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[MIPS] Import updates from i386's i8259.c
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Import many updates from i386's i8259.c, especially genirq transitions.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Atsushi Nemoto authored and Ralf Baechle committed Dec 6, 2006
1 parent 49afb1f commit 2cafe97
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Showing 2 changed files with 115 additions and 84 deletions.
162 changes: 86 additions & 76 deletions arch/mips/kernel/i8259.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,9 +19,6 @@
#include <asm/i8259.h>
#include <asm/io.h>

void enable_8259A_irq(unsigned int irq);
void disable_8259A_irq(unsigned int irq);

/*
* This is the 'legacy' 8259A Programmable Interrupt Controller,
* present in the majority of PC/AT boxes.
Expand All @@ -31,23 +28,16 @@ void disable_8259A_irq(unsigned int irq);
* moves to arch independent land
*/

static int i8259A_auto_eoi;
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);
}

/* some platforms call this... */
void mask_and_ack_8259A(unsigned int);

static struct irq_chip i8259A_irq_type = {
.typename = "XT-PIC",
.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 All @@ -59,8 +49,8 @@ static struct irq_chip i8259A_irq_type = {
*/
static unsigned int cached_irq_mask = 0xffff;

#define cached_21 (cached_irq_mask)
#define cached_A1 (cached_irq_mask >> 8)
#define cached_master_mask (cached_irq_mask)
#define cached_slave_mask (cached_irq_mask >> 8)

void disable_8259A_irq(unsigned int irq)
{
Expand All @@ -70,9 +60,9 @@ void disable_8259A_irq(unsigned int irq)
spin_lock_irqsave(&i8259A_lock, flags);
cached_irq_mask |= mask;
if (irq & 8)
outb(cached_A1,0xA1);
outb(cached_slave_mask, PIC_SLAVE_IMR);
else
outb(cached_21,0x21);
outb(cached_master_mask, PIC_MASTER_IMR);
spin_unlock_irqrestore(&i8259A_lock, flags);
}

Expand All @@ -84,9 +74,9 @@ void enable_8259A_irq(unsigned int irq)
spin_lock_irqsave(&i8259A_lock, flags);
cached_irq_mask &= mask;
if (irq & 8)
outb(cached_A1,0xA1);
outb(cached_slave_mask, PIC_SLAVE_IMR);
else
outb(cached_21,0x21);
outb(cached_master_mask, PIC_MASTER_IMR);
spin_unlock_irqrestore(&i8259A_lock, flags);
}

Expand All @@ -98,9 +88,9 @@ int i8259A_irq_pending(unsigned int irq)

spin_lock_irqsave(&i8259A_lock, flags);
if (irq < 8)
ret = inb(0x20) & mask;
ret = inb(PIC_MASTER_CMD) & mask;
else
ret = inb(0xA0) & (mask >> 8);
ret = inb(PIC_SLAVE_CMD) & (mask >> 8);
spin_unlock_irqrestore(&i8259A_lock, flags);

return ret;
Expand All @@ -109,7 +99,7 @@ int i8259A_irq_pending(unsigned int irq)
void make_8259A_irq(unsigned int irq)
{
disable_irq_nosync(irq);
set_irq_chip(irq, &i8259A_irq_type);
set_irq_chip_and_handler(irq, &i8259A_chip, handle_level_irq);
enable_irq(irq);
}

Expand All @@ -125,14 +115,14 @@ static inline int i8259A_irq_real(unsigned int irq)
int irqmask = 1 << irq;

if (irq < 8) {
outb(0x0B,0x20); /* ISR register */
value = inb(0x20) & irqmask;
outb(0x0A,0x20); /* back to the IRR register */
outb(0x0B,PIC_MASTER_CMD); /* ISR register */
value = inb(PIC_MASTER_CMD) & irqmask;
outb(0x0A,PIC_MASTER_CMD); /* back to the IRR register */
return value;
}
outb(0x0B,0xA0); /* ISR register */
value = inb(0xA0) & (irqmask >> 8);
outb(0x0A,0xA0); /* back to the IRR register */
outb(0x0B,PIC_SLAVE_CMD); /* ISR register */
value = inb(PIC_SLAVE_CMD) & (irqmask >> 8);
outb(0x0A,PIC_SLAVE_CMD); /* back to the IRR register */
return value;
}

