linux/arch/parisc/kernel/irq.c

437 lines
10 KiB
C
Raw Normal View History

/*
* Code to handle x86 style IRQs plus some generic interrupt stuff.
*
* Copyright (C) 1992 Linus Torvalds
* Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle
* Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
* Copyright (C) 1999-2000 Grant Grundler
* Copyright (c) 2005 Matthew Wilcox
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <asm/io.h>
#include <asm/smp.h>
#undef PARISC_IRQ_CR16_COUNTS
extern irqreturn_t timer_interrupt(int, void *);
extern irqreturn_t ipi_interrupt(int, void *);
#define EIEM_MASK(irq) (1UL<<(CPU_IRQ_MAX - irq))
/* Bits in EIEM correlate with cpu_irq_action[].
** Numbered *Big Endian*! (ie bit 0 is MSB)
*/
static volatile unsigned long cpu_eiem = 0;
/*
** ack bitmap ... habitually set to 1, but reset to zero
** between ->ack() and ->end() of the interrupt to prevent
** re-interruption of a processing interrupt.
*/
static volatile unsigned long global_ack_eiem = ~0UL;
/*
** Local bitmap, same as above but for per-cpu interrupts
*/
static DEFINE_PER_CPU(unsigned long, local_ack_eiem) = ~0UL;
static void cpu_disable_irq(unsigned int irq)
{
unsigned long eirr_bit = EIEM_MASK(irq);
cpu_eiem &= ~eirr_bit;
/* Do nothing on the other CPUs. If they get this interrupt,
* The & cpu_eiem in the do_cpu_irq_mask() ensures they won't
* handle it, and the set_eiem() at the bottom will ensure it
* then gets disabled */
}
static void cpu_enable_irq(unsigned int irq)
{
unsigned long eirr_bit = EIEM_MASK(irq);
cpu_eiem |= eirr_bit;
/* This is just a simple NOP IPI. But what it does is cause
* all the other CPUs to do a set_eiem(cpu_eiem) at the end
* of the interrupt handler */
smp_send_all_nop();
}
static unsigned int cpu_startup_irq(unsigned int irq)
{
cpu_enable_irq(irq);
return 0;
}
void no_ack_irq(unsigned int irq) { }
void no_end_irq(unsigned int irq) { }
void cpu_ack_irq(unsigned int irq)
{
unsigned long mask = EIEM_MASK(irq);
int cpu = smp_processor_id();
/* Clear in EIEM so we can no longer process */
if (CHECK_IRQ_PER_CPU(irq_desc[irq].status))
per_cpu(local_ack_eiem, cpu) &= ~mask;
else
global_ack_eiem &= ~mask;
/* disable the interrupt */
set_eiem(cpu_eiem & global_ack_eiem & per_cpu(local_ack_eiem, cpu));
/* and now ack it */
mtctl(mask, 23);
}
void cpu_end_irq(unsigned int irq)
{
unsigned long mask = EIEM_MASK(irq);
int cpu = smp_processor_id();
/* set it in the eiems---it's no longer in process */
if (CHECK_IRQ_PER_CPU(irq_desc[irq].status))
per_cpu(local_ack_eiem, cpu) |= mask;
else
global_ack_eiem |= mask;
/* enable the interrupt */
set_eiem(cpu_eiem & global_ack_eiem & per_cpu(local_ack_eiem, cpu));
}
#ifdef CONFIG_SMP
int cpu_check_affinity(unsigned int irq, cpumask_t *dest)
{
int cpu_dest;
/* timer and ipi have to always be received on all CPUs */
if (CHECK_IRQ_PER_CPU(irq)) {
/* Bad linux design decision. The mask has already
* been set; we must reset it */
irq_desc[irq].affinity = CPU_MASK_ALL;
return -EINVAL;
}
/* whatever mask they set, we just allow one CPU */
cpu_dest = first_cpu(*dest);
*dest = cpumask_of_cpu(cpu_dest);
return 0;
}
static void cpu_set_affinity_irq(unsigned int irq, cpumask_t dest)
{
if (cpu_check_affinity(irq, &dest))
return;
irq_desc[irq].affinity = dest;
}
#endif
static struct hw_interrupt_type cpu_interrupt_type = {
.typename = "CPU",
.startup = cpu_startup_irq,
.shutdown = cpu_disable_irq,
.enable = cpu_enable_irq,
.disable = cpu_disable_irq,
.ack = cpu_ack_irq,
.end = cpu_end_irq,
#ifdef CONFIG_SMP
.set_affinity = cpu_set_affinity_irq,
#endif
/* XXX: Needs to be written. We managed without it so far, but
* we really ought to write it.
