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| author | Joerg Roedel <joerg.roedel@amd.com> | 2008-09-17 14:19:15 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-09-18 09:25:44 +0200 |
| commit | 7e4f88da7bf1887563f70bd5edbbd0479e31dc12 (patch) | |
| tree | eacefdd0980b384a89463cca211c042c7faa9b1d /arch/x86/kernel/amd_iommu.c | |
| parent | ee2fa7435b6dddf1ca119f298ad0100cf50c0397 (diff) | |
| download | talos-obmc-linux-7e4f88da7bf1887563f70bd5edbbd0479e31dc12.tar.gz talos-obmc-linux-7e4f88da7bf1887563f70bd5edbbd0479e31dc12.zip | |
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.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index a96d8c049a88..042fdc27bc92 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; } |
