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authorBen Widawsky <ben.widawsky@intel.com>2021-02-17 07:09:53 +0300
committerDan Williams <dan.j.williams@intel.com>2021-02-17 07:36:38 +0300
commit583fa5e71caeb79e04e477e9837e2f7fa53b71e4 (patch)
tree86f2720d26afc073b5460acd08a0e10d493299d9 /Documentation/driver-api/cxl
parentb39cb1052a5cf41bc12201ec1c0ddae5cb8be868 (diff)
downloadlinux-583fa5e71caeb79e04e477e9837e2f7fa53b71e4.tar.xz
cxl/mem: Add basic IOCTL interface
Add a straightforward IOCTL that provides a mechanism for userspace to query the supported memory device commands. CXL commands as they appear to userspace are described as part of the UAPI kerneldoc. The command list returned via this IOCTL will contain the full set of commands that the driver supports, however, some of those commands may not be available for use by userspace. Memory device commands first appear in the CXL 2.0 specification. They are submitted through a mailbox mechanism specified in the CXL 2.0 specification. The send command allows userspace to issue mailbox commands directly to the hardware. The list of available commands to send are the output of the query command. The driver verifies basic properties of the command and possibly inspect the input (or output) payload to determine whether or not the command is allowed (or might taint the kernel). Reported-by: kernel test robot <lkp@intel.com> # bug in earlier revision Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> (v2) Cc: Al Viro <viro@zeniv.linux.org.uk> Link: https://lore.kernel.org/r/20210217040958.1354670-5-ben.widawsky@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'Documentation/driver-api/cxl')
-rw-r--r--Documentation/driver-api/cxl/memory-devices.rst12
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/driver-api/cxl/memory-devices.rst b/Documentation/driver-api/cxl/memory-devices.rst
index 1fef2c0a167d..1bad466f9167 100644
--- a/Documentation/driver-api/cxl/memory-devices.rst
+++ b/Documentation/driver-api/cxl/memory-devices.rst
@@ -32,3 +32,15 @@ CXL Bus
-------
.. kernel-doc:: drivers/cxl/bus.c
:doc: cxl bus
+
+External Interfaces
+===================
+
+CXL IOCTL Interface
+-------------------
+
+.. kernel-doc:: include/uapi/linux/cxl_mem.h
+ :doc: UAPI
+
+.. kernel-doc:: include/uapi/linux/cxl_mem.h
+ :internal: