2024-05-16 10:21:41

by Fabio M. De Francesco

[permalink] [raw]
Subject: [PATCH v2] cxl/events: Use a common struct for DRAM and General Media events

cxl_event_common was a poor naming choice and caused confusion with the
existing Common Event Record.

Use cxl_event_media as a common structure to record information about DRAM
and General Media events because it simplifies handling the two events.

Suggested-by: Dan Williams <[email protected]>
Fixes: 6aec00139d3a ("cxl/core: Add region info to cxl_general_media and cxl_dram events")
Signed-off-by: Fabio M. De Francesco <[email protected]>
---

Changes for v2:
- Extend the commit message (Alison);
- Add a "Fixes" tag (Alison, thanks).

drivers/cxl/core/mbox.c | 6 ++--
drivers/cxl/core/trace.h | 4 +--
include/linux/cxl-event.h | 70 +++++++++++++++---------------------
tools/testing/cxl/test/mem.c | 4 +--
4 files changed, 36 insertions(+), 48 deletions(-)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 2626f3fff201..ad4d7b0f7f4d 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -875,16 +875,16 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
guard(rwsem_read)(&cxl_region_rwsem);
guard(rwsem_read)(&cxl_dpa_rwsem);

- dpa = le64_to_cpu(evt->common.phys_addr) & CXL_DPA_MASK;
+ dpa = le64_to_cpu(evt->media_common.phys_addr) & CXL_DPA_MASK;
cxlr = cxl_dpa_to_region(cxlmd, dpa);
if (cxlr)
hpa = cxl_trace_hpa(cxlr, cxlmd, dpa);

if (event_type == CXL_CPER_EVENT_GEN_MEDIA)
trace_cxl_general_media(cxlmd, type, cxlr, hpa,
- &evt->gen_media);
+ &evt->media_general);
else if (event_type == CXL_CPER_EVENT_DRAM)
- trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->dram);
+ trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->media_dram);
}
}
EXPORT_SYMBOL_NS_GPL(cxl_event_trace_record, CXL);
diff --git a/drivers/cxl/core/trace.h b/drivers/cxl/core/trace.h
index 07a0394b1d99..2c7293761bb2 100644
--- a/drivers/cxl/core/trace.h
+++ b/drivers/cxl/core/trace.h
@@ -316,7 +316,7 @@ 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, struct cxl_event_media *rec),

TP_ARGS(cxlmd, log, cxlr, hpa, rec),

@@ -413,7 +413,7 @@ 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, struct cxl_event_media *rec),

TP_ARGS(cxlmd, log, cxlr, hpa, rec),

diff --git a/include/linux/cxl-event.h b/include/linux/cxl-event.h
index 60b25020281f..e417556cc120 100644
--- a/include/linux/cxl-event.h
+++ b/include/linux/cxl-event.h
@@ -32,41 +32,38 @@ struct cxl_event_generic {
* CXL rev 3.0 Section 8.2.9.2.1.1; Table 8-43
*/
#define CXL_EVENT_GEN_MED_COMP_ID_SIZE 0x10
-struct cxl_event_gen_media {
- struct cxl_event_record_hdr hdr;
- __le64 phys_addr;
- u8 descriptor;
- u8 type;
- u8 transaction_type;
- u8 validity_flags[2];
- u8 channel;
- u8 rank;
- u8 device[3];
- u8 component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
- u8 reserved[46];
-} __packed;
-
/*
* DRAM Event Record - DER
* CXL rev 3.0 section 8.2.9.2.1.2; Table 3-44
*/
#define CXL_EVENT_DER_CORRECTION_MASK_SIZE 0x20
-struct cxl_event_dram {
+struct cxl_event_media {
struct cxl_event_record_hdr hdr;
- __le64 phys_addr;
- u8 descriptor;
- u8 type;
- u8 transaction_type;
- u8 validity_flags[2];
- u8 channel;
- u8 rank;
- u8 nibble_mask[3];
- u8 bank_group;
- u8 bank;
- u8 row[3];
- u8 column[2];
- u8 correction_mask[CXL_EVENT_DER_CORRECTION_MASK_SIZE];
- u8 reserved[0x17];
+ struct_group_tagged(cxl_event_media_hdr, media_hdr,
+ __le64 phys_addr;
+ u8 descriptor;
+ u8 type;
+ u8 transaction_type;
+ u8 validity_flags[2];
+ u8 channel;
+ u8 rank;
+ );
+ union {
+ struct_group(general,
+ u8 device[3];
+ u8 component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
+ u8 gen_reserved[46];
+ );
+ struct_group(dram,
+ u8 nibble_mask[3];
+ u8 bank_group;
+ u8 bank;
+ u8 row[3];
+ u8 column[2];
+ u8 correction_mask[CXL_EVENT_DER_CORRECTION_MASK_SIZE];
+ u8 dram_reserved[0x17];
+ );
+ };
} __packed;

