[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

(v2)
Add TODO comment to have client parts specific condition (Anshuman)
Remove prelim prefix from the sysfs node name (Aravind)

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 | 28 ++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 8e1892d147741..1d59b84b86ad2 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6606,6 +6606,8 @@
 #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..69df2012bd10e 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 +234,36 @@ static void i915_setup_error_capture(struct device *kdev) {}
 static void i915_teardown_error_capture(struct device *kdev) {}
 #endif
 
+static ssize_t
+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(lmem_max_bw_Mbps);
+
 void i915_setup_sysfs(struct drm_i915_private *dev_priv)
 {
 	struct device *kdev = dev_priv->drm.primary->kdev;
 	int ret;
 
+	/*TODO: Need to add client Parts condition check. */
+	if (IS_DG1(dev_priv) || IS_DG2(dev_priv)) {
+		ret = sysfs_create_file(&kdev->kobj, &dev_attr_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