Messages in this thread | | | Date | Thu, 25 Aug 2022 11:46:32 +0100 | From | Jonathan Cameron <> | Subject | Re: [RFC PATCH 5/9] cxl/mem: Trace DRAM Event Record |
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On Fri, 12 Aug 2022 22:32:39 -0700 ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com> > > CXL v3.0 section 8.2.9.2.1.2 defines the DRAM Event Record. > > Determine if the event read is a DRAM event record and if so trace the > record. > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > This record has a very odd byte layout with 2 - 16 bit fields > (validity_flags and column) aligned on an odd byte boundary. In > addition nibble_mask and row are oddly aligned. > > I've made my best guess as to how the endianess of these fields should > be resolved. But I'm happy to hear from other folks if what I have is > wrong. My assumption is same as you. We should sanity check of course by poking relevant people.
Similar comments in here to previous. Use the get_unaligned_le24() accessors + consider not printing invalid fields. > > struct cxl_evt_dram_rec { > struct cxl_event_record_hdr hdr; > __le64 phys_addr; > u8 descriptor; > u8 type; > u8 transaction_type; > u16 validity_flags; > u8 channel; > u8 rank; > u8 nibble_mask[CXL_EVT_DER_NIBBLE_MASK_SIZE]; > u8 bank_group; > u8 bank; > u8 row[CXL_EVT_DER_ROW_SIZE]; > u16 column; > u8 correction_mask[CXL_EVT_DER_CORRECTION_MASK_SIZE]; > } __packed; > --- > drivers/cxl/core/mbox.c | 16 +++++ > drivers/cxl/cxlmem.h | 24 +++++++ > include/trace/events/cxl-events.h | 114 ++++++++++++++++++++++++++++++ > 3 files changed, 154 insertions(+) > > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c > index 0e433f072163..6414588a3c7b 100644 > --- a/drivers/cxl/core/mbox.c > +++ b/drivers/cxl/core/mbox.c > @@ -717,6 +717,14 @@ static const uuid_t gen_media_event_uuid = > UUID_INIT(0xfbcd0a77, 0xc260, 0x417f, > 0x85, 0xa9, 0x08, 0x8b, 0x16, 0x21, 0xeb, 0xa6); > > +/* > + * DRAM Event Record > + * CXL v3.0 section 8.2.9.2.1.2; Table 8-44 rev3.0, r3.0 or just 3.0
> + */ > +static const uuid_t dram_event_uuid = > + UUID_INIT(0x601dcbb3, 0x9c06, 0x4eab, > + 0xb8, 0xaf, 0x4e, 0x9b, 0xfb, 0x5c, 0x96, 0x24); > + > static void cxl_trace_event_record(const char *dev_name, > enum cxl_event_log_type type, > struct cxl_get_event_payload *payload) > @@ -731,6 +739,14 @@ static void cxl_trace_event_record(const char *dev_name, > return; > } > > + if (uuid_equal(id, &dram_event_uuid)) { Why not else if? Should be obvious to compiler that multiple uuid_equal conditions can't match, but even better to not make it try hard perhaps?
> + struct cxl_evt_dram_rec *rec = > + (struct cxl_evt_dram_rec *)&payload->record; > + > + trace_cxl_dram_event(dev_name, type, rec); > + return; > + } > + > /* For unknown record types print just the header */ > trace_cxl_event(dev_name, type, &payload->record); > } > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > index 33669459ae4b..50536c0a7850 100644 > --- a/drivers/cxl/cxlmem.h > +++ b/drivers/cxl/cxlmem.h > @@ -421,6 +421,30 @@ struct cxl_evt_gen_media { > u8 component_id[CXL_EVT_GEN_MED_COMP_ID_SIZE]; > } __packed; > > +/* > + * DRAM Event Record - DER > + * CXL v3.0 section 8.2.9.2.1.2; Table 3-44 > + */ > +#define CXL_EVT_DER_NIBBLE_MASK_SIZE 3 > +#define CXL_EVT_DER_ROW_SIZE 3 > +#define CXL_EVT_DER_CORRECTION_MASK_SIZE 0x20 > +struct cxl_evt_dram_rec { > + struct cxl_event_record_hdr hdr; > + __le64 phys_addr; > + u8 descriptor; > + u8 type; > + u8 transaction_type; > + u16 validity_flags; I've not tried it, but can we just mark these as __le16 and use the unaligned accessors? get_unaligned_le16 etc Also there is get_unaligned_le24() for the 3 byte ones.
