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[PATCH] genirq: convert the i386 architecture to irq-chips
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This patch converts all the i386 PIC controllers (except VisWS and Voyager,
which I could not test - but which should still work as old-style IRQ layers)
to the new and simpler irq-chip interrupt handling layer.

[akpm@osdl.org: build fix]
[mingo@elte.hu: enable fasteoi handler for i386 level-triggered IO-APIC irqs]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Ingo Molnar authored and Linus Torvalds committed Oct 4, 2006
1 parent f29bd1b commit f5b9ed7
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Showing 4 changed files with 80 additions and 146 deletions.
45 changes: 13 additions & 32 deletions arch/i386/kernel/i8259.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,35 +34,15 @@
* moves to arch independent land
*/

DEFINE_SPINLOCK(i8259A_lock);

static void end_8259A_irq (unsigned int irq)
{
if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)) &&
irq_desc[irq].action)
enable_8259A_irq(irq);
}

#define shutdown_8259A_irq disable_8259A_irq

static int i8259A_auto_eoi;

DEFINE_SPINLOCK(i8259A_lock);
static void mask_and_ack_8259A(unsigned int);

unsigned int startup_8259A_irq(unsigned int irq)
{
enable_8259A_irq(irq);
return 0; /* never anything pending */
}

static struct hw_interrupt_type i8259A_irq_type = {
.typename = "XT-PIC",
.startup = startup_8259A_irq,
.shutdown = shutdown_8259A_irq,
.enable = enable_8259A_irq,
.disable = disable_8259A_irq,
.ack = mask_and_ack_8259A,
.end = end_8259A_irq,
static struct irq_chip i8259A_chip = {
.name = "XT-PIC",
.mask = disable_8259A_irq,
.unmask = enable_8259A_irq,
.mask_ack = mask_and_ack_8259A,
};

/*
Expand Down Expand Up @@ -133,7 +113,7 @@ void make_8259A_irq(unsigned int irq)
{
disable_irq_nosync(irq);
io_apic_irqs &= ~(1<<irq);
irq_desc[irq].chip = &i8259A_irq_type;
set_irq_chip_and_handler(irq, &i8259A_chip, handle_level_irq);
enable_irq(irq);
}

Expand Down Expand Up @@ -327,12 +307,12 @@ void init_8259A(int auto_eoi)
outb_p(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR); /* (slave's support for AEOI in flat mode is to be investigated) */
if (auto_eoi)
/*
* in AEOI mode we just have to mask the interrupt
* In AEOI mode we just have to mask the interrupt
* when acking.
*/
i8259A_irq_type.ack = disable_8259A_irq;
i8259A_chip.mask_ack = disable_8259A_irq;
else
i8259A_irq_type.ack = mask_and_ack_8259A;
i8259A_chip.mask_ack = mask_and_ack_8259A;

udelay(100); /* wait for 8259A to initialize */

Expand Down Expand Up @@ -389,12 +369,13 @@ void __init init_ISA_irqs (void)
/*
* 16 old-style INTA-cycle interrupts:
*/
irq_desc[i].chip = &i8259A_irq_type;
set_irq_chip_and_handler(i, &i8259A_chip,
handle_level_irq);
} else {
/*
* 'high' PCI IRQs filled in on demand
*/
irq_desc[i].chip = &no_irq_type;
irq_desc[i].chip = &no_irq_chip;
}
}
}
Expand Down
160 changes: 56 additions & 104 deletions arch/i386/kernel/io_apic.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1219,8 +1219,7 @@ int assign_irq_vector(int irq)
return vector;
}

static struct hw_interrupt_type ioapic_level_type;
static struct hw_interrupt_type ioapic_edge_type;
static struct irq_chip ioapic_chip;

#define IOAPIC_AUTO -1
#define IOAPIC_EDGE 0
Expand All @@ -1234,9 +1233,11 @@ static void ioapic_register_intr(int irq, int vector, unsigned long trigger)

if ((trigger == IOAPIC_AUTO && IO_APIC_irq_trigger(irq)) ||
trigger == IOAPIC_LEVEL)
irq_desc[idx].chip = &ioapic_level_type;
set_irq_chip_and_handler(idx, &ioapic_chip,
handle_fasteoi_irq);
else
irq_desc[idx].chip = &ioapic_edge_type;
set_irq_chip_and_handler(idx, &ioapic_chip,
handle_edge_irq);
set_intr_gate(vector, interrupt[idx]);
}