/*
@@ -95,21 +92,12 @@ struct cxl_event_mem_module {
u8 reserved[0x3d];
} __packed;

-/*
- * General Media or DRAM Event Common Fields
- * - provides common access to phys_addr
- */
-struct cxl_event_common {
- struct cxl_event_record_hdr hdr;
- __le64 phys_addr;
-} __packed;
-
union cxl_event {
struct cxl_event_generic generic;
- struct cxl_event_gen_media gen_media;
- struct cxl_event_dram dram;
+ struct cxl_event_media media_general;
+ struct cxl_event_media media_dram;
struct cxl_event_mem_module mem_module;
- struct cxl_event_common common;
+ struct cxl_event_media media_common;
} __packed;

/*
diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
index 6584443144de..0a8fd145c391 100644
--- a/tools/testing/cxl/test/mem.c
+++ b/tools/testing/cxl/test/mem.c
@@ -378,7 +378,7 @@ struct cxl_event_record_raw hardware_replace = {

struct cxl_test_gen_media {
uuid_t id;
- struct cxl_event_gen_media rec;
+ struct cxl_event_media rec;
} __packed;

struct cxl_test_gen_media gen_media = {
@@ -402,7 +402,7 @@ struct cxl_test_gen_media gen_media = {

struct cxl_test_dram {
uuid_t id;
- struct cxl_event_dram rec;
+ struct cxl_event_media rec;
} __packed;

struct cxl_test_dram dram = {
--
2.45.0



2024-05-16 16:33:34

by Jonathan Cameron

[permalink] [raw]
Subject: Re: [PATCH v2] cxl/events: Use a common struct for DRAM and General Media events

On Thu, 16 May 2024 12:19:53 +0200
"Fabio M. De Francesco" <[email protected]> wrote:

> cxl_event_common was a poor naming choice and caused confusion with the
> existing Common Event Record.
>
> Use cxl_event_media as a common structure to record information about DRAM
> and General Media events because it simplifies handling the two events.
>
> Suggested-by: Dan Williams <[email protected]>
> Fixes: 6aec00139d3a ("cxl/core: Add region info to cxl_general_media and cxl_dram events")
> Signed-off-by: Fabio M. De Francesco <[email protected]>
> ---

Packing question inline.

