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linux/arch/mips/sni/rm200.c
Wu Zhangjin 5a4a4ad851 MIPS: Mark cascade and low level interrupts IRQF_NO_THREAD 
Mark interrupts with no_action handler, cascade interrupts, low level
interrupts (bus error, halt ..) with IRQF_NO_THREAD to exclude them
from forced threading.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-09-21 17:52:15 +02:00

491 lines
12 KiB
C
Raw Blame History

/*
* RM200 specific code
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2006,2007 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
*
* i8259 parts ripped out of arch/mips/kernel/i8259.c
*/
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/serial_8250.h>
#include <linux/io.h>
#include <asm/sni.h>
#include <asm/time.h>
#include <asm/irq_cpu.h>
#define RM200_I8259A_IRQ_BASE 32
#define MEMPORT(_base,_irq) \
{ \
.mapbase = _base, \
.irq = _irq, \
.uartclk = 1843200, \
.iotype = UPIO_MEM, \
.flags = UPF_BOOT_AUTOCONF|UPF_IOREMAP, \
}
static struct plat_serial8250_port rm200_data[] = {
MEMPORT(0x160003f8, RM200_I8259A_IRQ_BASE + 4),
MEMPORT(0x160002f8, RM200_I8259A_IRQ_BASE + 3),
{ },
};
static struct platform_device rm200_serial8250_device = {
.name = "serial8250",
.id = PLAT8250_DEV_PLATFORM,
.dev = {
.platform_data = rm200_data,
},
};
static struct resource rm200_ds1216_rsrc[] = {
{
.start = 0x1cd41ffc,
.end = 0x1cd41fff,
.flags = IORESOURCE_MEM
}
};
static struct platform_device rm200_ds1216_device = {
.name = "rtc-ds1216",
.num_resources = ARRAY_SIZE(rm200_ds1216_rsrc),
.resource = rm200_ds1216_rsrc
};
static struct resource snirm_82596_rm200_rsrc[] = {
{
.start = 0x18000000,
.end = 0x180fffff,
.flags = IORESOURCE_MEM
},
{
.start = 0x1b000000,
.end = 0x1b000004,
.flags = IORESOURCE_MEM
},
{
.start = 0x1ff00000,
.end = 0x1ff00020,
.flags = IORESOURCE_MEM
},
{
.start = 27,
.end = 27,
.flags = IORESOURCE_IRQ
},
{
.flags = 0x00
}
};
static struct platform_device snirm_82596_rm200_pdev = {
.name = "snirm_82596",
.num_resources = ARRAY_SIZE(snirm_82596_rm200_rsrc),
.resource = snirm_82596_rm200_rsrc
};
static struct resource snirm_53c710_rm200_rsrc[] = {
{
.start = 0x19000000,
.end = 0x190fffff,
.flags = IORESOURCE_MEM
},
{
.start = 26,
.end = 26,
.flags = IORESOURCE_IRQ
}
};
static struct platform_device snirm_53c710_rm200_pdev = {
.name = "snirm_53c710",
.num_resources = ARRAY_SIZE(snirm_53c710_rm200_rsrc),
.resource = snirm_53c710_rm200_rsrc
};
static int __init snirm_setup_devinit(void)
{
if (sni_brd_type == SNI_BRD_RM200) {
platform_device_register(&rm200_serial8250_device);
platform_device_register(&rm200_ds1216_device);
platform_device_register(&snirm_82596_rm200_pdev);
platform_device_register(&snirm_53c710_rm200_pdev);
sni_eisa_root_init();
}
return 0;
}
device_initcall(snirm_setup_devinit);
/*
* RM200 has an ISA and an EISA bus. The iSA bus is only used
* for onboard devices and also has twi i8259 PICs. Since these
* PICs are no accessible via inb/outb the following code uses
* readb/writeb to access them
*/
static DEFINE_RAW_SPINLOCK(sni_rm200_i8259A_lock);
#define PIC_CMD 0x00
#define PIC_IMR 0x01
#define PIC_ISR PIC_CMD
#define PIC_POLL PIC_ISR
#define PIC_OCW3 PIC_ISR
/* i8259A PIC related value */
#define PIC_CASCADE_IR 2
#define MASTER_ICW4_DEFAULT 0x01
#define SLAVE_ICW4_DEFAULT 0x01
/*
* This contains the irq mask for both 8259A irq controllers,
*/
static unsigned int rm200_cached_irq_mask = 0xffff;
static __iomem u8 *rm200_pic_master;
static __iomem u8 *rm200_pic_slave;
#define cached_master_mask (rm200_cached_irq_mask)
#define cached_slave_mask (rm200_cached_irq_mask >> 8)
static void sni_rm200_disable_8259A_irq(struct irq_data *d)
{
unsigned int mask, irq = d->irq - RM200_I8259A_IRQ_BASE;
unsigned long flags;
mask = 1 << irq;
raw_spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
rm200_cached_irq_mask |= mask;
if (irq & 8)
writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
else
writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
raw_spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
}
static void sni_rm200_enable_8259A_irq(struct irq_data *d)
{
unsigned int mask, irq = d->irq - RM200_I8259A_IRQ_BASE;
unsigned long flags;
mask = ~(1 << irq);
raw_spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
rm200_cached_irq_mask &= mask;
if (irq & 8)
writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
else
writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
raw_spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
}
static inline int sni_rm200_i8259A_irq_real(unsigned int irq)
{
int value;
int irqmask = 1 << irq;
if (irq < 8) {
writeb(0x0B, rm200_pic_master + PIC_CMD);
value = readb(rm200_pic_master + PIC_CMD) & irqmask;
writeb(0x0A, rm200_pic_master + PIC_CMD);
return value;
}
writeb(0x0B, rm200_pic_slave + PIC_CMD); /* ISR register */
value = readb(rm200_pic_slave + PIC_CMD) & (irqmask >> 8);
writeb(0x0A, rm200_pic_slave + PIC_CMD);
return value;
}
/*
* Careful! The 8259A is a fragile beast, it pretty
* much _has_ to be done exactly like this (mask it
* first, _then_ send the EOI, and the order of EOI
* to the two 8259s is important!
