linux_dsm_epyc7002/arch/mn10300/kernel/irq.c

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/* MN10300 Arch-specific interrupt handling
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <asm/setup.h>
unsigned long __mn10300_irq_enabled_epsw = EPSW_IE | EPSW_IM_7;
EXPORT_SYMBOL(__mn10300_irq_enabled_epsw);
atomic_t irq_err_count;
/*
MN10300: Fix IRQ handling Fix the IRQ handling on the MN10300 arch. This patch makes a number of significant changes: (1) It separates the irq_chip definition for edge-triggered interrupts from the one for level-triggered interrupts. This is necessary because the MN10300 PIC latches the IRQ channel's interrupt request bit (GxICR_REQUEST), even after the device has ceased to assert its interrupt line and the interrupt channel has been disabled in the PIC. So for level-triggered interrupts we need to clear this bit when we re-enable - which is achieved by setting GxICR_DETECT but not GxICR_REQUEST when writing to the register. Not doing this results in spurious interrupts occurring because calling mask_ack() at the start of handle_level_irq() is insufficient - it fails to clear the REQUEST latch because the device that caused the interrupt is still asserting its interrupt line at this point. (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (4) The end() operation is now left to the default (no-operation) as __do_IRQ() is compiled out. This may affect misrouted_irq(), but according to Thomas Gleixner it's the correct thing to do. (5) handle_level_irq() is used for edge-triggered interrupts rather than handle_edge_irq() as the MN10300 PIC latches interrupt events even on masked IRQ channels, thus rendering IRQ_PENDING unnecessary. It is sufficient to call mask_ack() at the start and unmask() at the end. (6) For level-triggered interrupts, ack() is now NULL as it's not used, and there is no effective ACK function on the PIC. mask_ack() is now the same as mask() as the latch continues to latch, even when the channel is masked. Further, the patch discards the disable() op implementation as its now the same as the mask() op implementation, which is used instead. It also discards the enable() op implementations as they're now the same as the unmask() op implementations, which are used instead. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-01 19:47:06 +07:00
* MN10300 interrupt controller operations
*/
static void mn10300_cpupic_ack(unsigned int irq)
{
u16 tmp;
*(volatile u8 *) &GxICR(irq) = GxICR_DETECT;
tmp = GxICR(irq);
}
static void mn10300_cpupic_mask(unsigned int irq)
{
u16 tmp = GxICR(irq);
GxICR(irq) = (tmp & GxICR_LEVEL);
tmp = GxICR(irq);
}
static void mn10300_cpupic_mask_ack(unsigned int irq)
{
u16 tmp = GxICR(irq);
GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_DETECT;
tmp = GxICR(irq);
}
static void mn10300_cpupic_unmask(unsigned int irq)
{
u16 tmp = GxICR(irq);
MN10300: Fix IRQ handling Fix the IRQ handling on the MN10300 arch. This patch makes a number of significant changes: (1) It separates the irq_chip definition for edge-triggered interrupts from the one for level-triggered interrupts. This is necessary because the MN10300 PIC latches the IRQ channel's interrupt request bit (GxICR_REQUEST), even after the device has ceased to assert its interrupt line and the interrupt channel has been disabled in the PIC. So for level-triggered interrupts we need to clear this bit when we re-enable - which is achieved by setting GxICR_DETECT but not GxICR_REQUEST when writing to the register. Not doing this results in spurious interrupts occurring because calling mask_ack() at the start of handle_level_irq() is insufficient - it fails to clear the REQUEST latch because the device that caused the interrupt is still asserting its interrupt line at this point. (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (4) The end() operation is now left to the default (no-operation) as __do_IRQ() is compiled out. This may affect misrouted_irq(), but according to Thomas Gleixner it's the correct thing to do. (5) handle_level_irq() is used for edge-triggered interrupts rather than handle_edge_irq() as the MN10300 PIC latches interrupt events even on masked IRQ channels, thus rendering IRQ_PENDING unnecessary. It is sufficient to call mask_ack() at the start and unmask() at the end. (6) For level-triggered interrupts, ack() is now NULL as it's not used, and there is no effective ACK function on the PIC. mask_ack() is now the same as mask() as the latch continues to latch, even when the channel is masked. Further, the patch discards the disable() op implementation as its now the same as the mask() op implementation, which is used instead. It also discards the enable() op implementations as they're now the same as the unmask() op implementations, which are used instead. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-01 19:47:06 +07:00
GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE;
tmp = GxICR(irq);
}
MN10300: Fix IRQ handling Fix the IRQ handling on the MN10300 arch. This patch makes a number of significant changes: (1) It separates the irq_chip definition for edge-triggered interrupts from the one for level-triggered interrupts. This is necessary because the MN10300 PIC latches the IRQ channel's interrupt request bit (GxICR_REQUEST), even after the device has ceased to assert its interrupt line and the interrupt channel has been disabled in the PIC. So for level-triggered interrupts we need to clear this bit when we re-enable - which is achieved by setting GxICR_DETECT but not GxICR_REQUEST when writing to the register. Not doing this results in spurious interrupts occurring because calling mask_ack() at the start of handle_level_irq() is insufficient - it fails to clear the REQUEST latch because the device that caused the interrupt is still asserting its interrupt line at this point. (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (4) The end() operation is now left to the default (no-operation) as __do_IRQ() is compiled out. This may affect misrouted_irq(), but according to Thomas Gleixner it's the correct thing to do. (5) handle_level_irq() is used for edge-triggered interrupts rather than handle_edge_irq() as the MN10300 PIC latches interrupt events even on masked IRQ channels, thus rendering IRQ_PENDING unnecessary. It is sufficient to call mask_ack() at the start and unmask() at the end. (6) For level-triggered interrupts, ack() is now NULL as it's not used, and there is no effective ACK function on the PIC. mask_ack() is now the same as mask() as the latch continues to latch, even when the channel is masked. Further, the patch discards the disable() op implementation as its now the same as the mask() op implementation, which is used instead. It also discards the enable() op implementations as they're now the same as the unmask() op implementations, which are used instead. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-01 19:47:06 +07:00
static void mn10300_cpupic_unmask_clear(unsigned int irq)
{
MN10300: Fix IRQ handling Fix the IRQ handling on the MN10300 arch. This patch makes a number of significant changes: (1) It separates the irq_chip definition for edge-triggered interrupts from the one for level-triggered interrupts. This is necessary because the MN10300 PIC latches the IRQ channel's interrupt request bit (GxICR_REQUEST), even after the device has ceased to assert its interrupt line and the interrupt channel has been disabled in the PIC. So for level-triggered interrupts we need to clear this bit when we re-enable - which is achieved by setting GxICR_DETECT but not GxICR_REQUEST when writing to the register. Not doing this results in spurious interrupts occurring because calling mask_ack() at the start of handle_level_irq() is insufficient - it fails to clear the REQUEST latch because the device that caused the interrupt is still asserting its interrupt line at this point. (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (4) The end() operation is now left to the default (no-operation) as __do_IRQ() is compiled out. This may affect misrouted_irq(), but according to Thomas Gleixner it's the correct thing to do. (5) handle_level_irq() is used for edge-triggered interrupts rather than handle_edge_irq() as the MN10300 PIC latches interrupt events even on masked IRQ channels, thus rendering IRQ_PENDING unnecessary. It is sufficient to call mask_ack() at the start and unmask() at the end. (6) For level-triggered interrupts, ack() is now NULL as it's not used, and there is no effective ACK function on the PIC. mask_ack() is now the same as mask() as the latch continues to latch, even when the channel is masked. Further, the patch discards the disable() op implementation as its now the same as the mask() op implementation, which is used instead. It also discards the enable() op implementations as they're now the same as the unmask() op implementations, which are used instead. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-01 19:47:06 +07:00
/* the MN10300 PIC latches its interrupt request bit, even after the
* device has ceased to assert its interrupt line and the interrupt
* channel has been disabled in the PIC, so for level-triggered
* interrupts we need to clear the request bit when we re-enable */
u16 tmp = GxICR(irq);