>
> Changes for v2:
> - Extend the commit message (Alison);
> - Add a "Fixes" tag (Alison, thanks).
>
> drivers/cxl/core/mbox.c | 6 ++--
> drivers/cxl/core/trace.h | 4 +--
> include/linux/cxl-event.h | 70 +++++++++++++++---------------------
> tools/testing/cxl/test/mem.c | 4 +--
> 4 files changed, 36 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 2626f3fff201..ad4d7b0f7f4d 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -875,16 +875,16 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
> guard(rwsem_read)(&cxl_region_rwsem);
> guard(rwsem_read)(&cxl_dpa_rwsem);
>
> - dpa = le64_to_cpu(evt->common.phys_addr) & CXL_DPA_MASK;
> + dpa = le64_to_cpu(evt->media_common.phys_addr) & CXL_DPA_MASK;
> cxlr = cxl_dpa_to_region(cxlmd, dpa);
> if (cxlr)
> hpa = cxl_trace_hpa(cxlr, cxlmd, dpa);
>
> if (event_type == CXL_CPER_EVENT_GEN_MEDIA)
> trace_cxl_general_media(cxlmd, type, cxlr, hpa,
> - &evt->gen_media);
> + &evt->media_general);
> else if (event_type == CXL_CPER_EVENT_DRAM)
> - trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->dram);
> + trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->media_dram);
> }
> }
> EXPORT_SYMBOL_NS_GPL(cxl_event_trace_record, CXL);
> diff --git a/drivers/cxl/core/trace.h b/drivers/cxl/core/trace.h
> index 07a0394b1d99..2c7293761bb2 100644
> --- a/drivers/cxl/core/trace.h
> +++ b/drivers/cxl/core/trace.h
> @@ -316,7 +316,7 @@ 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, struct cxl_event_media *rec),
>
> TP_ARGS(cxlmd, log, cxlr, hpa, rec),
>
> @@ -413,7 +413,7 @@ 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, struct cxl_event_media *rec),
>
> TP_ARGS(cxlmd, log, cxlr, hpa, rec),
>
> diff --git a/include/linux/cxl-event.h b/include/linux/cxl-event.h
> index 60b25020281f..e417556cc120 100644
> --- a/include/linux/cxl-event.h
> +++ b/include/linux/cxl-event.h
> @@ -32,41 +32,38 @@ struct cxl_event_generic {
> * CXL rev 3.0 Section 8.2.9.2.1.1; Table 8-43
> */
> #define CXL_EVENT_GEN_MED_COMP_ID_SIZE 0x10
> -struct cxl_event_gen_media {
> - struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> - u8 descriptor;
> - u8 type;
> - u8 transaction_type;
> - u8 validity_flags[2];
> - u8 channel;
> - u8 rank;
> - u8 device[3];
> - u8 component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
> - u8 reserved[46];
> -} __packed;
> -
> /*
> * DRAM Event Record - DER
> * CXL rev 3.0 section 8.2.9.2.1.2; Table 3-44
> */
> #define CXL_EVENT_DER_CORRECTION_MASK_SIZE 0x20
> -struct cxl_event_dram {
> +struct cxl_event_media {
> struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> - u8 descriptor;
> - u8 type;
> - u8 transaction_type;
> - u8 validity_flags[2];
> - u8 channel;
> - u8 rank;
> - u8 nibble_mask[3];
> - u8 bank_group;
> - u8 bank;
> - u8 row[3];
> - u8 column[2];
> - u8 correction_mask[CXL_EVENT_DER_CORRECTION_MASK_SIZE];
> - u8 reserved[0x17];
> + struct_group_tagged(cxl_event_media_hdr, media_hdr,
> + __le64 phys_addr;
> + u8 descriptor;
> + u8 type;
> + u8 transaction_type;
> + u8 validity_flags[2];
> + u8 channel;
> + u8 rank;
> + );

Does the struct that is created end up __packed?
Also, why is tagged useful here?

> + union {
> + struct_group(general,
> + u8 device[3];
> + u8 component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
> + u8 gen_reserved[46];
> + );
> + struct_group(dram,
> + u8 nibble_mask[3];
> + u8 bank_group;
> + u8 bank;
> + u8 row[3];
> + u8 column[2];
> + u8 correction_mask[CXL_EVENT_DER_CORRECTION_MASK_SIZE];
> + u8 dram_reserved[0x17];
> + );
> + };
> } __packed;
>
> /*
> @@ -95,21 +92,12 @@ struct cxl_event_mem_module {
> u8 reserved[0x3d];
> } __packed;
>
> -/*
> - * General Media or DRAM Event Common Fields
> - * - provides common access to phys_addr
> - */
> -struct cxl_event_common {
> - struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> -} __packed;
> -
> union cxl_event {
> struct cxl_event_generic generic;
> - struct cxl_event_gen_media gen_media;
> - struct cxl_event_dram dram;
> + struct cxl_event_media media_general;
> + struct cxl_event_media media_dram;
> struct cxl_event_mem_module mem_module;
> - struct cxl_event_common common;
> + struct cxl_event_media media_common;
> } __packed;
>
> /*
> diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
> index 6584443144de..0a8fd145c391 100644
> --- a/tools/testing/cxl/test/mem.c
> +++ b/tools/testing/cxl/test/mem.c
> @@ -378,7 +378,7 @@ struct cxl_event_record_raw hardware_replace = {
>
> struct cxl_test_gen_media {
> uuid_t id;
> - struct cxl_event_gen_media rec;
> + struct cxl_event_media rec;
> } __packed;
>
> struct cxl_test_gen_media gen_media = {
> @@ -402,7 +402,7 @@ struct cxl_test_gen_media gen_media = {
>
> struct cxl_test_dram {
> uuid_t id;
> - struct cxl_event_dram rec;
> + struct cxl_event_media rec;
> } __packed;
>
> struct cxl_test_dram dram = {