Expand All @@ -149,32 +139,34 @@ void mask_and_ack_8259A(unsigned int irq)

spin_lock_irqsave(&i8259A_lock, flags);
/*
* Lightweight spurious IRQ detection. We do not want to overdo
* spurious IRQ handling - it's usually a sign of hardware problems, so
* we only do the checks we can do without slowing down good hardware
* nnecesserily.
* Lightweight spurious IRQ detection. We do not want
* to overdo spurious IRQ handling - it's usually a sign
* of hardware problems, so we only do the checks we can
* do without slowing down good hardware unnecessarily.
*
* Note that IRQ7 and IRQ15 (the two spurious IRQs usually resulting
* rom the 8259A-1|2 PICs) occur even if the IRQ is masked in the 8259A.
* Thus we can check spurious 8259A IRQs without doing the quite slow
* i8259A_irq_real() call for every IRQ. This does not cover 100% of
* spurious interrupts, but should be enough to warn the user that
* there is something bad going on ...
* Note that IRQ7 and IRQ15 (the two spurious IRQs
* usually resulting from the 8259A-1|2 PICs) occur
* even if the IRQ is masked in the 8259A. Thus we
* can check spurious 8259A IRQs without doing the
* quite slow i8259A_irq_real() call for every IRQ.
* This does not cover 100% of spurious interrupts,
* but should be enough to warn the user that there
* is something bad going on ...
*/
if (cached_irq_mask & irqmask)
goto spurious_8259A_irq;
cached_irq_mask |= irqmask;

handle_real_irq:
if (irq & 8) {
inb(0xA1); /* DUMMY - (do we need this?) */
outb(cached_A1,0xA1);
outb(0x60+(irq&7),0xA0);/* 'Specific EOI' to slave */
outb(0x62,0x20); /* 'Specific EOI' to master-IRQ2 */
inb(PIC_SLAVE_IMR); /* DUMMY - (do we need this?) */
outb(cached_slave_mask, PIC_SLAVE_IMR);
outb(0x60+(irq&7),PIC_SLAVE_CMD);/* 'Specific EOI' to slave */
outb(0x60+PIC_CASCADE_IR,PIC_MASTER_CMD); /* 'Specific EOI' to master-IRQ2 */
} else {
inb(0x21); /* DUMMY - (do we need this?) */
outb(cached_21,0x21);
outb(0x60+irq,0x20); /* 'Specific EOI' to master */
inb(PIC_MASTER_IMR); /* DUMMY - (do we need this?) */
outb(cached_master_mask, PIC_MASTER_IMR);
outb(0x60+irq,PIC_MASTER_CMD); /* 'Specific EOI to master */
}
#ifdef CONFIG_MIPS_MT_SMTC
if (irq_hwmask[irq] & ST0_IM)
Expand All @@ -195,7 +187,7 @@ void mask_and_ack_8259A(unsigned int irq)
goto handle_real_irq;

{
static int spurious_irq_mask = 0;
static int spurious_irq_mask;
/*
* At this point we can be sure the IRQ is spurious,
* lets ACK and report it. [once per IRQ]
Expand All @@ -216,13 +208,25 @@ void mask_and_ack_8259A(unsigned int irq)

static int i8259A_resume(struct sys_device *dev)
{
init_8259A(0);
init_8259A(i8259A_auto_eoi);
return 0;
}

static int i8259A_shutdown(struct sys_device *dev)
{
/* Put the i8259A into a quiescent state that
* the kernel initialization code can get it
* out of.
*/
outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-1 */
return 0;
}

static struct sysdev_class i8259_sysdev_class = {
set_kset_name("i8259"),
.resume = i8259A_resume,
.shutdown = i8259A_shutdown,
};

static struct sys_device device_i8259A = {
Expand All @@ -244,41 +248,41 @@ void __init init_8259A(int auto_eoi)
{
unsigned long flags;

i8259A_auto_eoi = auto_eoi;

spin_lock_irqsave(&i8259A_lock, flags);

outb(0xff, 0x21); /* mask all of 8259A-1 */
outb(0xff, 0xA1); /* mask all of 8259A-2 */
outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */

/*
* outb_p - this has to work on a wide range of PC hardware.
*/
outb_p(0x11, 0x20); /* ICW1: select 8259A-1 init */
outb_p(0x00, 0x21); /* ICW2: 8259A-1 IR0-7 mapped to 0x00-0x07 */
outb_p(0x04, 0x21); /* 8259A-1 (the master) has a slave on IR2 */
if (auto_eoi)
outb_p(0x03, 0x21); /* master does Auto EOI */
else
outb_p(0x01, 0x21); /* master expects normal EOI */

outb_p(0x11, 0xA0); /* ICW1: select 8259A-2 init */
outb_p(0x08, 0xA1); /* ICW2: 8259A-2 IR0-7 mapped to 0x08-0x0f */
outb_p(0x02, 0xA1); /* 8259A-2 is a slave on master's IR2 */
outb_p(0x01, 0xA1); /* (slave's support for AEOI in flat mode
is to be investigated) */

outb_p(0x11, PIC_MASTER_CMD); /* ICW1: select 8259A-1 init */
outb_p(I8259A_IRQ_BASE + 0, PIC_MASTER_IMR); /* ICW2: 8259A-1 IR0 mapped to I8259A_IRQ_BASE + 0x00 */
outb_p(1U << PIC_CASCADE_IR, PIC_MASTER_IMR); /* 8259A-1 (the master) has a slave on IR2 */
if (auto_eoi) /* master does Auto EOI */
outb_p(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR);
else /* master expects normal EOI */
outb_p(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR);