Expand Down Expand Up @@ -1346,7 +1347,8 @@ static void __init setup_ExtINT_IRQ0_pin(unsigned int apic, unsigned int pin, in
* The timer IRQ doesn't have to know that behind the
* scene we have a 8259A-master in AEOI mode ...
*/
irq_desc[0].chip = &ioapic_edge_type;
irq_desc[0].chip = &ioapic_chip;
set_irq_handler(0, handle_edge_irq);

/*
* Add it to the IO-APIC irq-routing table:
Expand Down Expand Up @@ -1918,15 +1920,19 @@ static int __init timer_irq_works(void)
*/

/*
* Startup quirk:
*
* Starting up a edge-triggered IO-APIC interrupt is
* nasty - we need to make sure that we get the edge.
* If it is already asserted for some reason, we need
* return 1 to indicate that is was pending.
*
* This is not complete - we should be able to fake
* an edge even if it isn't on the 8259A...
*
* (We do this for level-triggered IRQs too - it cannot hurt.)
*/
static unsigned int startup_edge_ioapic_irq(unsigned int irq)
static unsigned int startup_ioapic_irq(unsigned int irq)
{
int was_pending = 0;
unsigned long flags;
Expand All @@ -1943,42 +1949,13 @@ static unsigned int startup_edge_ioapic_irq(unsigned int irq)
return was_pending;
}

/*
* Once we have recorded IRQ_PENDING already, we can mask the
* interrupt for real. This prevents IRQ storms from unhandled
* devices.
*/
static void ack_edge_ioapic_irq(unsigned int irq)
static void ack_ioapic_irq(unsigned int irq)
{
move_irq(irq);
if ((irq_desc[irq].status & (IRQ_PENDING | IRQ_DISABLED))
== (IRQ_PENDING | IRQ_DISABLED))
mask_IO_APIC_irq(irq);
ack_APIC_irq();
}

/*
* Level triggered interrupts can just be masked,
* and shutting down and starting up the interrupt
* is the same as enabling and disabling them -- except
* with a startup need to return a "was pending" value.
*
* Level triggered interrupts are special because we
* do not touch any IO-APIC register while handling
* them. We ack the APIC in the end-IRQ handler, not
* in the start-IRQ-handler. Protection against reentrance
* from the same interrupt is still provided, both by the
* generic IRQ layer and by the fact that an unacked local
* APIC does not accept IRQs.
*/
static unsigned int startup_level_ioapic_irq (unsigned int irq)
{
unmask_IO_APIC_irq(irq);

return 0; /* don't check for pending */
}

static void end_level_ioapic_irq (unsigned int irq)
static void ack_ioapic_quirk_irq(unsigned int irq)
{
unsigned long v;
int i;
Expand Down Expand Up @@ -2018,35 +1995,27 @@ static void end_level_ioapic_irq (unsigned int irq)
}
}

#ifdef CONFIG_PCI_MSI
static unsigned int startup_edge_ioapic_vector(unsigned int vector)
static unsigned int startup_ioapic_vector(unsigned int vector)
{
int irq = vector_to_irq(vector);

return startup_edge_ioapic_irq(irq);
return startup_ioapic_irq(irq);
}

static void ack_edge_ioapic_vector(unsigned int vector)
static void ack_ioapic_vector(unsigned int vector)
{
int irq = vector_to_irq(vector);

move_native_irq(vector);
ack_edge_ioapic_irq(irq);
ack_ioapic_irq(irq);
}

static unsigned int startup_level_ioapic_vector (unsigned int vector)
{
int irq = vector_to_irq(vector);

return startup_level_ioapic_irq (irq);
}

static void end_level_ioapic_vector (unsigned int vector)
static void ack_ioapic_quirk_vector(unsigned int vector)
{
int irq = vector_to_irq(vector);

move_native_irq(vector);
end_level_ioapic_irq(irq);
ack_ioapic_quirk_irq(irq);
}

static void mask_IO_APIC_vector (unsigned int vector)
Expand All @@ -2063,7 +2032,12 @@ static void unmask_IO_APIC_vector (unsigned int vector)
unmask_IO_APIC_irq(irq);
}

