Ira Weiny 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
> callback to process the events through the trace subsystem.
>
> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
>
> ---
> Changes from v1:
> [djbw: use single registration function]
> ---
> drivers/cxl/core/mbox.c | 31 ++++++++++++++++++++++++-----
> drivers/cxl/cxlmem.h | 6 ++++++
> drivers/cxl/pci.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++-
> 3 files changed, 83 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index a67161f8764a..da262bbc3519 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -854,9 +854,30 @@ 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;
> @@ -979,8 +1000,8 @@ 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/cxlmem.h b/drivers/cxl/cxlmem.h
> index e5d770e26e02..7a891b4641cc 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -481,6 +481,8 @@ struct cxl_memdev_state {
> struct cxl_security_state security;
> struct cxl_fw_state fw;
>
> + struct notifier_block cxl_cper_nb;
> +
> struct rcuwait mbox_wait;
> int (*mbox_send)(struct cxl_memdev_state *mds,
> struct cxl_mbox_cmd *cmd);
> @@ -802,6 +804,10 @@ void set_exclusive_cxl_commands(struct cxl_memdev_state *mds,
> void clear_exclusive_cxl_commands(struct cxl_memdev_state *mds,
> unsigned long *cmds);
> void cxl_mem_get_event_records(struct cxl_memdev_state *mds, u32 status);
> +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);
> int cxl_set_timestamp(struct cxl_memdev_state *mds);
> int cxl_poison_state_init(struct cxl_memdev_state *mds);
> int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index 0155fb66b580..30a98399d013 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 +970,55 @@ static struct pci_driver cxl_pci_driver = {
> },
> };
>
> +#define CXL_EVENT_HDR_FLAGS_REC_SEVERITY GENMASK(1, 0)
> +static void cxl_cper_event_call(struct cxl_cper_event_data *ev_data)
> +{
> + struct cper_cxl_event_devid *device_id = &ev_data->rec->hdr.device_id;
> + struct cxl_dev_state *cxlds = NULL;
> + enum cxl_event_log_type log_type;
> + struct pci_dev *pdev;
> + 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);
What if pci_get_domain_bus_and_slot() returned NULL?
> +
> + guard(mutex)(&pdev->dev.mutex);
Lets not open code this since device_lock() is so prevalent it deserves
its own guard() type:
DEFINE_GUARD(device, struct device *, device_lock(_T), device_unlock(_T))
> + if (pdev->driver == &cxl_pci_driver)
> + cxlds = pci_get_drvdata(pdev);
> + if (!cxlds)
> + goto out;
Lets not mix usage of cleanup.h helpers with usage of goto. The helpers
are there to eliminate goto errors. Just add a new helper:
DEFINE_FREE(pci_dev_put, struct pci_dev *, if (_T) pci_dev_put(_T))
...and declare @pdev as:
struct pci_dev *pdev __free(pci_dev_put) = NULL;
> +
> + /* Fabricate a log type */
> + hdr_flags = get_unaligned_le24(ev_data->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_data->event_type,
> + &ev_data->rec->event);
> +out:
> + pci_dev_put(pdev);
> +}
> +
> +static int __init cxl_pci_driver_init(void)
> +{
> + int rc;
> +
> + rc = pci_register_driver(&cxl_pci_driver);
> + if (rc)
> + return rc;
> +
> + cxl_cper_register_notifier(cxl_cper_event_call);
> + return 0;
> +}
> +
> +static void __exit cxl_pci_driver_exit(void)
> +{
> + cxl_cper_unregister_notifier();
> + pci_unregister_driver(&cxl_pci_driver);
> +}
> +
> +module_init(cxl_pci_driver_init);
> +module_exit(cxl_pci_driver_exit);
> MODULE_LICENSE("GPL v2");
> -module_pci_driver(cxl_pci_driver);
> MODULE_IMPORT_NS(CXL);
>
> --
> 2.43.0
>