*/
.retrigger = NULL,
};
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
unsigned long flags;
if (i == 0) {
seq_puts(p, " ");
for_each_online_cpu(j)
seq_printf(p, " CPU%d", j);
#ifdef PARISC_IRQ_CR16_COUNTS
seq_printf(p, " [min/avg/max] (CPU cycle counts)");
#endif
seq_putc(p, '\n');
}
if (i < NR_IRQS) {
struct irqaction *action;
spin_lock_irqsave(&irq_desc[i].lock, flags);
action = irq_desc[i].action;
if (!action)
goto skip;
seq_printf(p, "%3d: ", i);
#ifdef CONFIG_SMP
for_each_online_cpu(j)
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#else
seq_printf(p, "%10u ", kstat_irqs(i));
#endif
[PATCH] genirq: rename desc->handler to desc->chip This patch-queue improves the generic IRQ layer to be truly generic, by adding various abstractions and features to it, without impacting existing functionality. While the queue can be best described as "fix and improve everything in the generic IRQ layer that we could think of", and thus it consists of many smaller features and lots of cleanups, the one feature that stands out most is the new 'irq chip' abstraction. The irq-chip abstraction is about describing and coding and IRQ controller driver by mapping its raw hardware capabilities [and quirks, if needed] in a straightforward way, without having to think about "IRQ flow" (level/edge/etc.) type of details. This stands in contrast with the current 'irq-type' model of genirq architectures, which 'mixes' raw hardware capabilities with 'flow' details. The patchset supports both types of irq controller designs at once, and converts i386 and x86_64 to the new irq-chip design. As a bonus side-effect of the irq-chip approach, chained interrupt controllers (master/slave PIC constructs, etc.) are now supported by design as well. The end result of this patchset intends to be simpler architecture-level code and more consolidation between architectures. We reused many bits of code and many concepts from Russell King's ARM IRQ layer, the merging of which was one of the motivations for this patchset. This patch: rename desc->handler to desc->chip. Originally i did not want to do this, because it's a big patch. But having both "desc->handler", "desc->handle_irq" and "action->handler" caused a large degree of confusion and made the code appear alot less clean than it truly is. I have also attempted a dual approach as well by introducing a desc->chip alias - but that just wasnt robust enough and broke frequently. So lets get over with this quickly. The conversion was done automatically via scripts and converts all the code in the kernel. This renaming patch is the first one amongst the patches, so that the remaining patches can stay flexible and can be merged and split up without having some big monolithic patch act as a merge barrier. [akpm@osdl.org: build fix] [akpm@osdl.org: another build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 09:24:36 +00:00
seq_printf(p, " %14s", irq_desc[i].chip->typename);
#ifndef PARISC_IRQ_CR16_COUNTS
seq_printf(p, " %s", action->name);
while ((action = action->next))
seq_printf(p, ", %s", action->name);
#else
for ( ;action; action = action->next) {
unsigned int k, avg, min, max;
min = max = action->cr16_hist[0];
for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) {
int hist = action->cr16_hist[k];
if (hist) {
avg += hist;
} else
break;
if (hist > max) max = hist;
if (hist < min) min = hist;
}
avg /= k;
seq_printf(p, " %s[%d/%d/%d]", action->name,
min,avg,max);
}
#endif
seq_putc(p, '\n');
skip:
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
}
return 0;
