diff mbox series

[v4,06/23] cxl: Add callback to parse the DSLBIS subtable from CDAT

Message ID 168193569717.1178687.294428469465996536.stgit@djiang5-mobl3
State New
Headers show
Series cxl: Add support for QTG ID retrieval for CXL subsystem | expand

Commit Message

Dave Jiang April 19, 2023, 8:21 p.m. UTC
Provide a callback to parse the Device Scoped Latency and Bandwidth
Information Structure (DSLBIS) in the CDAT structures. The DSLBIS
contains the bandwidth and latency information that's tied to a DSMAS
handle. The driver will retrieve the read and write latency and
bandwidth associated with the DSMAS which is tied to a DPA range.

Coherent Device Attribute Table 1.03 2.1 Device Scoped Latency and
Bandwidth Information Structure (DSLBIS)

Signed-off-by: Dave Jiang <dave.jiang@intel.com>

---
v3:
- Added spec section in commit header. (Alison)
- Remove void * recast. (Alison)
- Rework comment. (Alison)
- Move CDAT parse to cxl_endpoint_port_probe()
- Convert to use 'struct node_hmem_attrs'

v2:
- Add size check to DSLIBIS table. (Lukas)
- Remove unnecessary entry type check. (Jonathan)
- Move data_type check to after match. (Jonathan)
- Skip unknown data type. (Jonathan)
- Add overflow check for unit multiply. (Jonathan)
- Use dev_warn() when entries parsing fail. (Jonathan)
---
 drivers/cxl/core/cdat.c |   68 +++++++++++++++++++++++++++++++++++++++++++++++
 drivers/cxl/cxlpci.h    |   34 +++++++++++++++++++++++-
 drivers/cxl/port.c      |   11 +++++++-
 3 files changed, 111 insertions(+), 2 deletions(-)

Comments

Jonathan Cameron April 20, 2023, 11:40 a.m. UTC | #1
On Wed, 19 Apr 2023 13:21:37 -0700
Dave Jiang <dave.jiang@intel.com> wrote:

> Provide a callback to parse the Device Scoped Latency and Bandwidth
> Information Structure (DSLBIS) in the CDAT structures. The DSLBIS
> contains the bandwidth and latency information that's tied to a DSMAS
> handle. The driver will retrieve the read and write latency and
> bandwidth associated with the DSMAS which is tied to a DPA range.
> 
> Coherent Device Attribute Table 1.03 2.1 Device Scoped Latency and
> Bandwidth Information Structure (DSLBIS)
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> 

One comment inline.

> +/* Flags for DSLBIS subtable */
> +#define DSLBIS_MEM_MASK		GENMASK(3, 0)
> +#define DSLBIS_MEM_MEMORY	0
> +
>  int devm_cxl_port_enumerate_dports(struct cxl_port *port);
>  struct cxl_dev_state;
>  int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
> @@ -136,5 +164,9 @@ cdat_table_parse(dsmas);
>  cdat_table_parse(dslbis);
>  cdat_table_parse(sslbis);
>  
> -int cxl_dsmas_parse_entry(struct cdat_entry_header *header, void *arg);
> +#define cxl_parse_entry(x) \
> +int cxl_##x##_parse_entry(struct cdat_entry_header *header, void *arg)
I'm not sure this is worthwhile. What was your reasoning for it?
Also wrecks typing that arg argument as I suggested earlier...

> +
> +cxl_parse_entry(dsmas);
> +cxl_parse_entry(dslbis);
Dave Jiang April 20, 2023, 11:25 p.m. UTC | #2
On 4/20/23 4:40 AM, Jonathan Cameron wrote:
> On Wed, 19 Apr 2023 13:21:37 -0700
> Dave Jiang <dave.jiang@intel.com> wrote:
> 
>> Provide a callback to parse the Device Scoped Latency and Bandwidth
>> Information Structure (DSLBIS) in the CDAT structures. The DSLBIS
>> contains the bandwidth and latency information that's tied to a DSMAS
>> handle. The driver will retrieve the read and write latency and
>> bandwidth associated with the DSMAS which is tied to a DPA range.
>>
>> Coherent Device Attribute Table 1.03 2.1 Device Scoped Latency and
>> Bandwidth Information Structure (DSLBIS)
>>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>>
> 
> One comment inline.
> 
>> +/* Flags for DSLBIS subtable */
>> +#define DSLBIS_MEM_MASK		GENMASK(3, 0)
>> +#define DSLBIS_MEM_MEMORY	0
>> +
>>   int devm_cxl_port_enumerate_dports(struct cxl_port *port);
>>   struct cxl_dev_state;
>>   int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
>> @@ -136,5 +164,9 @@ cdat_table_parse(dsmas);
>>   cdat_table_parse(dslbis);
>>   cdat_table_parse(sslbis);
>>   
>> -int cxl_dsmas_parse_entry(struct cdat_entry_header *header, void *arg);
>> +#define cxl_parse_entry(x) \
>> +int cxl_##x##_parse_entry(struct cdat_entry_header *header, void *arg)
> I'm not sure this is worthwhile. What was your reasoning for it?
> Also wrecks typing that arg argument as I suggested earlier...

