[patch 5/5, 2.6.9-rc3] generic irq subsystem, ppc64 port

From: Ingo Molnar
Date: Fri Oct 01 2004 - 16:57:23 EST



ppc64 port of generic hardirq handling.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>

--- linux/arch/ppc64/Kconfig.orig
+++ linux/arch/ppc64/Kconfig
@@ -207,6 +207,13 @@ config PREEMPT
Say Y here if you are building a kernel for a desktop, embedded
or real-time system. Say N if you are unsure.

+#
+# Use the generic interrupt handling code in kernel/hardirq.c:
+#
+config GENERIC_HARDIRQS
+ bool
+ default y
+
config MSCHUNKS
bool
depends on PPC_ISERIES
--- linux/arch/ppc64/kernel/misc.S.orig
+++ linux/arch/ppc64/kernel/misc.S
@@ -115,12 +115,12 @@ _GLOBAL(call_do_softirq)
mtlr r0
blr

-_GLOBAL(call_handle_irq_event)
+_GLOBAL(call_handle_IRQ_event)
mflr r0
std r0,16(r1)
stdu r1,THREAD_SIZE-112(r6)
mr r1,r6
- bl .handle_irq_event
+ bl .handle_IRQ_event
ld r1,0(r1)
ld r0,16(r1)
mtlr r0
--- linux/arch/ppc64/kernel/irq.c.orig
+++ linux/arch/ppc64/kernel/irq.c
@@ -60,259 +60,12 @@
extern void iSeries_smp_message_recv( struct pt_regs * );
#endif

-static void register_irq_proc (unsigned int irq);
-
-irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = {
- [0 ... NR_IRQS-1] = {
- .lock = SPIN_LOCK_UNLOCKED
- }
-};
+extern irq_desc_t irq_desc[NR_IRQS];

int __irq_offset_value;
int ppc_spurious_interrupts;
unsigned long lpevent_count;

