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x86, ioapic: Consolidate the explicit EOI code
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Consolidate the io-apic EOI code in clear_IO_APIC_pin() and
eoi_ioapic_irq().

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Rafael Wysocki <rjw@novell.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: lchiquitto@novell.com
Cc: jbeulich@novell.com
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/20110825190657.259696697@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Suresh Siddha authored and Ingo Molnar committed Sep 21, 2011
1 parent e57253a commit c020570
Showing 1 changed file with 65 additions and 74 deletions.
139 changes: 65 additions & 74 deletions arch/x86/kernel/apic/io_apic.c
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Original file line number Diff line number Diff line change
Expand Up @@ -581,6 +581,66 @@ static void unmask_ioapic_irq(struct irq_data *data)
unmask_ioapic(data->chip_data);
}

/*
* IO-APIC versions below 0x20 don't support EOI register.
* For the record, here is the information about various versions:
* 0Xh 82489DX
* 1Xh I/OAPIC or I/O(x)APIC which are not PCI 2.2 Compliant
* 2Xh I/O(x)APIC which is PCI 2.2 Compliant
* 30h-FFh Reserved
*
* Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic
* version as 0x2. This is an error with documentation and these ICH chips
* use io-apic's of version 0x20.
*
* For IO-APIC's with EOI register, we use that to do an explicit EOI.
* Otherwise, we simulate the EOI message manually by changing the trigger
* mode to edge and then back to level, with RTE being masked during this.
*/
static void __eoi_ioapic_pin(int apic, int pin, int vector, struct irq_cfg *cfg)
{
if (mpc_ioapic_ver(apic) >= 0x20) {
/*
* Intr-remapping uses pin number as the virtual vector
* in the RTE. Actual vector is programmed in
* intr-remapping table entry. Hence for the io-apic
* EOI we use the pin number.
*/
if (cfg && irq_remapped(cfg))
io_apic_eoi(apic, pin);
else
io_apic_eoi(apic, vector);
} else {
struct IO_APIC_route_entry entry, entry1;

entry = entry1 = __ioapic_read_entry(apic, pin);

/*
* Mask the entry and change the trigger mode to edge.
*/
entry1.mask = 1;
entry1.trigger = IOAPIC_EDGE;

__ioapic_write_entry(apic, pin, entry1);

/*
* Restore the previous level triggered entry.
*/
__ioapic_write_entry(apic, pin, entry);
}
}

static void eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg)
{
struct irq_pin_list *entry;
unsigned long flags;

raw_spin_lock_irqsave(&ioapic_lock, flags);
for_each_irq_pin(entry, cfg->irq_2_pin)
__eoi_ioapic_pin(entry->apic, entry->pin, cfg->vector, cfg);
raw_spin_unlock_irqrestore(&ioapic_lock, flags);
}

static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
{
struct IO_APIC_route_entry entry;
Expand All @@ -601,6 +661,8 @@ static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
}

if (entry.irr) {
unsigned long flags;

/*
* Make sure the trigger mode is set to level. Explicit EOI
* doesn't clear the remote-IRR if the trigger mode is not
Expand All @@ -611,23 +673,9 @@ static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
ioapic_write_entry(apic, pin, entry);
}

if (mpc_ioapic_ver(apic) >= 0x20) {
unsigned long flags;

raw_spin_lock_irqsave(&ioapic_lock, flags);
io_apic_eoi(apic, entry.vector);
raw_spin_unlock_irqrestore(&ioapic_lock, flags);
} else {
/*
* Mechanism by which we clear remote-IRR in this
* case is by changing the trigger mode to edge and
* back to level.
*/
entry.trigger = IOAPIC_EDGE;
ioapic_write_entry(apic, pin, entry);
entry.trigger = IOAPIC_LEVEL;
ioapic_write_entry(apic, pin, entry);
}
raw_spin_lock_irqsave(&ioapic_lock, flags);
__eoi_ioapic_pin(apic, pin, entry.vector, NULL);
raw_spin_unlock_irqrestore(&ioapic_lock, flags);
}

/*
Expand Down Expand Up @@ -2457,63 +2505,6 @@ static void ack_apic_edge(struct irq_data *data)

atomic_t irq_mis_count;

/*
* IO-APIC versions below 0x20 don't support EOI register.
* For the record, here is the information about various versions:
* 0Xh 82489DX
* 1Xh I/OAPIC or I/O(x)APIC which are not PCI 2.2 Compliant
* 2Xh I/O(x)APIC which is PCI 2.2 Compliant
* 30h-FFh Reserved
*
* Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic
* version as 0x2. This is an error with documentation and these ICH chips
* use io-apic's of version 0x20.
*
* For IO-APIC's with EOI register, we use that to do an explicit EOI.
* Otherwise, we simulate the EOI message manually by changing the trigger
* mode to edge and then back to level, with RTE being masked during this.
*/
static void eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg)
{
struct irq_pin_list *entry;
unsigned long flags;

raw_spin_lock_irqsave(&ioapic_lock, flags);
for_each_irq_pin(entry, cfg->irq_2_pin) {
if (mpc_ioapic_ver(entry->apic) >= 0x20) {
/*
* Intr-remapping uses pin number as the virtual vector
* in the RTE. Actual vector is programmed in
* intr-remapping table entry. Hence for the io-apic
* EOI we use the pin number.
*/
if (irq_remapped(cfg))
io_apic_eoi(entry->apic, entry->pin);
else
io_apic_eoi(entry->apic, cfg->vector);
} else {
struct IO_APIC_route_entry rte, rte1;

rte = rte1 =
__ioapic_read_entry(entry->apic, entry->pin);

/*
* Mask the entry and change the trigger mode to edge.
*/
rte1.mask = 1;
rte1.trigger = IOAPIC_EDGE;

__ioapic_write_entry(apic, pin, rte1);

/*
* Restore the previous level triggered entry.
*/
__ioapic_write_entry(apic, pin, rte);
}
}
raw_spin_unlock_irqrestore(&ioapic_lock, flags);
}

static void ack_apic_level(struct irq_data *data)
{
struct irq_cfg *cfg = data->chip_data;
Expand Down

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