}
/*
** The following form a "set": Virtual IRQ, Transaction Address, Trans Data.
** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit.
**
** To use txn_XXX() interfaces, get a Virtual IRQ first.
** Then use that to get the Transaction address and data.
*/
int cpu_claim_irq(unsigned int irq, struct irq_chip *type, void *data)
{
if (irq_desc[irq].action)
return -EBUSY;
[PATCH] genirq: rename desc->handler to desc->chip This patch-queue improves the generic IRQ layer to be truly generic, by adding various abstractions and features to it, without impacting existing functionality. While the queue can be best described as "fix and improve everything in the generic IRQ layer that we could think of", and thus it consists of many smaller features and lots of cleanups, the one feature that stands out most is the new 'irq chip' abstraction. The irq-chip abstraction is about describing and coding and IRQ controller driver by mapping its raw hardware capabilities [and quirks, if needed] in a straightforward way, without having to think about "IRQ flow" (level/edge/etc.) type of details. This stands in contrast with the current 'irq-type' model of genirq architectures, which 'mixes' raw hardware capabilities with 'flow' details. The patchset supports both types of irq controller designs at once, and converts i386 and x86_64 to the new irq-chip design. As a bonus side-effect of the irq-chip approach, chained interrupt controllers (master/slave PIC constructs, etc.) are now supported by design as well. The end result of this patchset intends to be simpler architecture-level code and more consolidation between architectures. We reused many bits of code and many concepts from Russell King's ARM IRQ layer, the merging of which was one of the motivations for this patchset. This patch: rename desc->handler to desc->chip. Originally i did not want to do this, because it's a big patch. But having both "desc->handler", "desc->handle_irq" and "action->handler" caused a large degree of confusion and made the code appear alot less clean than it truly is. I have also attempted a dual approach as well by introducing a desc->chip alias - but that just wasnt robust enough and broke frequently. So lets get over with this quickly. The conversion was done automatically via scripts and converts all the code in the kernel. This renaming patch is the first one amongst the patches, so that the remaining patches can stay flexible and can be merged and split up without having some big monolithic patch act as a merge barrier. [akpm@osdl.org: build fix] [akpm@osdl.org: another build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 09:24:36 +00:00
if (irq_desc[irq].chip != &cpu_interrupt_type)
return -EBUSY;
if (type) {
[PATCH] genirq: rename desc->handler to desc->chip This patch-queue improves the generic IRQ layer to be truly generic, by adding various abstractions and features to it, without impacting existing functionality. While the queue can be best described as "fix and improve everything in the generic IRQ layer that we could think of", and thus it consists of many smaller features and lots of cleanups, the one feature that stands out most is the new 'irq chip' abstraction. The irq-chip abstraction is about describing and coding and IRQ controller driver by mapping its raw hardware capabilities [and quirks, if needed] in a straightforward way, without having to think about "IRQ flow" (level/edge/etc.) type of details. This stands in contrast with the current 'irq-type' model of genirq architectures, which 'mixes' raw hardware capabilities with 'flow' details. The patchset supports both types of irq controller designs at once, and converts i386 and x86_64 to the new irq-chip design. As a bonus side-effect of the irq-chip approach, chained interrupt controllers (master/slave PIC constructs, etc.) are now supported by design as well. The end result of this patchset intends to be simpler architecture-level code and more consolidation between architectures. We reused many bits of code and many concepts from Russell King's ARM IRQ layer, the merging of which was one of the motivations for this patchset. This patch: rename desc->handler to desc->chip. Originally i did not want to do this, because it's a big patch. But having both "desc->handler", "desc->handle_irq" and "action->handler" caused a large degree of confusion and made the code appear alot less clean than it truly is. I have also attempted a dual approach as well by introducing a desc->chip alias - but that just wasnt robust enough and broke frequently. So lets get over with this quickly. The conversion was done automatically via scripts and converts all the code in the kernel. This renaming patch is the first one amongst the patches, so that the remaining patches can stay flexible and can be merged and split up without having some big monolithic patch act as a merge barrier. [akpm@osdl.org: build fix] [akpm@osdl.org: another build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 09:24:36 +00:00
irq_desc[irq].chip = type;
irq_desc[irq].chip_data = data;
cpu_interrupt_type.enable(irq);
}
return 0;
}
int txn_claim_irq(int irq)
{
return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
}
/*
* The bits_wide parameter accommodates the limitations of the HW/SW which
* use these bits:
* Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register)
* V-class (EPIC): 6 bits
* N/L/A-class (iosapic): 8 bits
* PCI 2.2 MSI: 16 bits
* Some PCI devices: 32 bits (Symbios SCSI/ATM/HyperFabric)
*
* On the service provider side:
* o PA 1.1 (and PA2.0 narrow mode) 5-bits (width of EIR register)
* o PA 2.0 wide mode 6-bits (per processor)
* o IA64 8-bits (0-256 total)
*
* So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported
* by the processor...and the N/L-class I/O subsystem supports more bits than
* PA2.0 has. The first case is the problem.