-int
-setup_irq(unsigned int irq, struct irqaction * new)
-{
- int shared = 0;
- unsigned long flags;
- struct irqaction *old, **p;
- irq_desc_t *desc = get_irq_desc(irq);
-
- /*
- * Some drivers like serial.c use request_irq() heavily,
- * so we have to be careful not to interfere with a
- * running system.
- */
- if (new->flags & SA_SAMPLE_RANDOM) {
- /*
- * This function might sleep, we want to call it first,
- * outside of the atomic block.
- * Yes, this might clear the entropy pool if the wrong
- * driver is attempted to be loaded, without actually
- * installing a new handler, but is this really a problem,
- * only the sysadmin is able to do this.
- */
- rand_initialize_irq(irq);
- }
-
- /*
- * The following block of code has to be executed atomically
- */
- spin_lock_irqsave(&desc->lock,flags);
- p = &desc->action;
- if ((old = *p) != NULL) {
- /* Can't share interrupts unless both agree to */
- if (!(old->flags & new->flags & SA_SHIRQ)) {
- spin_unlock_irqrestore(&desc->lock,flags);
- return -EBUSY;
- }
-
- /* add new interrupt at end of irq queue */
- do {
- p = &old->next;
- old = *p;
- } while (old);
- shared = 1;
- }
-
- *p = new;
-
- if (!shared) {
- desc->depth = 0;
- desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING | IRQ_INPROGRESS);
- if (desc->handler && desc->handler->startup)
- desc->handler->startup(irq);
- unmask_irq(irq);
- }
- spin_unlock_irqrestore(&desc->lock,flags);
-
- register_irq_proc(irq);
- return 0;
-}
-
-#ifdef CONFIG_SMP
-
-inline void synchronize_irq(unsigned int irq)
-{
- while (get_irq_desc(irq)->status & IRQ_INPROGRESS)
- cpu_relax();
-}
-
-EXPORT_SYMBOL(synchronize_irq);
-
-#endif /* CONFIG_SMP */
-
-int request_irq(unsigned int irq,
- irqreturn_t (*handler)(int, void *, struct pt_regs *),
- unsigned long irqflags, const char * devname, void *dev_id)
-{
- struct irqaction *action;
- int retval;
-
- if (irq >= NR_IRQS)
- return -EINVAL;
- if (!handler)
- return -EINVAL;
-
- action = (struct irqaction *)
- kmalloc(sizeof(struct irqaction), GFP_KERNEL);
- if (!action) {
- printk(KERN_ERR "kmalloc() failed for irq %d !\n", irq);
- return -ENOMEM;
- }
-
- action->handler = handler;
- action->flags = irqflags;
- cpus_clear(action->mask);
- action->name = devname;
- action->dev_id = dev_id;
- action->next = NULL;
-
- retval = setup_irq(irq, action);
- if (retval)
- kfree(action);
-
- return 0;
-}
-
-EXPORT_SYMBOL(request_irq);
-
-void free_irq(unsigned int irq, void *dev_id)
-{
- irq_desc_t *desc = get_irq_desc(irq);
- struct irqaction **p;
- unsigned long flags;
-
- spin_lock_irqsave(&desc->lock,flags);
- p = &desc->action;
- for (;;) {
- struct irqaction * action = *p;
- if (action) {
- struct irqaction **pp = p;
- p = &action->next;
- if (action->dev_id != dev_id)
- continue;
-
- /* Found it - now remove it from the list of entries */
- *pp = action->next;
- if (!desc->action) {
- desc->status |= IRQ_DISABLED;
- mask_irq(irq);
- }
- spin_unlock_irqrestore(&desc->lock,flags);
-
- /* Wait to make sure it's not being used on another CPU */
- synchronize_irq(irq);
- kfree(action);
- return;
- }
- printk("Trying to free free IRQ%d\n",irq);
- spin_unlock_irqrestore(&desc->lock,flags);
- break;
- }
- return;
-}
-
-EXPORT_SYMBOL(free_irq);
-
-/*
- * Generic enable/disable code: this just calls
- * down into the PIC-specific version for the actual
- * hardware disable after having gotten the irq
- * controller lock.
- */
-
-/**
- * disable_irq_nosync - disable an irq without waiting
- * @irq: Interrupt to disable
- *
- * Disable the selected interrupt line. Disables of an interrupt
- * stack. Unlike disable_irq(), this function does not ensure existing
- * instances of the IRQ handler have completed before returning.
- *
- * This function may be called from IRQ context.
- */
-
-inline void disable_irq_nosync(unsigned int irq)
-{
- irq_desc_t *desc = get_irq_desc(irq);
- unsigned long flags;
-
- spin_lock_irqsave(&desc->lock, flags);
- if (!desc->depth++) {
- if (!(desc->status & IRQ_PER_CPU))
- desc->status |= IRQ_DISABLED;
- mask_irq(irq);
- }
- spin_unlock_irqrestore(&desc->lock, flags);
-}
-
-EXPORT_SYMBOL(disable_irq_nosync);
-
-/**
- * disable_irq - disable an irq and wait for completion
- * @irq: Interrupt to disable
- *
- * Disable the selected interrupt line. Disables of an interrupt
- * stack. That is for two disables you need two enables. This
- * function waits for any pending IRQ handlers for this interrupt
- * to complete before returning. If you use this function while
- * holding a resource the IRQ handler may need you will deadlock.
- *
- * This function may be called - with care - from IRQ context.
- */
-
-void disable_irq(unsigned int irq)
-{
- irq_desc_t *desc = get_irq_desc(irq);
- disable_irq_nosync(irq);
- if (desc->action)
- synchronize_irq(irq);
-}
-
-EXPORT_SYMBOL(disable_irq);
-
-/**
- * enable_irq - enable interrupt handling on an irq
- * @irq: Interrupt to enable
- *
- * Re-enables the processing of interrupts on this IRQ line
- * providing no disable_irq calls are now in effect.
- *
- * This function may be called from IRQ context.
- */
-
-void enable_irq(unsigned int irq)
-{
- irq_desc_t *desc = get_irq_desc(irq);
- unsigned long flags;
-
- spin_lock_irqsave(&desc->lock, flags);
- switch (desc->depth) {
- case 1: {
- unsigned int status = desc->status & ~IRQ_DISABLED;
- desc->status = status;
- if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
- desc->status = status | IRQ_REPLAY;
- hw_resend_irq(desc->handler,irq);
- }
- unmask_irq(irq);
- /* fall-through */
- }
- default:
- desc->depth--;
- break;
- case 0:
- printk("enable_irq(%u) unbalanced from %p\n", irq,
- __builtin_return_address(0));
- }
- spin_unlock_irqrestore(&desc->lock, flags);
-}
-
-EXPORT_SYMBOL(enable_irq);
-
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
@@ -360,107 +113,7 @@ skip:
return 0;
}

