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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
*
* (C) COPYRIGHT 2020-2021 ARM Limited. All rights reserved.
*
* This program is free software and is provided to you under the terms of the
* GNU General Public License version 2 as published by the Free Software
* Foundation, and any use by you of this program is subject to the terms
* of such GNU license.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
*/
#ifndef _KBASE_CCSWE_H_
#define _KBASE_CCSWE_H_
#include <linux/spinlock.h>
/**
* struct kbase_ccswe - Cycle count software estimator.
*
* @access: Spinlock protecting this structure access.
* @timestamp_ns: Timestamp(ns) when the last frequency change
* occurred.
* @cycles_elapsed: Number of cycles elapsed before the last frequency
* change
* @gpu_freq: Current GPU frequency(Hz) value.
* @prev_gpu_freq: Previous GPU frequency(Hz) before the last frequency
* change.
*/
struct kbase_ccswe {
spinlock_t access;
u64 timestamp_ns;
u64 cycles_elapsed;
u32 gpu_freq;
u32 prev_gpu_freq;
};
/**
* kbase_ccswe_init() - initialize the cycle count estimator.
*
* @self: Cycles count software estimator instance.
*/
void kbase_ccswe_init(struct kbase_ccswe *self);
/**
* kbase_ccswe_cycle_at() - Estimate cycle count at given timestamp.
*
* @self: Cycles count software estimator instance.
* @timestamp_ns: The timestamp(ns) for cycle count estimation.
*
* The timestamp must be bigger than the timestamp of the penultimate
* frequency change. If only one frequency change occurred, the
* timestamp must be bigger than the timestamp of the frequency change.
* This is to allow the following code to be executed w/o synchronization.
* If lines below executed atomically, it is safe to assume that only
* one frequency change may happen in between.
*
* u64 ts = ktime_get_raw_ns();
* u64 cycle = kbase_ccswe_cycle_at(&ccswe, ts)
*
* Returns: estimated value of cycle count at a given time.
*/
u64 kbase_ccswe_cycle_at(struct kbase_ccswe *self, u64 timestamp_ns);
/**
* kbase_ccswe_freq_change() - update GPU frequency.
*
* @self: Cycles count software estimator instance.
* @timestamp_ns: Timestamp(ns) when frequency change occurred.
* @gpu_freq: New GPU frequency value.
*
* The timestamp must be bigger than the timestamp of the previous
* frequency change. The function is to be called at the frequency
* change moment (not later).
*/
void kbase_ccswe_freq_change(
struct kbase_ccswe *self, u64 timestamp_ns, u32 gpu_freq);
/**
* kbase_ccswe_reset() - reset estimator state
*
* @self: Cycles count software estimator instance.
*/
void kbase_ccswe_reset(struct kbase_ccswe *self);
#endif /* _KBASE_CCSWE_H_ */