diff options
| -rw-r--r-- | drivers/iommu/amd_iommu.c | 35 | ||||
| -rw-r--r-- | drivers/iommu/amd_iommu_init.c | 2 | ||||
| -rw-r--r-- | drivers/iommu/amd_iommu_types.h | 2 |
3 files changed, 26 insertions, 13 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index d7748955184b..d81c895ff4f4 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -874,19 +874,20 @@ static int wait_on_sem(volatile u64 *sem) } static void copy_cmd_to_buffer(struct amd_iommu *iommu, - struct iommu_cmd *cmd, - u32 tail) + struct iommu_cmd *cmd) { u8 *target; - target = iommu->cmd_buf + tail; - tail = (tail + sizeof(*cmd)) % CMD_BUFFER_SIZE; + target = iommu->cmd_buf + iommu->cmd_buf_tail; + + iommu->cmd_buf_tail += sizeof(*cmd); + iommu->cmd_buf_tail %= CMD_BUFFER_SIZE; /* Copy command to buffer */ memcpy(target, cmd, sizeof(*cmd)); /* Tell the IOMMU about it */ - writel(tail, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET); + writel(iommu->cmd_buf_tail, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET); } static void build_completion_wait(struct iommu_cmd *cmd, u64 address) @@ -1044,23 +1045,31 @@ static int __iommu_queue_command_sync(struct amd_iommu *iommu, struct iommu_cmd *cmd, bool sync) { - u32 left, tail, head, next_tail; + bool read_head = true; + u32 left, next_tail; + next_tail = (iommu->cmd_buf_tail + sizeof(*cmd)) % CMD_BUFFER_SIZE; again: - - head = readl(iommu->mmio_base + MMIO_CMD_HEAD_OFFSET); - tail = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET); - next_tail = (tail + sizeof(*cmd)) % CMD_BUFFER_SIZE; - left = (head - next_tail) % CMD_BUFFER_SIZE; + 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; build_completion_wait(&sync_cmd, (u64)&iommu->cmd_sem); - copy_cmd_to_buffer(iommu, &sync_cmd, tail); + copy_cmd_to_buffer(iommu, &sync_cmd); if ((ret = wait_on_sem(&iommu->cmd_sem)) != 0) return ret; @@ -1068,7 +1077,7 @@ again: goto again; } - copy_cmd_to_buffer(iommu, cmd, tail); + copy_cmd_to_buffer(iommu, cmd); /* We need to sync now to make sure all commands are processed */ iommu->need_sync = sync; diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index 5a11328f4d98..3fa7e3b35507 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -588,6 +588,8 @@ void amd_iommu_reset_cmd_buffer(struct amd_iommu *iommu) writel(0x00, iommu->mmio_base + MMIO_CMD_HEAD_OFFSET); writel(0x00, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET); + iommu->cmd_buf_head = 0; + iommu->cmd_buf_tail = 0; iommu_feature_enable(iommu, CONTROL_CMDBUF_EN); } diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h index 4de8f4160bb8..6960d7db2fab 100644 --- a/drivers/iommu/amd_iommu_types.h +++ b/drivers/iommu/amd_iommu_types.h @@ -516,6 +516,8 @@ struct amd_iommu { /* command buffer virtual address */ u8 *cmd_buf; + u32 cmd_buf_head; + u32 cmd_buf_tail; /* event buffer virtual address */ u8 *evt_buf; |