-int handle_irq_event(int irq, struct pt_regs *regs, struct irqaction *action)
-{
- int status = 0;
- int ret, retval = 0;
-
- if (!(action->flags & SA_INTERRUPT))
- local_irq_enable();
-
- 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 & SA_SAMPLE_RANDOM)
- add_interrupt_randomness(irq);
- local_irq_disable();
- return retval;
-}
-
-static void __report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
-{
- struct irqaction *action;
-
- if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
- printk(KERN_ERR "irq event %d: bogus return value %x\n",
- irq, action_ret);
- } else {
- printk(KERN_ERR "irq %d: nobody cared!\n", irq);
- }
- dump_stack();
- printk(KERN_ERR "handlers:\n");
- action = desc->action;
- do {
- printk(KERN_ERR "[<%p>]", action->handler);
- print_symbol(" (%s)",
- (unsigned long)action->handler);
- printk("\n");
- action = action->next;
- } while (action);
-}
-
-static void report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
-{
- static int count = 100;
-
- if (count) {
- count--;
- __report_bad_irq(irq, desc, action_ret);
- }
-}
-
-static int noirqdebug;
-
-static int __init noirqdebug_setup(char *str)
-{
- noirqdebug = 1;
- printk("IRQ lockup detection disabled\n");
- return 1;
-}
-
-__setup("noirqdebug", noirqdebug_setup);
-
-/*
- * If 99,900 of the previous 100,000 interrupts have not been handled then
- * assume that the IRQ is stuck in some manner. Drop a diagnostic and try to
- * turn the IRQ off.
- *
- * (The other 100-of-100,000 interrupts may have been a correctly-functioning
- * device sharing an IRQ with the failing one)
- *
- * Called under desc->lock
- */
-static void note_interrupt(int irq, irq_desc_t *desc, irqreturn_t action_ret)
-{
- if (action_ret != IRQ_HANDLED) {
- desc->irqs_unhandled++;
- if (action_ret != IRQ_NONE)
- report_bad_irq(irq, desc, action_ret);
- }
-
- desc->irq_count++;
- if (desc->irq_count < 100000)
- return;
-
- desc->irq_count = 0;
- if (desc->irqs_unhandled > 99900) {
- /*
- * The interrupt is stuck
- */
- __report_bad_irq(irq, desc, action_ret);
- /*
- * Now kill the IRQ
- */
- printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
- desc->status |= IRQ_DISABLED;
- desc->handler->disable(irq);
- }
- desc->irqs_unhandled = 0;
-}
+extern int noirqdebug;

/*
* Eventually, this should take an array of interrupts and an array size
@@ -482,7 +135,7 @@ void ppc_irq_dispatch_handler(struct pt_
if (desc->status & IRQ_PER_CPU) {
/* no locking required for CPU-local interrupts: */
ack_irq(irq);
- action_ret = handle_irq_event(irq, regs, desc->action);
+ action_ret = handle_IRQ_event(irq, regs, desc->action);
desc->handler->end(irq);
return;
}
@@ -550,13 +203,13 @@ void ppc_irq_dispatch_handler(struct pt_
if (curtp != irqtp) {
irqtp->task = curtp->task;
irqtp->flags = 0;
- action_ret = call_handle_irq_event(irq, regs, action, irqtp);
+ action_ret = call_handle_IRQ_event(irq, regs, action, irqtp);
irqtp->task = NULL;
if (irqtp->flags)
set_bits(irqtp->flags, &curtp->flags);
} else
#endif
- action_ret = handle_irq_event(irq, regs, action);
+ action_ret = handle_IRQ_event(irq, regs, action);

spin_lock(&desc->lock);
if (!noirqdebug)
@@ -658,27 +311,6 @@ void do_IRQ(struct pt_regs *regs)
}
#endif /* CONFIG_PPC_ISERIES */