*/
int txn_alloc_irq(unsigned int bits_wide)
{
int irq;
/* never return irq 0 cause that's the interval timer */
for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) {
if (cpu_claim_irq(irq, NULL, NULL) < 0)
continue;
if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide))
continue;
return irq;
}
/* unlikely, but be prepared */
return -1;
}
unsigned long txn_affinity_addr(unsigned int irq, int cpu)
{
#ifdef CONFIG_SMP
irq_desc[irq].affinity = cpumask_of_cpu(cpu);
#endif
return cpu_data[cpu].txn_addr;
}
unsigned long txn_alloc_addr(unsigned int virt_irq)
{
static int next_cpu = -1;
next_cpu++; /* assign to "next" CPU we want this bugger on */
/* validate entry */
while ((next_cpu < NR_CPUS) && (!cpu_data[next_cpu].txn_addr ||
!cpu_online(next_cpu)))
next_cpu++;
if (next_cpu >= NR_CPUS)
next_cpu = 0; /* nothing else, assign monarch */
return txn_affinity_addr(virt_irq, next_cpu);
}
unsigned int txn_alloc_data(unsigned int virt_irq)
{
return virt_irq - CPU_IRQ_BASE;
}
static inline int eirr_to_irq(unsigned long eirr)
{
#ifdef CONFIG_64BIT
int bit = fls64(eirr);
#else
int bit = fls(eirr);
#endif
return (BITS_PER_LONG - bit) + TIMER_IRQ;
}
/* ONLY called from entry.S:intr_extint() */
void do_cpu_irq_mask(struct pt_regs *regs)
{
unsigned long eirr_val;
int irq, cpu = smp_processor_id();
#ifdef CONFIG_SMP
cpumask_t dest;
#endif
local_irq_disable();
irq_enter();
eirr_val = mfctl(23) & cpu_eiem & global_ack_eiem &
per_cpu(local_ack_eiem, cpu);
if (!eirr_val)
goto set_out;
irq = eirr_to_irq(eirr_val);
#ifdef CONFIG_SMP
dest = irq_desc[irq].affinity;
if (CHECK_IRQ_PER_CPU(irq_desc[irq].status) &&
!cpu_isset(smp_processor_id(), dest)) {
int cpu = first_cpu(dest);
printk(KERN_DEBUG "redirecting irq %d from CPU %d to %d\n",
irq, smp_processor_id(), cpu);
gsc_writel(irq + CPU_IRQ_BASE,
cpu_data[cpu].hpa);
goto set_out;
}
#endif
__do_IRQ(irq);
[PARISC] Disable nesting of interrupts Disable nesting of interrupts - still has holes The offending sequence starts out like this: 1) take external interrupt 2) set_eiem() to only allow TIMER_IRQ; local interrupts still disabled 3) read the EIRR to get a "list" of pending interrupts 4) clear EIRR of pending interrupts we intend to handle 5) call __do_IRQ() to handle IRQ. 6) handle_IRQ_event() enables local interrupts (I-Bit) 7) take a timer interrupt 8) read EIRR to get a new list of pending interrupts 9) clear EIRR of pending interrupts we just read 10) handle pending interrupts found in (8) 11) set_eiem(cpu_eiem) and return [ TROUBLE! all enabled CPU IRQs are unmasked. } 12) handle remaining interrupts pending from (3) e.g. call __do_IRQ() -> handle_IRQ_event()..etc [ TROUBLE! call to handle_IRQ_event() can now enable *any* IRQ. } 13) set_eiem(cpu_eiem) and return The problem is we now get into ugly race conditions with Timer and IPI interrupts at this point. I'm not exactly sure what happens when things go wrong (perhaps nest calls to IPI or timer interrupt?). But I'm certain it's not good. This sequence will break sooner if (10) would accidentally leave interrupts enabled. I'm pretty sure the right answer is now to make cpu_eiem a per CPU variable since all external interrupts on parisc are per CPU. This means we will NOT need to send an IPI to every CPU in the system when enabling or disabling an IRQ since only one CPU needs to change it's EIEM. Thanks to James Bottomley for (once again) pointing out the problem. Signed-off-by: Grant Grundler <grundler@parisc-linux.org> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 21:26:20 +00:00