*/
void sni_rm200_mask_and_ack_8259A(struct irq_data *d)
{
unsigned int irqmask, irq = d->irq - RM200_I8259A_IRQ_BASE;
unsigned long flags;
irqmask = 1 << irq;
raw_spin_lock_irqsave(&sni_rm200_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 unnecessarily.
*
* 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 (rm200_cached_irq_mask & irqmask)
goto spurious_8259A_irq;
rm200_cached_irq_mask |= irqmask;
handle_real_irq:
if (irq & 8) {
readb(rm200_pic_slave + PIC_IMR);
writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
writeb(0x60+(irq & 7), rm200_pic_slave + PIC_CMD);
writeb(0x60+PIC_CASCADE_IR, rm200_pic_master + PIC_CMD);
} else {
readb(rm200_pic_master + PIC_IMR);
writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
writeb(0x60+irq, rm200_pic_master + PIC_CMD);
}
raw_spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
return;
spurious_8259A_irq:
/*
* this is the slow path - should happen rarely.
*/
if (sni_rm200_i8259A_irq_real(irq))
/*
* oops, the IRQ _is_ in service according to the
* 8259A - not spurious, go handle it.
*/
goto handle_real_irq;
{
static int spurious_irq_mask;
/*
* At this point we can be sure the IRQ is spurious,
* lets ACK and report it. [once per IRQ]
*/
if (!(spurious_irq_mask & irqmask)) {
printk(KERN_DEBUG
"spurious RM200 8259A interrupt: IRQ%d.\n", irq);
spurious_irq_mask |= irqmask;
}
atomic_inc(&irq_err_count);
/*
* Theoretically we do not have to handle this IRQ,
* but in Linux this does not cause problems and is
* simpler for us.
*/
goto handle_real_irq;
}
}
static struct irq_chip sni_rm200_i8259A_chip = {
.name = "RM200-XT-PIC",
.irq_mask = sni_rm200_disable_8259A_irq,
.irq_unmask = sni_rm200_enable_8259A_irq,
.irq_mask_ack = sni_rm200_mask_and_ack_8259A,
};
/*
* Do the traditional i8259 interrupt polling thing. This is for the few
* cases where no better interrupt acknowledge method is available and we
* absolutely must touch the i8259.
*/
static inline int sni_rm200_i8259_irq(void)
{
int irq;
raw_spin_lock(&sni_rm200_i8259A_lock);
/* Perform an interrupt acknowledge cycle on controller 1. */
writeb(0x0C, rm200_pic_master + PIC_CMD); /* prepare for poll */
irq = readb(rm200_pic_master + PIC_CMD) & 7;
if (irq == PIC_CASCADE_IR) {
/*
* Interrupt is cascaded so perform interrupt
* acknowledge on controller 2.
*/
writeb(0x0C, rm200_pic_slave + PIC_CMD); /* prepare for poll */
irq = (readb(rm200_pic_slave + PIC_CMD) & 7) + 8;
}
if (unlikely(irq == 7)) {
/*
* This may be a spurious interrupt.
*
* Read the interrupt status register (ISR). If the most
* significant bit is not set then there is no valid
* interrupt.