-unsigned long probe_irq_on (void)
-{
- return 0;
-}
-
-EXPORT_SYMBOL(probe_irq_on);
-
-int probe_irq_off (unsigned long irqs)
-{
- return 0;
-}
-
-EXPORT_SYMBOL(probe_irq_off);
-
-unsigned int probe_irq_mask(unsigned long irqs)
-{
- return 0;
-}
-
-EXPORT_SYMBOL(probe_irq_mask);
-
void __init init_IRQ(void)
{
static int once = 0;
@@ -692,130 +324,6 @@ void __init init_IRQ(void)
irq_ctx_init();
}

-static struct proc_dir_entry * root_irq_dir;
-static struct proc_dir_entry * irq_dir [NR_IRQS];
-static struct proc_dir_entry * smp_affinity_entry [NR_IRQS];
-
-/* Protected by get_irq_desc(irq)->lock. */
-#ifdef CONFIG_IRQ_ALL_CPUS
-cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL };
-#else /* CONFIG_IRQ_ALL_CPUS */
-cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_NONE };
-#endif /* CONFIG_IRQ_ALL_CPUS */
-
-static int irq_affinity_read_proc (char *page, char **start, off_t off,
- int count, int *eof, void *data)
-{
- int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]);
- if (count - len < 2)
- return -EINVAL;
- len += sprintf(page + len, "\n");
- return len;
-}
-
-static int irq_affinity_write_proc (struct file *file, const char __user *buffer,
- unsigned long count, void *data)
-{
- unsigned int irq = (long)data;
- irq_desc_t *desc = get_irq_desc(irq);
- int ret;
- cpumask_t new_value, tmp;
-
- if (!desc->handler->set_affinity)
- return -EIO;
-
- ret = cpumask_parse(buffer, count, new_value);
- if (ret != 0)
- return ret;
-
- /*
- * We check for CPU_MASK_ALL in xics to send irqs to all cpus.
- * In some cases CPU_MASK_ALL is smaller than the cpumask (eg
- * NR_CPUS == 32 and cpumask is a long), so we mask it here to
- * be consistent.
- */
- cpus_and(new_value, new_value, CPU_MASK_ALL);
-
- /*
- * Grab lock here so cpu_online_map can't change, and also
- * protect irq_affinity[].
- */
- spin_lock(&desc->lock);
-
- /*
- * Do not allow disabling IRQs completely - it's a too easy
- * way to make the system unusable accidentally :-) At least
- * one online CPU still has to be targeted.
- */
- cpus_and(tmp, new_value, cpu_online_map);
- if (cpus_empty(tmp)) {
- ret = -EINVAL;
- goto out;
- }
-
- irq_affinity[irq] = new_value;
- desc->handler->set_affinity(irq, new_value);
- ret = count;
-
-out:
- spin_unlock(&desc->lock);
- return ret;
-}
-
-#define MAX_NAMELEN 10
-
-static void register_irq_proc (unsigned int irq)
-{
- struct proc_dir_entry *entry;
- char name [MAX_NAMELEN];
-
- if (!root_irq_dir || (irq_desc[irq].handler == NULL) || irq_dir[irq])
- return;
-
- memset(name, 0, MAX_NAMELEN);
- sprintf(name, "%d", irq);
-
- /* create /proc/irq/1234 */
- irq_dir[irq] = proc_mkdir(name, root_irq_dir);
-
- /* create /proc/irq/1234/smp_affinity */
- entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
-
- if (entry) {
- entry->nlink = 1;
- entry->data = (void *)(long)irq;
- entry->read_proc = irq_affinity_read_proc;
- entry->write_proc = irq_affinity_write_proc;
- }
-
- smp_affinity_entry[irq] = entry;
-}
-
-void init_irq_proc (void)
-{
- int i;
-
- /* create /proc/irq */
- root_irq_dir = proc_mkdir("irq", NULL);
-
- /* create /proc/irq/prof_cpu_mask */
- create_prof_cpu_mask(root_irq_dir);
-
- /*
- * Create entries for all existing IRQs.
- */
- for_each_irq(i) {
- if (get_irq_desc(i)->handler == NULL)
- continue;
- register_irq_proc(i);
- }
-}
-
-irqreturn_t no_action(int irq, void *dev, struct pt_regs *regs)
-{
- return IRQ_NONE;
-}
-
#ifndef CONFIG_PPC_ISERIES
/*
* Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
--- linux/include/asm-ppc64/irq.h.orig
+++ linux/include/asm-ppc64/irq.h
@@ -17,10 +17,6 @@
*/
#define NR_IRQS 512

