iommu/amd: Remove cmd_buf_size and evt_buf_size from struct amd_iommu

The driver always uses a constant size for these buffers
anyway, so there is no need to waste memory to store the
sizes.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index fe112bb..02b8ad7 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -534,7 +534,7 @@
 
 	while (head != tail) {
 		iommu_print_event(iommu, iommu->evt_buf + head);
-		head = (head + EVENT_ENTRY_SIZE) % iommu->evt_buf_size;
+		head = (head + EVENT_ENTRY_SIZE) % EVT_BUFFER_SIZE;
 	}
 
 	writel(head, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);
@@ -684,7 +684,7 @@
 	u8 *target;
 
 	target = iommu->cmd_buf + tail;
-	tail   = (tail + sizeof(*cmd)) % iommu->cmd_buf_size;
+	tail   = (tail + sizeof(*cmd)) % CMD_BUFFER_SIZE;
 
 	/* Copy command to buffer */
 	memcpy(target, cmd, sizeof(*cmd));
@@ -851,15 +851,13 @@
 	u32 left, tail, head, next_tail;
 	unsigned long flags;
 
-	WARN_ON(iommu->cmd_buf_size & CMD_BUFFER_UNINITIALIZED);
-
 again:
 	spin_lock_irqsave(&iommu->lock, flags);
 
 	head      = readl(iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
 	tail      = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
-	next_tail = (tail + sizeof(*cmd)) % iommu->cmd_buf_size;
-	left      = (head - next_tail) % iommu->cmd_buf_size;
+	next_tail = (tail + sizeof(*cmd)) % CMD_BUFFER_SIZE;
+	left      = (head - next_tail) % CMD_BUFFER_SIZE;
 
 	if (left <= 2) {
 		struct iommu_cmd sync_cmd;