[v6] drm/xe: Add vram frequency sysfs attributes
Gupta, Anshuman
anshuman.gupta at intel.com
Tue Dec 26 14:28:56 UTC 2023
> -----Original Message-----
> From: Sundaresan, Sujaritha <sujaritha.sundaresan at intel.com>
> Sent: Tuesday, December 26, 2023 10:02 AM
> To: Gupta, Anshuman <anshuman.gupta at intel.com>; intel-
> xe at lists.freedesktop.org
> Cc: Vivi, Rodrigo <rodrigo.vivi at intel.com>
> Subject: Re: [v6] drm/xe: Add vram frequency sysfs attributes
>
>
> On 12/22/2023 7:34 PM, Gupta, Anshuman wrote:
> >
> >> -----Original Message-----
> >> From: Sundaresan, Sujaritha <sujaritha.sundaresan at intel.com>
> >> Sent: Friday, December 22, 2023 4:37 PM
> >> To: intel-xe at lists.freedesktop.org
> >> Cc: Vivi, Rodrigo <rodrigo.vivi at intel.com>; Gupta, Anshuman
> >> <anshuman.gupta at intel.com>; Sundaresan, Sujaritha
> >> <sujaritha.sundaresan at intel.com>
> >> Subject: [v6] drm/xe: Add vram frequency sysfs attributes
> >>
> >> Add vram frequency sysfs attributes under the below hierarchy;
> >>
> >> /device/tile#/memory/freq0
> >> |-max_freq
> >> |-min_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)
> >>
> >> v6: Rename attributes to max/min_freq (Anshuman)
> >> Fix review comments (Rodrigo)
> >>
> >> Signed-off-by: Sujaritha Sundaresan <sujaritha.sundaresan at intel.com>
> >> ---
> >> drivers/gpu/drm/xe/xe_pcode_api.h | 7 +++
> >> drivers/gpu/drm/xe/xe_tile_sysfs.c | 86
> >> ++++++++++++++++++++++++++++++
> >> 2 files changed, 93 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/xe/xe_pcode_api.h
> >> b/drivers/gpu/drm/xe/xe_pcode_api.h
> >> index 5935cfe30204..f153ce96f69a 100644
> >> --- a/drivers/gpu/drm/xe/xe_pcode_api.h
> >> +++ b/drivers/gpu/drm/xe/xe_pcode_api.h
> >> @@ -42,6 +42,13 @@
> >> #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
> >> +/* Frequency Config Sub Commands (param1) */
> >> +#define PCODE_MBOX_FC_SC_READ_FUSED_P0 0x0
> >> +#define PCODE_MBOX_FC_SC_READ_FUSED_PN 0x1
> >> +/* Domain IDs (param2) */
> >> +#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..cdc9dbbc97b0 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/max_freq - Maximum Frequency, not a
> >> configuration and read-only.
> > Let's increase verbosity of doc something explaining it is a fixed fuse point not a
> configuration.
> Sure
> >> + * device/tile#/memory/freq0/min_freq - Minimum Frequency, not a
> >> configuration and read-only.
> >> + */
> >> +
> >> 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 max_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(max_freq);
> >> +
> >> +static ssize_t min_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);
> > If you are missing to create a kobject for freq0 , then this should be
> > kobj->parent->parent.
>
> I don't think a kobject is needed for freq0, since it we are only using
> attribute_group for it.
>
> Similar to throttle_reasons.
Sure, thanks for explanation.
>
> >> + 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(min_freq);
> >> +
> >> +static struct attribute *freq_attrs[] = {
> >> + &dev_attr_max_freq.attr,
> >> + &dev_attr_min_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);
> > How freq0 is getting added, I am unable to see the freq0 kobject as per the path
> "device/tile#/memory/freq0/"
> freq0 is being added as an attribute group. It is similar to the throttle_reasons
> implementation.
> >> + if (!kobj)
> >> + drm_warn(&xe->drm, "failed to add memory
> >> directory, err: %d\n", -ENOMEM);
> >> + }
> >> +
> >> + 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;
> >> + }
> >> + }
> > Don't we need sysfs cleanup and kobject_put in tile_sysfs_fini() ?
> > Have you made sure kmemleak won't complain here on memory leak ?
Check the kobject_release() , this will only get call , when all ref count of that kobj is being put.
Here you are creating a object and it will never be released.
Also we need to call the sysfs_remove_group() as well in fini function ?
Thanks,
Anshuman.
> >
> > Thanks,
> > Anshuman Gupta.
>
> I have already checked for mem leaks during the cleanup. The kobject_put is not
> needed.
>
> Thanks,
>
> Suja
>
> >> +
> >> 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
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