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authorIra Weiny <ira.weiny@intel.com>2023-02-02 17:04:26 -0800
committerDan Williams <dan.j.williams@intel.com>2023-02-10 17:54:45 -0800
commit814a15f3b4131d3205bd47e23b50ccc6c666ce1d (patch)
treeae54a8dc438841b4c29bac66bb9aa014b6644821
parent11ef026e467b05eac0a2ceb981d351ddc4b12216 (diff)
cxl/uapi: Tag commands from cxl_query_cmd()
It was pointed out that commands not supported by the device or excluded by the kernel were being returned in cxl_query_cmd().[1] While libcxl correctly handles failing commands, it is more efficient to not issue an invalid command in the first place. This can't be done without additional information being returned from cxl_query_cmd(). In addition, information about the availability of commands can be useful for debugging. Add flags to struct cxl_command_info which reflect if a command is enabled and/or exclusive to the kernel. [1] https://lore.kernel.org/all/63b4ec4e37cc1_5178e2941d@dwillia2-xfh.jf.intel.com.notmuch/ Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20221222-cxl-misc-v4-3-62f701c1cdd1@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--drivers/cxl/core/mbox.c9
-rw-r--r--include/uapi/linux/cxl_mem.h19
2 files changed, 24 insertions, 4 deletions
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 202d49dd9911..fd3b13b0fb7f 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -451,9 +451,14 @@ int cxl_query_cmd(struct cxl_memdev *cxlmd,
* structures.
*/
cxl_for_each_cmd(cmd) {
- const struct cxl_command_info *info = &cmd->info;
+ struct cxl_command_info info = cmd->info;
- if (copy_to_user(&q->commands[j++], info, sizeof(*info)))
+ if (test_bit(info.id, cxlmd->cxlds->enabled_cmds))
+ info.flags |= CXL_MEM_COMMAND_FLAG_ENABLED;
+ if (test_bit(info.id, cxlmd->cxlds->exclusive_cmds))
+ info.flags |= CXL_MEM_COMMAND_FLAG_EXCLUSIVE;
+
+ if (copy_to_user(&q->commands[j++], &info, sizeof(info)))
return -EFAULT;
if (j == n_commands)
diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
index 459a3f7f764b..9fe832afee37 100644
--- a/include/uapi/linux/cxl_mem.h
+++ b/include/uapi/linux/cxl_mem.h
@@ -72,6 +72,19 @@ static const struct {
* struct cxl_command_info - Command information returned from a query.
* @id: ID number for the command.
* @flags: Flags that specify command behavior.
+ *
+ * CXL_MEM_COMMAND_FLAG_USER_ENABLED
+ *
+ * The given command id is supported by the driver and is supported by
+ * a related opcode on the device.
+ *
+ * CXL_MEM_COMMAND_FLAG_EXCLUSIVE
+ *
+ * Requests with the given command id will terminate with EBUSY as the
+ * kernel actively owns management of the given resource. For example,
+ * the label-storage-area can not be written while the kernel is
+ * actively managing that space.
+ *
* @size_in: Expected input size, or ~0 if variable length.
* @size_out: Expected output size, or ~0 if variable length.
*
@@ -81,7 +94,7 @@ static const struct {
* bytes of output.
*
* - @id = 10
- * - @flags = 0
+ * - @flags = CXL_MEM_COMMAND_FLAG_ENABLED
* - @size_in = ~0
* - @size_out = 0
*
@@ -91,7 +104,9 @@ struct cxl_command_info {
__u32 id;
__u32 flags;
-#define CXL_MEM_COMMAND_FLAG_MASK GENMASK(0, 0)
+#define CXL_MEM_COMMAND_FLAG_MASK GENMASK(1, 0)
+#define CXL_MEM_COMMAND_FLAG_ENABLED BIT(0)
+#define CXL_MEM_COMMAND_FLAG_EXCLUSIVE BIT(1)
__u32 size_in;
__u32 size_out;