outb_p(0x11, PIC_SLAVE_CMD); /* ICW1: select 8259A-2 init */
outb_p(I8259A_IRQ_BASE + 8, PIC_SLAVE_IMR); /* ICW2: 8259A-2 IR0 mapped to I8259A_IRQ_BASE + 0x08 */
outb_p(PIC_CASCADE_IR, PIC_SLAVE_IMR); /* 8259A-2 is a slave on master's IR2 */
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 */

outb(cached_21, 0x21); /* restore master IRQ mask */
outb(cached_A1, 0xA1); /* restore slave IRQ mask */
outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
outb(cached_slave_mask, PIC_SLAVE_IMR); /* restore slave IRQ mask */

spin_unlock_irqrestore(&i8259A_lock, flags);
}
Expand All @@ -291,11 +295,17 @@ static struct irqaction irq2 = {
};

static struct resource pic1_io_resource = {
.name = "pic1", .start = 0x20, .end = 0x21, .flags = IORESOURCE_BUSY
.name = "pic1",
.start = PIC_MASTER_CMD,
.end = PIC_MASTER_IMR,
.flags = IORESOURCE_BUSY
};

static struct resource pic2_io_resource = {
.name = "pic2", .start = 0xa0, .end = 0xa1, .flags = IORESOURCE_BUSY
.name = "pic2",
.start = PIC_SLAVE_CMD,
.end = PIC_SLAVE_IMR,
.flags = IORESOURCE_BUSY
};

/*
Expand All @@ -313,7 +323,7 @@ void __init init_i8259_irqs (void)
init_8259A(0);

for (i = 0; i < 16; i++)
set_irq_chip(i, &i8259A_irq_type);
set_irq_chip_and_handler(i, &i8259A_chip, handle_level_irq);

setup_irq(2, &irq2);
setup_irq(PIC_CASCADE_IR, &irq2);
}
37 changes: 29 additions & 8 deletions include/asm-mips/i8259.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,10 +19,31 @@

#include <asm/io.h>

/* i8259A PIC registers */
#define PIC_MASTER_CMD 0x20
#define PIC_MASTER_IMR 0x21
#define PIC_MASTER_ISR PIC_MASTER_CMD
#define PIC_MASTER_POLL PIC_MASTER_ISR
#define PIC_MASTER_OCW3 PIC_MASTER_ISR
#define PIC_SLAVE_CMD 0xa0
#define PIC_SLAVE_IMR 0xa1

/* i8259A PIC related value */
#define PIC_CASCADE_IR 2
#define MASTER_ICW4_DEFAULT 0x01
#define SLAVE_ICW4_DEFAULT 0x01
#define PIC_ICW4_AEOI 2

extern spinlock_t i8259A_lock;

extern void init_8259A(int auto_eoi);
extern void enable_8259A_irq(unsigned int irq);
extern void disable_8259A_irq(unsigned int irq);

extern void init_i8259_irqs(void);

#define I8259A_IRQ_BASE 0

/*
* Do the traditional i8259 interrupt polling thing. This is for the few
* cases where no better interrupt acknowledge method is available and we
Expand All @@ -35,15 +56,15 @@ static inline int i8259_irq(void)
spin_lock(&i8259A_lock);

/* Perform an interrupt acknowledge cycle on controller 1. */
outb(0x0C, 0x20); /* prepare for poll */
irq = inb(0x20) & 7;
if (irq == 2) {
outb(0x0C, PIC_MASTER_CMD); /* prepare for poll */
irq = inb(PIC_MASTER_CMD) & 7;
if (irq == PIC_CASCADE_IR) {
/*
* Interrupt is cascaded so perform interrupt
* acknowledge on controller 2.
*/
outb(0x0C, 0xA0); /* prepare for poll */
irq = (inb(0xA0) & 7) + 8;
outb(0x0C, PIC_SLAVE_CMD); /* prepare for poll */
irq = (inb(PIC_SLAVE_CMD) & 7) + 8;
}

if (unlikely(irq == 7)) {
Expand All @@ -54,14 +75,14 @@ static inline int i8259_irq(void)
* significant bit is not set then there is no valid
* interrupt.
*/
outb(0x0B, 0x20); /* ISR register */
if(~inb(0x20) & 0x80)
outb(0x0B, PIC_MASTER_ISR); /* ISR register */
if(~inb(PIC_MASTER_ISR) & 0x80)
irq = -1;
}

spin_unlock(&i8259A_lock);

return irq;
return likely(irq >= 0) ? irq + I8259A_IRQ_BASE : irq;
}

#endif /* _ASM_I8259_H */

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