/**
* handle_IRQ_event - irq action chain handler
* @irq: the interrupt number
* @regs: pointer to a register structure
* @action: the interrupt action chain for this irq
*
* Handles the action chain of an irq event
*/
irqreturn_t handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
struct irqaction *action)
{
irqreturn_t ret, retval = IRQ_NONE;
unsigned int status = 0;
trace_irq_entry(irq, regs);
handle_dynamic_tick(action);
if (!(action->flags & IRQF_DISABLED))
local_irq_enable_in_hardirq();
do {
ret = action->handler(irq, action->dev_id, regs);
if (ret == IRQ_HANDLED)
status |= action->flags;
retval |= ret;
action = action->next;
} while (action);
if (status & IRQF_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
local_irq_disable();
trace_irq_exit(irq, retval);
return retval;
}
/**
* handle_IRQ_event - irq action chain handler
* @irq: the interrupt number
* @action: the interrupt action chain for this irq
*
* Handles the action chain of an irq event
*/
irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
{
irqreturn_t ret, retval = IRQ_NONE;
unsigned int status = 0;
struct pt_regs *regs = get_irq_regs();
trace_mark(kernel_irq_entry, "irq_id %u kernel_mode %u", irq,
(regs)?(!user_mode(regs)):(1));
handle_dynamic_tick(action);
if (!(action->flags & IRQF_DISABLED))
local_irq_enable_in_hardirq();
do {
ret = action->handler(irq, action->dev_id);
if (ret == IRQ_HANDLED)
status |= action->flags;
retval |= ret;
action = action->next;
} while (action);
if (status & IRQF_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
local_irq_disable();
trace_mark(kernel_irq_exit, MARK_NOARGS);
return retval;
}
/**
* handle_IRQ_event - irq action chain handler
* @irq: the interrupt number
* @action: the interrupt action chain for this irq
*
* Handles the action chain of an irq event
*/
irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
{
irqreturn_t ret, retval = IRQ_NONE;
unsigned int status = 0;
handle_dynamic_tick(action);
//如果第一个处理程序函数中没有设置IRQF_DISABLED，
//则用local_irq_enable_in_hardirq启用(当前CPU的)中断。
//换句话说，该处理程序可以被其他IRQ中断。但根据电流类型，
//也可能一直屏蔽刚处理的IRQ
if (!(action->flags & IRQF_DISABLED))
local_irq_enable_in_hardirq();
//在共享IRQ时
do
{
ret = action->handler(irq, action->dev_id);
if (ret == IRQ_HANDLED)
status |= action->flags;
retval |= ret;
action = action->next;
} while (action);
//如果该IRQ设置了IRQF_SAMPLE_RANDOM，
//则调用add_interrupt_randomness，将事件的时间作为熵池的一个源
//(如果中断是随机发生的，那么他们是理想的源)
if (status & IRQF_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
//禁用中断。
//因为中断的启用和禁用是不嵌套的，与中断在处理开始时是否启用是不相关的。
//handle_IRQ_event在调用时禁用中断，在退出时然然预期禁用中断
local_irq_disable();
return retval;
}
/*
* This routine busy-waits for the drive status to be not "busy".
* It then checks the status for all of the "good" bits and none
* of the "bad" bits, and if all is okay it returns 0. All other
* cases return error -- caller may then invoke ide_error().
*
* This routine should get fixed to not hog the cpu during extra long waits..
* That could be done by busy-waiting for the first jiffy or two, and then
* setting a timer to wake up at half second intervals thereafter,
* until timeout is achieved, before timing out.
*/
int __ide_wait_stat(ide_drive_t *drive, u8 good, u8 bad,
unsigned long timeout, u8 *rstat)
{
ide_hwif_t *hwif = drive->hwif;
const struct ide_tp_ops *tp_ops = hwif->tp_ops;
unsigned long flags;
bool irqs_threaded = force_irqthreads;
int i;
u8 stat;
udelay(1); /* spec allows drive 400ns to assert "BUSY" */
stat = tp_ops->read_status(hwif);
if (stat & ATA_BUSY) {
if (!irqs_threaded) {
local_save_flags(flags);
local_irq_enable_in_hardirq();
}
timeout += jiffies;
while ((stat = tp_ops->read_status(hwif)) & ATA_BUSY) {
if (time_after(jiffies, timeout)) {
/*
* One last read after the timeout in case
* heavy interrupt load made us not make any
* progress during the timeout..