2024-05-16 21:34:50

by Ira Weiny

[permalink] [raw]
Subject: Re: [PATCH v2] cxl/events: Use a common struct for DRAM and General Media events

Fabio M. De Francesco wrote:
> cxl_event_common was a poor naming choice and caused confusion with the
> existing Common Event Record.
>
> Use cxl_event_media as a common structure to record information about DRAM
> and General Media events because it simplifies handling the two events.
>
> Suggested-by: Dan Williams <[email protected]>
> Fixes: 6aec00139d3a ("cxl/core: Add region info to cxl_general_media and cxl_dram events")
> Signed-off-by: Fabio M. De Francesco <[email protected]>
> ---
>
> Changes for v2:
> - Extend the commit message (Alison);
> - Add a "Fixes" tag (Alison, thanks).
>
> drivers/cxl/core/mbox.c | 6 ++--
> drivers/cxl/core/trace.h | 4 +--
> include/linux/cxl-event.h | 70 +++++++++++++++---------------------
> tools/testing/cxl/test/mem.c | 4 +--
> 4 files changed, 36 insertions(+), 48 deletions(-)

Still not convinced this is worth the churn.
Ira

>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 2626f3fff201..ad4d7b0f7f4d 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -875,16 +875,16 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
> guard(rwsem_read)(&cxl_region_rwsem);
> guard(rwsem_read)(&cxl_dpa_rwsem);
>
> - dpa = le64_to_cpu(evt->common.phys_addr) & CXL_DPA_MASK;
> + dpa = le64_to_cpu(evt->media_common.phys_addr) & CXL_DPA_MASK;
> cxlr = cxl_dpa_to_region(cxlmd, dpa);
> if (cxlr)
> hpa = cxl_trace_hpa(cxlr, cxlmd, dpa);
>
> if (event_type == CXL_CPER_EVENT_GEN_MEDIA)
> trace_cxl_general_media(cxlmd, type, cxlr, hpa,
> - &evt->gen_media);
> + &evt->media_general);
> else if (event_type == CXL_CPER_EVENT_DRAM)
> - trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->dram);
> + trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->media_dram);
> }
> }
> EXPORT_SYMBOL_NS_GPL(cxl_event_trace_record, CXL);
> diff --git a/drivers/cxl/core/trace.h b/drivers/cxl/core/trace.h
> index 07a0394b1d99..2c7293761bb2 100644
> --- a/drivers/cxl/core/trace.h
> +++ b/drivers/cxl/core/trace.h
> @@ -316,7 +316,7 @@ 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, struct cxl_event_media *rec),
>
> TP_ARGS(cxlmd, log, cxlr, hpa, rec),
>
> @@ -413,7 +413,7 @@ 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, struct cxl_event_media *rec),
>
> TP_ARGS(cxlmd, log, cxlr, hpa, rec),
>
> diff --git a/include/linux/cxl-event.h b/include/linux/cxl-event.h
> index 60b25020281f..e417556cc120 100644
> --- a/include/linux/cxl-event.h
> +++ b/include/linux/cxl-event.h
> @@ -32,41 +32,38 @@ struct cxl_event_generic {
> * CXL rev 3.0 Section 8.2.9.2.1.1; Table 8-43
> */
> #define CXL_EVENT_GEN_MED_COMP_ID_SIZE 0x10
> -struct cxl_event_gen_media {
> - struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> - u8 descriptor;
> - u8 type;
> - u8 transaction_type;
> - u8 validity_flags[2];
> - u8 channel;
> - u8 rank;
> - u8 device[3];
> - u8 component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
> - u8 reserved[46];
> -} __packed;
> -
> /*
> * DRAM Event Record - DER
> * CXL rev 3.0 section 8.2.9.2.1.2; Table 3-44
> */
> #define CXL_EVENT_DER_CORRECTION_MASK_SIZE 0x20
> -struct cxl_event_dram {
> +struct cxl_event_media {
> struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> - u8 descriptor;
