Ira Weiny wrote: > BIOS can configure memory devices as firmware first. This will send CXL > events to the firmware instead of the OS. The firmware can then inform > the OS of these events via UEFI. + linux-acpi [I missed adding this list.] > > UEFI v2.10 section N.2.14 defines a Common Platform Error Record (CPER) > format for CXL Component Events. The format is mostly the same as the > CXL Common Event Record Format. The difference lies in the use of a > GUID as the CPER Section Type which matches the UUID defined in CXL 3.1 > Table 8-43. > > Currently a configuration such as this will trace a non standard event > in the log omitting useful details of the event. In addition the CXL > sub-system contains additional region and HPA information useful to the > user.[0] > > The CXL code is required to be called from process context as it needs > to take a device lock. The GHES code may be in interrupt context. This > complicated the use of a callback. Dan Williams suggested the use of > work items as an atomic way of switching between the callback execution > and a default handler.[1] > > The use of a kfifo simplifies queue processing by providing lock free > fifo operations. cxl_cper_kfifo_get() allows easier management of the > kfifo between the ghes and cxl modules. > > CXL 3.1 Table 8-127 requires a device to have a queue depth of 1 for > each of the four event logs. A combined queue depth of 32 is chosen to > provide room for 8 entries of each log type. > > Add GHES support to detect CXL CPER records. Add the ability for the > CXL sub-system to register a work queue to process the events. > > This patch adds back the functionality which was removed to fix the > report by Dan Carpenter[2]. > > Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> > Cc: Rafael J. Wysocki <rafael@xxxxxxxxxx> > Cc: Tony Luck <tony.luck@xxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxxxx> > Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx> > Link: http://lore.kernel.org/r/cover.1711598777.git.alison.schofield@xxxxxxxxx [0] > Link: http://lore.kernel.org/r/65d111eb87115_6c745294ac@xxxxxxxxxxxxxxxxxxxxxxxxx.notmuch [1] > Link: http://lore.kernel.org/r/b963c490-2c13-4b79-bbe7-34c6568423c7@moroto.mountain [2] > Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> > --- > Changes: > [iweiny: pick up tag] > [djbw: use proper link format] > --- > drivers/acpi/apei/ghes.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/cxl-event.h | 27 ++++++++++++ > 2 files changed, 137 insertions(+) > > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index 512067cac170..2247a1535b52 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -26,6 +26,8 @@ > #include <linux/interrupt.h> > #include <linux/timer.h> > #include <linux/cper.h> > +#include <linux/cleanup.h> > +#include <linux/cxl-event.h> > #include <linux/platform_device.h> > #include <linux/mutex.h> > #include <linux/ratelimit.h> > @@ -33,6 +35,7 @@ > #include <linux/irq_work.h> > #include <linux/llist.h> > #include <linux/genalloc.h> > +#include <linux/kfifo.h> > #include <linux/pci.h> > #include <linux/pfn.h> > #include <linux/aer.h> > @@ -673,6 +676,101 @@ static void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata, > schedule_work(&entry->work); > } > > +/* CXL Event record UUIDs are formated as GUIDs and reported in section type */ > + > +/* > + * General Media Event Record > + * CXL rev 3.0 Section 8.2.9.2.1.1; Table 8-43 > + */ > +#define CPER_SEC_CXL_GEN_MEDIA_GUID \ > + GUID_INIT(0xfbcd0a77, 0xc260, 0x417f, \ > + 0x85, 0xa9, 0x08, 0x8b, 0x16, 0x21, 0xeb, 0xa6) > + > +/* > + * DRAM Event Record > + * CXL rev 3.0 section 8.2.9.2.1.2; Table 8-44 > + */ > +#define CPER_SEC_CXL_DRAM_GUID \ > + GUID_INIT(0x601dcbb3, 0x9c06, 0x4eab, \ > + 0xb8, 0xaf, 0x4e, 0x9b, 0xfb, 0x5c, 0x96, 0x24) > + > +/* > + * Memory Module Event Record > + * CXL rev 3.0 section 8.2.9.2.1.3; Table 8-45 > + */ > +#define CPER_SEC_CXL_MEM_MODULE_GUID \ > + GUID_INIT(0xfe927475, 0xdd59, 0x4339, \ > + 0xa5, 0x86, 