From: Ashok Raj <ashok.raj@intel.com>
Made GENERIC_HARDIRQ mechanism work for ia64 and CPU hotplug. When write
to /proc/irq is handled it is not appropriate to perform set_rte
immediatly, since there is a race when the interrupt is asserted while the
re-program is happening. Hence such programming is only safe when we do
the re-program at the time of servicing an interrupt. This got broken when
GENERIC_HARDIRQ got introduced for ia64.
- added CONFIG_PENDING_IRQ so default /proc/irq write handler can do the right
thing.
TBD: We currently dont handle redirectable hint either in the display, or
when we handle writes to /proc/irq/XX/smp_affinity. We need an arch
specific way to account for the presence of "r" hint when we handle the
proc write.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/ia64/kernel/irq.c | 12 ++++++++++--
25-akpm/kernel/irq/proc.c | 10 ++++++++--
2 files changed, 18 insertions(+), 4 deletions(-)
diff -puN arch/ia64/kernel/irq.c~fix-irq_affinity-write-from-proc-for-ia64 arch/ia64/kernel/irq.c
--- 25/arch/ia64/kernel/irq.c~fix-irq_affinity-write-from-proc-for-ia64 2005-03-14 18:42:30.000000000 -0800
+++ 25-akpm/arch/ia64/kernel/irq.c 2005-03-14 18:42:30.000000000 -0800
@@ -94,12 +94,20 @@ skip:
/*
* This is updated when the user sets irq affinity via /proc
*/
-cpumask_t __cacheline_aligned pending_irq_cpumask[NR_IRQS];
+static cpumask_t __cacheline_aligned pending_irq_cpumask[NR_IRQS];
static unsigned long pending_irq_redir[BITS_TO_LONGS(NR_IRQS)];
-static cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL };
static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
+/*
+ * Arch specific routine for deferred write to iosapic rte to reprogram
+ * intr destination.
+ */
+void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
+{
+ pending_irq_cpumask[irq] = mask_val;
+}
+
void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
{
cpumask_t mask = CPU_MASK_NONE;
diff -puN kernel/irq/proc.c~fix-irq_affinity-write-from-proc-for-ia64 kernel/irq/proc.c
--- 25/kernel/irq/proc.c~fix-irq_affinity-write-from-proc-for-ia64 2005-03-14 18:42:30.000000000 -0800
+++ 25-akpm/kernel/irq/proc.c 2005-03-14 18:42:30.000000000 -0800
@@ -19,6 +19,13 @@ static struct proc_dir_entry *root_irq_d
*/
static struct proc_dir_entry *smp_affinity_entry[NR_IRQS];
+void __attribute__((weak))
+proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
+{
+ irq_affinity[irq] = mask_val;
+ irq_desc[irq].handler->set_affinity(irq, mask_val);
+}
+
static int irq_affinity_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
@@ -53,8 +60,7 @@ static int irq_affinity_write_proc(struc
if (cpus_empty(tmp))
return -EINVAL;
- irq_affinity[irq] = new_value;
- irq_desc[irq].handler->set_affinity(irq, new_value);
+ proc_set_irq_affinity(irq, new_value);
return full_count;
}
_