platform/mellanox: mlxbf-pmc: Add support for monitoring cycle count

Add support for programming any counter to monitor the cycle count.
This will allow the user to repurpose and dedicate any of the counters
in the block to counting cycles.

Signed-off-by: Shravan Kumar Ramani <shravankr@nvidia.com>
Reviewed-by: David Thompson <davthompson@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/bd7747897cf1ce77e2e39e271cac21684830f7e7.1736413033.git.shravankr@nvidia.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/mellanox/mlxbf-pmc.c b/drivers/platform/mellanox/mlxbf-pmc.c
index 9ff7b487dc4892b9a276ae606f699bf2b2822dc4..6d3abc438a9d24a6f2fdf2aaae1c58e22ded2807 100644 (file)
--- a/drivers/platform/mellanox/mlxbf-pmc.c
+++ b/drivers/platform/mellanox/mlxbf-pmc.c
@@ -88,6 +88,7 @@
 #define MLXBF_PMC_CRSPACE_PERFMON_CTL(n) (n * MLXBF_PMC_CRSPACE_PERFMON_REG0_SZ)
 #define MLXBF_PMC_CRSPACE_PERFMON_EN BIT(30)
 #define MLXBF_PMC_CRSPACE_PERFMON_CLR BIT(28)
+#define MLXBF_PMC_CRSPACE_PERFMON_COUNT_CLOCK(n) (MLXBF_PMC_CRSPACE_PERFMON_CTL(n) + 0x4)
 #define MLXBF_PMC_CRSPACE_PERFMON_VAL0(n) (MLXBF_PMC_CRSPACE_PERFMON_CTL(n) + 0xc)
 
 /**
@@ -114,6 +115,7 @@ struct mlxbf_pmc_attribute {
  * @attr_event: Attributes for "event" sysfs files
  * @attr_event_list: Attributes for "event_list" sysfs files
  * @attr_enable: Attributes for "enable" sysfs files
+ * @attr_count_clock: Attributes for "count_clock" sysfs files
  * @block_attr: All attributes needed for the block
  * @block_attr_grp: Attribute group for the block
  */
@@ -126,6 +128,7 @@ struct mlxbf_pmc_block_info {
        struct mlxbf_pmc_attribute *attr_event;
        struct mlxbf_pmc_attribute attr_event_list;
        struct mlxbf_pmc_attribute attr_enable;
+       struct mlxbf_pmc_attribute attr_count_clock;
        struct attribute *block_attr[MLXBF_PMC_MAX_ATTRS];
        struct attribute_group block_attr_grp;
 };
@@ -1763,6 +1766,49 @@ static ssize_t mlxbf_pmc_enable_store(struct device *dev,
        return count;
 }
 
+/* Show function for "count_clock" sysfs files - only for crspace */
+static ssize_t mlxbf_pmc_count_clock_show(struct device *dev,
+                                         struct device_attribute *attr, char *buf)
+{
+       struct mlxbf_pmc_attribute *attr_count_clock = container_of(
+               attr, struct mlxbf_pmc_attribute, dev_attr);
+       unsigned int blk_num;
+       u32 reg;
+
+       blk_num = attr_count_clock->nr;
+
+       if (mlxbf_pmc_readl(pmc->block[blk_num].mmio_base +
+                       MLXBF_PMC_CRSPACE_PERFMON_COUNT_CLOCK(pmc->block[blk_num].counters),
+                       &reg))
+               return -EINVAL;
+
+       return sysfs_emit(buf, "%u\n", reg);
+}
+
+/* Store function for "count_clock" sysfs files - only for crspace */
+static ssize_t mlxbf_pmc_count_clock_store(struct device *dev,
+                                          struct device_attribute *attr,
+                                          const char *buf, size_t count)
+{
+       struct mlxbf_pmc_attribute *attr_count_clock = container_of(
+               attr, struct mlxbf_pmc_attribute, dev_attr);
+       unsigned int blk_num;
+       u32 reg;
+       int err;
+
+       blk_num = attr_count_clock->nr;
+
+       err = kstrtouint(buf, 0, &reg);
+       if (err < 0)
+               return err;
+
+       mlxbf_pmc_write(pmc->block[blk_num].mmio_base +
+               MLXBF_PMC_CRSPACE_PERFMON_COUNT_CLOCK(pmc->block[blk_num].counters),
+               MLXBF_PMC_WRITE_REG_32, reg);
+
+       return count;
+}
+
 /* Populate attributes for blocks with counters to monitor performance */
 static int mlxbf_pmc_init_perftype_counter(struct device *dev, unsigned int blk_num)
 {
@@ -1801,6 +1847,21 @@ static int mlxbf_pmc_init_perftype_counter(struct device *dev, unsigned int blk_
                attr = NULL;
        }
 
+       if (pmc->block[blk_num].type == MLXBF_PMC_TYPE_CRSPACE) {
+               /* Program crspace counters to count clock cycles using "count_clock" sysfs */
+               attr = &pmc->block[blk_num].attr_count_clock;
+               attr->dev_attr.attr.mode = 0644;
+               attr->dev_attr.show = mlxbf_pmc_count_clock_show;
+               attr->dev_attr.store = mlxbf_pmc_count_clock_store;
+               attr->nr = blk_num;
+               attr->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
+                                                         "count_clock");
+               if (!attr->dev_attr.attr.name)
+                       return -ENOMEM;
+               pmc->block[blk_num].block_attr[++i] = &attr->dev_attr.attr;
+               attr = NULL;
+       }
+
        pmc->block[blk_num].attr_counter = devm_kcalloc(
                dev, pmc->block[blk_num].counters,
                sizeof(struct mlxbf_pmc_attribute), GFP_KERNEL);