diff options
Diffstat (limited to 'drivers/iommu/amd_iommu.c')
| -rw-r--r-- | drivers/iommu/amd_iommu.c | 33 |
1 files changed, 13 insertions, 20 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index d81c895ff4f4..1efbef7f3b61 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1045,7 +1045,7 @@ static int __iommu_queue_command_sync(struct amd_iommu *iommu, struct iommu_cmd *cmd, bool sync) { - bool read_head = true; + unsigned int count = 0; u32 left, next_tail; next_tail = (iommu->cmd_buf_tail + sizeof(*cmd)) % CMD_BUFFER_SIZE; @@ -1053,33 +1053,26 @@ again: left = (iommu->cmd_buf_head - next_tail) % CMD_BUFFER_SIZE; if (left <= 0x20) { - struct iommu_cmd sync_cmd; - int ret; - - if (read_head) { - /* Update head and recheck remaining space */ - iommu->cmd_buf_head = readl(iommu->mmio_base + - MMIO_CMD_HEAD_OFFSET); - read_head = false; - goto again; - } - - read_head = true; - - iommu->cmd_sem = 0; + /* Skip udelay() the first time around */ + if (count++) { + if (count == LOOP_TIMEOUT) { + pr_err("AMD-Vi: Command buffer timeout\n"); + return -EIO; + } - build_completion_wait(&sync_cmd, (u64)&iommu->cmd_sem); - copy_cmd_to_buffer(iommu, &sync_cmd); + udelay(1); + } - if ((ret = wait_on_sem(&iommu->cmd_sem)) != 0) - return ret; + /* Update head and recheck remaining space */ + iommu->cmd_buf_head = readl(iommu->mmio_base + + MMIO_CMD_HEAD_OFFSET); goto again; } copy_cmd_to_buffer(iommu, cmd); - /* We need to sync now to make sure all commands are processed */ + /* Do we need to make sure all commands are processed? */ iommu->need_sync = sync; return 0; |