0x79, 0xba, 0xb1, 0x13, 0xb7, 0x74) > + > +/* Room for 8 entries for each of the 4 event log queues */ > +#define CXL_CPER_FIFO_DEPTH 32 > +DEFINE_KFIFO(cxl_cper_fifo, struct cxl_cper_work_data, CXL_CPER_FIFO_DEPTH); > + > +/* Synchronize schedule_work() with cxl_cper_work changes */ > +static DEFINE_SPINLOCK(cxl_cper_work_lock); > +struct work_struct *cxl_cper_work; > + > +static void cxl_cper_post_event(enum cxl_event_type event_type, > + struct cxl_cper_event_rec *rec) > +{ > + struct cxl_cper_work_data wd; > + > + if (rec->hdr.length <= sizeof(rec->hdr) || > + rec->hdr.length > sizeof(*rec)) { > + pr_err(FW_WARN "CXL CPER Invalid section length (%u)\n", > + rec->hdr.length); > + return; > + } > + > + if (!(rec->hdr.validation_bits & CPER_CXL_COMP_EVENT_LOG_VALID)) { > + pr_err(FW_WARN "CXL CPER invalid event\n"); > + return; > + } > + > + guard(spinlock_irqsave)(&cxl_cper_work_lock); > + > + if (!cxl_cper_work) > + return; > + > + wd.event_type = event_type; > + memcpy(&wd.rec, rec, sizeof(wd.rec)); > + > + if (!kfifo_put(&cxl_cper_fifo, wd)) { > + pr_err_ratelimited("CXL CPER kfifo overflow\n"); > + return; > + } > + > + schedule_work(cxl_cper_work); > +} > + > +int cxl_cper_register_work(struct work_struct *work) > +{ > + if (cxl_cper_work) > + return -EINVAL; > + > + guard(spinlock)(&cxl_cper_work_lock); > + cxl_cper_work = work; > + return 0; > +} > +EXPORT_SYMBOL_NS_GPL(cxl_cper_register_work, CXL); > + > +int cxl_cper_unregister_work(struct work_struct *work) > +{ > + if (cxl_cper_work != work) > + return -EINVAL; > + > + guard(spinlock)(&cxl_cper_work_lock); > + cxl_cper_work = NULL; > + return 0; > +} > +EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_work, CXL); > + > +int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd) > +{ > + return kfifo_get(&cxl_cper_fifo, wd); > +} > +EXPORT_SYMBOL_NS_GPL(cxl_cper_kfifo_get, CXL); > + > static bool ghes_do_proc(struct ghes *ghes, > const struct acpi_hest_generic_status *estatus) > { > @@ -707,6 +805,18 @@ static bool ghes_do_proc(struct ghes *ghes, > } > else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) { > queued = ghes_handle_arm_hw_error(gdata, sev, sync); > + } else if (guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID)) { > + struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata); > + > + cxl_cper_post_event(CXL_CPER_EVENT_GEN_MEDIA, rec); > + } else if (guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID)) { > + struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata); > + > + cxl_cper_post_event(CXL_CPER_EVENT_DRAM, rec); > + } else if (guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) { > + struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata); > + > + cxl_cper_post_event(CXL_CPER_EVENT_MEM_MODULE, rec); > } else { > void *err = acpi_hest_get_payload(gdata); > > diff --git a/include/linux/cxl-event.h b/include/linux/cxl-event.h > index 03fa6d50d46f..a0067c49e2ca 100644 > --- a/include/linux/cxl-event.h > +++ b/include/linux/cxl-event.h > @@ -3,6 +3,8 @@ > #ifndef _LINUX_CXL_EVENT_H > #define _LINUX_CXL_EVENT_H > > +#include <linux/workqueue_types.h> > + > /* > * Common Event Record Format > * CXL rev 3.0 section 8.2.9.2.1; Table 8-42 > @@ -140,4 +142,29 @@ struct cxl_cper_event_rec { > union cxl_event event; > } __packed; > > +struct cxl_cper_work_data { > + enum cxl_event_type event_type; > + struct cxl_cper_event_rec rec; > +}; > + > +#ifdef CONFIG_ACPI_APEI_GHES > +int cxl_cper_register_work(struct work_struct *work); > +int cxl_cper_unregister_work(struct work_struct *work); > +int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd); > +#else > +static inline int cxl_cper_register_work(struct work_struct *work); > +{ > + return 0; > +} > + > +static inline int cxl_cper_unregister_work(struct work_struct *work); > +{ > + return 0; > +} > +static inline int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd) > +{ > + return 0; > +} > +#endif > + > #endif /* _LINUX_CXL_EVENT_H */ > > -- > 2.44.0 >
