[Intel-gfx] [PATCH 1/1] drm/i915: Export LMEM max memory bandwidth via sysfs.

[Himal Prasad Ghimiray]

Export lmem maximum memory bandwidth to the userspace via sysfs.

Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h   |  2 ++
 drivers/gpu/drm/i915/i915_sysfs.c | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index c4921c9a60770..3ba1efa995ca9 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6603,6 +6603,8 @@
 #define	    POWER_SETUP_I1_WATTS		REG_BIT(31)
 #define	    POWER_SETUP_I1_SHIFT		6	/* 10.6 fixed point format */
 #define	    POWER_SETUP_I1_DATA_MASK		REG_GENMASK(15, 0)
+#define	  PCODE_MEMORY_CONFIG			0x70
+#define	    MEMORY_CONFIG_SUBCOMMAND_READ_MAX_BANDWIDTH 0x0
 #define GEN12_PCODE_READ_SAGV_BLOCK_TIME_US	0x23
 #define   XEHP_PCODE_FREQUENCY_CONFIG		0x6e	/* xehpsdv, pvc */
 /* XEHP_PCODE_FREQUENCY_CONFIG sub-commands (param1) */
diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index 595e8b5749907..0a6efc300998b 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -37,7 +37,10 @@
 
 #include "i915_drv.h"
 #include "i915_sysfs.h"
+#include "i915_reg.h"
 #include "intel_pm.h"
+#include "intel_pcode.h"
+
 
 struct drm_i915_private *kdev_minor_to_i915(struct device *kdev)
 {
@@ -231,11 +234,35 @@ static void i915_setup_error_capture(struct device *kdev) {}
 static void i915_teardown_error_capture(struct device *kdev) {}
 #endif
 
+static ssize_t
+prelim_lmem_max_bw_Mbps_show(struct device *dev, struct device_attribute *attr, char *buff)
+{
+	struct drm_i915_private *i915 = kdev_minor_to_i915(dev);
+	u32 val;
+	int err;
+
+	err = snb_pcode_read_p(&i915->uncore, PCODE_MEMORY_CONFIG,
+			       MEMORY_CONFIG_SUBCOMMAND_READ_MAX_BANDWIDTH,
+			       0x0, &val);
+	if (err)
+		return err;
+
+	return sysfs_emit(buff, "%u\n", val);
+}
+
+static DEVICE_ATTR_RO(prelim_lmem_max_bw_Mbps);
+
 void i915_setup_sysfs(struct drm_i915_private *dev_priv)
 {
 	struct device *kdev = dev_priv->drm.primary->kdev;
 	int ret;
 
+	if (IS_DG1(dev_priv) || IS_DG2(dev_priv)) {
+		ret = sysfs_create_file(&kdev->kobj, &dev_attr_prelim_lmem_max_bw_Mbps.attr);
+		if (ret)
+			drm_err(&dev_priv->drm, "Setting up sysfs to read max B/W failed\n");
+	}
+
 	if (HAS_L3_DPF(dev_priv)) {
 		ret = device_create_bin_file(kdev, &dpf_attrs);
 		if (ret)
-- 
2.25.1