On Fri, 15 Dec 2023 15:26:33 -0800 Ira Weiny <ira.weiny@xxxxxxxxx> wrote: > If the firmware has configured CXL event support to be firmware first > the OS can process those events through CPER records. The CXL layer has > unique DPA to HPA knowledge and standard event trace parsing in place. > > CPER records contain Bus, Device, Function information which can be used > to identify the PCI device which is sending the event. > > Change pci driver registration to include registration for a CXL CPER > notifier to process the events through the trace subsystem. > > Define and use scoped based management to simplify the handling of the > pci device object. > > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> I'd break out the pci guard stuff as a precursor patch. That's likely to be used elsewhere so it would help for backporting for other users if it wasn't buried in a patch doing other stuff. Not to mention that has a different set of likely reviewers to the rest of this patch. More generally maybe we should just hardcode the UUID in the tracepoint definitions? I think for everything other than the generic one we only ever call trace_cxl_memory_module(... &mem_mod_event_uuid..) etc. It's a little ugly to match on the UUID to call a function where it hard coded, but less so than inserting the UUID like this does. Better I think to make it obvious that this isn't actually a variable (for the ones we understand). Jonathan > > --- > NOTE this patch depends on Dan's addition of a device guard[1]. > > [1] https://lore.kernel.org/all/170250854466.1522182.17555361077409628655.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx/ > > Changes for v3/v4: > [djbw: define a __free(pci_dev_put) to release the device automatically] > [djbw: use device guard from Vishal] > [iweiny: delete old notifier block structure] > [iweiny: adjust for new notifier interface] > --- > drivers/cxl/core/mbox.c | 31 +++++++++++++++++++++++----- > drivers/cxl/cxlmem.h | 4 ++++ > drivers/cxl/pci.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++- > include/linux/pci.h | 2 ++ > 4 files changed, 86 insertions(+), 6 deletions(-) > > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c > index b7efa058a100..c9aa723e3391 100644 > --- a/drivers/cxl/core/mbox.c > +++ b/drivers/cxl/core/mbox.c > @@ -840,9 +840,30 @@ static const uuid_t gen_media_event_uuid = CXL_EVENT_GEN_MEDIA_UUID; > static const uuid_t dram_event_uuid = CXL_EVENT_DRAM_UUID; > static const uuid_t mem_mod_event_uuid = CXL_EVENT_MEM_MODULE_UUID; > > -static void cxl_event_trace_record(const struct cxl_memdev *cxlmd, > - enum cxl_event_log_type type, > - struct cxl_event_record_raw *record) > +void cxl_event_trace_record(const struct cxl_memdev *cxlmd, > + enum cxl_event_log_type type, > + enum cxl_event_type event_type, > + union cxl_event *event) > +{ > + switch (event_type) { > + case CXL_CPER_EVENT_GEN_MEDIA: > + trace_cxl_general_media(cxlmd, type, &gen_media_event_uuid, > + &event->gen_media); > + break; > + case CXL_CPER_EVENT_DRAM: > + trace_cxl_dram(cxlmd, type, &dram_event_uuid, &event->dram); > + break; > + case CXL_CPER_EVENT_MEM_MODULE: > + trace_cxl_memory_module(cxlmd, type, &mem_mod_event_uuid, > + &event->mem_module); > + break; > + } > +} > +EXPORT_SYMBOL_NS_GPL(cxl_event_trace_record, CXL); > + > +static void __cxl_event_trace_record(const struct cxl_memdev *cxlmd, > + enum cxl_event_log_type type, > + struct cxl_event_record_raw *record) > { > union cxl_event *evt = &record->event; > uuid_t *id = &record->id; > @@ -965,8 +986,8 @@ static void cxl_mem_get_records_log(struct cxl_memdev_state *mds, > break; > > for (i = 0; i < nr_rec; i++) > - cxl_event_trace_record(cxlmd, type, > - &payload->records[i]); > + __cxl_event_trace_record(cxlmd, type, > + &payload->records[i]); > > if (payload->flags & CXL_GET_EVENT_FLAG_OVERFLOW) > trace_cxl_overflow(cxlmd, type, payload); > diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c > index 0155fb66b580..638275569d63 100644 > --- a/drivers/cxl/pci.c > +++ b/drivers/cxl/pci.c > @@ -1,5 +1,6 @@ > // SPDX-License-Identifier: GPL-2.0-only > /* Copyright(c) 2020 Intel Corporation. All rights reserved. */ > +#include <asm-generic/unaligned.h> > #include <linux/io-64-nonatomic-lo-hi.h> > #include <linux/moduleparam.h> > #include <linux/module.h> > @@ -969,6 +970,58 @@ static struct pci_driver cxl_pci_driver = { > }, > }; > > +#define CXL_EVENT_HDR_FLAGS_REC_SEVERITY GENMASK(1, 0) > +static void cxl_cper_event_call(enum cxl_event_type ev_type, > + struct cxl_cper_event_rec *rec) > +{ > + struct cper_cxl_event_devid *device_id = &rec->hdr.device_id; > + struct pci_dev *pdev __free(pci_dev_put) = NULL; > + struct cxl_dev_state *cxlds = NULL; > + enum cxl_event_log_type log_type; > + unsigned int devfn; > + u32 hdr_flags; > + > + devfn = PCI_DEVFN(device_id->device_num, device_id->func_num); > + pdev = pci_get_domain_bus_and_slot(device_id->segment_num, > + device_id->bus_num, devfn); > + if (!pdev) > + return; > + > + guard(device)(&pdev->dev); > + if (pdev->driver == &cxl_pci_driver) > + cxlds = pci_get_drvdata(pdev); > + if (!cxlds) > + return; This is handling two conditions. I'd find it more readable split like: if (pdev->driver != &cxl_pci_driver) return; cxlds = pci_get_drvdata(pdev); if (!cxlds) return; and drop the = NULL above. > + > + /* Fabricate a log type */ > + hdr_flags = get_unaligned_le24(rec->event.generic.hdr.flags); > + log_type = FIELD_GET(CXL_EVENT_HDR_FLAGS_REC_SEVERITY, hdr_flags); > + > + cxl_event_trace_record(cxlds->cxlmd, log_type, ev_type, &rec->event); > +} > +