*/
stat = tp_ops->read_status(hwif);
if ((stat & ATA_BUSY) == 0)
break;
if (!irqs_threaded)
local_irq_restore(flags);
*rstat = stat;
return -EBUSY;
}
}
if (!irqs_threaded)
local_irq_restore(flags);
}
/*
* Allow status to settle, then read it again.
* A few rare drives vastly violate the 400ns spec here,
* so we'll wait up to 10usec for a "good" status
* rather than expensively fail things immediately.
* This fix courtesy of Matthew Faupel & Niccolo Rigacci.
*/
for (i = 0; i < 10; i++) {
udelay(1);
stat = tp_ops->read_status(hwif);
if (OK_STAT(stat, good, bad)) {
*rstat = stat;
return 0;
}
}
*rstat = stat;
return -EFAULT;
}
/* The performance counters used by NMI_LOCAL_APIC don't trigger when
* the CPU is idle. To make sure the NMI watchdog really ticks on all
* CPUs during the test make them busy.
*/
static __init void nmi_cpu_busy(void *data)
{
local_irq_enable_in_hardirq();
/* Intentionally don't use cpu_relax here. This is
to make sure that the performance counter really ticks,
even if there is a simulator or similar that catches the
pause instruction. On a real HT machine this is fine because
all other CPUs are busy with "useless" delay loops and don't
care if they get somewhat less cycles. */
while (endflag == 0)
mb();
}
/*
* recal_intr() is invoked on completion of a WIN_RESTORE (recalibrate) cmd.
*/
static ide_startstop_t recal_intr(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
u8 stat;
local_irq_enable_in_hardirq();
stat = hwif->tp_ops->read_status(hwif);
if (!OK_STAT(stat, READY_STAT, BAD_STAT))
return ide_error(drive, "recal_intr", stat);
return ide_stopped;
}
/*
* Handler for commands without a data phase
*/
static ide_startstop_t task_no_data_intr(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
ide_task_t *task = &hwif->task;
struct ide_taskfile *tf = &task->tf;
int custom = (task->tf_flags & IDE_TFLAG_CUSTOM_HANDLER) ? 1 : 0;
int retries = (custom && tf->command == ATA_CMD_INIT_DEV_PARAMS) ? 5 : 1;
u8 stat;
local_irq_enable_in_hardirq();
while (1) {
stat = hwif->tp_ops->read_status(hwif);
if ((stat & ATA_BUSY) == 0 || retries-- == 0)
break;
udelay(10);
};
if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
if (custom && tf->command == ATA_CMD_SET_MULTI) {
drive->mult_req = drive->mult_count = 0;
drive->special.b.recalibrate = 1;
(void)ide_dump_status(drive, __func__, stat);
return ide_stopped;
} else if (custom && tf->command == ATA_CMD_INIT_DEV_PARAMS) {
if ((stat & (ATA_ERR | ATA_DRQ)) == 0) {
ide_set_handler(drive, &task_no_data_intr,
WAIT_WORSTCASE, NULL);
return ide_started;
}
}
return ide_error(drive, "task_no_data_intr", stat);
/* calls ide_end_drive_cmd */
}
if (!custom)
ide_end_drive_cmd(drive, stat, ide_read_error(drive));
else if (tf->command == ATA_CMD_IDLEIMMEDIATE) {
hwif->tp_ops->tf_read(drive, task);
if (tf->lbal != 0xc4) {
printk(KERN_ERR "%s: head unload failed!\n",
drive->name);
ide_tf_dump(drive->name, tf);
} else
drive->dev_flags |= IDE_DFLAG_PARKED;
ide_end_drive_cmd(drive, stat, ide_read_error(drive));
