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

["Iddamsetty, Aravind" <aravind.iddamsetty@intel.com>]

On 15-11-2022 13:38, Himal Prasad Ghimiray wrote:
> Export lmem maximum memory bandwidth to the userspace via sysfs.
> 
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@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
>  

prelim naming shall not be used.

Thanks,
Aravind.
> +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)