[Patch V4 37/42] x86, irq: introduce helper functions to release IOAPIC pin

Jiang Liu
2014-06-09T08:20:06Z

Introduce function mp_unmap_irq() to release IOAPIC IRQ when IRQ is not
used any more, which will typically called by pcibios_disabled_irq.

And function mp_irqdomain_unmap() is a common implementation of
irq_domain_ops.unmap for IOAPIC.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
arch/x86/include/asm/io_apic.h | 3 ++
arch/x86/kernel/apic/io_apic.c | 61 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 64 insertions(+)

diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index af6f9d4309bf..0aeed5ca356e 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -187,10 +187,12 @@ extern int mp_find_ioapic(u32 gsi);
extern int mp_find_ioapic_pin(int ioapic, u32 gsi);
extern u32 mp_pin_to_gsi(int ioapic, int pin);
extern int mp_map_gsi_to_irq(u32 gsi, unsigned int flags);
+extern void mp_unmap_irq(int irq);
extern void __init mp_register_ioapic(int id, u32 address, u32 gsi_base,
struct ioapic_domain_cfg *cfg);
extern int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hwirq);
+extern void mp_irqdomain_unmap(struct irq_domain *domain, unsigned int virq);
extern int mp_set_gsi_attr(u32 gsi, int trigger, int polarity, int node);
extern void __init pre_init_apic_IRQ0(void);

@@ -234,6 +236,7 @@ static inline void ioapic_insert_resources(void) { }
static inline int mp_find_ioapic(u32 gsi) { return 0; }
static inline u32 mp_pin_to_gsi(int ioapic, int pin) { return UINT_MAX; }
static inline int mp_map_gsi_to_irq(u32 gsi, unsigned int flags) { return gsi; }
+static inline void mp_unmap_irq(int irq) { }

static inline int save_ioapic_entries(void)
{
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 5fc76cf51e44..60555354b331 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -467,6 +467,21 @@ static int __add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pi
return 0;
}

+static void __remove_pin_from_irq(struct irq_cfg *cfg, int apic, int pin)
+{
+ struct irq_pin_list **last, *entry;
+
+ last = &cfg->irq_2_pin;
+ for_each_irq_pin(entry, cfg->irq_2_pin)
+ if (entry->apic == apic && entry->pin == pin) {
+ *last = entry->next;
+ kfree(entry);
+ return;
+ } else {
+ last = &entry->next;
+ }
+}
+
static void add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin)
{
if (__add_pin_to_irq_node(cfg, node, apic, pin))
@@ -1119,6 +1134,31 @@ int mp_map_gsi_to_irq(u32 gsi, unsigned int flags)
return mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags);
}

+void mp_unmap_irq(int irq)
+{
+ struct irq_data *data = irq_get_irq_data(irq);
+ struct mp_pin_info *info;
+ int ioapic, pin;
+
+ if (!data || !data->domain)
+ return;
+
+ ioapic = (int)(long)data->domain->host_data;
+ pin = (int)data->hwirq;
+ info = mp_pin_info(ioapic, pin);
+
+ mutex_lock(&ioapic_mutex);
+ if (--info->count == 0) {
+ info->set = 0;
+ if (irq < nr_legacy_irqs() &&
+ ioapics[ioapic].irqdomain_cfg.type == IOAPIC_DOMAIN_LEGACY)
+ mp_irqdomain_unmap(data->domain, irq);
+ else
+ irq_dispose_mapping(irq);
+ }
+ mutex_unlock(&ioapic_mutex);
+}
+
/*
* Find a specific PCI IRQ entry.
* Not an __init, possibly needed by modules
@@ -3874,6 +3914,27 @@ int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
return io_apic_setup_irq_pin(virq, info->node, &attr);
}

+void mp_irqdomain_unmap(struct irq_domain *domain, unsigned int virq)
+{
+ struct irq_data *data = irq_get_irq_data(virq);
+ struct irq_cfg *cfg = irq_cfg(virq);
+ int ioapic = (int)(long)domain->host_data;
+ int pin = (int)data->hwirq;
+
+ /*
+ * Skip the timer IRQ if there's a quirk handler installed and if it
+ * returns 1:
+ */
+ if (apic->multi_timer_check &&
+ apic->multi_timer_check(ioapic, virq))
+ return;
+
+ ioapic_mask_entry(ioapic, pin);
+ __remove_pin_from_irq(cfg, ioapic, pin);
+ WARN_ON(cfg->irq_2_pin != NULL);
+ arch_teardown_hwirq(virq);
+}
+
int mp_set_gsi_attr(u32 gsi, int trigger, int polarity, int node)
{
int ret = 0;
--
1.7.10.4