} else if (tf->command == ATA_CMD_SET_MULTI)
drive->mult_count = drive->mult_req;
return ide_stopped;
}
static ide_startstop_t task_no_data_intr(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
struct ide_cmd *cmd = &hwif->cmd;
struct ide_taskfile *tf = &cmd->tf;
int custom = (cmd->tf_flags & IDE_TFLAG_CUSTOM_HANDLER) ? 1 : 0;
int retries = (custom && tf->command == ATA_CMD_INIT_DEV_PARAMS) ? 5 : 1;
u8 stat;
local_irq_enable_in_hardirq();
while (1) {
stat = hwif->tp_ops->read_status(hwif);
if ((stat & ATA_BUSY) == 0 || retries-- == 0)
break;
udelay(10);
};
if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
if (custom && tf->command == ATA_CMD_SET_MULTI) {
drive->mult_req = drive->mult_count = 0;
drive->special_flags |= IDE_SFLAG_RECALIBRATE;
(void)ide_dump_status(drive, __func__, stat);
return ide_stopped;
} else if (custom && tf->command == ATA_CMD_INIT_DEV_PARAMS) {
if ((stat & (ATA_ERR | ATA_DRQ)) == 0) {
ide_set_handler(drive, &task_no_data_intr,
WAIT_WORSTCASE);
return ide_started;
}
}
return ide_error(drive, "task_no_data_intr", stat);
}
if (custom && tf->command == ATA_CMD_SET_MULTI)
drive->mult_count = drive->mult_req;
if (custom == 0 || tf->command == ATA_CMD_IDLEIMMEDIATE ||
tf->command == ATA_CMD_CHK_POWER) {
struct request *rq = hwif->rq;
if (blk_pm_request(rq))
ide_complete_pm_rq(drive, rq);
else
ide_finish_cmd(drive, cmd, stat);
}
return ide_stopped;
}
/*
* set_multmode_intr() is invoked on completion of a WIN_SETMULT cmd.
*/
static ide_startstop_t set_multmode_intr(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
u8 stat;
local_irq_enable_in_hardirq();
stat = hwif->tp_ops->read_status(hwif);
if (OK_STAT(stat, READY_STAT, BAD_STAT))
drive->mult_count = drive->mult_req;
else {
drive->mult_req = drive->mult_count = 0;
drive->special.b.recalibrate = 1;
(void) ide_dump_status(drive, "set_multmode", stat);
}
return ide_stopped;
}
/*
* Handler for commands without a data phase
*/
static ide_startstop_t task_no_data_intr(ide_drive_t *drive)
{
ide_task_t *args = HWGROUP(drive)->rq->special;
u8 stat;
local_irq_enable_in_hardirq();
stat = ide_read_status(drive);
if (!OK_STAT(stat, READY_STAT, BAD_STAT))
return ide_error(drive, "task_no_data_intr", stat);
/* calls ide_end_drive_cmd */
if (args)
ide_end_drive_cmd(drive, stat, ide_read_error(drive));
return ide_stopped;
}
/*
* Handler for commands without a data phase
*/
static ide_startstop_t task_no_data_intr(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
ide_task_t *args = hwif->hwgroup->rq->special;
u8 stat;
local_irq_enable_in_hardirq();
stat = hwif->tp_ops->read_status(hwif);
if (!OK_STAT(stat, READY_STAT, BAD_STAT))
return ide_error(drive, "task_no_data_intr", stat);
/* calls ide_end_drive_cmd */
if (args)
ide_end_drive_cmd(drive, stat, ide_read_error(drive));
return ide_stopped;
}
/* The performance counters used by NMI_LOCAL_APIC don't trigger when
* the CPU is idle. To make sure the NMI watchdog really ticks on all
* CPUs during the test make them busy.
