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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2022, Linaro Limited, All rights reserved.4 * Author: Mike Leach <mike.leach@linaro.org>5 */6#include <linux/coresight.h>7#include <linux/coresight-pmu.h>8#include <linux/cpumask.h>9#include <linux/kernel.h>10#include <linux/spinlock.h>11#include <linux/types.h>12 13#include "coresight-trace-id.h"14 15/* Default trace ID map. Used in sysfs mode and for system sources */16static DEFINE_PER_CPU(atomic_t, id_map_default_cpu_ids) = ATOMIC_INIT(0);17static struct coresight_trace_id_map id_map_default = {18 .cpu_map = &id_map_default_cpu_ids,19 .lock = __SPIN_LOCK_UNLOCKED(id_map_default.lock)20};21 22/* #define TRACE_ID_DEBUG 1 */23#if defined(TRACE_ID_DEBUG) || defined(CONFIG_COMPILE_TEST)24 25static void coresight_trace_id_dump_table(struct coresight_trace_id_map *id_map,26 const char *func_name)27{28 pr_debug("%s id_map::\n", func_name);29 pr_debug("Used = %*pb\n", CORESIGHT_TRACE_IDS_MAX, id_map->used_ids);30}31#define DUMP_ID_MAP(map) coresight_trace_id_dump_table(map, __func__)32#define DUMP_ID_CPU(cpu, id) pr_debug("%s called; cpu=%d, id=%d\n", __func__, cpu, id)33#define DUMP_ID(id) pr_debug("%s called; id=%d\n", __func__, id)34#define PERF_SESSION(n) pr_debug("%s perf count %d\n", __func__, n)35#else36#define DUMP_ID_MAP(map)37#define DUMP_ID(id)38#define DUMP_ID_CPU(cpu, id)39#define PERF_SESSION(n)40#endif41 42/* unlocked read of current trace ID value for given CPU */43static int _coresight_trace_id_read_cpu_id(int cpu, struct coresight_trace_id_map *id_map)44{45 return atomic_read(per_cpu_ptr(id_map->cpu_map, cpu));46}47 48/* look for next available odd ID, return 0 if none found */49static int coresight_trace_id_find_odd_id(struct coresight_trace_id_map *id_map)50{51 int found_id = 0, bit = 1, next_id;52 53 while ((bit < CORESIGHT_TRACE_ID_RES_TOP) && !found_id) {54 /*55 * bitmap length of CORESIGHT_TRACE_ID_RES_TOP,56 * search from offset `bit`.57 */58 next_id = find_next_zero_bit(id_map->used_ids,59 CORESIGHT_TRACE_ID_RES_TOP, bit);60 if ((next_id < CORESIGHT_TRACE_ID_RES_TOP) && (next_id & 0x1))61 found_id = next_id;62 else63 bit = next_id + 1;64 }65 return found_id;66}67 68/*69 * Allocate new ID and set in use70 *71 * if @preferred_id is a valid id then try to use that value if available.72 * if @preferred_id is not valid and @prefer_odd_id is true, try for odd id.73 *74 * Otherwise allocate next available ID.75 */76static int coresight_trace_id_alloc_new_id(struct coresight_trace_id_map *id_map,77 int preferred_id, bool prefer_odd_id)78{79 int id = 0;80 81 /* for backwards compatibility, cpu IDs may use preferred value */82 if (IS_VALID_CS_TRACE_ID(preferred_id) &&83 !test_bit(preferred_id, id_map->used_ids)) {84 id = preferred_id;85 goto trace_id_allocated;86 } else if (prefer_odd_id) {87 /* may use odd ids to avoid preferred legacy cpu IDs */88 id = coresight_trace_id_find_odd_id(id_map);89 if (id)90 goto trace_id_allocated;91 }92 93 /*94 * skip reserved bit 0, look at bitmap length of95 * CORESIGHT_TRACE_ID_RES_TOP from offset of bit 1.96 */97 id = find_next_zero_bit(id_map->used_ids, CORESIGHT_TRACE_ID_RES_TOP, 1);98 if (id >= CORESIGHT_TRACE_ID_RES_TOP)99 return -EINVAL;100 101 /* mark as used */102trace_id_allocated:103 set_bit(id, id_map->used_ids);104 return id;105}106 107static void coresight_trace_id_free(int id, struct coresight_trace_id_map *id_map)108{109 if (WARN(!IS_VALID_CS_TRACE_ID(id), "Invalid Trace ID %d\n", id))110 return;111 if (WARN(!test_bit(id, id_map->used_ids), "Freeing unused ID %d\n", id))112 return;113 clear_bit(id, id_map->used_ids);114}115 116/*117 * Release all IDs and clear CPU associations.118 */119static void coresight_trace_id_release_all(struct coresight_trace_id_map *id_map)120{121 unsigned long flags;122 int cpu;123 124 spin_lock_irqsave(&id_map->lock, flags);125 bitmap_zero(id_map->used_ids, CORESIGHT_TRACE_IDS_MAX);126 for_each_possible_cpu(cpu)127 atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);128 spin_unlock_irqrestore(&id_map->lock, flags);129 DUMP_ID_MAP(id_map);130}131 132static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map *id_map)133{134 unsigned long flags;135 int id;136 137 spin_lock_irqsave(&id_map->lock, flags);138 