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

[Ghimiray, Himal Prasad]

> -----Original Message-----
> From: Gupta, Anshuman <anshuman.gupta at intel.com>
> Sent: 16 November 2022 15:38
> To: Ghimiray, Himal Prasad <himal.prasad.ghimiray at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Iddamsetty, Aravind <aravind.iddamsetty at intel.com>
> Subject: RE: [Intel-gfx] [PATCH 1/1] drm/i915: Export LMEM max memory
> bandwidth via sysfs.
> 
> 
> 
> > -----Original Message-----
> > From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of
> > Himal Prasad Ghimiray
> > Sent: Tuesday, November 15, 2022 1:39 PM
> > To: intel-gfx at lists.freedesktop.org
> > Subject: [Intel-gfx] [PATCH 1/1] drm/i915: Export LMEM max memory
> > bandwidth via sysfs.
> >
> > 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
> Please re-arrange the macros in  increasing order of pcode command.
> > +#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
> Please don't use mixed case here,
> How about i915_lmem_max_bw_mbps_show ?
[Ghimiray, Himal Prasad] 
We need to differentiate between Mb (Mega bit) vs MB(MegaByte) ,Hence I used camelCase.
Using i915_lmem_max_bw_mbps_show will not give clarity whether the value is in Mb or MB.

BR
Himal Ghimiray
> > +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)) {
> This seems to discrete agnostic.
> How about HAS_LMEM ?
> > +		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");
> Why this sys fs is outside gt directory ?
> Thanks,
> Anshuman.
> > +	}
> > +
> >  	if (HAS_L3_DPF(dev_priv)) {
> >  		ret = device_create_bin_file(kdev, &dpf_attrs);
> >  		if (ret)
> > --
> > 2.25.1