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authorChris Metcalf <cmetcalf@tilera.com>2012-03-27 15:40:20 -0400
committerChris Metcalf <cmetcalf@tilera.com>2012-05-25 12:48:20 -0400
commit51007004f44c9588d70ffb77e1f52479bd5b0e37 (patch)
treeddf8dd2f83554ecbe9de0c690cfab3889308397b /arch/tile/kernel/entry.S
parent76e10d158efb6d4516018846f60c2ab5501900bc (diff)
arch/tile: use interrupt critical sections less
In general we want to avoid ever touching memory while within an interrupt critical section, since the page fault path goes through a different path from the hypervisor when in an interrupt critical section, and we carefully decided with tilegx that we didn't need to support this path in the kernel. (On tilepro we did implement that path as part of supporting atomic instructions in software.) In practice we always need to touch the kernel stack, since that's where we store the interrupt state before releasing the critical section, but this change cleans up a few things. The IRQ_ENABLE macro is split up so that when we want to enable interrupts in a deferred way (e.g. for cpu_idle or for interrupt return) we can read the per-cpu enable mask before entering the critical section. The cache-migration code is changed to use interrupt masking instead of interrupt critical sections. And, the interrupt-entry code is changed so that we defer loading "tp" from per-cpu data until after we have released the interrupt critical section. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Diffstat (limited to 'arch/tile/kernel/entry.S')
-rw-r--r--arch/tile/kernel/entry.S3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/tile/kernel/entry.S b/arch/tile/kernel/entry.S
index ec91568df880..133c4b56a99e 100644
--- a/arch/tile/kernel/entry.S
+++ b/arch/tile/kernel/entry.S
@@ -100,8 +100,9 @@ STD_ENTRY(smp_nap)
*/
STD_ENTRY(_cpu_idle)
movei r1, 1
+ IRQ_ENABLE_LOAD(r2, r3)
mtspr INTERRUPT_CRITICAL_SECTION, r1
- IRQ_ENABLE(r2, r3) /* unmask, but still with ICS set */
+ IRQ_ENABLE_APPLY(r2, r3) /* unmask, but still with ICS set */
mtspr INTERRUPT_CRITICAL_SECTION, zero
.global _cpu_idle_nap
_cpu_idle_nap: