diff options
| author | Ben Widawsky <ben.widawsky@intel.com> | 2021-02-17 07:09:54 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2021-02-17 07:36:38 +0300 |
| commit | 13237183c735f5cba4ae26bc782c613ae0d4e4d3 (patch) | |
| tree | 097c6359d749a8b4729d6fb599bc83612ea21a2b /drivers/cxl/Kconfig | |
| parent | 583fa5e71caeb79e04e477e9837e2f7fa53b71e4 (diff) | |
| download | linux-13237183c735f5cba4ae26bc782c613ae0d4e4d3.tar.xz | |
cxl/mem: Add a "RAW" send command
The CXL memory device send interface will have a number of supported
commands. The raw command is not such a command. Raw commands allow
userspace to send a specified opcode to the underlying hardware and
bypass all driver checks on the command. The primary use for this
command is to [begrudgingly] allow undocumented vendor specific hardware
commands.
While not the main motivation, it also allows prototyping new hardware
commands without a driver patch and rebuild.
While this all sounds very powerful it comes with a couple of caveats:
1. Bug reports using raw commands will not get the same level of
attention as bug reports using supported commands (via taint).
2. Supported commands will be rejected by the RAW command.
With this comes new debugfs knob to allow full access to your toes with
your weapon of choice.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com> (v2)
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Ariel Sibley <Ariel.Sibley@microchip.com>
Link: https://lore.kernel.org/r/20210217040958.1354670-6-ben.widawsky@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl/Kconfig')
| -rw-r--r-- | drivers/cxl/Kconfig | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index 9e80b311e928..97dc4d751651 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -32,4 +32,22 @@ config CXL_MEM Chapter 2.3 Type 3 CXL Device in the CXL 2.0 specification. If unsure say 'm'. + +config CXL_MEM_RAW_COMMANDS + bool "RAW Command Interface for Memory Devices" + depends on CXL_MEM + help + Enable CXL RAW command interface. + + The CXL driver ioctl interface may assign a kernel ioctl command + number for each specification defined opcode. At any given point in + time the number of opcodes that the specification defines and a device + may implement may exceed the kernel's set of associated ioctl function + numbers. The mismatch is either by omission, specification is too new, + or by design. When prototyping new hardware, or developing / debugging + the driver it is useful to be able to submit any possible command to + the hardware, even commands that may crash the kernel due to their + potential impact to memory currently in use by the kernel. + + If developing CXL hardware or the driver say Y, otherwise say N. endif |