diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2021-09-14 12:03:04 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2021-09-21 13:44:57 -0700 |
| commit | 12f3856ad42d6ce0dbd4266e105c04ae999f908c (patch) | |
| tree | 6fb0e896a522491e6015c7f326b5573e92cd16b8 /drivers/cxl/core/mbox.c | |
| parent | ff56ab9e164d71c4a6ae33fc61ae856faec265a1 (diff) | |
| download | linux-12f3856ad42d6ce0dbd4266e105c04ae999f908c.tar.gz | |
cxl/mbox: Add exclusive kernel command support
The CXL_PMEM driver expects exclusive control of the label storage area
space. Similar to the LIBNVDIMM expectation that the label storage area
is only writable from userspace when the corresponding memory device is
not active in any region, the expectation is the native CXL_PCI UAPI
path is disabled while the cxl_nvdimm for a given cxl_memdev device is
active in LIBNVDIMM.
Add the ability to toggle the availability of a given command for the
UAPI path. Use that new capability to shutdown changes to partitions and
the label storage area while the cxl_nvdimm device is actively proxying
commands for LIBNVDIMM.
Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
Link: https://lore.kernel.org/r/163164579468.2830966.6980053377428474263.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl/core/mbox.c')
| -rw-r--r-- | drivers/cxl/core/mbox.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index 422999740649..82e79da195fa 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -221,6 +221,7 @@ static bool cxl_mem_raw_command_allowed(u16 opcode) * * %-EINVAL - Reserved fields or invalid values were used. * * %-ENOMEM - Input or output buffer wasn't sized properly. * * %-EPERM - Attempted to use a protected command. + * * %-EBUSY - Kernel has claimed exclusive access to this opcode * * The result of this command is a fully validated command in @out_cmd that is * safe to send to the hardware. @@ -296,6 +297,10 @@ static int cxl_validate_cmd_from_user(struct cxl_mem *cxlm, if (!test_bit(info->id, cxlm->enabled_cmds)) return -ENOTTY; + /* Check that the command is not claimed for exclusive kernel use */ + if (test_bit(info->id, cxlm->exclusive_cmds)) + return -EBUSY; + /* Check the input buffer is the expected size */ if (info->size_in >= 0 && info->size_in != send_cmd->in.size) return -ENOMEM; |