[Patch V4 35/42] x86, irq: simplify the way to handle ISA IRQ

Jiang Liu
2014-06-09T08:20:04Z

On startup, setup_IO_APIC_irqs() will program all IOAPIC pins for ISA
IRQs. Later when mp_map_pin_to_irq() is called, it just returns ISA IRQ
number without programming corresponding IOAPIC pin.

This patch consolidates the way to program IOAPIC pins for both ISA and
non-ISA IRQs into mp_map_pin_to_irq() as below:
1) For ISA IRQs, mp_irqs array is used to map IOAPIC pin to IRQ and
mp_irqdomain_map() is used to actually program the pin.
2) For non-ISA IRQs, irqdomain is used to map IOAPIC pin to IRQ, and
mp_irqdomain_map() is also used to actually program the pin.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
arch/x86/kernel/acpi/boot.c | 15 +-----
arch/x86/kernel/apic/io_apic.c | 98 ++++++++++++++++------------------------
2 files changed, 40 insertions(+), 73 deletions(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index edb48a8e0a0d..ef3336ab6432 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -101,17 +101,6 @@ static u32 isa_irq_to_gsi[NR_IRQS_LEGACY] __read_mostly = {

#define ACPI_INVALID_GSI INT_MIN

-static int map_gsi_to_irq(unsigned int gsi, unsigned int flags)
-{
- int i;
-
- for (i = 0; i < nr_legacy_irqs(); i++)
- if (isa_irq_to_gsi[i] == gsi)
- return i;
-
- return mp_map_gsi_to_irq(gsi, flags);
-}
-
/*
* This is just a simple wrapper around early_ioremap(),
* with sanity checks for phys == 0 and size == 0.
@@ -422,7 +411,7 @@ static int mp_register_gsi(struct device *dev, u32 gsi, int trigger,
return -1;
}

- irq = map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC);
+ irq = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC);
if (irq < 0)
return irq;

@@ -603,7 +592,7 @@ void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger)

int acpi_gsi_to_irq(u32 gsi, unsigned int *irqp)
{
- int irq = map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC | IOAPIC_MAP_CHECK);
+ int irq = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC | IOAPIC_MAP_CHECK);

if (irq >= 0) {
*irqp = irq;
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 1623f5dba6c2..5fc76cf51e44 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -204,8 +204,6 @@ static int __init parse_noapic(char *str)
}
early_param("noapic", parse_noapic);

-static int io_apic_setup_irq_pin(unsigned int irq, int node,
- struct io_apic_irq_attr *attr);
static struct irq_cfg *alloc_irq_and_cfg_at(unsigned int at, int node);

/* Will be called in mpparse/acpi/sfi codes for saving IRQ info */
@@ -1021,6 +1019,16 @@ static int mp_map_pin_to_irq(u32 gsi, int idx, int ioapic, int pin,
struct irq_domain *domain = mp_ioapic_irqdomain(ioapic);
struct mp_pin_info *info = mp_pin_info(ioapic, pin);