I can remove the macros. They are patterned after the code in ACPI.

> 
>> +
>> +cxl_parse_entry(dsmas);
>> +cxl_parse_entry(dslbis);
>
Dan Williams April 24, 2023, 10:46 p.m. UTC | #3
Dave Jiang wrote:
> Provide a callback to parse the Device Scoped Latency and Bandwidth
> Information Structure (DSLBIS) in the CDAT structures. The DSLBIS
> contains the bandwidth and latency information that's tied to a DSMAS
> handle. The driver will retrieve the read and write latency and
> bandwidth associated with the DSMAS which is tied to a DPA range.
> 
> Coherent Device Attribute Table 1.03 2.1 Device Scoped Latency and
> Bandwidth Information Structure (DSLBIS)
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> 
> ---
> v3:
> - Added spec section in commit header. (Alison)
> - Remove void * recast. (Alison)
> - Rework comment. (Alison)
> - Move CDAT parse to cxl_endpoint_port_probe()
> - Convert to use 'struct node_hmem_attrs'
> 
> v2:
> - Add size check to DSLIBIS table. (Lukas)
> - Remove unnecessary entry type check. (Jonathan)
> - Move data_type check to after match. (Jonathan)
> - Skip unknown data type. (Jonathan)
> - Add overflow check for unit multiply. (Jonathan)
> - Use dev_warn() when entries parsing fail. (Jonathan)
> ---
>  drivers/cxl/core/cdat.c |   68 +++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/cxl/cxlpci.h    |   34 +++++++++++++++++++++++-
>  drivers/cxl/port.c      |   11 +++++++-
>  3 files changed, 111 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
> index 6f20af83a3ed..e8b9bb99dfdf 100644
> --- a/drivers/cxl/core/cdat.c
> +++ b/drivers/cxl/core/cdat.c
> @@ -1,5 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0-only
>  /* Copyright(c) 2023 Intel Corporation. All rights reserved. */
> +#include <linux/overflow.h>
>  #include "cxlpci.h"
>  #include "cxl.h"
>  
> @@ -124,3 +125,70 @@ int cxl_dsmas_parse_entry(struct cdat_entry_header *header, void *arg)
>  	return 0;
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_dsmas_parse_entry, CXL);
> +
> +static void cxl_hmem_attrs_set(struct node_hmem_attrs *attrs,
> +			       int access, unsigned int val)
> +{
> +	switch (access) {
> +	case HMAT_SLLBIS_ACCESS_LATENCY:
> +		attrs->read_latency = val;
> +		attrs->write_latency = val;
> +		break;
> +	case HMAT_SLLBIS_READ_LATENCY:
> +		attrs->read_latency = val;
> +		break;
> +	case HMAT_SLLBIS_WRITE_LATENCY:
> +		attrs->write_latency = val;
> +		break;
> +	case HMAT_SLLBIS_ACCESS_BANDWIDTH:
> +		attrs->read_bandwidth = val;
> +		attrs->write_bandwidth = val;
> +		break;
> +	case HMAT_SLLBIS_READ_BANDWIDTH:
> +		attrs->read_bandwidth = val;
> +		break;
> +	case HMAT_SLLBIS_WRITE_BANDWIDTH:
> +		attrs->write_bandwidth = val;
> +		break;
> +	}
> +}
> +
> +int cxl_dslbis_parse_entry(struct cdat_entry_header *header, void *arg)
> +{
> +	struct cdat_dslbis *dslbis = (struct cdat_dslbis *)header;
> +	struct list_head *dsmas_list = arg;
> +	struct dsmas_entry *dent;
> +
> +	if (dslbis->hdr.length != sizeof(*dslbis)) {
> +		pr_warn("Malformed DSLBIS table length: (%lu:%u)\n",
> +			(unsigned long)sizeof(*dslbis), dslbis->hdr.length);
> +		return -EINVAL;
> +	}
> +
> +	/* Skip unrecognized data type */
> +	if (dslbis->data_type >= HMAT_SLLBIS_DATA_TYPE_MAX)
> +		return 0;
> +
> +	list_for_each_entry(dent, dsmas_list, list) {
> +		u64 val;
> +		int rc;
> +
> +		if (dslbis->handle != dent->handle)
> +			continue;