MN10300: Fix IRQ handling Fix the IRQ handling on the MN10300 arch. This patch makes a number of significant changes: (1) It separates the irq_chip definition for edge-triggered interrupts from the one for level-triggered interrupts. This is necessary because the MN10300 PIC latches the IRQ channel's interrupt request bit (GxICR_REQUEST), even after the device has ceased to assert its interrupt line and the interrupt channel has been disabled in the PIC. So for level-triggered interrupts we need to clear this bit when we re-enable - which is achieved by setting GxICR_DETECT but not GxICR_REQUEST when writing to the register. Not doing this results in spurious interrupts occurring because calling mask_ack() at the start of handle_level_irq() is insufficient - it fails to clear the REQUEST latch because the device that caused the interrupt is still asserting its interrupt line at this point. (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (4) The end() operation is now left to the default (no-operation) as __do_IRQ() is compiled out. This may affect misrouted_irq(), but according to Thomas Gleixner it's the correct thing to do. (5) handle_level_irq() is used for edge-triggered interrupts rather than handle_edge_irq() as the MN10300 PIC latches interrupt events even on masked IRQ channels, thus rendering IRQ_PENDING unnecessary. It is sufficient to call mask_ack() at the start and unmask() at the end. (6) For level-triggered interrupts, ack() is now NULL as it's not used, and there is no effective ACK function on the PIC. mask_ack() is now the same as mask() as the latch continues to latch, even when the channel is masked. Further, the patch discards the disable() op implementation as its now the same as the mask() op implementation, which is used instead. It also discards the enable() op implementations as they're now the same as the unmask() op implementations, which are used instead. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-01 19:47:06 +07:00
GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
tmp = GxICR(irq);
}
MN10300: Fix IRQ handling Fix the IRQ handling on the MN10300 arch. This patch makes a number of significant changes: (1) It separates the irq_chip definition for edge-triggered interrupts from the one for level-triggered interrupts. This is necessary because the MN10300 PIC latches the IRQ channel's interrupt request bit (GxICR_REQUEST), even after the device has ceased to assert its interrupt line and the interrupt channel has been disabled in the PIC. So for level-triggered interrupts we need to clear this bit when we re-enable - which is achieved by setting GxICR_DETECT but not GxICR_REQUEST when writing to the register. Not doing this results in spurious interrupts occurring because calling mask_ack() at the start of handle_level_irq() is insufficient - it fails to clear the REQUEST latch because the device that caused the interrupt is still asserting its interrupt line at this point. (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (4) The end() operation is now left to the default (no-operation) as __do_IRQ() is compiled out. This may affect misrouted_irq(), but according to Thomas Gleixner it's the correct thing to do. (5) handle_level_irq() is used for edge-triggered interrupts rather than handle_edge_irq() as the MN10300 PIC latches interrupt events even on masked IRQ channels, thus rendering IRQ_PENDING unnecessary. It is sufficient to call mask_ack() at the start and unmask() at the end. (6) For level-triggered interrupts, ack() is now NULL as it's not used, and there is no effective ACK function on the PIC. mask_ack() is now the same as mask() as the latch continues to latch, even when the channel is masked. Further, the patch discards the disable() op implementation as its now the same as the mask() op implementation, which is used instead. It also discards the enable() op implementations as they're now the same as the unmask() op implementations, which are used instead. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-01 19:47:06 +07:00
/*
* MN10300 PIC level-triggered IRQ handling.
*
* The PIC has no 'ACK' function per se. It is possible to clear individual
* channel latches, but each latch relatches whether or not the channel is
* masked, so we need to clear the latch when we unmask the channel.
*
* Also for this reason, we don't supply an ack() op (it's unused anyway if
* mask_ack() is provided), and mask_ack() just masks.
*/
static struct irq_chip mn10300_cpu_pic_level = {
.name = "cpu_l",
.disable = mn10300_cpupic_mask,
.enable = mn10300_cpupic_unmask_clear,
.ack = NULL,
.mask = mn10300_cpupic_mask,
.mask_ack = mn10300_cpupic_mask,
.unmask = mn10300_cpupic_unmask_clear,
};
/*
* MN10300 PIC edge-triggered IRQ handling.
