[v5 1/3] drm/xe: Add vram frequency sysfs attributes

[Rodrigo Vivi]

On Tue, Dec 19, 2023 at 03:37:09PM +0530, Sujaritha Sundaresan wrote:
> Add vram frequency sysfs attributes under the below hierarchy;
> 
> /device/tile#/memory/freq0
> 			|-rp0_freq
> 			|-rpn_freq
> 
> v2: Drop "vram" from attribute names (Rodrigo)
> 
> v3: Add documentation for new sysfs (Riana)
>     Drop prefix from XEHP_PCODE_FREQUENCY_CONFIG (Riana)
> 
> v4: Create sysfs under tile#/freq0 after removal of
>     physical_memsize attrbute
> 
> v5: Revert back to creating sysfs under tile#/memory/freq0
>     Remove definition of GT_FREQUENCY_MULTIPLIER (Rodrigo)
> 
> Signed-off-by: Sujaritha Sundaresan <sujaritha.sundaresan at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_pcode_api.h  |  8 +++
>  drivers/gpu/drm/xe/xe_tile_sysfs.c | 86 ++++++++++++++++++++++++++++++
>  2 files changed, 94 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_pcode_api.h b/drivers/gpu/drm/xe/xe_pcode_api.h
> index 5935cfe30204..4076a4e9daf3 100644
> --- a/drivers/gpu/drm/xe/xe_pcode_api.h
> +++ b/drivers/gpu/drm/xe/xe_pcode_api.h
> @@ -42,6 +42,14 @@
>  #define	    POWER_SETUP_I1_SHIFT		6	/* 10.6 fixed point format */
>  #define	    POWER_SETUP_I1_DATA_MASK		REG_GENMASK(15, 0)
>  
> +#define   PCODE_FREQUENCY_CONFIG		0x6e
> +/* PCODE_FREQUENCY_CONFIG sub-commands (param1) */
> +#define     PCODE_MBOX_FC_SC_READ_FUSED_P0	0x0
> +#define     PCODE_MBOX_FC_SC_READ_FUSED_PN	0x1
> +/* PCODE_MBOX_DOMAIN_* - mailbox domain IDs */
> +/* PCODE_FREQUENCY_CONFIG param2 */