out:
irq_exit();
return;
set_out:
set_eiem(cpu_eiem & global_ack_eiem & per_cpu(local_ack_eiem, cpu));
goto out;
}
static struct irqaction timer_action = {
.handler = timer_interrupt,
.name = "timer",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_PERCPU,
};
#ifdef CONFIG_SMP
static struct irqaction ipi_action = {
.handler = ipi_interrupt,
.name = "IPI",
.flags = IRQF_DISABLED | IRQF_PERCPU,
};
#endif
static void claim_cpu_irqs(void)
{
int i;
for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
[PATCH] genirq: rename desc->handler to desc->chip This patch-queue improves the generic IRQ layer to be truly generic, by adding various abstractions and features to it, without impacting existing functionality. While the queue can be best described as "fix and improve everything in the generic IRQ layer that we could think of", and thus it consists of many smaller features and lots of cleanups, the one feature that stands out most is the new 'irq chip' abstraction. The irq-chip abstraction is about describing and coding and IRQ controller driver by mapping its raw hardware capabilities [and quirks, if needed] in a straightforward way, without having to think about "IRQ flow" (level/edge/etc.) type of details. This stands in contrast with the current 'irq-type' model of genirq architectures, which 'mixes' raw hardware capabilities with 'flow' details. The patchset supports both types of irq controller designs at once, and converts i386 and x86_64 to the new irq-chip design. As a bonus side-effect of the irq-chip approach, chained interrupt controllers (master/slave PIC constructs, etc.) are now supported by design as well. The end result of this patchset intends to be simpler architecture-level code and more consolidation between architectures. We reused many bits of code and many concepts from Russell King's ARM IRQ layer, the merging of which was one of the motivations for this patchset. This patch: rename desc->handler to desc->chip. Originally i did not want to do this, because it's a big patch. But having both "desc->handler", "desc->handle_irq" and "action->handler" caused a large degree of confusion and made the code appear alot less clean than it truly is. I have also attempted a dual approach as well by introducing a desc->chip alias - but that just wasnt robust enough and broke frequently. So lets get over with this quickly. The conversion was done automatically via scripts and converts all the code in the kernel. This renaming patch is the first one amongst the patches, so that the remaining patches can stay flexible and can be merged and split up without having some big monolithic patch act as a merge barrier. [akpm@osdl.org: build fix] [akpm@osdl.org: another build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 09:24:36 +00:00
irq_desc[i].chip = &cpu_interrupt_type;
}
irq_desc[TIMER_IRQ].action = &timer_action;
irq_desc[TIMER_IRQ].status |= IRQ_PER_CPU;
#ifdef CONFIG_SMP
irq_desc[IPI_IRQ].action = &ipi_action;
irq_desc[IPI_IRQ].status = IRQ_PER_CPU;
#endif
}
void __init init_IRQ(void)
{
local_irq_disable(); /* PARANOID - should already be disabled */
mtctl(~0UL, 23); /* EIRR : clear all pending external intr */
claim_cpu_irqs();
#ifdef CONFIG_SMP
if (!cpu_eiem)
cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
#else
cpu_eiem = EIEM_MASK(TIMER_IRQ);
#endif
set_eiem(cpu_eiem); /* EIEM : enable all external intr */
}
void ack_bad_irq(unsigned int irq)
{
printk("unexpected IRQ %d\n", irq);
}