Introduce mechanism to support different vector allocation policies,
so platform or user may choose the best suitable CPU vector allocation
policy. Currently two policies are supported:
1) allocate CPU vector from cpumask_of_node(dev_to_node(dev))
2) allocate from apic->target_cpus(), this is the default policy
Platform driver may call set_vector_alloc_policy() to choose the
preferred policies.
This mechanism may be used to support NumaConnect systems to allocate
CPU vectors from device local node.
We may also enhance to support per-cpu vector allocation if it's needed.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
Cc: Daniel J Blueman <daniel@xxxxxxxxxxxxx>
---
arch/x86/include/asm/hw_irq.h | 12 ++++++++
arch/x86/kernel/apic/vector.c | 66 +++++++++++++++++++++++++++++++++++------
2 files changed, 69 insertions(+), 9 deletions(-)
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 236aea888847..d37ad7b25063 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -168,6 +168,17 @@ struct irq_alloc_info {
/* Request contigious CPU vectors */
#define X86_IRQ_ALLOC_CONTIGOUS_VECTORS 0x1
+enum {
+ /* Allocate vector from cpumask_of_node(dev_to_node(dev)) */
+ X86_VECTOR_POL_NODE = 0x1,
+ /* Allocate vector from apic->target_cpus() */
+ X86_VECTOR_POL_DEFAULT = 0x2,
+ /* Allocate vector from cpumask assigned by caller */
+ X86_VECTOR_POL_CALLER = 0x4,
+ X86_VECTOR_POL_MIN = X86_VECTOR_POL_NODE,
+ X86_VECTOR_POL_MAX = X86_VECTOR_POL_CALLER,
+};
+
struct irq_cfg {
unsigned int dest_apicid;
u8 vector;
@@ -183,6 +194,7 @@ extern struct irq_cfg *irq_cfg(unsigned int irq);
extern struct irq_cfg *irqd_cfg(struct irq_data *irq_data);
extern void lock_vector_lock(void);
extern void unlock_vector_lock(void);
+extern void set_vector_alloc_policy(unsigned int policy);
extern void setup_vector_irq(int cpu);
#ifdef CONFIG_SMP
extern void send_cleanup_vector(struct irq_cfg *);
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index c6c954bb2947..a3f640d34b1e 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -28,6 +28,8 @@ struct apic_chip_data {
u8 move_in_progress : 1;
};
+static unsigned int x86_vector_alloc_policy = X86_VECTOR_POL_DEFAULT |
+ X86_VECTOR_POL_CALLER;
struct irq_domain *x86_vector_domain;
static DEFINE_RAW_SPINLOCK(vector_lock);
static struct irq_chip vector_chip;
@@ -71,6 +73,12 @@ struct irq_cfg *irq_cfg(unsigned int irq)
return irqd_cfg(irq_get_irq_data(irq));
}
+void set_vector_alloc_policy(unsigned int policy)
+{
+ if (!WARN_ON((policy & (X86_VECTOR_POL_MAX - 1)) == 0))
+ x86_vector_alloc_policy = policy | X86_VECTOR_POL_CALLER;
+}
+
static struct apic_chip_data *alloc_apic_chip_data(int node)
{
struct apic_chip_data *data;
@@ -259,12 +267,6 @@ void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src)
memset(dst, 0, sizeof(*dst));
}
-static inline const struct cpumask *
-irq_alloc_info_get_mask(struct irq_alloc_info *info)
-{
- return (!info || !info->mask) ? apic->target_cpus() : info->mask;
-}
-
static void x86_vector_free_irqs(struct irq_domain *domain,
unsigned int virq, unsigned int nr_irqs)
{
@@ -285,13 +287,59 @@ static void x86_vector_free_irqs(struct irq_domain *domain,
}
}
+static int assign_irq_vector_policy(int irq, int node,
+ struct apic_chip_data *data,
+ struct irq_alloc_info *info)
+{
+ int err = -EBUSY;
+ unsigned int policy;
+ const struct cpumask *mask;
+
+ if (info && info->mask)
+ policy = X86_VECTOR_POL_CALLER;
+ else
+ policy = X86_VECTOR_POL_MIN;
+
+ for (; policy <= X86_VECTOR_POL_MAX; policy <<= 1) {
+ if (!(x86_vector_alloc_policy & policy))
+ continue;
+
+ switch (policy) {
+ case X86_VECTOR_POL_NODE:
+ if (node >= 0)
+ mask = cpumask_of_node(node);
+ else
+ mask = NULL;
+ break;
+ case X86_VECTOR_POL_DEFAULT:
+ mask = apic->target_cpus();
+ break;
+ case X86_VECTOR_POL_CALLER:
+ if (info && info->mask)
+ mask = info->mask;
+ else
+ mask = NULL;
+ break;
+ default:
+ mask = NULL;
+ break;
+ }
+ if (mask) {
+ err = assign_irq_vector(irq, data, mask);
+ if (!err)
+ return 0;
+ }
+ }
+
+ return err;
+}
+
static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
int i, err;
struct apic_chip_data *data;
struct irq_data *irq_data;
- const struct cpumask *mask;
struct irq_alloc_info *info = arg;
if (disable_apic)
@@ -301,7 +349,6 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
if ((info->flags & X86_IRQ_ALLOC_CONTIGOUS_VECTORS) && nr_irqs > 1)
return -ENOSYS;
- mask = irq_alloc_info_get_mask(info);
for (i = 0; i < nr_irqs; i++) {
irq_data = irq_domain_get_irq_data(domain, virq + i);
BUG_ON(!irq_data);
@@ -319,7 +366,8 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
irq_data->chip = &vector_chip;
irq_data->chip_data = data;
irq_data->hwirq = virq + i;
- err = assign_irq_vector(virq, data, mask);
+ err = assign_irq_vector_policy(virq, irq_data->node, data,
+ info);
if (err)
goto error;
}
--
1.7.10.4
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