*
* We use the latch clearing function of the PIC as the 'ACK' function.
*/
static struct irq_chip mn10300_cpu_pic_edge = {
.name = "cpu_e",
.disable = mn10300_cpupic_mask,
.enable = mn10300_cpupic_unmask,
.ack = mn10300_cpupic_ack,
.mask = mn10300_cpupic_mask,
.mask_ack = mn10300_cpupic_mask_ack,
.unmask = mn10300_cpupic_unmask,
};
/*
* 'what should we do if we get a hw irq event on an illegal vector'.
* each architecture has to answer this themselves.
*/
void ack_bad_irq(int irq)
{
printk(KERN_WARNING "unexpected IRQ trap at vector %02x\n", irq);
}
/*
* change the level at which an IRQ executes
* - must not be called whilst interrupts are being processed!
*/
void set_intr_level(int irq, u16 level)
{
u16 tmp;
if (in_interrupt())
BUG();
tmp = GxICR(irq);
GxICR(irq) = (tmp & GxICR_ENABLE) | level;
tmp = GxICR(irq);
}
/*
* mark an interrupt to be ACK'd after interrupt handlers have been run rather
* than before
* - see Documentation/mn10300/features.txt
*/
void set_intr_postackable(int irq)
{
MN10300: Fix IRQ handling Fix the IRQ handling on the MN10300 arch. This patch makes a number of significant changes: (1) It separates the irq_chip definition for edge-triggered interrupts from the one for level-triggered interrupts. This is necessary because the MN10300 PIC latches the IRQ channel's interrupt request bit (GxICR_REQUEST), even after the device has ceased to assert its interrupt line and the interrupt channel has been disabled in the PIC. So for level-triggered interrupts we need to clear this bit when we re-enable - which is achieved by setting GxICR_DETECT but not GxICR_REQUEST when writing to the register. Not doing this results in spurious interrupts occurring because calling mask_ack() at the start of handle_level_irq() is insufficient - it fails to clear the REQUEST latch because the device that caused the interrupt is still asserting its interrupt line at this point. (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (4) The end() operation is now left to the default (no-operation) as __do_IRQ() is compiled out. This may affect misrouted_irq(), but according to Thomas Gleixner it's the correct thing to do. (5) handle_level_irq() is used for edge-triggered interrupts rather than handle_edge_irq() as the MN10300 PIC latches interrupt events even on masked IRQ channels, thus rendering IRQ_PENDING unnecessary. It is sufficient to call mask_ack() at the start and unmask() at the end. (6) For level-triggered interrupts, ack() is now NULL as it's not used, and there is no effective ACK function on the PIC. mask_ack() is now the same as mask() as the latch continues to latch, even when the channel is masked. Further, the patch discards the disable() op implementation as its now the same as the mask() op implementation, which is used instead. It also discards the enable() op implementations as they're now the same as the unmask() op implementations, which are used instead. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-01 19:47:06 +07:00
set_irq_chip_and_handler(irq, &mn10300_cpu_pic_level,
handle_level_irq);
}
/*
* initialise the interrupt system
*/
void __init init_IRQ(void)
{
int irq;
for (irq = 0; irq < NR_IRQS; irq++)
if (irq_desc[irq].chip == &no_irq_chip)
MN10300: Fix IRQ handling Fix the IRQ handling on the MN10300 arch. This patch makes a number of significant changes: (1) It separates the irq_chip definition for edge-triggered interrupts from the one for level-triggered interrupts. This is necessary because the MN10300 PIC latches the IRQ channel's interrupt request bit (GxICR_REQUEST), even after the device has ceased to assert its interrupt line and the interrupt channel has been disabled in the PIC. So for level-triggered interrupts we need to clear this bit when we re-enable - which is achieved by setting GxICR_DETECT but not GxICR_REQUEST when writing to the