Commit f3bc5bb4 authored by Niranjana Vishwanathapura's avatar Niranjana Vishwanathapura Committed by Rodrigo Vivi
Browse files

drm/xe: Allow userspace to configure CCS mode 



Allow user to configure the CCS mode setting through a
'ccs_mode' sysfs interface. Also report the current
CCS mode configuration and number of compute slices
available through this interface.

v2: Rebase, make it platform agnostic
v3: Separte out num_cslices sysfs interface and make
    xe_gt_ccs_mode_sysfs_init() return void

Reviewed-by: default avatarAndi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: default avatarNiranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
parent 0d97ecce

drivers/gpu/drm/xe/xe_gt.c

+3 −0
Original line number Diff line number Diff line
@@ -378,6 +378,9 @@ static int gt_fw_domain_init(struct xe_gt *gt) 
			 "failed to register engines sysfs directory, err: %d\n",

			 err);



	/* Initialize CCS mode sysfs after early initialization of HW engines */

	xe_gt_ccs_mode_sysfs_init(gt);



	err = xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);

	XE_WARN_ON(err);

	xe_device_mem_access_put(gt_to_xe(gt));

drivers/gpu/drm/xe/xe_gt_ccs_mode.c

+103 −0
Original line number Diff line number Diff line
@@ -3,10 +3,13 @@ 
 * Copyright © 2023 Intel Corporation

 */



#include <drm/drm_managed.h>



#include "regs/xe_gt_regs.h"

#include "xe_assert.h"

#include "xe_gt.h"

#include "xe_gt_ccs_mode.h"

#include "xe_gt_sysfs.h"

#include "xe_mmio.h"



static void __xe_gt_apply_ccs_mode(struct xe_gt *gt, u32 num_engines)
@@ -76,3 +79,103 @@ void xe_gt_apply_ccs_mode(struct xe_gt *gt) 


	__xe_gt_apply_ccs_mode(gt, gt->ccs_mode);

}



static ssize_t

num_cslices_show(struct device *kdev,

		 struct device_attribute *attr, char *buf)

{

	struct xe_gt *gt = kobj_to_gt(&kdev->kobj);



	return sysfs_emit(buf, "%u\n", hweight32(CCS_MASK(gt)));

}



static DEVICE_ATTR_RO(num_cslices);



static ssize_t

ccs_mode_show(struct device *kdev,

	      struct device_attribute *attr, char *buf)

{

	struct xe_gt *gt = kobj_to_gt(&kdev->kobj);



	return sysfs_emit(buf, "%u\n", gt->ccs_mode);

}



static ssize_t

ccs_mode_store(struct device *kdev, struct device_attribute *attr,

	       const char *buff, size_t count)

{

	struct xe_gt *gt = kobj_to_gt(&kdev->kobj);

	u32 num_engines, num_slices;

	int ret;



	ret = kstrtou32(buff, 0, &num_engines);

	if (ret)

		return ret;



	/*

	 * Ensure number of engines specified is valid and there is an

	 * exact multiple of engines for slices.

	 */

	num_slices = hweight32(CCS_MASK(gt));

	if (!num_engines || num_engines > num_slices || num_slices % num_engines) {

		xe_gt_dbg(gt, "Invalid compute config, %d engines %d slices\n",

			  num_engines, num_slices);

		return -EINVAL;

	}



	if (gt->ccs_mode != num_engines) {

		xe_gt_info(gt, "Setting compute mode to %d\n", num_engines);

		gt->ccs_mode = num_engines;

		xe_gt_reset_async(gt);

	}



	return count;

}



static DEVICE_ATTR_RW(ccs_mode);



static const struct attribute *gt_ccs_mode_attrs[] = {

	&dev_attr_ccs_mode.attr,

	&dev_attr_num_cslices.attr,

	NULL,

};



static void xe_gt_ccs_mode_sysfs_fini(struct drm_device *drm, void *arg)

{

	struct xe_gt *gt = arg;



	sysfs_remove_files(gt->sysfs, gt_ccs_mode_attrs);

}



/**

 * xe_gt_ccs_mode_sysfs_init - Initialize CCS mode sysfs interfaces

 * @gt: GT structure

 *

 * Through a per-gt 'ccs_mode' sysfs interface, the user can enable a fixed

 * number of compute hardware engines to which the available compute slices

 * are to be allocated. This user configuration change triggers a gt reset

 * and it is expected that there are no open drm clients while doing so.

 * The number of available compute slices is exposed to user through a per-gt

 * 'num_cslices' sysfs interface.

 */

void xe_gt_ccs_mode_sysfs_init(struct xe_gt *gt)

{

	struct xe_device *xe = gt_to_xe(gt);

	int err;



	if (!xe_gt_ccs_mode_enabled(gt))

		return;



	err = sysfs_create_files(gt->sysfs, gt_ccs_mode_attrs);

	if (err) {

		drm_warn(&xe->drm, "Sysfs creation for ccs_mode failed err: %d\n", err);

		return;

	}



	err = drmm_add_action_or_reset(&xe->drm, xe_gt_ccs_mode_sysfs_fini, gt);

	if (err) {

		sysfs_remove_files(gt->sysfs, gt_ccs_mode_attrs);

		drm_warn(&xe->drm, "%s: drmm_add_action_or_reset failed, err: %d\n",

			 __func__, err);

	}

}

drivers/gpu/drm/xe/xe_gt_ccs_mode.h

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include "xe_platform_types.h"



void xe_gt_apply_ccs_mode(struct xe_gt *gt);

void xe_gt_ccs_mode_sysfs_init(struct xe_gt *gt);



static inline bool xe_gt_ccs_mode_enabled(const struct xe_gt *gt)

{