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authorJoerg Roedel <joerg.roedel@amd.com>2008-09-17 14:19:15 +0200
committerIngo Molnar <mingo@elte.hu>2008-09-18 09:25:44 +0200
commit7e4f88da7bf1887563f70bd5edbbd0479e31dc12 (patch)
treeeacefdd0980b384a89463cca211c042c7faa9b1d /arch/x86/kernel/amd_iommu.c
parentee2fa7435b6dddf1ca119f298ad0100cf50c0397 (diff)
AMD IOMMU: protect completion wait loop with iommu lock
The unlocked polling of the ComWaitInt bit in the IOMMU completion wait path is racy. Protect it with the iommu lock. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/amd_iommu.c')
-rw-r--r--arch/x86/kernel/amd_iommu.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index a96d8c049a8..042fdc27bc9 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -101,10 +101,10 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
*/
static int iommu_completion_wait(struct amd_iommu *iommu)
{
- int ret, ready = 0;
+ int ret = 0, ready = 0;
unsigned status = 0;
struct iommu_cmd cmd;
- unsigned long i = 0;
+ unsigned long flags, i = 0;
memset(&cmd, 0, sizeof(cmd));
cmd.data[0] = CMD_COMPL_WAIT_INT_MASK;
@@ -112,10 +112,12 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
iommu->need_sync = 0;
- ret = iommu_queue_command(iommu, &cmd);
+ spin_lock_irqsave(&iommu->lock, flags);
+
+ ret = __iommu_queue_command(iommu, &cmd);
if (ret)
- return ret;
+ goto out;
while (!ready && (i < EXIT_LOOP_COUNT)) {
++i;
@@ -130,6 +132,8 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
if (unlikely((i == EXIT_LOOP_COUNT) && printk_ratelimit()))
printk(KERN_WARNING "AMD IOMMU: Completion wait loop failed\n");
+out:
+ spin_unlock_irqrestore(&iommu->lock, flags);
return 0;
}