register. Not doing this results in spurious interrupts occurring because calling mask_ack() at the start of handle_level_irq() is insufficient - it fails to clear the REQUEST latch because the device that caused the interrupt is still asserting its interrupt line at this point. (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt request flag for edge-triggered interrupts lest it lose an interrupt. (4) The end() operation is now left to the default (no-operation) as __do_IRQ() is compiled out. This may affect misrouted_irq(), but according to Thomas Gleixner it's the correct thing to do. (5) handle_level_irq() is used for edge-triggered interrupts rather than handle_edge_irq() as the MN10300 PIC latches interrupt events even on masked IRQ channels, thus rendering IRQ_PENDING unnecessary. It is sufficient to call mask_ack() at the start and unmask() at the end. (6) For level-triggered interrupts, ack() is now NULL as it's not used, and there is no effective ACK function on the PIC. mask_ack() is now the same as mask() as the latch continues to latch, even when the channel is masked. Further, the patch discards the disable() op implementation as its now the same as the mask() op implementation, which is used instead. It also discards the enable() op implementations as they're now the same as the unmask() op implementations, which are used instead. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-01 19:47:06 +07:00
/* due to the PIC latching interrupt requests, even
* when the IRQ is disabled, IRQ_PENDING is superfluous
* and we can use handle_level_irq() for edge-triggered
* interrupts */
set_irq_chip_and_handler(irq, &mn10300_cpu_pic_edge,
handle_level_irq);
unit_init_IRQ();
}
/*
* handle normal device IRQs
*/
asmlinkage void do_IRQ(void)
{
unsigned long sp, epsw, irq_disabled_epsw, old_irq_enabled_epsw;
int irq;
sp = current_stack_pointer();
if (sp - (sp & ~(THREAD_SIZE - 1)) < STACK_WARN)
BUG();
/* make sure local_irq_enable() doesn't muck up the interrupt priority
* setting in EPSW */
old_irq_enabled_epsw = __mn10300_irq_enabled_epsw;
local_save_flags(epsw);
__mn10300_irq_enabled_epsw = EPSW_IE | (EPSW_IM & epsw);
irq_disabled_epsw = EPSW_IE | MN10300_CLI_LEVEL;
__IRQ_STAT(smp_processor_id(), __irq_count)++;
irq_enter();
for (;;) {
/* ask the interrupt controller for the next IRQ to process
* - the result we get depends on EPSW.IM
*/
irq = IAGR & IAGR_GN;
if (!irq)
break;
local_irq_restore(irq_disabled_epsw);
generic_handle_irq(irq >> 2);
/* restore IRQ controls for IAGR access */
local_irq_restore(epsw);
}
__mn10300_irq_enabled_epsw = old_irq_enabled_epsw;
irq_exit();
}
/*
* Display interrupt management information through /proc/interrupts
*/
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j, cpu;
struct irqaction *action;
unsigned long flags;
switch (i) {
/* display column title bar naming CPUs */
case 0:
seq_printf(p, " ");
for (j = 0; j < NR_CPUS; j++)
if (cpu_online(j))
seq_printf(p, "CPU%d ", j);
seq_putc(p, '\n');
break;
/* display information rows, one per active CPU */
case 1 ... NR_IRQS - 1:
raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
action = irq_desc[i].action;
if (action) {
seq_printf(p, "%3d: ", i);
for_each_present_cpu(cpu)
seq_printf(p, "%10u ", kstat_irqs_cpu(i, cpu));
seq_printf(p, " %14s.%u", irq_desc[i].chip->name,
(GxICR(i) & GxICR_LEVEL) >>
GxICR_LEVEL_SHIFT);
seq_printf(p, " %s", action->name);
for (action = action->next;
action;
action = action->next)
seq_printf(p, ", %s", action->name);
seq_putc(p, '\n');
}
raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
break;
/* polish off with NMI and error counters */
case NR_IRQS:
seq_printf(p, "NMI: ");
for (j = 0; j < NR_CPUS; j++)
if (cpu_online(j))
seq_printf(p, "%10u ", nmi_count(j));
seq_putc(p, '\n');
seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
break;
}
return 0;
}