Messages in this thread | | | Date | Thu, 1 Dec 2022 13:26:18 +0000 | From | Jonathan Cameron <> | Subject | Re: [PATCH V2 03/11] cxl/mem: Implement Clear Event Records command |
| |
On Wed, 30 Nov 2022 16:27:11 -0800 ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com> > > CXL rev 3.0 section 8.2.9.2.3 defines the Clear Event Records mailbox > command. After an event record is read it needs to be cleared from the > event log. > > Implement cxl_clear_event_record() to clear all record retrieved from > the device. > > Each record is cleared explicitly. A clear all bit is specified but > events could arrive between a get and any final clear all operation. > This means events would be missed. > Therefore each event is cleared specifically. > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> I think there is a type issue on the min_t() calculation with that addressed this looks good to me.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > --- > Changes from V1: > Clear Event Record allows for u8 handles while Get Event Record > allows for u16 records to be returned. Based on Jonathan's > feedback; allow for all event records to be handled in this > clear. Which means a double loop with potentially multiple > Clear Event payloads being sent to clear all events sent. > > Changes from RFC: > Jonathan > Clean up init of payload and use return code. > Also report any error to clear the event. > s/v3.0/rev 3.0 > --- > drivers/cxl/core/mbox.c | 61 +++++++++++++++++++++++++++++++----- > drivers/cxl/cxlmem.h | 14 +++++++++ > include/uapi/linux/cxl_mem.h | 1 + > 3 files changed, 69 insertions(+), 7 deletions(-) > > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c > index 70b681027a3d..076a3df0ba38 100644 > --- a/drivers/cxl/core/mbox.c > +++ b/drivers/cxl/core/mbox.c > @@ -52,6 +52,7 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = { > #endif > CXL_CMD(GET_SUPPORTED_LOGS, 0, CXL_VARIABLE_PAYLOAD, CXL_CMD_FLAG_FORCE_ENABLE), > CXL_CMD(GET_EVENT_RECORD, 1, CXL_VARIABLE_PAYLOAD, 0), > + CXL_CMD(CLEAR_EVENT_RECORD, CXL_VARIABLE_PAYLOAD, 0, 0), > CXL_CMD(GET_FW_INFO, 0, 0x50, 0), > CXL_CMD(GET_PARTITION_INFO, 0, 0x20, 0), > CXL_CMD(GET_LSA, 0x8, CXL_VARIABLE_PAYLOAD, 0), > @@ -708,6 +709,42 @@ int cxl_enumerate_cmds(struct cxl_dev_state *cxlds) > } > EXPORT_SYMBOL_NS_GPL(cxl_enumerate_cmds, CXL); > > +static int cxl_clear_event_record(struct cxl_dev_state *cxlds, > + enum cxl_event_log_type log, > + struct cxl_get_event_payload *get_pl, > + u16 total) > +{ > + struct cxl_mbox_clear_event_payload payload = { > + .event_log = log, > + }; > + int cnt; > + > + /* > + * Clear Event Records uses u8 for the handle cnt while Get Event > + * Record can return up to 0xffff records. > + */ > + for (cnt = 0; cnt < total; /* cnt incremented internally */) { > + u8 nr_recs = min_t(u8, (total - cnt), > + CXL_CLEAR_EVENT_MAX_HANDLES);
I might be half asleep but isn't this assuming that (total - cnt) fits in an u8? Shouldn't this be min_t(u16, ..) Also, maybe u16 cnt would be simpler.
Hmm. This is safe but only because of how you call it alongside handling of a particular Get event records response (which must have fitted in the mailbox and has a longer header).
Looking at this function in isolation, I think the mailbox could be small enough that we might not fit 255 records + the header. Perhaps we need a comment to say that, or at minimum a check and error return if it won't fit?
> + int i, rc; > + > + for (i = 0; i < nr_recs; i++, cnt++) { > + payload.handle[i] = get_pl->records[cnt].hdr.handle; > + dev_dbg(cxlds->dev, "Event log '%s': Clearning %u\n", > + cxl_event_log_type_str(log), > + le16_to_cpu(payload.handle[i])); > + } > + payload.nr_recs = nr_recs; > + > + rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_CLEAR_EVENT_RECORD, > + &payload, sizeof(payload), NULL, 0); > + if (rc) > + return rc; > + } > + > + return 0; > +} > + > static void cxl_mem_get_records_log(struct cxl_dev_state *cxlds, > enum cxl_event_log_type type) > { > @@ -732,13 +769,22 @@ static void cxl_mem_get_records_log(struct cxl_dev_state *cxlds, This feels miss named now but I can't immediately think of better naming so on that basis fine to leave it as is if you don't have a better idea!.
> } > > nr_rec = le16_to_cpu(payload->record_count); > - if (trace_cxl_generic_event_enabled()) { > + if (nr_rec > 0) { > int i; > > - for (i = 0; i < nr_rec; i++) > - trace_cxl_generic_event(dev_name(cxlds->dev), > - type, > - &payload->records[i]); > + if (trace_cxl_generic_event_enabled()) { > + for (i = 0; i < nr_rec; i++) > + trace_cxl_generic_event(dev_name(cxlds->dev), > + type, > + &payload->records[i]); > + } > + > + rc = cxl_clear_event_record(cxlds, type, payload, nr_rec); > + if (rc) { > + dev_err(cxlds->dev, "Event log '%s': Failed to clear events : %d", > + cxl_event_log_type_str(type), rc); > + return; > + } > }
| |