1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 /* 3 * 4 * (C) COPYRIGHT 2020-2022 ARM Limited. All rights reserved. 5 * 6 * This program is free software and is provided to you under the terms of the 7 * GNU General Public License version 2 as published by the Free Software 8 * Foundation, and any use by you of this program is subject to the terms 9 * of such GNU license. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, you can access it online at 18 * http://www.gnu.org/licenses/gpl-2.0.html. 19 * 20 */ 21 22 #ifndef _KBASE_CCSWE_H_ 23 #define _KBASE_CCSWE_H_ 24 25 #include <linux/spinlock.h> 26 27 /** 28 * struct kbase_ccswe - Cycle count software estimator. 29 * 30 * @access: Spinlock protecting this structure access. 31 * @timestamp_ns: Timestamp(ns) when the last frequency change 32 * occurred. 33 * @cycles_elapsed: Number of cycles elapsed before the last frequency 34 * change 35 * @gpu_freq: Current GPU frequency(Hz) value. 36 * @prev_gpu_freq: Previous GPU frequency(Hz) before the last frequency 37 * change. 38 */ 39 struct kbase_ccswe { 40 spinlock_t access; 41 u64 timestamp_ns; 42 u64 cycles_elapsed; 43 u32 gpu_freq; 44 u32 prev_gpu_freq; 45 }; 46 47 /** 48 * kbase_ccswe_init() - initialize the cycle count estimator. 49 * 50 * @self: Cycles count software estimator instance. 51 */ 52 void kbase_ccswe_init(struct kbase_ccswe *self); 53 54 /** 55 * kbase_ccswe_cycle_at() - Estimate cycle count at given timestamp. 56 * 57 * @self: Cycles count software estimator instance. 58 * @timestamp_ns: The timestamp(ns) for cycle count estimation. 59 * 60 * The timestamp must be bigger than the timestamp of the penultimate 61 * frequency change. If only one frequency change occurred, the 62 * timestamp must be bigger than the timestamp of the frequency change. 63 * This is to allow the following code to be executed w/o synchronization. 64 * If lines below executed atomically, it is safe to assume that only 65 * one frequency change may happen in between. 66 * 67 * u64 ts = ktime_get_raw_ns(); 68 * u64 cycle = kbase_ccswe_cycle_at(&ccswe, ts) 69 * 70 * Return: estimated value of cycle count at a given time. 71 */ 72 u64 kbase_ccswe_cycle_at(struct kbase_ccswe *self, u64 timestamp_ns); 73 74 /** 75 * kbase_ccswe_freq_change() - update GPU frequency. 76 * 77 * @self: Cycles count software estimator instance. 78 * @timestamp_ns: Timestamp(ns) when frequency change occurred. 79 * @gpu_freq: New GPU frequency value. 80 * 81 * The timestamp must be bigger than the timestamp of the previous 82 * frequency change. The function is to be called at the frequency 83 * change moment (not later). 84 */ 85 void kbase_ccswe_freq_change( 86 struct kbase_ccswe *self, u64 timestamp_ns, u32 gpu_freq); 87 88 /** 89 * kbase_ccswe_reset() - reset estimator state 90 * 91 * @self: Cycles count software estimator instance. 92 */ 93 void kbase_ccswe_reset(struct kbase_ccswe *self); 94 95 #endif /* _KBASE_CCSWE_H_ */ 96