[PARISC] Fix our interrupts not to use smp_call_function
Fix our interrupts not to use smp_call_function
On K and D class smp, the generic code calls this under an irq
spinlock, which causes the WARN_ON() message in smp_call_function()
(and is also illegal because it could deadlock).
The fix is to use a new scheme based on the IPI_NOP.
Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index 21a9c5a..3998c0c 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -43,26 +43,34 @@
*/
static volatile unsigned long cpu_eiem = 0;
-static void cpu_set_eiem(void *info)
-{
- set_eiem((unsigned long) info);
-}
-
-static inline void cpu_disable_irq(unsigned int irq)
+static void cpu_disable_irq(unsigned int irq)
{
unsigned long eirr_bit = EIEM_MASK(irq);
cpu_eiem &= ~eirr_bit;
- on_each_cpu(cpu_set_eiem, (void *) cpu_eiem, 1, 1);
+ /* 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);
- mtctl(eirr_bit, 23); /* clear EIRR bit before unmasking */
cpu_eiem |= eirr_bit;
- on_each_cpu(cpu_set_eiem, (void *) cpu_eiem, 1, 1);
+
+ /* FIXME: while our interrupts aren't nested, we cannot reset
+ * the eiem mask if we're already in an interrupt. Once we
+ * implement nested interrupts, this can go away
+ */
+ if (!in_interrupt())
+ set_eiem(cpu_eiem);
+
+ /* 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)
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 268b0f2..ce89da0 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -181,12 +181,19 @@
while (ops) {
unsigned long which = ffz(~ops);
+ ops &= ~(1 << which);
+
switch (which) {
+ case IPI_NOP:
+#if (kDEBUG>=100)
+ printk(KERN_DEBUG "CPU%d IPI_NOP\n",this_cpu);
+#endif /* kDEBUG */
+ break;
+
case IPI_RESCHEDULE:
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d IPI_RESCHEDULE\n",this_cpu);
#endif /* kDEBUG */
- ops &= ~(1 << IPI_RESCHEDULE);
/*
* Reschedule callback. Everything to be
* done is done by the interrupt return path.
@@ -197,7 +204,6 @@
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d IPI_CALL_FUNC\n",this_cpu);
#endif /* kDEBUG */
- ops &= ~(1 << IPI_CALL_FUNC);
{
volatile struct smp_call_struct *data;
void (*func)(void *info);
@@ -231,7 +237,6 @@
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d IPI_CPU_START\n",this_cpu);
#endif /* kDEBUG */
- ops &= ~(1 << IPI_CPU_START);
#ifdef ENTRY_SYS_CPUS
p->state = STATE_RUNNING;
#endif
@@ -241,7 +246,6 @@
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d IPI_CPU_STOP\n",this_cpu);
#endif /* kDEBUG */
- ops &= ~(1 << IPI_CPU_STOP);
#ifdef ENTRY_SYS_CPUS
#else
halt_processor();
@@ -252,13 +256,11 @@
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d is alive!\n",this_cpu);
#endif /* kDEBUG */
- ops &= ~(1 << IPI_CPU_TEST);
break;
default:
printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
this_cpu, which);
- ops &= ~(1 << which);
return IRQ_NONE;
} /* Switch */
} /* while (ops) */
@@ -312,6 +314,12 @@
void
smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
+void
+smp_send_all_nop(void)
+{
+ send_IPI_allbutself(IPI_NOP);
+}
+
/**
* Run a function on all other CPUs.
diff --git a/include/asm-parisc/smp.h b/include/asm-parisc/smp.h
index 9413f67..a519195 100644
--- a/include/asm-parisc/smp.h
+++ b/include/asm-parisc/smp.h
@@ -29,6 +29,7 @@
#define cpu_logical_map(cpu) (cpu)
extern void smp_send_reschedule(int cpu);
+extern void smp_send_all_nop(void);
#endif /* !ASSEMBLY */