[PATCH v4 12/18] nvme: Add a nvme_pr_type enum

[Mike Christie]

The next patch adds support to report the reservation type, so we need to
be able to convert from the NVMe PR value we get from the device to the
linux block layer PR value that will be returned to callers. To prepare
for that, this patch adds a nvme_pr_type enum and renames the nvme_pr_type
function.

Signed-off-by: Mike Christie <michael.christie at oracle.com>
---

Note for Chaitanya, Keith and Bart. For these patches where we convert
between block and nvme pr values, it seemed like Chaitanya and Keith
didn't have a strong preference. Bart had the suggestion to keep the
switch and drop the default so the compiler can warn us if new types
are added. This seemed like a nice benefit so I went that way.


 drivers/nvme/host/pr.c | 24 ++++++++++++------------
 include/linux/nvme.h   |  9 +++++++++
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
index ac6b9008e7e1..66086369dbce 100644
--- a/drivers/nvme/host/pr.c
+++ b/drivers/nvme/host/pr.c
@@ -6,24 +6,24 @@
 
 #include "nvme.h"
 
-static char nvme_pr_type(enum pr_type type)
+static enum nvme_pr_type nvme_pr_type_from_blk(enum pr_type type)
 {
 	switch (type) {
 	case PR_WRITE_EXCLUSIVE:
-		return 1;
+		return NVME_PR_WRITE_EXCLUSIVE;
 	case PR_EXCLUSIVE_ACCESS:
-		return 2;
+		return NVME_PR_EXCLUSIVE_ACCESS;
 	case PR_WRITE_EXCLUSIVE_REG_ONLY:
-		return 3;
+		return NVME_PR_WRITE_EXCLUSIVE_REG_ONLY;
 	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
-		return 4;
+		return NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY;
 	case PR_WRITE_EXCLUSIVE_ALL_REGS:
-		return 5;
+		return NVME_PR_WRITE_EXCLUSIVE_ALL_REGS;
 	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
-		return 6;
-	default:
-		return 0;
+		return NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS;
 	}
+
+	return 0;
 }
 
 static int nvme_send_ns_head_pr_command(struct block_device *bdev,
@@ -124,7 +124,7 @@ static int nvme_pr_reserve(struct block_device *bdev, u64 key,
 	if (flags & ~PR_FL_IGNORE_KEY)
 		return -EOPNOTSUPP;
 
-	cdw10 = nvme_pr_type(type) << 8;
+	cdw10 = nvme_pr_type_from_blk(type) << 8;
 	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
 }
@@ -132,7 +132,7 @@ static int nvme_pr_reserve(struct block_device *bdev, u64 key,
 static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
 		enum pr_type type, bool abort)
 {
-	u32 cdw10 = nvme_pr_type(type) << 8 | (abort ? 2 : 1);
+	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (abort ? 2 : 1);
 
 	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
 }
@@ -146,7 +146,7 @@ static int nvme_pr_clear(struct block_device *bdev, u64 key)
 
 static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
 {
-	u32 cdw10 = nvme_pr_type(type) << 8 | (key ? 0 : 1 << 3);
+	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (key ? 0 : 1 << 3);
 
 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
 }
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 50fc596ec888..bae08167735a 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -759,6 +759,15 @@ enum {
 	NVME_LBART_ATTRIB_HIDE	= 1 << 1,
 };
 
+enum nvme_pr_type {
+	NVME_PR_WRITE_EXCLUSIVE			= 1,
+	NVME_PR_EXCLUSIVE_ACCESS		= 2,
+	NVME_PR_WRITE_EXCLUSIVE_REG_ONLY	= 3,
+	NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY	= 4,
+	NVME_PR_WRITE_EXCLUSIVE_ALL_REGS	= 5,
+	NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS	= 6,
+};
+
 enum nvme_eds {
 	NVME_EXTENDED_DATA_STRUCT	= 0x1,
 };
-- 
2.25.1