[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.ghimi...@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