let's keep some consistency here.
probably a single like like

/* Frequency Config Sub Commands (param1) */
above

and

/* Domain IDs (param2) */
here

> +#define     PCODE_MBOX_DOMAIN_HBM		0x2
> +
>  struct pcode_err_decode {
>  	int errno;
>  	const char *str;
> diff --git a/drivers/gpu/drm/xe/xe_tile_sysfs.c b/drivers/gpu/drm/xe/xe_tile_sysfs.c
> index 0f8d3e7fce46..1d34912e6184 100644
> --- a/drivers/gpu/drm/xe/xe_tile_sysfs.c
> +++ b/drivers/gpu/drm/xe/xe_tile_sysfs.c
> @@ -7,9 +7,21 @@
>  #include <linux/sysfs.h>
>  #include <drm/drm_managed.h>
>  
> +#include "xe_gt_types.h"
> +#include "xe_pcode.h"
> +#include "xe_pcode_api.h"
>  #include "xe_tile.h"
>  #include "xe_tile_sysfs.h"
>  
> +/**
> + * DOC: Xe Tile sysfs
> + *
> + * Provides sysfs entries for frequency in tile
> + *
> + * device/tile#/memory/freq0/rp0_freq - The Render Performance 0 level, which is the maximum one.
> + * device/tile#/memory/freq0/rpn_freq - The Render Performance N level, which is the minimal one.
> + */
> +
>  static void xe_tile_sysfs_kobj_release(struct kobject *kobj)
>  {
>  	kfree(kobj);
> @@ -20,6 +32,65 @@ static const struct kobj_type xe_tile_sysfs_kobj_type = {
>  	.sysfs_ops = &kobj_sysfs_ops,
>  };
>  
> +static ssize_t rp0_freq_show(struct device *kdev, struct device_attribute *attr,
> +			     char *buf)
> +{
> +	struct kobject *kobj = &kdev->kobj;
> +	struct xe_tile *tile = kobj_to_tile(kobj->parent);
> +	struct xe_gt *gt = tile->primary_gt;
> +	u32 val, mbox;
> +	int err;
> +
> +	mbox = REG_FIELD_PREP(PCODE_MB_COMMAND, PCODE_FREQUENCY_CONFIG)
> +		| REG_FIELD_PREP(PCODE_MB_PARAM1, PCODE_MBOX_FC_SC_READ_FUSED_P0)
> +		| REG_FIELD_PREP(PCODE_MB_PARAM2, PCODE_MBOX_DOMAIN_HBM);
> +
> +	err = xe_pcode_read(gt, mbox, &val, NULL);
> +	if (err)
> +		return err;
> +
> +	/* data_out - Fused P0 for domain ID in units of 50 MHz */
> +	val *= 50;
> +
> +	return sysfs_emit(buf, "%u\n", val);
> +}
> +static DEVICE_ATTR_RO(rp0_freq);
> +
> +static ssize_t rpn_freq_show(struct device *kdev, struct device_attribute *attr,
> +			     char *buf)
> +{
> +	struct kobject *kobj = &kdev->kobj;
> +	struct xe_tile *tile = kobj_to_tile(kobj->parent);
> +	struct xe_gt *gt = tile->primary_gt;
> +	u32 val, mbox;
> +	int err;
> +
> +	mbox = REG_FIELD_PREP(PCODE_MB_COMMAND, PCODE_FREQUENCY_CONFIG)
> +		| REG_FIELD_PREP(PCODE_MB_PARAM1, PCODE_MBOX_FC_SC_READ_FUSED_PN)
> +		| REG_FIELD_PREP(PCODE_MB_PARAM2, PCODE_MBOX_DOMAIN_HBM);
> +
> +	err = xe_pcode_read(gt, mbox, &val, NULL);
> +	if (err)
> +		return err;
> +
> +	/* data_out - Fused Pn for domain ID in units of 50 MHz */
> +	val *= 50;
> +
> +	return sysfs_emit(buf, "%u\n", val);
> +}
> +static DEVICE_ATTR_RO(rpn_freq);
> +
> +static struct attribute *freq_attrs[] = {
> +	&dev_attr_rp0_freq.attr,
> +	&dev_attr_rpn_freq.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group freq_group_attrs = {
> +	.name = "freq0",
> +	.attrs = freq_attrs,
> +};
> +
>  static void tile_sysfs_fini(struct drm_device *drm, void *arg)
>  {
>  	struct xe_tile *tile = arg;
> @@ -32,6 +103,7 @@ void xe_tile_sysfs_init(struct xe_tile *tile)
>  	struct xe_device *xe = tile_to_xe(tile);
>  	struct device *dev = xe->drm.dev;
>  	struct kobj_tile *kt;
> +	struct kobject *kobj;
>  	int err;
>  
>  	kt = kzalloc(sizeof(*kt), GFP_KERNEL);
> @@ -50,6 +122,20 @@ void xe_tile_sysfs_init(struct xe_tile *tile)
>  
>  	tile->sysfs = &kt->base;
>  
> +	if (xe->info.platform == XE_PVC) {
> +		kobj = kobject_create_and_add("memory", tile->sysfs);
> +		if (!kobj)
> +			drm_warn(&xe->drm, "%s failed, err: %d\n", __func__, -ENOMEM);

Please do not make up the error here. If it is a single error return by
the function we should probably do something like
 drm_warn(&xe->drm, "failed to add Tile memory directory\n");

> +	}
> +
> +	if (kobj && xe->info.platform == XE_PVC) {
> +		err = sysfs_create_group(kobj, &freq_group_attrs);
> +		if (err) {
> +			drm_warn(&xe->drm, "failed to register vram freq sysfs, err: %d\n", err);
> +			return;
> +		}
> +	}
> +
>  	err = drmm_add_action_or_reset(&xe->drm, tile_sysfs_fini, tile);
>  	if (err)
>  		drm_warn(&xe->drm, "%s: drmm_add_action_or_reset failed, err: %d\n",
> -- 
> 2.25.1
>