drm/xe: Add vram frequency sysfs attributes

Add vram frequency sysfs attributes under the below hierarchy;

/device/tile#/memory/freq0
			|-max_freq
			|-min_freq

v2: Drop "vram" from attribute names (Rodrigo)

v3: Add documentation for new sysfs (Riana)
    Drop prefix from XEHP_PCODE_FREQUENCY_CONFIG (Riana)

v4: Create sysfs under tile#/freq0 after removal of
    physical_memsize attrbute

v5: Revert back to creating sysfs under tile#/memory/freq0
    Remove definition of GT_FREQUENCY_MULTIPLIER (Rodrigo)

v6: Rename attributes to max/min_freq (Anshuman)
    Fix review comments (Rodrigo)

v7: Make documentation more verbose
    Move sysfs to separate file (Anshuman)

v8: Fix platform specific conditions and add kernel doc (Anshuman)
    Fix typos and remove redundant headers (Riana)

v9: Fix typo (Riana)
    Change function name to include "sysfs" (Lucas)

Signed-off-by: Sujaritha Sundaresan <sujaritha.sundaresan@intel.com>
Reviewed-by: Anshuman Gupta <anshuman.gupta@intel.com>
Link: https://lore.kernel.org/r/20240109110418.2065101-1-sujaritha.sundaresan@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

1 files changed, 129 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_vram_freq.c b/drivers/gpu/drm/xe/xe_vram_freq.c
new file mode 100644
index 000000000000..733146293307
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_vram_freq.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+#include <linux/sysfs.h>
+#include <drm/drm_managed.h>
+
+#include "xe_gt_types.h"
+#include "xe_pcode.h"
+#include "xe_pcode_api.h"
+#include "xe_tile.h"
+#include "xe_tile_sysfs.h"
+#include "xe_vram_freq.h"
+
+/**
+ * DOC: Xe VRAM freq
+ *
+ * Provides sysfs entries for vram frequency in tile
+ *
+ * device/tile#/memory/freq0/max_freq - This is maximum frequency. This value is read-only as it
+ *					is the fixed fuse point P0. It is not the system
+ *					configuration.
+ * device/tile#/memory/freq0/min_freq - This is minimum frequency. This value is read-only as it
+ *					is the fixed fuse point PN. It is not the system
+ *					configuration.
+ */
+
+static struct xe_tile *dev_to_tile(struct device *dev)
+{
+	return kobj_to_tile(dev->kobj.parent);
+}
+
+static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct xe_tile *tile = dev_to_tile(dev);
+	struct xe_gt *gt = tile->primary_gt;
+	u32 val, mbox;
+	int err;
+
+	mbox = REG_FIELD_PREP(PCODE_MB_COMMAND, PCODE_FREQUENCY_CONFIG)
+		| REG_FIELD_PREP(PCODE_MB_PARAM1, PCODE_MBOX_FC_SC_READ_FUSED_P0)
+		| REG_FIELD_PREP(PCODE_MB_PARAM2, PCODE_MBOX_DOMAIN_HBM);
+
+	err = xe_pcode_read(gt, mbox, &val, NULL);
+	if (err)
+		return err;
+
+	/* data_out - Fused P0 for domain ID in units of 50 MHz */
+	val *= 50;
+
+	return sysfs_emit(buf, "%u\n", val);
+}
+static DEVICE_ATTR_RO(max_freq);
+
+static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct xe_tile *tile = dev_to_tile(dev);
+	struct xe_gt *gt = tile->primary_gt;
+	u32 val, mbox;
+	int err;
+
+	mbox = REG_FIELD_PREP(PCODE_MB_COMMAND, PCODE_FREQUENCY_CONFIG)
+		| REG_FIELD_PREP(PCODE_MB_PARAM1, PCODE_MBOX_FC_SC_READ_FUSED_PN)
+		| REG_FIELD_PREP(PCODE_MB_PARAM2, PCODE_MBOX_DOMAIN_HBM);
+
+	err = xe_pcode_read(gt, mbox, &val, NULL);
+	if (err)
+		return err;
+
+	/* data_out - Fused Pn for domain ID in units of 50 MHz */
+	val *= 50;
+
+	return sysfs_emit(buf, "%u\n", val);
+}
+static DEVICE_ATTR_RO(min_freq);
+
+static struct attribute *freq_attrs[] = {
+	&dev_attr_max_freq.attr,
+	&dev_attr_min_freq.attr,
+	NULL
+};
+
+static const struct attribute_group freq_group_attrs = {
+	.name = "freq0",
+	.attrs = freq_attrs,
+};
+
+static void vram_freq_sysfs_fini(struct drm_device *drm, void *arg)
+{
+	struct kobject *kobj = arg;
+
+	sysfs_remove_group(kobj, &freq_group_attrs);
+	kobject_put(kobj);
+}
+
+/*
+ * xe_vram_freq_init - Initialize vram frequency component
+ * @tile: Xe Tile object
+ *
+ * It needs to be initialized after the main tile component is ready
+ */
+
+void xe_vram_freq_sysfs_init(struct xe_tile *tile)
+{
+	struct xe_device *xe = tile_to_xe(tile);
+	struct kobject *kobj;
+	int err;
+
+	if (xe->info.platform != XE_PVC)
+		return;
+
+	kobj = kobject_create_and_add("memory", tile->sysfs);
+	if (!kobj)
+		drm_warn(&xe->drm, "failed to add memory directory, err: %d\n", -ENOMEM);
+
+	err = sysfs_create_group(kobj, &freq_group_attrs);
+	if (err) {
+		kobject_put(kobj);
+		drm_warn(&xe->drm, "failed to register vram freq sysfs, err: %d\n", err);
+		return;
+	}
+
+	err = drmm_add_action_or_reset(&xe->drm, vram_freq_sysfs_fini, kobj);
+	if (err)
+		drm_warn(&xe->drm, "%s: drmm_add_action_or_reset failed, err: %d\n",
+			 __func__, err);
+}