On Mon, Mar 27, 2023 at 02:44:39PM -0700, 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.
>
> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
>
> ---
> 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 | 41 +++++++++++++++++++++++++++++++++++++++++
> drivers/cxl/cxlpci.h | 34 +++++++++++++++++++++++++++++++++-
> drivers/cxl/port.c | 9 ++++++++-
> 3 files changed, 82 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
> index d068609fb6f9..0e88973e9f38 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 +125,43 @@ int cxl_dsmas_parse_entry(struct cdat_entry_header *header, void *arg)
> return 0;
> }
> EXPORT_SYMBOL_NS_GPL(cxl_dsmas_parse_entry, CXL);
> +
> +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 = (struct list_head *)arg;
cast from void ?
> + 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;
> + }
> +
> + /* Unrecognized data type, we can skip */
/* 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");
Must this be shouted !
I have a vague recollection of being told not to use exclamation points
in user visible messages.
> +
> + dent->qos[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..1429de49e0c4 100644
> --- a/drivers/cxl/cxlpci.h
> +++ b/drivers/cxl/cxlpci.h
> @@ -104,10 +104,21 @@ 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;
> + u64 qos[HMAT_SLLBIS_DATA_TYPE_MAX];
> };
>
> /* Sub-table 0: Device Scoped Memory Affinity Structure (DSMAS) */
> @@ -120,6 +131,23 @@ 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 subtable above */
/* 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 c8136797d528..6f2b327f7128 100644
> --- a/drivers/cxl/port.c
> +++ b/drivers/cxl/port.c
> @@ -152,8 +152,15 @@ static int cxl_port_probe(struct device *dev)
> 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(dev, "Failed to parse DSLBIS: %d\n", rc);
> + } else {
> dev_warn(dev, "Failed to parse DSMAS: %d\n", rc);
> + }
I see you touch this func more than once. Maybe some earlier nips and
tucks, makes this more readable.
>
> dsmas_list_destroy(&dsmas_list);
> }
>
>
