@@ -525,22 +525,11 @@ static int get_genport_coordinates(struct device *dev, struct cxl_dport *dport)
{
struct acpi_device *hb = to_cxl_host_bridge(NULL, dev);
u32 uid;
- int rc;
if (kstrtou32(acpi_device_uid(hb), 0, &uid))
return -EINVAL;
- rc = acpi_get_genport_coordinates(uid, dport->coord);
- if (rc < 0)
- return rc;
-
- /* Adjust back to picoseconds from nanoseconds */
- for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {
- dport->coord[i].read_latency *= 1000;
- dport->coord[i].write_latency *= 1000;
- }
-
- return 0;
+ return acpi_get_genport_coordinates(uid, dport->coord);
}
static int add_host_bridge_dport(struct device *match, void *arg)
@@ -20,6 +20,37 @@ struct dsmas_entry {
int qos_class;
};
+static u32 cdat_normalize(u16 entry, u64 base, u8 type)
+{
+ u32 value;
+
+ /*
+ * Check for invalid and overflow values
+ */
+ if (entry == 0xffff || !entry)
+ return 0;
+ else if (base > (UINT_MAX / (entry)))
+ return 0;
+
+ value = entry * base;
+ switch (type) {
+ case ACPI_HMAT_ACCESS_LATENCY:
+ case ACPI_HMAT_READ_LATENCY:
+ case ACPI_HMAT_WRITE_LATENCY:
+ value = DIV_ROUND_UP(value, 1000);
+ /*
+ * With latency being converted from picoseconds to nanoseconds,
+ * ensure that latency is at least 1 for sub-nanosecond latency
+ * values.
+ */
+ value = min_not_zero((u32)1, value);
+ break;
+ default:
+ break;
+ }
+ return value;
+}
+
static int cdat_dsmas_handler(union acpi_subtable_headers *header, void *arg,
const unsigned long end)
{
@@ -104,7 +135,6 @@ static int cdat_dslbis_handler(union acpi_subtable_headers *header, void *arg,
__le16 le_val;
u64 val;
u16 len;
- int rc;
len = le16_to_cpu((__force __le16)hdr->length);
if (len != size || (unsigned long)hdr + len > end) {
@@ -131,10 +161,8 @@ static int cdat_dslbis_handler(union acpi_subtable_headers *header, void *arg,
le_base = (__force __le64)dslbis->entry_base_unit;
le_val = (__force __le16)dslbis->entry[0];
- rc = check_mul_overflow(le64_to_cpu(le_base),
- le16_to_cpu(le_val), &val);
- if (rc)
- pr_warn("DSLBIS value overflowed.\n");
+ val = cdat_normalize(le16_to_cpu(le_val), le64_to_cpu(le_base),
+ dslbis->data_type);
cxl_access_coordinate_set(dent->coord, dslbis->data_type, val);
@@ -456,10 +484,8 @@ static int cdat_sslbis_handler(union acpi_subtable_headers *header, void *arg,
le_base = (__force __le64)tbl->sslbis_header.entry_base_unit;
le_val = (__force __le16)tbl->entries[i].latency_or_bandwidth;
-
- if (check_mul_overflow(le64_to_cpu(le_base),
- le16_to_cpu(le_val), &val))
- dev_warn(dev, "SSLBIS value overflowed!\n");
+ val = cdat_normalize(le16_to_cpu(le_val), le64_to_cpu(le_base),
+ sslbis->data_type);
xa_for_each(&port->dports, index, dport) {
if (dsp_id == ACPI_CDAT_SSLBIS_ANY_PORT ||
@@ -559,16 +585,6 @@ void cxl_region_perf_data_calculate(struct cxl_region *cxlr,
perf->coord[i].write_latency);
cxlr->coord[i].read_bandwidth += perf->coord[i].read_bandwidth;
cxlr->coord[i].write_bandwidth += perf->coord[i].write_bandwidth;
-
- /*
- * Convert latency to nanosec from picosec to be consistent
- * with the resulting latency coordinates computed by the
- * HMAT_REPORTING code.
- */
- cxlr->coord[i].read_latency =
- DIV_ROUND_UP(cxlr->coord[i].read_latency, 1000);
- cxlr->coord[i].write_latency =
- DIV_ROUND_UP(cxlr->coord[i].write_latency, 1000);
}
}
Current math in cxl_region_perf_data_calculate divides the latency by 1000 every time the function gets called. This causes the region latency to be divided by 1000 per memory device and the math is incorrect. This is user visible as the latency access_coordinate exposed via sysfs will show incorrect latency data. Normalize values from CDAT to nanoseconds. Adjust sub-nanoseconds latency to at least 1. Remove adjustment of perf numbers from the generic target since hmat handling code has already normalized those numbers. Now all computation and stored numbers should be in nanoseconds. Fixes: 3d9f4a197230 ("cxl/region: Calculate performance data for a region") Signed-off-by: Dave Jiang <dave.jiang@intel.com> --- v6: - Normalize values from CDAT to nanoseconds. (Dan) --- drivers/cxl/acpi.c | 13 +--------- drivers/cxl/core/cdat.c | 54 ++++++++++++++++++++++++++--------------- 2 files changed, 36 insertions(+), 31 deletions(-)