diff mbox series

[3/4] cxl: Add extended linear cache address alias emission for cxl events

Message ID 20241204224827.2097263-4-dave.jiang@intel.com
State New
Headers show
Series acpi/hmat / cxl: Add exclusive caching enumeration and RAS support | expand

Commit Message

Dave Jiang Dec. 4, 2024, 10:46 p.m. UTC 
Add the aliased address of extended linear cache when emitting event
trace for DRAM and general media of CXL events.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
RFC:
- Drop mmio hole discovery code
---
 drivers/cxl/core/core.h   |  5 +++++
 drivers/cxl/core/mbox.c   | 27 ++++++++++++++++++++++++---
 drivers/cxl/core/region.c | 12 ++++++++++++
 drivers/cxl/core/trace.h  | 24 ++++++++++++++++--------
 4 files changed, 57 insertions(+), 11 deletions(-)

Comments

Jonathan Cameron Dec. 24, 2024, 12:11 p.m. UTC | #1 
On Wed, 4 Dec 2024 15:46:48 -0700
Dave Jiang <dave.jiang@intel.com> wrote:

> Add the aliased address of extended linear cache when emitting event
> trace for DRAM and general media of CXL events.
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
I wonder if you want to future proof the hpa_alias for potential case
of there being more than 1?  hpa_alias0 or similar so that we can add
more as needed?


Otherwise, looks like there is either a null point dereference or
overly paranoid existing code. I haven't checked which but changes
needed either way.

Jonathan

> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 5175138c4fb7..4017b7afa78a 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -856,6 +856,24 @@ int cxl_enumerate_cmds(struct cxl_memdev_state *mds)
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_enumerate_cmds, CXL);
>  
> +static u64 cxlr_hpa_cache_alias(struct cxl_region *cxlr, u64 hpa)
> +{
> +	struct cxl_region_params *p = &cxlr->params;

Bad idea to unconditionally dereference I think. See below.

> +	int nid;
> +
> +	if (!p->cache_size)
> +		return ~0ULL;
> +
> +	nid = cxl_region_nid(cxlr);
> +	if (nid == NUMA_NO_NODE)
> +		nid = 0;
> +
> +	if (hpa >= p->res->start + p->cache_size)
> +		return hpa - p->cache_size;
> +
> +	return hpa + p->cache_size;
> +}
> +
>  void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
>  			    enum cxl_event_log_type type,
>  			    enum cxl_event_type event_type,
> @@ -871,7 +889,7 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
>  	}
>  
>  	if (trace_cxl_general_media_enabled() || trace_cxl_dram_enabled()) {
> -		u64 dpa, hpa = ULLONG_MAX;
> +		u64 dpa, hpa = ULLONG_MAX, hpa_alias;
>  		struct cxl_region *cxlr;
>  
>  		/*
> @@ -887,11 +905,14 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
>  		if (cxlr)
>  			hpa = cxl_dpa_to_hpa(cxlr, cxlmd, dpa);
>  
> +		hpa_alias = cxlr_hpa_cache_alias(cxlr, hpa);

If there is no region, and hence no hpa does it make sense to call this?
Particularly as first thing done in this is to dereference cxlr.


> +
>  		if (event_type == CXL_CPER_EVENT_GEN_MEDIA)
>  			trace_cxl_general_media(cxlmd, type, cxlr, hpa,
> -						&evt->gen_media);
> +						hpa_alias, &evt->gen_media);
>  		else if (event_type == CXL_CPER_EVENT_DRAM)
> -			trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->dram);
> +			trace_cxl_dram(cxlmd, type, cxlr, hpa, hpa_alias,
> +				       &evt->dram);
>  	}
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_event_trace_record, CXL);
diff mbox series

Patch

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 0fb779b612d1..afbefc72c8fa 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -30,8 +30,13 @@  int cxl_get_poison_by_endpoint(struct cxl_port *port);
 struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa);
 u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd,
 		   u64 dpa);
+int cxl_region_nid(struct cxl_region *cxlr);
 
 #else
+static inline int cxl_region_nid(struct cxl_region *cxlr)
+{
+	return NUMA_NO_NODE;
+}
 static inline u64 cxl_dpa_to_hpa(struct cxl_region *cxlr,
 				 const struct cxl_memdev *cxlmd, u64 dpa)
 {
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 5175138c4fb7..4017b7afa78a 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -856,6 +856,24 @@  int cxl_enumerate_cmds(struct cxl_memdev_state *mds)
 }
 EXPORT_SYMBOL_NS_GPL(cxl_enumerate_cmds, CXL);
 
+static u64 cxlr_hpa_cache_alias(struct cxl_region *cxlr, u64 hpa)
+{
+	struct cxl_region_params *p = &cxlr->params;
+	int nid;
+
+	if (!p->cache_size)
+		return ~0ULL;
+
+	nid = cxl_region_nid(cxlr);
+	if (nid == NUMA_NO_NODE)
+		nid = 0;
+
+	if (hpa >= p->res->start + p->cache_size)
+		return hpa - p->cache_size;
+
+	return hpa + p->cache_size;
+}
+
 void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
 			    enum cxl_event_log_type type,
 			    enum cxl_event_type event_type,
@@ -871,7 +889,7 @@  void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
 	}
 
 	if (trace_cxl_general_media_enabled() || trace_cxl_dram_enabled()) {
-		u64 dpa, hpa = ULLONG_MAX;
+		u64 dpa, hpa = ULLONG_MAX, hpa_alias;
 		struct cxl_region *cxlr;
 
 		/*
@@ -887,11 +905,14 @@  void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
 		if (cxlr)
 			hpa = cxl_dpa_to_hpa(cxlr, cxlmd, dpa);
 
+		hpa_alias = cxlr_hpa_cache_alias(cxlr, hpa);
+
 		if (event_type == CXL_CPER_EVENT_GEN_MEDIA)
 			trace_cxl_general_media(cxlmd, type, cxlr, hpa,
-						&evt->gen_media);
+						hpa_alias, &evt->gen_media);
 		else if (event_type == CXL_CPER_EVENT_DRAM)
-			trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->dram);
+			trace_cxl_dram(cxlmd, type, cxlr, hpa, hpa_alias,
+				       &evt->dram);
 	}
 }
 EXPORT_SYMBOL_NS_GPL(cxl_event_trace_record, CXL);
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 72ede9842dab..8bf4efb2c48c 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -2406,6 +2406,18 @@  static bool cxl_region_update_coordinates(struct cxl_region *cxlr, int nid)
 	return true;
 }
 
+int cxl_region_nid(struct cxl_region *cxlr)
+{
+	struct cxl_region_params *p = &cxlr->params;
+	struct resource *res;
+
+	guard(rwsem_read)(&cxl_region_rwsem);
+	res = p->res;
+	if (!res)
+		return NUMA_NO_NODE;
+	return phys_to_target_node(res->start);
+}
+
 static int cxl_region_perf_attrs_callback(struct notifier_block *nb,
 					  unsigned long action, void *arg)
 {
diff --git a/drivers/cxl/core/trace.h b/drivers/cxl/core/trace.h
index 8389a94adb1a..bdf11fe3ccc4 100644
--- a/drivers/cxl/core/trace.h
+++ b/drivers/cxl/core/trace.h
@@ -316,9 +316,10 @@  TRACE_EVENT(cxl_generic_event,
 TRACE_EVENT(cxl_general_media,
 
 	TP_PROTO(const struct cxl_memdev *cxlmd, enum cxl_event_log_type log,
-		 struct cxl_region *cxlr, u64 hpa, struct cxl_event_gen_media *rec),
+		 struct cxl_region *cxlr, u64 hpa, u64 hpa_alias,
+		 struct cxl_event_gen_media *rec),
 
-	TP_ARGS(cxlmd, log, cxlr, hpa, rec),
+	TP_ARGS(cxlmd, log, cxlr, hpa, hpa_alias, rec),
 