Oh, now I see why the list is needed. Update the changelog of the
previous patch to indicate that the entries are cached to a list so they
can be cross referenced during dslbis parsing. At least that would have
saved me from picking on it.


> +
> +		/* Not a memory type, skip */
> +		if ((dslbis->flags & DSLBIS_MEM_MASK) != DSLBIS_MEM_MEMORY)
> +			return 0;
> +
> +		rc = check_mul_overflow(le64_to_cpu(dslbis->entry_base_unit),
> +					le16_to_cpu(dslbis->entry[0]), &val);
> +		if (unlikely(rc))

Don't use likely() / unlikely() without performance numbers. The
compiler generally does a better job and this is not a hot path.
Dave Jiang April 24, 2023, 10:59 p.m. UTC | #4
On 4/24/23 3:46 PM, Dan Williams wrote:
> Dave Jiang wrote:
>> Provide a callback to parse the Device Scoped Latency and Bandwidth
>> Information Structure (DSLBIS) in the CDAT structures. The DSLBIS
>> contains the bandwidth and latency information that's tied to a DSMAS
>> handle. The driver will retrieve the read and write latency and
>> bandwidth associated with the DSMAS which is tied to a DPA range.
>>
>> Coherent Device Attribute Table 1.03 2.1 Device Scoped Latency and
>> Bandwidth Information Structure (DSLBIS)
>>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>>
>> ---
>> v3:
>> - Added spec section in commit header. (Alison)
>> - Remove void * recast. (Alison)
>> - Rework comment. (Alison)
>> - Move CDAT parse to cxl_endpoint_port_probe()
>> - Convert to use 'struct node_hmem_attrs'
>>
>> v2:
>> - Add size check to DSLIBIS table. (Lukas)
>> - Remove unnecessary entry type check. (Jonathan)
>> - Move data_type check to after match. (Jonathan)
>> - Skip unknown data type. (Jonathan)
>> - Add overflow check for unit multiply. (Jonathan)
>> - Use dev_warn() when entries parsing fail. (Jonathan)
>> ---
>>   drivers/cxl/core/cdat.c |   68 +++++++++++++++++++++++++++++++++++++++++++++++
>>   drivers/cxl/cxlpci.h    |   34 +++++++++++++++++++++++-
>>   drivers/cxl/port.c      |   11 +++++++-
>>   3 files changed, 111 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
>> index 6f20af83a3ed..e8b9bb99dfdf 100644
>> --- a/drivers/cxl/core/cdat.c
>> +++ b/drivers/cxl/core/cdat.c
>> @@ -1,5 +1,6 @@
>>   // SPDX-License-Identifier: GPL-2.0-only
>>   /* Copyright(c) 2023 Intel Corporation. All rights reserved. */
>> +#include <linux/overflow.h>
>>   #include "cxlpci.h"
>>   #include "cxl.h"
>>   
>> @@ -124,3 +125,70 @@ int cxl_dsmas_parse_entry(struct cdat_entry_header *header, void *arg)
>>   	return 0;
>>   }
>>   EXPORT_SYMBOL_NS_GPL(cxl_dsmas_parse_entry, CXL);
>> +
>> +static void cxl_hmem_attrs_set(struct node_hmem_attrs *attrs,
>> +			       int access, unsigned int val)
>> +{
>> +	switch (access) {
>> +	case HMAT_SLLBIS_ACCESS_LATENCY:
>> +		attrs->read_latency = val;
>> +		attrs->write_latency = val;
>> +		break;
>> +	case HMAT_SLLBIS_READ_LATENCY:
>> +		attrs->read_latency = val;
>> +		break;
>> +	case HMAT_SLLBIS_WRITE_LATENCY:
>> +		attrs->write_latency = val;
>> +		break;
>> +	case HMAT_SLLBIS_ACCESS_BANDWIDTH:
>> +		attrs->read_bandwidth = val;
>> +		attrs->write_bandwidth = val;
>> +		break;
>> +	case HMAT_SLLBIS_READ_BANDWIDTH:
>> +		attrs->read_bandwidth = val;
>> +		break;
>> +	case HMAT_SLLBIS_WRITE_BANDWIDTH:
>> +		attrs->write_bandwidth = val;
>> +		break;
>> +	}
>> +}
>> +
>> +int cxl_dslbis_parse_entry(struct cdat_entry_header *header, void *arg)
>> +{
>> +	struct cdat_dslbis *dslbis = (struct cdat_dslbis *)header;
>> +	struct list_head *dsmas_list = arg;
>> +	struct dsmas_entry *dent;
>> +
>> +	if (dslbis->hdr.length != sizeof(*dslbis)) {
>> +		pr_warn("Malformed DSLBIS table length: (%lu:%u)\n",
>> +			(unsigned long)sizeof(*dslbis), dslbis->hdr.length);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* Skip unrecognized data type */
>> +	if (dslbis->data_type >= HMAT_SLLBIS_DATA_TYPE_MAX)
>> +		return 0;
>> +
>> +	list_for_each_entry(dent, dsmas_list, list) {
>> +		u64 val;
>> +		int rc;
>> +
>> +		if (dslbis->handle != dent->handle)
>> +			continue;
> 
> Oh, now I see why the list is needed. Update the changelog of the
> previous patch to indicate that the entries are cached to a list so they
> can be cross referenced during dslbis parsing. At least that would have
> saved me from picking on it.