*/
static __init void nmi_cpu_busy(void *data)
{
volatile int *endflag = data;
/*
* avoid a warning, on PREEMPT_RT this wont run in hardirq context:
*/
#ifndef CONFIG_PREEMPT_RT
local_irq_enable_in_hardirq();
#endif
/* Intentionally don't use cpu_relax here. This is
to make sure that the performance counter really ticks,
even if there is a simulator or similar that catches the
pause instruction. On a real HT machine this is fine because
all other CPUs are busy with "useless" delay loops and don't
care if they get somewhat less cycles. */
while (*endflag == 0)
barrier();
}
int __ide_wait_stat(ide_drive_t *drive, u8 good, u8 bad,
unsigned long timeout, u8 *rstat)
{
ide_hwif_t *hwif = drive->hwif;
const struct ide_tp_ops *tp_ops = hwif->tp_ops;
unsigned long flags;
int i;
u8 stat;
udelay(1);
stat = tp_ops->read_status(hwif);
if (stat & ATA_BUSY) {
local_save_flags(flags);
local_irq_enable_in_hardirq();
timeout += jiffies;
while ((stat = tp_ops->read_status(hwif)) & ATA_BUSY) {
if (time_after(jiffies, timeout)) {
stat = tp_ops->read_status(hwif);
if ((stat & ATA_BUSY) == 0)
break;
local_irq_restore(flags);
*rstat = stat;
return -EBUSY;
}
}
local_irq_restore(flags);
}
for (i = 0; i < 10; i++) {
udelay(1);
stat = tp_ops->read_status(hwif);
if (OK_STAT(stat, good, bad)) {
*rstat = stat;
return 0;
}
}
*rstat = stat;
return -EFAULT;
}
/*
* set_geometry_intr() is invoked on completion of a WIN_SPECIFY cmd.
*/
static ide_startstop_t set_geometry_intr(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
int retries = 5;
u8 stat;
local_irq_enable_in_hardirq();
while (1) {
stat = hwif->tp_ops->read_status(hwif);
if ((stat & BUSY_STAT) == 0 || retries-- == 0)
break;
udelay(10);
};
if (OK_STAT(stat, READY_STAT, BAD_STAT))
return ide_stopped;
if (stat & (ERR_STAT|DRQ_STAT))
return ide_error(drive, "set_geometry_intr", stat);
ide_set_handler(drive, &set_geometry_intr, WAIT_WORSTCASE, NULL);
return ide_started;
}
irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
{
irqreturn_t ret, retval = IRQ_NONE;
unsigned int status = 0;
struct timeval tv;
do_gettimeofday(&tv);
irq_history_int[irq_history_idx] = irq;
irq_history_fp[irq_history_idx] = action->handler;
irq_history_us[irq_history_idx] = tv.tv_usec;
irq_history_idx = (irq_history_idx+1) % IRQ_HIST_NUM;
if (!(action->flags & IRQF_DISABLED))
local_irq_enable_in_hardirq();
do {
trace_irq_handler_entry(irq, action);
ret = action->handler(irq, action->dev_id);
trace_irq_handler_exit(irq, action, ret);
switch (ret) {
case IRQ_WAKE_THREAD:
/*
* Set result to handled so the spurious check
* does not trigger.
*/
ret = IRQ_HANDLED;
/*
* Catch drivers which return WAKE_THREAD but
* did not set up a thread function
*/
if (unlikely(!action->thread_fn)) {
warn_no_thread(irq, action);
break;
}
/*
* Wake up the handler thread for this
* action. In case the thread crashed and was
* killed we just pretend that we handled the
* interrupt. The hardirq handler above has
* disabled the device interrupt, so no irq
* storm is lurking.
*/
if (likely(!test_bit(IRQTF_DIED,
&action->thread_flags))) {
set_bit(IRQTF_RUNTHREAD, &action->thread_flags);
wake_up_process(action->thread);
}
/* Fall through to add to randomness */
case IRQ_HANDLED:
status |= action->flags;
break;
default:
break;
}
retval |= ret;
action = action->next;
} while (action);
if (status & IRQF_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
local_irq_disable();
return retval;
}
irqreturn_t ide_intr (int irq, void *dev_id)
{
ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
ide_drive_t *uninitialized_var(drive);
ide_handler_t *handler;
unsigned long flags;
ide_startstop_t startstop;
irqreturn_t irq_ret = IRQ_NONE;
int plug_device = 0;
if (hwif->host->host_flags & IDE_HFLAG_SERIALIZE) {
if (hwif != hwif->host->cur_port)
goto out_early;
}
spin_lock_irqsave(&hwif->lock, flags);
if (!ide_ack_intr(hwif))
goto out;
handler = hwif->handler;
if (handler == NULL || hwif->polling) {
/*
* Not expecting an interrupt from this drive.
* That means this could be:
* (1) an interrupt from another PCI device
* sharing the same PCI INT# as us.
* or (2) a drive just entered sleep or standby mode,
* and is interrupting to let us know.
