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authorAnton Blanchard <anton@samba.org>2012-06-03 19:42:13 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-07-03 14:14:46 +1000
commitc1703e85a7b20ffcefd5360e2542460737ecc15c (patch)
treea2aa1cb255beab5b00336121b2aeb9adefc24180 /arch/powerpc/platforms/pseries
parentb3f271e86e5a440713716bb222e1aa1227994c50 (diff)
powerpc/pseries: Disable interrupts around IOMMU percpu data accesses
tce_buildmulti_pSeriesLP uses a per cpu page to communicate with the hypervisor. We currently rely on the IOMMU table spinlock but subsequent patches will be removing that so disable interrupts around all accesses of tce_page. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms/pseries')
-rw-r--r--arch/powerpc/platforms/pseries/iommu.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index d5d1dd58ca7..07c09cbbfb1 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -192,12 +192,15 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
long l, limit;
long tcenum_start = tcenum, npages_start = npages;
int ret = 0;
+ unsigned long flags;
if (npages == 1) {
return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
direction, attrs);
}
+ local_irq_save(flags); /* to protect tcep and the page behind it */
+
tcep = __get_cpu_var(tce_page);
/* This is safe to do since interrupts are off when we're called
@@ -207,6 +210,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
tcep = (u64 *)__get_free_page(GFP_ATOMIC);
/* If allocation fails, fall back to the loop implementation */
if (!tcep) {
+ local_irq_restore(flags);
return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
direction, attrs);
}
@@ -240,6 +244,8 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
tcenum += limit;
} while (npages > 0 && !rc);
+ local_irq_restore(flags);
+
if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {
ret = (int)rc;
tce_freemulti_pSeriesLP(tbl, tcenum_start,