Jonathan had the same comment. It'll be updated for the next rev to make 
the connection.

> 
> 
>> +
>> +		/* Not a memory type, skip */
>> +		if ((dslbis->flags & DSLBIS_MEM_MASK) != DSLBIS_MEM_MEMORY)
>> +			return 0;
>> +
>> +		rc = check_mul_overflow(le64_to_cpu(dslbis->entry_base_unit),
>> +					le16_to_cpu(dslbis->entry[0]), &val);
>> +		if (unlikely(rc))
> 
> Don't use likely() / unlikely() without performance numbers. The
> compiler generally does a better job and this is not a hot path.
diff mbox series

Patch

diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
index 6f20af83a3ed..e8b9bb99dfdf 100644
--- a/drivers/cxl/core/cdat.c
+++ b/drivers/cxl/core/cdat.c
@@ -1,5 +1,6 @@ 
 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright(c) 2023 Intel Corporation. All rights reserved. */
+#include <linux/overflow.h>
 #include "cxlpci.h"
 #include "cxl.h"
 
@@ -124,3 +125,70 @@  int cxl_dsmas_parse_entry(struct cdat_entry_header *header, void *arg)
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(cxl_dsmas_parse_entry, CXL);
+
+static void cxl_hmem_attrs_set(struct node_hmem_attrs *attrs,
+			       int access, unsigned int val)
+{
+	switch (access) {
+	case HMAT_SLLBIS_ACCESS_LATENCY:
+		attrs->read_latency = val;
+		attrs->write_latency = val;
+		break;
+	case HMAT_SLLBIS_READ_LATENCY:
+		attrs->read_latency = val;
+		break;
+	case HMAT_SLLBIS_WRITE_LATENCY:
+		attrs->write_latency = val;
+		break;
+	case HMAT_SLLBIS_ACCESS_BANDWIDTH:
+		attrs->read_bandwidth = val;
+		attrs->write_bandwidth = val;
+		break;
+	case HMAT_SLLBIS_READ_BANDWIDTH:
+		attrs->read_bandwidth = val;
+		break;
+	case HMAT_SLLBIS_WRITE_BANDWIDTH:
+		attrs->write_bandwidth = val;
+		break;
+	}
+}
+
+int cxl_dslbis_parse_entry(struct cdat_entry_header *header, void *arg)
+{
+	struct cdat_dslbis *dslbis = (struct cdat_dslbis *)header;
+	struct list_head *dsmas_list = arg;
+	struct dsmas_entry *dent;
+
+	if (dslbis->hdr.length != sizeof(*dslbis)) {
+		pr_warn("Malformed DSLBIS table length: (%lu:%u)\n",
+			(unsigned long)sizeof(*dslbis), dslbis->hdr.length);
+		return -EINVAL;
+	}
+
+	/* Skip unrecognized data type */
+	if (dslbis->data_type >= HMAT_SLLBIS_DATA_TYPE_MAX)
+		return 0;
+
+	list_for_each_entry(dent, dsmas_list, list) {
+		u64 val;
+		int rc;
+
+		if (dslbis->handle != dent->handle)
+			continue;
+
+		/* Not a memory type, skip */
+		if ((dslbis->flags & DSLBIS_MEM_MASK) != DSLBIS_MEM_MEMORY)
+			return 0;
+
+		rc = check_mul_overflow(le64_to_cpu(dslbis->entry_base_unit),
+					le16_to_cpu(dslbis->entry[0]), &val);
+		if (unlikely(rc))
+			pr_warn("DSLBIS value overflowed.\n");
+
+		cxl_hmem_attrs_set(&dent->hmem_attrs, dslbis->data_type, val);
+		break;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_dslbis_parse_entry, CXL);
diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
index 9a2468a93d83..0f36fb23055c 100644
--- a/drivers/cxl/cxlpci.h
+++ b/drivers/cxl/cxlpci.h
@@ -2,6 +2,7 @@ 
 /* Copyright(c) 2020 Intel Corporation. All rights reserved. */
 #ifndef __CXL_PCI_H__
 #define __CXL_PCI_H__
+#include <linux/node.h>
 #include <linux/pci.h>
 #include "cxl.h"
 