> - u8 type;
> - u8 transaction_type;
> - u8 validity_flags[2];
> - u8 channel;
> - u8 rank;
> - u8 nibble_mask[3];
> - u8 bank_group;
> - u8 bank;
> - u8 row[3];
> - u8 column[2];
> - u8 correction_mask[CXL_EVENT_DER_CORRECTION_MASK_SIZE];
> - u8 reserved[0x17];
> + struct_group_tagged(cxl_event_media_hdr, media_hdr,
> + __le64 phys_addr;
> + u8 descriptor;
> + u8 type;
> + u8 transaction_type;
> + u8 validity_flags[2];
> + u8 channel;
> + u8 rank;
> + );
> + union {
> + struct_group(general,
> + u8 device[3];
> + u8 component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
> + u8 gen_reserved[46];
> + );
> + struct_group(dram,
> + u8 nibble_mask[3];
> + u8 bank_group;
> + u8 bank;
> + u8 row[3];
> + u8 column[2];
> + u8 correction_mask[CXL_EVENT_DER_CORRECTION_MASK_SIZE];
> + u8 dram_reserved[0x17];
> + );
> + };
> } __packed;
>
> /*
> @@ -95,21 +92,12 @@ struct cxl_event_mem_module {
> u8 reserved[0x3d];
> } __packed;
>
> -/*
> - * General Media or DRAM Event Common Fields
> - * - provides common access to phys_addr
> - */
> -struct cxl_event_common {
> - struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> -} __packed;
> -
> union cxl_event {
> struct cxl_event_generic generic;
> - struct cxl_event_gen_media gen_media;
> - struct cxl_event_dram dram;
> + struct cxl_event_media media_general;
> + struct cxl_event_media media_dram;
> struct cxl_event_mem_module mem_module;
> - struct cxl_event_common common;
> + struct cxl_event_media media_common;
> } __packed;
>
> /*
> diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
> index 6584443144de..0a8fd145c391 100644
> --- a/tools/testing/cxl/test/mem.c
> +++ b/tools/testing/cxl/test/mem.c
> @@ -378,7 +378,7 @@ struct cxl_event_record_raw hardware_replace = {
>
> struct cxl_test_gen_media {
> uuid_t id;
> - struct cxl_event_gen_media rec;
> + struct cxl_event_media rec;
> } __packed;
>
> struct cxl_test_gen_media gen_media = {
> @@ -402,7 +402,7 @@ struct cxl_test_gen_media gen_media = {
>
> struct cxl_test_dram {
> uuid_t id;
> - struct cxl_event_dram rec;
> + struct cxl_event_media rec;
> } __packed;
>
> struct cxl_test_dram dram = {
> --
> 2.45.0
>



2024-05-17 00:43:57

by Dan Williams

[permalink] [raw]
Subject: RE: [PATCH v2] cxl/events: Use a common struct for DRAM and General Media events

Fabio M. De Francesco wrote:
> cxl_event_common was a poor naming choice and caused confusion with the
> existing Common Event Record.

I would say "unfortunate" rather than "poor".

> Use cxl_event_media as a common structure to record information about DRAM
> and General Media events because it simplifies handling the two events.
>
> Suggested-by: Dan Williams <[email protected]>
> Fixes: 6aec00139d3a ("cxl/core: Add region info to cxl_general_media and cxl_dram events")

What is the fix? There is no user visible behavior changes that results from
this cleanup, right?

> Signed-off-by: Fabio M. De Francesco <[email protected]>
> ---
>
> Changes for v2:
> - Extend the commit message (Alison);
> - Add a "Fixes" tag (Alison, thanks).
>
> drivers/cxl/core/mbox.c | 6 ++--
> drivers/cxl/core/trace.h | 4 +--
> include/linux/cxl-event.h | 70 +++++++++++++++---------------------
> tools/testing/cxl/test/mem.c | 4 +--
> 4 files changed, 36 insertions(+), 48 deletions(-)

Oh, nice, net reduction in code I was not expecting.