-extern void disable_irq(unsigned int);
-extern void disable_irq_nosync(unsigned int);
-extern void enable_irq(unsigned int);
-
/* this number is used when no interrupt has been assigned */
#define NO_IRQ (-1)

@@ -80,7 +76,6 @@ static __inline__ int irq_canonicalize(i

struct irqaction;
struct pt_regs;
-int handle_irq_event(int, struct pt_regs *, struct irqaction *);

#ifdef CONFIG_IRQSTACKS
/*
@@ -91,7 +86,7 @@ extern struct thread_info *softirq_ctx[N

extern void irq_ctx_init(void);
extern void call_do_softirq(struct thread_info *tp);
-extern int call_handle_irq_event(int irq, struct pt_regs *regs,
+extern int call_handle_IRQ_event(int irq, struct pt_regs *regs,
struct irqaction *action, struct thread_info *tp);

#define __ARCH_HAS_DO_SOFTIRQ
--- linux/include/asm-ppc64/hardirq.h.orig
+++ linux/include/asm-ppc64/hardirq.h
@@ -19,45 +19,10 @@ typedef struct {

#include <linux/irq_cpustat.h> /* Standard mappings for irq_cpustat_t above */

-/*
- * We put the hardirq and softirq counter into the preemption
- * counter. The bitmask has the following meaning:
- *
- * - bits 0-7 are the preemption count (max preemption depth: 256)
- * - bits 8-15 are the softirq count (max # of softirqs: 256)
- * - bits 16-24 are the hardirq count (max # of hardirqs: 512)
- *
- * - ( bit 26 is the PREEMPT_ACTIVE flag. )
- *
- * PREEMPT_MASK: 0x000000ff
- * SOFTIRQ_MASK: 0x0000ff00
- * HARDIRQ_MASK: 0x01ff0000
- */
-
-#define PREEMPT_BITS 8
-#define SOFTIRQ_BITS 8
-#define HARDIRQ_BITS 9
-
-#define PREEMPT_SHIFT 0
-#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
-#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
-
-/*
- * The hardirq mask has to be large enough to have
- * space for potentially all IRQ sources in the system
- * nesting on a single CPU:
- */
-#if (1 << HARDIRQ_BITS) < NR_IRQS
-# error HARDIRQ_BITS is too low!
-#endif
-
-#define irq_enter() (preempt_count() += HARDIRQ_OFFSET)
-#define irq_exit() \
-do { \
- preempt_count() -= IRQ_EXIT_OFFSET; \
- if (!in_interrupt() && softirq_pending(smp_processor_id())) \
- do_softirq(); \
- preempt_enable_no_resched(); \
-} while (0)
+static inline void ack_bad_irq(int irq)
+{
+ printk(KERN_CRIT "illegal vector %d received!\n", irq);
+ BUG();
+}

#endif /* __ASM_HARDIRQ_H */
--- linux/include/asm-ppc64/smp.h.orig
+++ linux/include/asm-ppc64/smp.h
@@ -52,8 +52,6 @@ extern cpumask_t cpu_sibling_map[NR_CPUS
#endif
#define PPC_MSG_DEBUGGER_BREAK 3

-extern cpumask_t irq_affinity[];
-
void smp_init_iSeries(void);
void smp_init_pSeries(void);

-
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