series solves some inconsistency with how IRQ affinity masks are
  : handled between SMP and non-SMP configurations.
  :
  : In non-SMP configs, an IRQ's true affinity is always cpumask_of(0), so
  : irq_{,data_}get_affinity_mask now return that, instead of returning an
  : uninitialized per-IRQ cpumask. This change makes iterating over the
  : affinity mask do the right thing in both SMP and non-SMP configurations.
  :
  : To accomplish that:
  :  - patches 1-3 disable some library code that was broken anyway on !SMP
  :  - patches 4-7 refactor the code so that irq_{,data_}get_affinity_mask
  :    can return a const cpumask, since that is what cpumask_of provides
  :  - patch 8 drops the per-IRQ cpumask and replaces it with cpumask_of(0)"
  : .
  PCI: hv: Take a const cpumask in hv_compose_msi_req_get_cpu()
  genirq: Provide an IRQ affinity mask in non-SMP configs
  genirq: Return a const cpumask from irq_data_get_affinity_mask
  genirq: Add and use an irq_data_update_affinity helper
  genirq: Refactor accessors to use irq_data_get_affinity_mask
  genirq: Drop redundant irq_init_effective_affinity
  genirq: GENERIC_IRQ_EFFECTIVE_AFF_MASK depends on SMP
  genirq: GENERIC_IRQ_IPI depends on SMP
  irqchip/mips-gic: Only register IPI domain when SMP is enabled

Signed-off-by: Marc Zyngier <maz@kernel.org>

5 files changed, 18 insertions, 20 deletions

diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 10929eda9825..db3d174c53d4 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -24,6 +24,7 @@ config GENERIC_IRQ_SHOW_LEVEL
 
 # Supports effective affinity mask
 config GENERIC_IRQ_EFFECTIVE_AFF_MASK
+       depends on SMP
        bool
 
 # Support for delayed migration from interrupt context
@@ -82,6 +83,7 @@ config IRQ_FASTEOI_HIERARCHY_HANDLERS
 # Generic IRQ IPI support
 config GENERIC_IRQ_IPI
 	bool
+	depends on SMP
 	select IRQ_DOMAIN_HIERARCHY
 
 # Generic MSI interrupt support
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 886789dcee43..9c7ad2266317 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -188,7 +188,8 @@ enum {
 
 #ifdef CONFIG_SMP
 static int
-__irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force)
+__irq_startup_managed(struct irq_desc *desc, const struct cpumask *aff,
+		      bool force)
 {
 	struct irq_data *d = irq_desc_get_irq_data(desc);
 
@@ -224,7 +225,8 @@ __irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force)
 }
 #else
 static __always_inline int
-__irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force)
+__irq_startup_managed(struct irq_desc *desc, const struct cpumask *aff,
+		      bool force)
 {
 	return IRQ_STARTUP_NORMAL;
 }
@@ -252,7 +254,7 @@ static int __irq_startup(struct irq_desc *desc)
 int irq_startup(struct irq_desc *desc, bool resend, bool force)
 {
 	struct irq_data *d = irq_desc_get_irq_data(desc);
-	struct cpumask *aff = irq_data_get_affinity_mask(d);
+	const struct cpumask *aff = irq_data_get_affinity_mask(d);
 	int ret = 0;
 
 	desc->depth = 0;
diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c
index bc8e40cf2b65..bbcaac64038e 100644
--- a/kernel/irq/debugfs.c
+++ b/kernel/irq/debugfs.c
@@ -30,7 +30,7 @@ static void irq_debug_show_bits(struct seq_file *m, int ind, unsigned int state,
 static void irq_debug_show_masks(struct seq_file *m, struct irq_desc *desc)
 {
 	struct irq_data *data = irq_desc_get_irq_data(desc);
-	struct cpumask *msk;
+	const struct cpumask *msk;
 
 	msk = irq_data_get_affinity_mask(data);
 	seq_printf(m, "affinity: %*pbl\n", cpumask_pr_args(msk));
diff --git a/kernel/irq/ipi.c b/kernel/irq/ipi.c
index 08ce7da3b57c..bbd945bacef0 100644
--- a/kernel/irq/ipi.c
+++ b/kernel/irq/ipi.c
@@ -115,11 +115,11 @@ free_descs:
 int irq_destroy_ipi(unsigned int irq, const struct cpumask *dest)
 {
 	struct irq_data *data = irq_get_irq_data(irq);
-	struct cpumask *ipimask = data ? irq_data_get_affinity_mask(data) : NULL;
+	const struct cpumask *ipimask;
 	struct irq_domain *domain;
 	unsigned int nr_irqs;
 
-	if (!irq || !data || !ipimask)
+	if (!irq || !data)
 		return -EINVAL;
 
 	domain = data->domain;
@@ -131,7 +131,8 @@ int irq_destroy_ipi(unsigned int irq, const struct cpumask *dest)
 		return -EINVAL;
 	}
 
-	if (WARN_ON(!cpumask_subset(dest, ipimask)))
+	ipimask = irq_data_get_affinity_mask(data);
+	if (!ipimask || WARN_ON(!cpumask_subset(dest, ipimask)))
 		/*
 		 * Must be destroying a subset of CPUs to which this IPI
 		 * was set up to target
@@ -162,12 +163,13 @@ int irq_destroy_ipi(unsigned int irq, const struct cpumask *dest)
 irq_hw_number_t ipi_get_hwirq(unsigned int irq, unsigned int cpu)
 {
 	struct irq_data *data = irq_get_irq_data(irq);
-	struct cpumask *ipimask = data ? irq_data_get_affinity_mask(data) : NULL;
+	const struct cpumask *ipimask;
 
-	if (!data || !ipimask || cpu >= nr_cpu_ids)
+	if (!data || cpu >= nr_cpu_ids)
 		return INVALID_HWIRQ;
 
-	if (!cpumask_test_cpu(cpu, ipimask))
+	ipimask = irq_data_get_affinity_mask(data);
+	if (!ipimask || !cpumask_test_cpu(cpu, ipimask))
 		return INVALID_HWIRQ;
 
 	/*
@@ -186,7 +188,7 @@ EXPORT_SYMBOL_GPL(ipi_get_hwirq);
 static int ipi_send_verify(struct irq_chip *chip, struct irq_data *data,
 			   const struct cpumask *dest, unsigned int cpu)
 {
-	struct cpumask *ipimask = irq_data_get_affinity_mask(data);
+	const struct cpumask *ipimask = irq_data_get_affinity_mask(data);
 
 	if (!chip || !ipimask)
 		return -EINVAL;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 8c396319d5ac..40fe7806cc8c 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -205,16 +205,8 @@ static void irq_validate_effective_affinity(struct irq_data *data)
 	pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
 		     chip->name, data->irq);
 }
-
-static inline void irq_init_effective_affinity(struct irq_data *data,
-					       const struct cpumask *mask)
-{
-	cpumask_copy(irq_data_get_effective_affinity_mask(data), mask);
-}
 #else
 static inline void irq_validate_effective_affinity(struct irq_data *data) { }
-static inline void irq_init_effective_affinity(struct irq_data *data,
-					       const struct cpumask *mask) { }
 #endif
 
 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
@@ -347,7 +339,7 @@ static bool irq_set_affinity_deactivated(struct irq_data *data,
 		return false;
 
 	cpumask_copy(desc->irq_common_data.affinity, mask);
-	irq_init_effective_affinity(data, mask);
+	irq_data_update_effective_affinity(data, mask);
 	irqd_set(data, IRQD_AFFINITY_SET);
 	return true;
 }