139 /* check for existing allocation for this CPU */140 id = _coresight_trace_id_read_cpu_id(cpu, id_map);141 if (id)142 goto get_cpu_id_out_unlock;143 144 /*145 * Find a new ID.146 *147 * Use legacy values where possible in the dynamic trace ID allocator to148 * allow older tools to continue working if they are not upgraded at the149 * same time as the kernel drivers.150 *151 * If the generated legacy ID is invalid, or not available then the next152 * available dynamic ID will be used.153 */154 id = coresight_trace_id_alloc_new_id(id_map,155 CORESIGHT_LEGACY_CPU_TRACE_ID(cpu),156 false);157 if (!IS_VALID_CS_TRACE_ID(id))158 goto get_cpu_id_out_unlock;159 160 /* allocate the new id to the cpu */161 atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), id);162 163get_cpu_id_out_unlock:164 spin_unlock_irqrestore(&id_map->lock, flags);165 166 DUMP_ID_CPU(cpu, id);167 DUMP_ID_MAP(id_map);168 return id;169}170 171static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_map *id_map)172{173 unsigned long flags;174 int id;175 176 /* check for existing allocation for this CPU */177 id = _coresight_trace_id_read_cpu_id(cpu, id_map);178 if (!id)179 return;180 181 spin_lock_irqsave(&id_map->lock, flags);182 183 coresight_trace_id_free(id, id_map);184 atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);185 186 spin_unlock_irqrestore(&id_map->lock, flags);187 DUMP_ID_CPU(cpu, id);188 DUMP_ID_MAP(id_map);189}190 191static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map)192{193 unsigned long flags;194 int id;195 196 spin_lock_irqsave(&id_map->lock, flags);197 /* prefer odd IDs for system components to avoid legacy CPU IDS */198 id = coresight_trace_id_alloc_new_id(id_map, 0, true);199 spin_unlock_irqrestore(&id_map->lock, flags);200 201 DUMP_ID(id);202 DUMP_ID_MAP(id_map);203 return id;204}205 206static void coresight_trace_id_map_put_system_id(struct coresight_trace_id_map *id_map, int id)207{208 unsigned long flags;209 210 spin_lock_irqsave(&id_map->lock, flags);211 coresight_trace_id_free(id, id_map);212 spin_unlock_irqrestore(&id_map->lock, flags);213 214 DUMP_ID(id);215 DUMP_ID_MAP(id_map);216}217 218/* API functions */219 220int coresight_trace_id_get_cpu_id(int cpu)221{222 return _coresight_trace_id_get_cpu_id(cpu, &id_map_default);223}224EXPORT_SYMBOL_GPL(coresight_trace_id_get_cpu_id);225 226int coresight_trace_id_get_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map)227{228 return _coresight_trace_id_get_cpu_id(cpu, id_map);229}230EXPORT_SYMBOL_GPL(coresight_trace_id_get_cpu_id_map);231 232void coresight_trace_id_put_cpu_id(int cpu)233{234 _coresight_trace_id_put_cpu_id(cpu, &id_map_default);235}236EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id);237 238void coresight_trace_id_put_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map)239{240 _coresight_trace_id_put_cpu_id(cpu, id_map);241}242EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id_map);243 244int coresight_trace_id_read_cpu_id(int cpu)245{246 return _coresight_trace_id_read_cpu_id(cpu, &id_map_default);247}248EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id);249 250int coresight_trace_id_read_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map)251{252 return _coresight_trace_id_read_cpu_id(cpu, id_map);253}254EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id_map);255 256int coresight_trace_id_get_system_id(void)257{258 return coresight_trace_id_map_get_system_id(&id_map_default);259}260EXPORT_SYMBOL_GPL(coresight_trace_id_get_system_id);261 262void coresight_trace_id_put_system_id(int id)263{264 coresight_trace_id_map_put_system_id(&id_map_default, id);265}266EXPORT_SYMBOL_GPL(coresight_trace_id_put_system_id);267 268void coresight_trace_id_perf_start(struct coresight_trace_id_map *id_map)269{270 atomic_inc(&id_map->perf_cs_etm_session_active);271 PERF_SESSION(atomic_read(&id_map->perf_cs_etm_session_active));272}273EXPORT_SYMBOL_GPL(coresight_trace_id_perf_start);274 275void coresight_trace_id_perf_stop(struct coresight_trace_id_map *id_map)276{277 if (!atomic_dec_return(&id_map->perf_cs_etm_session_active))278 coresight_trace_id_release_all(id_map);279 PERF_SESSION(atomic_read(&id_map->perf_cs_etm_session_active));280}281EXPORT_SYMBOL_GPL(coresight_trace_id_perf_stop);282