 	TP_STRUCT__entry(
 		CXL_EVT_TP_entry
@@ -332,6 +333,7 @@  TRACE_EVENT(cxl_general_media,
 		__array(u8, comp_id, CXL_EVENT_GEN_MED_COMP_ID_SIZE)
 		/* Following are out of order to pack trace record */
 		__field(u64, hpa)
+		__field(u64, hpa_alias)
 		__field_struct(uuid_t, region_uuid)
 		__field(u16, validity_flags)
 		__field(u8, rank)
@@ -358,6 +360,7 @@  TRACE_EVENT(cxl_general_media,
 			CXL_EVENT_GEN_MED_COMP_ID_SIZE);
 		__entry->validity_flags = get_unaligned_le16(&rec->media_hdr.validity_flags);
 		__entry->hpa = hpa;
+		__entry->hpa_alias = hpa_alias;
 		if (cxlr) {
 			__assign_str(region_name);
 			uuid_copy(&__entry->region_uuid, &cxlr->params.uuid);
@@ -370,7 +373,7 @@  TRACE_EVENT(cxl_general_media,
 	CXL_EVT_TP_printk("dpa=%llx dpa_flags='%s' " \
 		"descriptor='%s' type='%s' transaction_type='%s' channel=%u rank=%u " \
 		"device=%x comp_id=%s validity_flags='%s' " \
-		"hpa=%llx region=%s region_uuid=%pUb",
+		"hpa=%llx hpa_alias=%llx region=%s region_uuid=%pUb",
 		__entry->dpa, show_dpa_flags(__entry->dpa_flags),
 		show_event_desc_flags(__entry->descriptor),
 		show_gmer_mem_event_type(__entry->type),
@@ -378,7 +381,8 @@  TRACE_EVENT(cxl_general_media,
 		__entry->channel, __entry->rank, __entry->device,
 		__print_hex(__entry->comp_id, CXL_EVENT_GEN_MED_COMP_ID_SIZE),
 		show_valid_flags(__entry->validity_flags),
-		__entry->hpa, __get_str(region_name), &__entry->region_uuid
+		__entry->hpa, __entry->hpa_alias, __get_str(region_name),
+		&__entry->region_uuid
 	)
 );
 
@@ -424,9 +428,10 @@  TRACE_EVENT(cxl_general_media,
 TRACE_EVENT(cxl_dram,
 
 	TP_PROTO(const struct cxl_memdev *cxlmd, enum cxl_event_log_type log,
-		 struct cxl_region *cxlr, u64 hpa, struct cxl_event_dram *rec),
+		 struct cxl_region *cxlr, u64 hpa, u64 hpa_alias,
+		 struct cxl_event_dram *rec),
 
-	TP_ARGS(cxlmd, log, cxlr, hpa, rec),
+	TP_ARGS(cxlmd, log, cxlr, hpa, hpa_alias, rec),
 
 	TP_STRUCT__entry(
 		CXL_EVT_TP_entry
@@ -442,6 +447,7 @@  TRACE_EVENT(cxl_dram,
 		__field(u32, row)
 		__array(u8, cor_mask, CXL_EVENT_DER_CORRECTION_MASK_SIZE)
 		__field(u64, hpa)
+		__field(u64, hpa_alias)
 		__field_struct(uuid_t, region_uuid)
 		__field(u8, rank)	/* Out of order to pack trace record */
 		__field(u8, bank_group)	/* Out of order to pack trace record */
@@ -472,6 +478,7 @@  TRACE_EVENT(cxl_dram,
 		memcpy(__entry->cor_mask, &rec->correction_mask,
 			CXL_EVENT_DER_CORRECTION_MASK_SIZE);
 		__entry->hpa = hpa;
+		__entry->hpa_alias = hpa_alias;
 		if (cxlr) {
 			__assign_str(region_name);
 			uuid_copy(&__entry->region_uuid, &cxlr->params.uuid);
@@ -485,7 +492,7 @@  TRACE_EVENT(cxl_dram,
 		"transaction_type='%s' channel=%u rank=%u nibble_mask=%x " \
 		"bank_group=%u bank=%u row=%u column=%u cor_mask=%s " \
 		"validity_flags='%s' " \
-		"hpa=%llx region=%s region_uuid=%pUb",
+		"hpa=%llx hpa_alias=%llx region=%s region_uuid=%pUb",
 		__entry->dpa, show_dpa_flags(__entry->dpa_flags),
 		show_event_desc_flags(__entry->descriptor),
 		show_dram_mem_event_type(__entry->type),
@@ -495,7 +502,8 @@  TRACE_EVENT(cxl_dram,
 		__entry->row, __entry->column,
 		__print_hex(__entry->cor_mask, CXL_EVENT_DER_CORRECTION_MASK_SIZE),
 		show_dram_valid_flags(__entry->validity_flags),
-		__entry->hpa, __get_str(region_name), &__entry->region_uuid
+		__entry->hpa_alias, __entry->hpa, __get_str(region_name),
+		&__entry->region_uuid
 	)
 );