[PATCH 1/4] nvme-core: use macro for ctrl page size default value

[Chaitanya Kulkarni]

This is a preparation patch which is needed to centralize the page shift
value for the have ctrl->page_size.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
---
 drivers/nvme/host/core.c | 15 +++++----------
 drivers/nvme/host/nvme.h |  7 +++++++
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 898885630ad8..e0b47e77cbca 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2344,12 +2344,7 @@ EXPORT_SYMBOL_GPL(nvme_disable_ctrl);
 
 int nvme_enable_ctrl(struct nvme_ctrl *ctrl)
 {
-	/*
-	 * Default to a 4K page size, with the intention to update this
-	 * path in the future to accomodate architectures with differing
-	 * kernel and IO page sizes.
-	 */
-	unsigned dev_page_min, page_shift = 12;
+	unsigned dev_page_min;
 	int ret;
 
 	ret = ctrl->ops->reg_read64(ctrl, NVME_REG_CAP, &ctrl->cap);
@@ -2359,20 +2354,20 @@ int nvme_enable_ctrl(struct nvme_ctrl *ctrl)
 	}
 	dev_page_min = NVME_CAP_MPSMIN(ctrl->cap) + 12;
 
-	if (page_shift < dev_page_min) {
+	if (NVME_CTRL_PAGE_SHIFT < dev_page_min) {
 		dev_err(ctrl->device,
 			"Minimum device page size %u too large for host (%u)\n",
-			1 << dev_page_min, 1 << page_shift);
+			1 << dev_page_min, 1 << NVME_CTRL_PAGE_SHIFT);
 		return -ENODEV;
 	}
 
-	ctrl->page_size = 1 << page_shift;
+	ctrl->page_size = 1 << NVME_CTRL_PAGE_SHIFT;
 
 	if (NVME_CAP_CSS(ctrl->cap) & NVME_CAP_CSS_CSI)
 		ctrl->ctrl_config = NVME_CC_CSS_CSI;
 	else
 		ctrl->ctrl_config = NVME_CC_CSS_NVM;
-	ctrl->ctrl_config |= (page_shift - 12) << NVME_CC_MPS_SHIFT;
+	ctrl->ctrl_config |= (NVME_CTRL_PAGE_SHIFT - 12) << NVME_CC_MPS_SHIFT;
 	ctrl->ctrl_config |= NVME_CC_AMS_RR | NVME_CC_SHN_NONE;
 	ctrl->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;
 	ctrl->ctrl_config |= NVME_CC_ENABLE;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 85d76981b66e..4a56897e9081 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -37,6 +37,13 @@ extern unsigned int admin_timeout;
 #define  NVME_INLINE_METADATA_SG_CNT  1
 #endif
 
+/*
+ * Default to a 4K page size, with the intention to update this
+ * path in the future to accomodate architectures with differing
+ * kernel and IO page sizes.
+ */
+#define NVME_CTRL_PAGE_SHIFT	12
+
 extern struct workqueue_struct *nvme_wq;
 extern struct workqueue_struct *nvme_reset_wq;
 extern struct workqueue_struct *nvme_delete_wq;
-- 
2.26.0