*/
writeb(0x0B, rm200_pic_master + PIC_ISR); /* ISR register */
if (~readb(rm200_pic_master + PIC_ISR) & 0x80)
irq = -1;
}
raw_spin_unlock(&sni_rm200_i8259A_lock);
return likely(irq >= 0) ? irq + RM200_I8259A_IRQ_BASE : irq;
}
void sni_rm200_init_8259A(void)
{
unsigned long flags;
raw_spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
writeb(0xff, rm200_pic_master + PIC_IMR);
writeb(0xff, rm200_pic_slave + PIC_IMR);
writeb(0x11, rm200_pic_master + PIC_CMD);
writeb(0, rm200_pic_master + PIC_IMR);
writeb(1U << PIC_CASCADE_IR, rm200_pic_master + PIC_IMR);
writeb(MASTER_ICW4_DEFAULT, rm200_pic_master + PIC_IMR);
writeb(0x11, rm200_pic_slave + PIC_CMD);
writeb(8, rm200_pic_slave + PIC_IMR);
writeb(PIC_CASCADE_IR, rm200_pic_slave + PIC_IMR);
writeb(SLAVE_ICW4_DEFAULT, rm200_pic_slave + PIC_IMR);
udelay(100); /* wait for 8259A to initialize */
writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
raw_spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
}
/*
* IRQ2 is cascade interrupt to second interrupt controller
*/
static struct irqaction sni_rm200_irq2 = {
.handler = no_action,
.name = "cascade",
.flags = IRQF_NO_THREAD,
};
static struct resource sni_rm200_pic1_resource = {
.name = "onboard ISA pic1",
.start = 0x16000020,
.end = 0x16000023,
.flags = IORESOURCE_BUSY
};
static struct resource sni_rm200_pic2_resource = {
.name = "onboard ISA pic2",
.start = 0x160000a0,
.end = 0x160000a3,
.flags = IORESOURCE_BUSY
};
/* ISA irq handler */
static irqreturn_t sni_rm200_i8259A_irq_handler(int dummy, void *p)
{
int irq;
irq = sni_rm200_i8259_irq();
if (unlikely(irq < 0))
return IRQ_NONE;
do_IRQ(irq);
return IRQ_HANDLED;
}
struct irqaction sni_rm200_i8259A_irq = {
.handler = sni_rm200_i8259A_irq_handler,
.name = "onboard ISA",
.flags = IRQF_SHARED
};
void __init sni_rm200_i8259_irqs(void)
{
int i;
rm200_pic_master = ioremap_nocache(0x16000020, 4);
if (!rm200_pic_master)
return;
rm200_pic_slave = ioremap_nocache(0x160000a0, 4);
if (!rm200_pic_slave) {
iounmap(rm200_pic_master);
return;
}
insert_resource(&iomem_resource, &sni_rm200_pic1_resource);
insert_resource(&iomem_resource, &sni_rm200_pic2_resource);
sni_rm200_init_8259A();
for (i = RM200_I8259A_IRQ_BASE; i < RM200_I8259A_IRQ_BASE + 16; i++)
irq_set_chip_and_handler(i, &sni_rm200_i8259A_chip,
handle_level_irq);
setup_irq(RM200_I8259A_IRQ_BASE + PIC_CASCADE_IR, &sni_rm200_irq2);
}
#define SNI_RM200_INT_STAT_REG CKSEG1ADDR(0xbc000000)
#define SNI_RM200_INT_ENA_REG CKSEG1ADDR(0xbc080000)
#define SNI_RM200_INT_START 24
#define SNI_RM200_INT_END 28
static void enable_rm200_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq - SNI_RM200_INT_START);
*(volatile u8 *)SNI_RM200_INT_ENA_REG &= ~mask;
}
void disable_rm200_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq - SNI_RM200_INT_START);
*(volatile u8 *)SNI_RM200_INT_ENA_REG |= mask;
}
static struct irq_chip rm200_irq_type = {
.name = "RM200",
.irq_mask = disable_rm200_irq,
.irq_unmask = enable_rm200_irq,
};
static void sni_rm200_hwint(void)
{
u32 pending = read_c0_cause() & read_c0_status();
u8 mask;
u8 stat;
int irq;
if (pending & C_IRQ5)
do_IRQ(MIPS_CPU_IRQ_BASE + 7);
else if (pending & C_IRQ0) {
clear_c0_status(IE_IRQ0);
mask = *(volatile u8 *)SNI_RM200_INT_ENA_REG ^ 0x1f;
stat = *(volatile u8 *)SNI_RM200_INT_STAT_REG ^ 0x14;
irq = ffs(stat & mask & 0x1f);
if (likely(irq > 0))
do_IRQ(irq + SNI_RM200_INT_START - 1);
set_c0_status(IE_IRQ0);
}
}
void __init sni_rm200_irq_init(void)
{
int i;
* (volatile u8 *)SNI_RM200_INT_ENA_REG = 0x1f;
sni_rm200_i8259_irqs();
mips_cpu_irq_init();
/* Actually we've got more interrupts to handle ... */
for (i = SNI_RM200_INT_START; i <= SNI_RM200_INT_END; i++)
irq_set_chip_and_handler(i, &rm200_irq_type, handle_level_irq);
sni_hwint = sni_rm200_hwint;
change_c0_status(ST0_IM, IE_IRQ0);
setup_irq(SNI_RM200_INT_START + 0, &sni_rm200_i8259A_irq);
setup_irq(SNI_RM200_INT_START + 1, &sni_isa_irq);
}
void __init sni_rm200_init(void)
{
}
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