diff options
| author | Davidlohr Bueso <dave@stgolabs.net> | 2023-05-23 10:09:27 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2023-05-23 12:55:12 -0700 |
| commit | ccadf1310fb0bc8d2cbcd14f94a6279c12ea9bee (patch) | |
| tree | 71d097162ca95f1faf2aea4651fe0f27f0f88715 /drivers/cxl/core/mbox.c | |
| parent | 9f7a320d167cd7f310114cf25009ceedf6a323ed (diff) | |
cxl/mbox: Add background cmd handling machinery
This adds support for handling background operations, as defined in
the CXL 3.0 spec. Commands that can take too long (over ~2 seconds)
can run in the background asynchronously (to the hardware).
The driver will deal with such commands synchronously, blocking all
other incoming commands for a specified period of time, allowing
time-slicing the command such that the caller can send incremental
requests to avoid monopolizing the driver/device. Any out of sync
(timeout) between the driver and hardware is just disregarded as
an invalid state until the next successful submission. Such timeouts
are considered a rare occurrence, either a real device problem or a
driver issue that needs to reduce the size of the background operation
to fit the timeout.
On devices where mbox interrupts are supported, this will still use
a poller that will wakeup in the specified wait intervals. The irq
handler will simply awake the blocked cmd, which is also safe vs a
task that is either waking (timing out) or already awoken. Similarly
any irq setup error during the probing falls back to polling, thus
avoids unnecessarily erroring out.
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/20230523170927.20685-5-dave@stgolabs.net
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 | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index 2c8dc7e2b84d..5993261e3e08 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -220,7 +220,8 @@ int cxl_internal_send_cmd(struct cxl_dev_state *cxlds, if (rc) return rc; - if (mbox_cmd->return_code != CXL_MBOX_CMD_RC_SUCCESS) + if (mbox_cmd->return_code != CXL_MBOX_CMD_RC_SUCCESS && + mbox_cmd->return_code != CXL_MBOX_CMD_RC_BACKGROUND) return cxl_mbox_cmd_rc2errno(mbox_cmd); if (!out_size) |