* or (3) a spurious interrupt of unknown origin.
*
* For PCI, we cannot tell the difference,
* so in that case we just ignore it and hope it goes away.
*
* FIXME: unexpected_intr should be hwif-> then we can
* remove all the ifdef PCI crap
*/
#ifdef CONFIG_BLK_DEV_IDEPCI
if (hwif->chipset != ide_pci)
#endif /* CONFIG_BLK_DEV_IDEPCI */
{
/*
* Probably not a shared PCI interrupt,
* so we can safely try to do something about it:
*/
unexpected_intr(irq, hwif);
#ifdef CONFIG_BLK_DEV_IDEPCI
} else {
/*
* Whack the status register, just in case
* we have a leftover pending IRQ.
*/
(void)hwif->tp_ops->read_status(hwif);
#endif /* CONFIG_BLK_DEV_IDEPCI */
}
goto out;
}
drive = hwif->cur_dev;
if (!drive_is_ready(drive))
/*
* This happens regularly when we share a PCI IRQ with
* another device. Unfortunately, it can also happen
* with some buggy drives that trigger the IRQ before
* their status register is up to date. Hopefully we have
* enough advance overhead that the latter isn't a problem.
*/
goto out;
hwif->handler = NULL;
hwif->req_gen++;
del_timer(&hwif->timer);
spin_unlock(&hwif->lock);
if (hwif->port_ops && hwif->port_ops->clear_irq)
hwif->port_ops->clear_irq(drive);
if (drive->dev_flags & IDE_DFLAG_UNMASK)
local_irq_enable_in_hardirq();
/* service this interrupt, may set handler for next interrupt */
startstop = handler(drive);
spin_lock_irq(&hwif->lock);
/*
* Note that handler() may have set things up for another
* interrupt to occur soon, but it cannot happen until
* we exit from this routine, because it will be the
* same irq as is currently being serviced here, and Linux
* won't allow another of the same (on any CPU) until we return.
*/
if (startstop == ide_stopped) {
BUG_ON(hwif->handler);
ide_unlock_port(hwif);
plug_device = 1;
}
irq_ret = IRQ_HANDLED;
out:
spin_unlock_irqrestore(&hwif->lock, flags);
out_early:
if (plug_device) {
ide_unlock_host(hwif->host);
ide_plug_device(drive);
}
return irq_ret;
}
/**
* handle_IRQ_event - irq action chain handler
* @irq: the interrupt number
* @action: the interrupt action chain for this irq
*
* Handles the action chain of an irq event
*/
irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
{
irqreturn_t ret, retval = IRQ_NONE;
unsigned int status = 0;
if (!(action->flags & IRQF_DISABLED))
local_irq_enable_in_hardirq();
do {
#ifdef CONFIG_TIVO_PLOG
plog_intr_enter(irq, current_thread_info()->regs->cp0_epc);
#endif
trace_irq_handler_entry(irq, action);
ret = action->handler(irq, action->dev_id);
trace_irq_handler_exit(irq, action, ret);
#ifdef CONFIG_TIVO_PLOG
plog_intr_leave(irq);
#endif
switch (ret) {
case IRQ_WAKE_THREAD:
/*
* Set result to handled so the spurious check
* does not trigger.
*/
ret = IRQ_HANDLED;
/*
* Catch drivers which return WAKE_THREAD but
* did not set up a thread function
*/
if (unlikely(!action->thread_fn)) {
warn_no_thread(irq, action);
break;
}
/*
* Wake up the handler thread for this
* action. In case the thread crashed and was
* killed we just pretend that we handled the
* interrupt. The hardirq handler above has
* disabled the device interrupt, so no irq
* storm is lurking.
*/
if (likely(!test_bit(IRQTF_DIED,
&action->thread_flags))) {
set_bit(IRQTF_RUNTHREAD, &action->thread_flags);
wake_up_process(action->thread);
}
/* Fall through to add to randomness */
case IRQ_HANDLED:
status |= action->flags;
break;
default:
break;
}
retval |= ret;
action = action->next;
} while (action);
if (status & IRQF_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
local_irq_disable();
return retval;
}
static __init void nmi_cpu_busy(void *data)
{
local_irq_enable_in_hardirq();
while (endflag == 0)
mb();
}