> + u8 channel; > + u8 rank; > + u8 nibble_mask[CXL_EVT_DER_NIBBLE_MASK_SIZE]; > + u8 bank_group; > + u8 bank; > + u8 row[CXL_EVT_DER_ROW_SIZE]; > + u16 column; > + u8 correction_mask[CXL_EVT_DER_CORRECTION_MASK_SIZE]; > +} __packed; > + > struct cxl_mbox_get_partition_info { > __le64 active_volatile_cap; > __le64 active_persistent_cap; > diff --git a/include/trace/events/cxl-events.h b/include/trace/events/cxl-events.h > index b51c51fd4e62..db9b34ddd240 100644 > --- a/include/trace/events/cxl-events.h > +++ b/include/trace/events/cxl-events.h > @@ -244,6 +244,120 @@ TRACE_EVENT(cxl_gen_media_event, > ) > ); > > +/* > + * DRAM Event Record - DER > + * > + * CXL v2.0 section 8.2.9.1.1.2; Table 155 > + */ > +/* > + * DRAM Event Record defines many fields the same as the General Media Event > + * Record. Reuse those definitions as appropriate. > + */ > +#define CXL_DER_VALID_CHANNEL BIT(0) > +#define CXL_DER_VALID_RANK BIT(1) > +#define CXL_DER_VALID_NIBBLE BIT(2) > +#define CXL_DER_VALID_BANK_GROUP BIT(3) > +#define CXL_DER_VALID_BANK BIT(4) > +#define CXL_DER_VALID_ROW BIT(5) > +#define CXL_DER_VALID_COLUMN BIT(6) > +#define CXL_DER_VALID_CORRECTION_MASK BIT(7) > +#define show_dram_valid_flags(flags) __print_flags(flags, "|", \ > + { CXL_DER_VALID_CHANNEL, "CHANNEL" }, \ > + { CXL_DER_VALID_RANK, "RANK" }, \ > + { CXL_DER_VALID_NIBBLE, "NIBBLE" }, \ > + { CXL_DER_VALID_BANK_GROUP, "BANK GROUP" }, \ > + { CXL_DER_VALID_BANK, "BANK" }, \ > + { CXL_DER_VALID_ROW, "ROW" }, \ > + { CXL_DER_VALID_COLUMN, "COLUMN" }, \ > + { CXL_DER_VALID_CORRECTION_MASK, "CORRECTION MASK" } \ > +) > + > +TRACE_EVENT(cxl_dram_event, > + > + TP_PROTO(const char *dev_name, enum cxl_event_log_type log, > + struct cxl_evt_dram_rec *rec), > + > + TP_ARGS(dev_name, log, rec), > + > + TP_STRUCT__entry( > + /* Common */ > + __string(dev_name, dev_name) > + __field(int, log) > + __array(u8, id, UUID_SIZE) > + __field(u32, flags) > + __field(u16, handle) > + __field(u16, related_handle) > + __field(u64, timestamp) > + > + /* DRAM */ > + __field(u64, phys_addr) > + __field(u8, descriptor) > + __field(u8, type) > + __field(u8, transaction_type) > + __field(u8, channel) > + __field(u16, validity_flags) > + __field(u16, column) /* Out of order to pack trace record */ > + __field(u32, nibble_mask) > + __field(u32, row) > + __array(u8, cor_mask, CXL_EVT_DER_CORRECTION_MASK_SIZE) > + __field(u8, rank) /* Out of order to pack trace record */ > + __field(u8, bank_group) /* Out of order to pack trace record */ > + __field(u8, bank) /* Out of order to pack trace record */ > + ), > + > + TP_fast_assign( > + /* Common */ > + __assign_str(dev_name, dev_name); > + memcpy(__entry->id, &rec->hdr.id, UUID_SIZE); > + __entry->log = log; > + __entry->flags = le32_to_cpu(rec->hdr.flags_length) >> 8; > + __entry->handle = le16_to_cpu(rec->hdr.handle); > + __entry->related_handle = le16_to_cpu(rec->hdr.related_handle); > + __entry->timestamp = le64_to_cpu(rec->hdr.timestamp); > + > + /* DRAM */ > + __entry->phys_addr = le64_to_cpu(rec->phys_addr); > + __entry->descriptor = rec->descriptor; > + __entry->type = rec->type; > + __entry->transaction_type = rec->transaction_type; > + __entry->validity_flags = le16_to_cpu(rec->validity_flags); > + __entry->channel = rec->channel; > + __entry->rank = rec->rank; > + __entry->nibble_mask = rec->nibble_mask[0] << 24 | > + rec->nibble_mask[1] << 16 | > + rec->nibble_mask[2] << 8; /* 3 byte LE ? */
Use get_unalinged_le24() ? I'd definitely expect these to be le24.
> + __entry->nibble_mask = le32_to_cpu(__entry->nibble_mask);
That doesn't look right. You will have unwound the endianness using the shifts above. Don't convert it again (noop on le systems, so you probably won't see a problem when testing).
> + __entry->bank_group = rec->bank_group; > + __entry->bank = rec->bank; > + __entry->row = rec->row[0] << 24 | > + rec->row[1] << 16 | > + rec->row[2] << 8; /* 3 byte LE ? */
get_unaligned_le24()
> + __entry->row = le32_to_cpu(__entry->row);
> + __entry->column = le16_to_cpu(rec->column); > + memcpy(__entry->cor_mask, &rec->correction_mask, > + CXL_EVT_DER_CORRECTION_MASK_SIZE); > + ), > + > + TP_printk("%s: %s time=%llu id=%pUl handle=%x related_handle=%x hdr_flags='%s': " \ > + "phys_addr=%llx volatile=%s desc='%s' type='%s' trans_type='%s' channel=%u " \ > + "rank=%u nibble_mask=%x bank_group=%u bank=%u row=%u column=%u " \ > + "cor_mask=%s valid_flags='%s'", > + __get_str(dev_name), show_log_type(__entry->log), > + __entry->timestamp, __entry->id, __entry->handle, > + __entry->related_handle, show_hdr_flags(__entry->flags), > + __entry->phys_addr & ~CXL_GMER_PHYS_ADDR_MASK, > + (__entry->phys_addr & CXL_GMER_PHYS_ADDR_VOLATILE) ? "TRUE" : "FALSE", > + show_event_desc_flags(__entry->descriptor), As before can we not print the invalid ones based on the validity flags?
Few years ago now, but I did something along those lines for the CCIX equivalent of this stuff. (honestly can't remember much about it now though!) Was a bit fiddly but lead to nicer prints in my opinion.
https://lore.kernel.org/all/20191114133919.32290-2-Jonathan.Cameron@huawei.com/
> + show_mem_event_type(__entry->type), > + show_trans_type(__entry->transaction_type), > + __entry->channel, __entry->rank, __entry->nibble_mask, > + __entry->bank_group, __entry->bank, > + __entry->row, __entry->column, > + __print_hex(__entry->cor_mask, CXL_EVT_DER_CORRECTION_MASK_SIZE), > + show_dram_valid_flags(__entry->validity_flags) > + ) > +); > + > #endif /* _CXL_TRACE_EVENTS_H */ > > /* This part must be outside protection */
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