From 11ef026e467b05eac0a2ceb981d351ddc4b12216 Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Thu, 2 Feb 2023 17:04:25 -0800 Subject: cxl/uapi: Add warning on CXL command enum The CXL command enum is exported to user space and must maintain backwards compatibility. Add comment that new defines must be added to the end of the list. Suggested-by: Dan Williams Reviewed-by: Jonathan Cameron Reviewed-by: Dave Jiang Signed-off-by: Ira Weiny Link: https://lore.kernel.org/r/20221222-cxl-misc-v4-2-62f701c1cdd1@intel.com Signed-off-by: Dan Williams --- include/uapi/linux/cxl_mem.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h index c71021a2a9ed..459a3f7f764b 100644 --- a/include/uapi/linux/cxl_mem.h +++ b/include/uapi/linux/cxl_mem.h @@ -19,6 +19,10 @@ #define CXL_MEM_QUERY_COMMANDS _IOR(0xCE, 1, struct cxl_mem_query_commands) #define CXL_MEM_SEND_COMMAND _IOWR(0xCE, 2, struct cxl_send_command) +/* + * NOTE: New defines must be added to the end of the list to preserve + * compatibility because this enum is exported to user space. + */ #define CXL_CMDS \ ___C(INVALID, "Invalid Command"), \ ___C(IDENTIFY, "Identify Command"), \ -- cgit v1.2.3 From 814a15f3b4131d3205bd47e23b50ccc6c666ce1d Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Thu, 2 Feb 2023 17:04:26 -0800 Subject: 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 Signed-off-by: Ira Weiny Link: https://lore.kernel.org/r/20221222-cxl-misc-v4-3-62f701c1cdd1@intel.com Signed-off-by: Dan Williams --- drivers/cxl/core/mbox.c | 9 +++++++-- include/uapi/linux/cxl_mem.h | 19 +++++++++++++++++-- 2 files changed, 24 insertions(+), 4 deletions(-) (limited to 'include/uapi/linux') 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; -- cgit v1.2.3 From af73370dcbe584f44168872b0bacac899f3c48f2 Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Thu, 2 Feb 2023 17:04:27 -0800 Subject: cxl/mem: Fix UAPI command comment The command comment had grammatical errors. In an attempt to fix those it was noted that the comment and the query command were not in sync. Now that the query command returns excluded and device unsupported command information. Update the kdoc and fix the grammatical errors. [1] https://lore.kernel.org/all/63b4ec4e37cc1_5178e2941d@dwillia2-xfh.jf.intel.com.notmuch/ Reviewed-by: Jonathan Cameron Signed-off-by: Ira Weiny Link: https://lore.kernel.org/r/20221222-cxl-misc-v4-4-62f701c1cdd1@intel.com Signed-off-by: Dan Williams --- include/uapi/linux/cxl_mem.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h index 9fe832afee37..86bbacf2a315 100644 --- a/include/uapi/linux/cxl_mem.h +++ b/include/uapi/linux/cxl_mem.h @@ -11,9 +11,10 @@ /** * DOC: UAPI * - * Not all of all commands that the driver supports are always available for use - * by userspace. Userspace must check the results from the QUERY command in - * order to determine the live set of commands. + * Not all of the commands that the driver supports are available for use by + * userspace at all times. Userspace can check the result of the QUERY command + * to determine the live set of commands. Alternatively, it can issue the + * command and check for failure. */ #define CXL_MEM_QUERY_COMMANDS _IOR(0xCE, 1, struct cxl_mem_query_commands) -- cgit v1.2.3