@@ -104,10 +105,21 @@  struct cdat_subtable_entry {
 	enum cdat_type type;
 };
 
+enum {
+	HMAT_SLLBIS_ACCESS_LATENCY = 0,
+	HMAT_SLLBIS_READ_LATENCY,
+	HMAT_SLLBIS_WRITE_LATENCY,
+	HMAT_SLLBIS_ACCESS_BANDWIDTH,
+	HMAT_SLLBIS_READ_BANDWIDTH,
+	HMAT_SLLBIS_WRITE_BANDWIDTH,
+	HMAT_SLLBIS_DATA_TYPE_MAX
+};
+
 struct dsmas_entry {
 	struct list_head list;
 	struct range dpa_range;
 	u8 handle;
+	struct node_hmem_attrs hmem_attrs;
 };
 
 /* Sub-table 0: Device Scoped Memory Affinity Structure (DSMAS) */
@@ -120,6 +132,22 @@  struct cdat_dsmas {
 	__le64 dpa_length;
 } __packed;
 
+/* Sub-table 1: Device Scoped Latency and Bandwidth Information Structure (DSLBIS) */
+struct cdat_dslbis {
+	struct cdat_entry_header hdr;
+	u8 handle;
+	u8 flags;
+	u8 data_type;
+	u8 reserved;
+	__le64 entry_base_unit;
+	__le16 entry[3];
+	__le16 reserved2;
+} __packed;
+
+/* Flags for DSLBIS subtable */
+#define DSLBIS_MEM_MASK		GENMASK(3, 0)
+#define DSLBIS_MEM_MEMORY	0
+
 int devm_cxl_port_enumerate_dports(struct cxl_port *port);
 struct cxl_dev_state;
 int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
@@ -136,5 +164,9 @@  cdat_table_parse(dsmas);
 cdat_table_parse(dslbis);
 cdat_table_parse(sslbis);
 
-int cxl_dsmas_parse_entry(struct cdat_entry_header *header, void *arg);
+#define cxl_parse_entry(x) \
+int cxl_##x##_parse_entry(struct cdat_entry_header *header, void *arg)
+
+cxl_parse_entry(dsmas);
+cxl_parse_entry(dslbis);
 #endif /* __CXL_PCI_H__ */
diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index 3022bdd52439..ab584b83010d 100644
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -141,8 +141,17 @@  static int cxl_endpoint_port_probe(struct cxl_port *port)
 		rc = cdat_table_parse_dsmas(port->cdat.table,
 					    cxl_dsmas_parse_entry,
 					    (void *)&dsmas_list);
-		if (rc < 0)
+		if (rc > 0) {
+			rc = cdat_table_parse_dslbis(port->cdat.table,
+						     cxl_dslbis_parse_entry,
+						     (void *)&dsmas_list);
+			if (rc <= 0) {
+				dev_warn(&port->dev,
+					 "Failed to parse DSLBIS: %d\n", rc);
+			}
+		} else {
 			dev_warn(&port->dev, "Failed to parse DSMAS: %d\n", rc);
+		}
 
 		dsmas_list_destroy(&dsmas_list);
 	}