+ if (!domain) {
+ /*
+ * Provide an identity mapping of gsi == irq except on truly
+ * weird platforms that have non isa irqs in the first 16 gsis.
+ */
+ return gsi >= nr_legacy_irqs() ? gsi : gsi_top + gsi;
+ }
+
+ mutex_lock(&ioapic_mutex);
+
/*
* Don't use irqdomain to manage ISA IRQs because there may be
* multiple IOAPIC pins sharing the same ISA IRQ number and
@@ -1033,28 +1041,30 @@ static int mp_map_pin_to_irq(u32 gsi, int idx, int ioapic, int pin,
* the interrupt routing logic. Thus there may be multiple pins
* sharing the same legacy IRQ number when ACPI is disabled.
*/
- if (idx >= 0 && test_bit(mp_irqs[idx].srcbus, mp_bus_not_pci))
- return mp_irqs[idx].srcbusirq;
-
- if (!domain) {
- /*
- * Provide an identity mapping of gsi == irq except on truly
- * weird platforms that have non isa irqs in the first 16 gsis.
- */
- return gsi >= nr_legacy_irqs() ? gsi : gsi_top + gsi;
+ if (idx >= 0 && test_bit(mp_irqs[idx].srcbus, mp_bus_not_pci)) {
+ irq = mp_irqs[idx].srcbusirq;
+ if (flags & IOAPIC_MAP_ALLOC) {
+ if (info->count == 0 &&
+ mp_irqdomain_map(domain, irq, pin) != 0)
+ irq = -1;
+
+ /* special handling for timer IRQ0 */
+ if (irq == 0)
+ info->count++;
+ }
+ } else {
+ irq = irq_find_mapping(domain, pin);
+ if (irq <= 0 && (flags & IOAPIC_MAP_ALLOC))
+ irq = alloc_irq_from_domain(domain, gsi, pin);
}

- mutex_lock(&ioapic_mutex);
- irq = irq_find_mapping(domain, pin);
- if (irq <= 0 && (flags & IOAPIC_MAP_ALLOC))
- irq = alloc_irq_from_domain(domain, gsi, pin);
-
if (flags & IOAPIC_MAP_ALLOC) {
if (irq > 0)
info->count++;
else if (info->count == 0)
info->set = 0;
}
+
mutex_unlock(&ioapic_mutex);

return irq > 0 ? irq : -1;
@@ -1471,55 +1481,23 @@ static void setup_ioapic_irq(unsigned int irq, struct irq_cfg *cfg,
ioapic_write_entry(attr->ioapic, attr->ioapic_pin, entry);
}

-static bool __init io_apic_pin_not_connected(int idx, int ioapic_idx, int pin)
-{
- if (idx != -1)
- return false;
-
- apic_printk(APIC_VERBOSE, KERN_DEBUG " apic %d pin %d not connected\n",
- mpc_ioapic_id(ioapic_idx), pin);
- return true;
-}
-
-static void __init __io_apic_setup_irqs(unsigned int ioapic_idx)
-{
- int idx, node = cpu_to_node(0);
- struct io_apic_irq_attr attr;
- unsigned int pin, irq;
-
- for_each_pin(ioapic_idx, pin) {
- idx = find_irq_entry(ioapic_idx, pin, mp_INT);
- if (io_apic_pin_not_connected(idx, ioapic_idx, pin))
- continue;
-
- irq = pin_2_irq(idx, ioapic_idx, pin,
- ioapic_idx ? 0 : IOAPIC_MAP_ALLOC);
- if (irq < 0 || !mp_init_irq_at_boot(ioapic_idx, irq))
- continue;
-
- /*
- * 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_idx, irq))
- continue;
-
- set_io_apic_irq_attr(&attr, ioapic_idx, pin, irq_trigger(idx),
- irq_polarity(idx));
-
- io_apic_setup_irq_pin(irq, node, &attr);
- }
-}
-
static void __init setup_IO_APIC_irqs(void)
{
- unsigned int ioapic_idx;
+ unsigned int ioapic, pin;
+ int idx;

apic_printk(APIC_VERBOSE, KERN_DEBUG "init IO_APIC IRQs\n");

- for_each_ioapic(ioapic_idx)
- __io_apic_setup_irqs(ioapic_idx);
+ for_each_ioapic_pin(ioapic, pin) {
+ idx = find_irq_entry(ioapic, pin, mp_INT);
+ if (idx < 0)
+ apic_printk(APIC_VERBOSE,
+ KERN_DEBUG " apic %d pin %d not connected\n",
+ mpc_ioapic_id(ioapic), pin);
+ else
+ pin_2_irq(idx, ioapic, pin,
+ ioapic ? 0 : IOAPIC_MAP_ALLOC);
+ }
}

/*
--
1.7.10.4