>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 2626f3fff201..ad4d7b0f7f4d 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -875,16 +875,16 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
> guard(rwsem_read)(&cxl_region_rwsem);
> guard(rwsem_read)(&cxl_dpa_rwsem);
>
> - dpa = le64_to_cpu(evt->common.phys_addr) & CXL_DPA_MASK;
> + dpa = le64_to_cpu(evt->media_common.phys_addr) & CXL_DPA_MASK;

I was hoping at the end of this to get rid of the word "common" to avoid any
more "common event record confusion".

> cxlr = cxl_dpa_to_region(cxlmd, dpa);
> if (cxlr)
> hpa = cxl_trace_hpa(cxlr, cxlmd, dpa);
>
> if (event_type == CXL_CPER_EVENT_GEN_MEDIA)
> trace_cxl_general_media(cxlmd, type, cxlr, hpa,
> - &evt->gen_media);
> + &evt->media_general);
> else if (event_type == CXL_CPER_EVENT_DRAM)
> - trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->dram);
> + trace_cxl_dram(cxlmd, type, cxlr, hpa, &evt->media_dram);
> }
> }
> EXPORT_SYMBOL_NS_GPL(cxl_event_trace_record, CXL);
> diff --git a/drivers/cxl/core/trace.h b/drivers/cxl/core/trace.h
> index 07a0394b1d99..2c7293761bb2 100644
> --- a/drivers/cxl/core/trace.h
> +++ b/drivers/cxl/core/trace.h
> @@ -316,7 +316,7 @@ 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, struct cxl_event_media *rec),
>
> TP_ARGS(cxlmd, log, cxlr, hpa, rec),
>
> @@ -413,7 +413,7 @@ 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, struct cxl_event_media *rec),
>
> TP_ARGS(cxlmd, log, cxlr, hpa, rec),
>
> diff --git a/include/linux/cxl-event.h b/include/linux/cxl-event.h
> index 60b25020281f..e417556cc120 100644
> --- a/include/linux/cxl-event.h
> +++ b/include/linux/cxl-event.h
> @@ -32,41 +32,38 @@ struct cxl_event_generic {
> * CXL rev 3.0 Section 8.2.9.2.1.1; Table 8-43
> */
> #define CXL_EVENT_GEN_MED_COMP_ID_SIZE 0x10
> -struct cxl_event_gen_media {
> - struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> - u8 descriptor;
> - u8 type;
> - u8 transaction_type;
> - u8 validity_flags[2];
> - u8 channel;
> - u8 rank;
> - u8 device[3];
> - u8 component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
> - u8 reserved[46];
> -} __packed;
> -
> /*
> * DRAM Event Record - DER
> * CXL rev 3.0 section 8.2.9.2.1.2; Table 3-44
> */
> #define CXL_EVENT_DER_CORRECTION_MASK_SIZE 0x20
> -struct cxl_event_dram {
> +struct cxl_event_media {
> struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> - u8 descriptor;
> - u8 type;
> - u8 transaction_type;
> - u8 validity_flags[2];
> - u8 channel;
> - u8 rank;
> - u8 nibble_mask[3];
> - u8 bank_group;
> - u8 bank;
> - u8 row[3];
> - u8 column[2];
> - u8 correction_mask[CXL_EVENT_DER_CORRECTION_MASK_SIZE];
> - u8 reserved[0x17];
> + struct_group_tagged(cxl_event_media_hdr, media_hdr,
> + __le64 phys_addr;
> + u8 descriptor;
> + u8 type;
> + u8 transaction_type;
> + u8 validity_flags[2];
> + u8 channel;
> + u8 rank;
> + );

Oh nice you went for the full 'struct_group_tagged' proposal. However, given
that Jonathan is already asking questions about "__packed", lets do the simpler
change, something like this, what do you think? This also preserves type-safety.

