diff options
| -rw-r--r-- | arch/x86/kernel/amd_iommu.c | 68 |
1 files changed, 45 insertions, 23 deletions
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 0922d5fe633..2280ef86651 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -196,6 +196,46 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd) } /* + * This function waits until an IOMMU has completed a completion + * wait command + */ +static void __iommu_wait_for_completion(struct amd_iommu *iommu) +{ + int ready = 0; + unsigned status = 0; + unsigned long i = 0; + + while (!ready && (i < EXIT_LOOP_COUNT)) { + ++i; + /* wait for the bit to become one */ + status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET); + ready = status & MMIO_STATUS_COM_WAIT_INT_MASK; + } + + /* set bit back to zero */ + status &= ~MMIO_STATUS_COM_WAIT_INT_MASK; + writel(status, iommu->mmio_base + MMIO_STATUS_OFFSET); + + if (unlikely(i == EXIT_LOOP_COUNT)) + panic("AMD IOMMU: Completion wait loop failed\n"); +} + +/* + * This function queues a completion wait command into the command + * buffer of an IOMMU + */ +static int __iommu_completion_wait(struct amd_iommu *iommu) +{ + struct iommu_cmd cmd; + + memset(&cmd, 0, sizeof(cmd)); + cmd.data[0] = CMD_COMPL_WAIT_INT_MASK; + CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT); + + return __iommu_queue_command(iommu, &cmd); +} + +/* * This function is called whenever we need to ensure that the IOMMU has * completed execution of all commands we sent. It sends a * COMPLETION_WAIT command and waits for it to finish. The IOMMU informs @@ -204,40 +244,22 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd) */ static int iommu_completion_wait(struct amd_iommu *iommu) { - int ret = 0, ready = 0; - unsigned status = 0; - struct iommu_cmd cmd; - unsigned long flags, i = 0; - - memset(&cmd, 0, sizeof(cmd)); - cmd.data[0] = CMD_COMPL_WAIT_INT_MASK; - CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT); + int ret = 0; + unsigned long flags; spin_lock_irqsave(&iommu->lock, flags); if (!iommu->need_sync) goto out; - iommu->need_sync = 0; + ret = __iommu_completion_wait(iommu); - ret = __iommu_queue_command(iommu, &cmd); + iommu->need_sync = 0; if (ret) goto out; - while (!ready && (i < EXIT_LOOP_COUNT)) { - ++i; - /* wait for the bit to become one */ - status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET); - ready = status & MMIO_STATUS_COM_WAIT_INT_MASK; - } - - /* set bit back to zero */ - status &= ~MMIO_STATUS_COM_WAIT_INT_MASK; - writel(status, iommu->mmio_base + MMIO_STATUS_OFFSET); - - if (unlikely(i == EXIT_LOOP_COUNT)) - panic("AMD IOMMU: Completion wait loop failed\n"); + __iommu_wait_for_completion(iommu); out: spin_unlock_irqrestore(&iommu->lock, flags); |