#ifdef CONFIG_SMP
/*
* Oh just glorious. If CONFIG_PCI_MSI we've done
* #define set_ioapic_affinity set_ioapic_affinity_vector
*/
#if defined (CONFIG_SMP) && defined(CONFIG_X86_IO_APIC) && \
defined(CONFIG_PCI_MSI)
static void set_ioapic_affinity_vector (unsigned int vector,
cpumask_t cpu_mask)
{
Expand All @@ -2073,50 +2047,29 @@ static void set_ioapic_affinity_vector (unsigned int vector,
set_ioapic_affinity_irq(irq, cpu_mask);
}
#endif
#endif

static int ioapic_retrigger(unsigned int irq)
static int ioapic_retrigger_vector(unsigned int vector)
{
int irq = vector_to_irq(vector);

send_IPI_self(IO_APIC_VECTOR(irq));

return 1;
}

/*
* Level and edge triggered IO-APIC interrupts need different handling,
* so we use two separate IRQ descriptors. Edge triggered IRQs can be
* handled with the level-triggered descriptor, but that one has slightly
* more overhead. Level-triggered interrupts cannot be handled with the
* edge-triggered handler, without risking IRQ storms and other ugly
* races.
*/
static struct hw_interrupt_type ioapic_edge_type __read_mostly = {
.typename = "IO-APIC-edge",
.startup = startup_edge_ioapic,
.shutdown = shutdown_edge_ioapic,
.enable = enable_edge_ioapic,
.disable = disable_edge_ioapic,
.ack = ack_edge_ioapic,
.end = end_edge_ioapic,
static struct irq_chip ioapic_chip __read_mostly = {
.name = "IO-APIC",
.startup = startup_ioapic_vector,
.mask = mask_IO_APIC_vector,
.unmask = unmask_IO_APIC_vector,
.ack = ack_ioapic_vector,
.eoi = ack_ioapic_quirk_vector,
#ifdef CONFIG_SMP
.set_affinity = set_ioapic_affinity,
#endif
.retrigger = ioapic_retrigger,
.retrigger = ioapic_retrigger_vector,
};

static struct hw_interrupt_type ioapic_level_type __read_mostly = {
.typename = "IO-APIC-level",
.startup = startup_level_ioapic,
.shutdown = shutdown_level_ioapic,
.enable = enable_level_ioapic,
.disable = disable_level_ioapic,
.ack = mask_and_ack_level_ioapic,
.end = end_level_ioapic,
#ifdef CONFIG_SMP
.set_affinity = set_ioapic_affinity,
#endif
.retrigger = ioapic_retrigger,
};

static inline void init_IO_APIC_traps(void)
{
Expand Down Expand Up @@ -2150,42 +2103,41 @@ static inline void init_IO_APIC_traps(void)
make_8259A_irq(irq);
else
/* Strange. Oh, well.. */
irq_desc[irq].chip = &no_irq_type;
irq_desc[irq].chip = &no_irq_chip;
}
}
}

static void enable_lapic_irq (unsigned int irq)
{
unsigned long v;
/*
* The local APIC irq-chip implementation:
*/

v = apic_read(APIC_LVT0);
apic_write_around(APIC_LVT0, v & ~APIC_LVT_MASKED);
static void ack_apic(unsigned int irq)
{
ack_APIC_irq();
}

static void disable_lapic_irq (unsigned int irq)
static void mask_lapic_irq (unsigned int irq)
{
unsigned long v;

v = apic_read(APIC_LVT0);
apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED);
}

static void ack_lapic_irq (unsigned int irq)
static void unmask_lapic_irq (unsigned int irq)
{
ack_APIC_irq();
}
unsigned long v;

static void end_lapic_irq (unsigned int i) { /* nothing */ }
v = apic_read(APIC_LVT0);
apic_write_around(APIC_LVT0, v & ~APIC_LVT_MASKED);
}

static struct hw_interrupt_type lapic_irq_type __read_mostly = {
.typename = "local-APIC-edge",
.startup = NULL, /* startup_irq() not used for IRQ0 */
.shutdown = NULL, /* shutdown_irq() not used for IRQ0 */
.enable = enable_lapic_irq,
.disable = disable_lapic_irq,
.ack = ack_lapic_irq,
.end = end_lapic_irq
static struct irq_chip lapic_chip __read_mostly = {
.name = "local-APIC-edge",
.mask = mask_lapic_irq,
.unmask = unmask_lapic_irq,
.eoi = ack_apic,
};

static void setup_nmi (void)
Expand Down Expand Up @@ -2356,7 +2308,7 @@ static inline void check_timer(void)
printk(KERN_INFO "...trying to set up timer as Virtual Wire IRQ...");

disable_8259A_irq(0);
irq_desc[0].chip = &lapic_irq_type;
set_irq_chip_and_handler(0, &lapic_chip, handle_fasteoi_irq);
apic_write_around(APIC_LVT0, APIC_DM_FIXED | vector); /* Fixed mode */
enable_8259A_irq(0);

Expand Down
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