Trivial cleanups for x86 vector allocation code:
1) reorganize apic_chip_data to optimize for size and cache efficiency
2) avoid redundant calling of irq_to_desc()
3) refine code comments
Signed-off-by: Jiang Liu <jiang....@linux.intel.com>
---
arch/x86/kernel/apic/vector.c | 54 ++++++++++++++++++-----------------------
1 file changed, 23 insertions(+), 31 deletions(-)
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index b63d6f84c0bb..0183c44a13cb 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -23,9 +23,9 @@
struct apic_chip_data {
struct irq_cfg cfg;
+ u8 move_in_progress : 1;
cpumask_var_t domain;
cpumask_var_t old_domain;
- u8 move_in_progress : 1;
};
struct irq_domain *x86_vector_domain;
@@ -38,7 +38,7 @@ static struct apic_chip_data *legacy_irq_data[NR_IRQS_LEGACY];
void lock_vector_lock(void)
{
- /* Used to the online set of cpus does not change
+ /* Used to ensure that the online set of cpus does not change
* during assign_irq_vector.
*/
raw_spin_lock(&vector_lock);
@@ -100,8 +100,7 @@ static void free_apic_chip_data(struct apic_chip_data *data)
}
}
-static int __assign_irq_vector(int irq, struct apic_chip_data *d,
- const struct cpumask *mask)
+static int assign_irq_vector(struct irq_data *data, const struct cpumask *mask)
{
/*
* NOTE! The local APIC isn't very good at handling
@@ -116,11 +115,15 @@ static int __assign_irq_vector(int irq, struct
apic_chip_data *d,
*/
static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START;
static int current_offset = VECTOR_OFFSET_START % 16;
- int cpu, err;
+ int cpu, err = -EBUSY;
+ struct irq_desc *desc = irq_data_to_desc(data);
+ struct apic_chip_data *d = data->chip_data;
unsigned int dest;
+ unsigned long flags;
+ raw_spin_lock_irqsave(&vector_lock, flags);
if (cpumask_intersects(d->old_domain, cpu_online_mask))
- return -EBUSY;
+ goto out;
/* Only try and allocate irqs on cpus that are present */
err = -ENOSPC;
@@ -187,7 +190,7 @@ next:
d->cfg.vector = vector;
d->cfg.dest_apicid = dest;
for_each_cpu_and(new_cpu, vector_cpumask, cpu_online_mask)
- per_cpu(vector_irq, new_cpu)[vector] = irq_to_desc(irq);
+ per_cpu(vector_irq, new_cpu)[vector] = desc;
cpumask_copy(d->domain, vector_cpumask);
err = 0;
break;
@@ -198,37 +201,27 @@ next:
cpumask_and(d->old_domain, d->old_domain, cpu_online_mask);
d->move_in_progress = !cpumask_empty(d->old_domain);
}
-
- return err;
-}
-
-static int assign_irq_vector(int irq, struct apic_chip_data *data,
- const struct cpumask *mask)
-{
- int err;
- unsigned long flags;
-
- raw_spin_lock_irqsave(&vector_lock, flags);
- err = __assign_irq_vector(irq, data, mask);
+out:
raw_spin_unlock_irqrestore(&vector_lock, flags);
+
return err;
}
-static int assign_irq_vector_policy(int irq, int node,
- struct apic_chip_data *data,
+static int assign_irq_vector_policy(struct irq_data *data, int node,
struct irq_alloc_info *info)
{
if (info && info->mask)
- return assign_irq_vector(irq, data, info->mask);
+ return assign_irq_vector(data, info->mask);
if (node != NUMA_NO_NODE &&
- assign_irq_vector(irq, data, cpumask_of_node(node)) == 0)
+ assign_irq_vector(data, cpumask_of_node(node)) == 0)
return 0;
- return assign_irq_vector(irq, data, apic->target_cpus());
+ return assign_irq_vector(data, apic->target_cpus());
}
-static void clear_irq_vector(int irq, struct apic_chip_data *data)
+static void clear_irq_vector(struct irq_data *irq_data)
{
- struct irq_desc *desc = irq_to_desc(irq);
+ struct irq_desc *desc = irq_data_to_desc(irq_data);
+ struct apic_chip_data *data = irq_data->chip_data;
int cpu, vector = data->cfg.vector;
BUG_ON(!vector);
@@ -276,7 +269,7 @@ static void x86_vector_free_irqs(struct irq_domain *domain,
irq_data = irq_domain_get_irq_data(x86_vector_domain, virq + i);
if (irq_data && irq_data->chip_data) {
raw_spin_lock_irqsave(&vector_lock, flags);
- clear_irq_vector(virq + i, irq_data->chip_data);
+ clear_irq_vector(irq_data);
free_apic_chip_data(irq_data->chip_data);
irq_domain_reset_irq_data(irq_data);
raw_spin_unlock_irqrestore(&vector_lock, flags);
@@ -321,7 +314,7 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain,
unsigned int virq,
irq_data->chip = &lapic_controller;
irq_data->chip_data = data;
irq_data->hwirq = virq + i;
- err = assign_irq_vector_policy(virq + i, node, data, info);
+ err = assign_irq_vector_policy(irq_data, node, info);
if (err)
goto error;
}
@@ -483,8 +476,7 @@ void apic_ack_edge(struct irq_data *data)
static int apic_set_affinity(struct irq_data *irq_data,
const struct cpumask *dest, bool force)
{
- struct apic_chip_data *data = irq_data->chip_data;
- int err, irq = irq_data->irq;
+ int err;
if (!config_enabled(CONFIG_SMP))
return -EPERM;
@@ -492,7 +484,7 @@ static int apic_set_affinity(struct irq_data *irq_data,
if (!cpumask_intersects(dest, cpu_online_mask))
return -EINVAL;
- err = assign_irq_vector(irq, data, dest);
+ err = assign_irq_vector(irq_data, dest);
return err ? err : IRQ_SET_MASK_OK;
}
--
1.7.10.4
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