diff --git a/include/linux/cxl-event.h b/include/linux/cxl-event.h
index 60b25020281f..f48b59943977 100644
--- a/include/linux/cxl-event.h
+++ b/include/linux/cxl-event.h
@@ -33,14 +33,16 @@ struct cxl_event_generic {
*/
#define CXL_EVENT_GEN_MED_COMP_ID_SIZE 0x10
struct cxl_event_gen_media {
- struct cxl_event_record_hdr hdr;
- __le64 phys_addr;
- u8 descriptor;
- u8 type;
- u8 transaction_type;
- u8 validity_flags[2];
- u8 channel;
- u8 rank;
+ struct cxl_event_media_hdr {
+ struct cxl_event_record_hdr hdr;
+ __le64 phys_addr;
+ u8 descriptor;
+ u8 type;
+ u8 transaction_type;
+ u8 validity_flags[2];
+ u8 channel;
+ u8 rank;
+ } hdr;
u8 device[3];
u8 component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
u8 reserved[46];
@@ -52,14 +54,7 @@ struct cxl_event_gen_media {
*/
#define CXL_EVENT_DER_CORRECTION_MASK_SIZE 0x20
struct cxl_event_dram {
- struct cxl_event_record_hdr hdr;
- __le64 phys_addr;
- u8 descriptor;
- u8 type;
- u8 transaction_type;
- u8 validity_flags[2];
- u8 channel;
- u8 rank;
+ struct cxl_event_media_hdr hdr;
u8 nibble_mask[3];
u8 bank_group;
u8 bank;
@@ -109,7 +104,7 @@ union cxl_event {
struct cxl_event_gen_media gen_media;
struct cxl_event_dram dram;
struct cxl_event_mem_module mem_module;
- struct cxl_event_common common;
+ struct cxl_event_media_hdr media_hdr;
} __packed;

/*

2024-05-17 12:36:43

by Fabio M. De Francesco

[permalink] [raw]
Subject: Re: [PATCH v2] cxl/events: Use a common struct for DRAM and General Media events

Jonathan,

Thanks for your comments.

On Thursday, May 16, 2024 6:33:19 PM GMT+2 Jonathan Cameron wrote:
> On Thu, 16 May 2024 12:19:53 +0200
>
> "Fabio M. De Francesco" <[email protected]> wrote:
> > cxl_event_common was a poor naming choice and caused confusion with the
> > existing Common Event Record.
> >
> > Use cxl_event_media as a common structure to record information about DRAM
> > and General Media events because it simplifies handling the two events.
> >
> > Suggested-by: Dan Williams <[email protected]>
> > Fixes: 6aec00139d3a ("cxl/core: Add region info to cxl_general_media and
> > cxl_dram events") Signed-off-by: Fabio M. De Francesco
> > <[email protected]> ---
>
> Packing question inline.
>
> > [...]
> >
> > -struct cxl_event_dram {
> > +struct cxl_event_media {
> >
> > struct cxl_event_record_hdr hdr;
> >
> > - __le64 phys_addr;
> > - u8 descriptor;
> > - u8 type;
> > - u8 transaction_type;
> > - u8 validity_flags[2];
> > - u8 channel;
> > - u8 rank;
> > - u8 nibble_mask[3];
> > - u8 bank_group;
> > - u8 bank;
> > - u8 row[3];
> > - u8 column[2];
> > - u8 correction_mask[CXL_EVENT_DER_CORRECTION_MASK_SIZE];
> > - u8 reserved[0x17];
> > + struct_group_tagged(cxl_event_media_hdr, media_hdr,
> > + __le64 phys_addr;
> > + u8 descriptor;
> > + u8 type;
> > + u8 transaction_type;
> > + u8 validity_flags[2];
> > + u8 channel;
> > + u8 rank;
> > + );
>
> Does the struct that is created end up __packed?

No, I should have noticed it.

> Also, why is tagged useful here?

It is not useful. I'll rework it not tagged.

Again thanks,

Fabio

> > + union {
> > + struct_group(general,
> > + u8 device[3];
> > + u8
component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
> > + u8 gen_reserved[46];
> > + );
> > + struct_group(dram,
> > + u8 nibble_mask[3];
> > + u8 bank_group;
> > + u8 bank;
> > + u8 row[3];
> > + u8 column[2];
> > + u8
correction_mask[CXL_EVENT_DER_CORRECTION_MASK_SIZE];
> > + u8 dram_reserved[0x17];
> > + );
> > + };
> >
> > } __packed;
> >



2024-05-17 16:55:22

by Fabio M. De Francesco

[permalink] [raw]
Subject: Re: [PATCH v2] cxl/events: Use a common struct for DRAM and General Media events

On Friday, May 17, 2024 2:43:33 AM GMT+2 Dan Williams wrote:
> Fabio M. De Francesco wrote:
> > cxl_event_common was a poor naming choice and caused confusion with the
> > existing Common Event Record.
>
> I would say "unfortunate" rather than "poor".
>

Agreed.

> > Use cxl_event_media as a common structure to record information about DRAM
> > and General Media events because it simplifies handling the two events.
> >
> > Suggested-by: Dan Williams <[email protected]>
> > Fixes: 6aec00139d3a ("cxl/core: Add region info to cxl_general_media and
> > cxl_dram events")
> What is the fix? There is no user visible behavior changes that results from
> this cleanup, right?

Right.

> > Signed-off-by: Fabio M. De Francesco
> > <[email protected]>
> > ---
> >
> > Changes for v2:
> > - Extend the commit message (Alison);
> > - Add a "Fixes" tag (Alison, thanks).
> >
> > drivers/cxl/core/mbox.c | 6 ++--
> > drivers/cxl/core/trace.h | 4 +--
> > include/linux/cxl-event.h | 70 +++++++++++++++---------------------
> > tools/testing/cxl/test/mem.c | 4 +--
> > 4 files changed, 36 insertions(+), 48 deletions(-)
>
> Oh, nice, net reduction in code I was not expecting.
>
> > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> > index 2626f3fff201..ad4d7b0f7f4d 100644
> > --- a/drivers/cxl/core/mbox.c
> > +++ b/drivers/cxl/core/mbox.c
> > @@ -875,16 +875,16 @@ void cxl_event_trace_record(const struct cxl_memdev
> > *cxlmd,>
> > guard(rwsem_read)(&cxl_region_rwsem);
> > guard(rwsem_read)(&cxl_dpa_rwsem);
> >
> > - dpa = le64_to_cpu(evt->common.phys_addr) &
CXL_DPA_MASK;
> > + dpa = le64_to_cpu(evt->media_common.phys_addr) &
CXL_DPA_MASK;
>
> I was hoping at the end of this to get rid of the word "common" to avoid any
> more "common event record confusion".

Right, still an unfortunate naming choice.

> > [...]
>
> Oh nice you went for the full 'struct_group_tagged' proposal. However, given
> that Jonathan is already asking questions about "__packed", lets do the
> simpler change, something like this, what do you think?

I think that these simpler changes are better.

> This also preserves
> type-safety.
>
> diff --git a/include/linux/cxl-event.h b/include/linux/cxl-event.h
> index 60b25020281f..f48b59943977 100644
> --- a/include/linux/cxl-event.h
> +++ b/include/linux/cxl-event.h
> @@ -33,14 +33,16 @@ struct cxl_event_generic {
> */
> #define CXL_EVENT_GEN_MED_COMP_ID_SIZE 0x10
> struct cxl_event_gen_media {
> - struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> - u8 descriptor;
> - u8 type;
> - u8 transaction_type;
> - u8 validity_flags[2];
> - u8 channel;
> - u8 rank;
> + struct cxl_event_media_hdr {
> + struct cxl_event_record_hdr hdr;
> + __le64 phys_addr;
> + u8 descriptor;
> + u8 type;
> + u8 transaction_type;
> + u8 validity_flags[2];
> + u8 channel;
> + u8 rank;
> + } hdr;
> u8 device[3];
> u8 component_id[CXL_EVENT_GEN_MED_COMP_ID_SIZE];
> u8 reserved[46];
> @@ -52,14 +54,7 @@ struct cxl_event_gen_media {
> */
> #define CXL_EVENT_DER_CORRECTION_MASK_SIZE 0x20
> struct cxl_event_dram {
> - struct cxl_event_record_hdr hdr;
> - __le64 phys_addr;
> - u8 descriptor;
> - u8 type;
> - u8 transaction_type;
> - u8 validity_flags[2];
> - u8 channel;
> - u8 rank;
> + struct cxl_event_media_hdr hdr;
> u8 nibble_mask[3];
> u8 bank_group;
> u8 bank;
> @@ -109,7 +104,7 @@ union cxl_event {
> struct cxl_event_gen_media gen_media;
> struct cxl_event_dram dram;
> struct cxl_event_mem_module mem_module;
> - struct cxl_event_common common;
> + struct cxl_event_media_hdr media_hdr;
> } __packed;
>
> /*

I'll make v3 according to the suggestion showed above.

Thanks,

Fabio