core/arch/arm/kernel/wait_queue.c

   1 /*
   2  * Copyright (c) 2015-2016, Linaro Limited
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright notice,
   9  * this list of conditions and the following disclaimer.
  10  *
  11  * 2. Redistributions in binary form must reproduce the above copyright notice,
  12  * this list of conditions and the following disclaimer in the documentation
  13  * and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  16  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  19  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  25  * POSSIBILITY OF SUCH DAMAGE.
  26  */
  27 #include <compiler.h>
  28 #include <types_ext.h>
  29 #include <tee_api_defines.h>
  30 #include <string.h>
  31 #include <optee_msg.h>
  32 #include <kernel/spinlock.h>
  33 #include <kernel/wait_queue.h>
  34 #include <kernel/thread.h>
  35 #include <trace.h>
  36
  37 static unsigned wq_spin_lock;
  38
  39
  40 void wq_init(struct wait_queue *wq)
  41 {
  42         *wq = (struct wait_queue)WAIT_QUEUE_INITIALIZER;
  43 }
  44
  45 static void wq_rpc(uint32_t func, int id, const void *sync_obj __maybe_unused,
  46                         const char *fname, int lineno __maybe_unused)
  47 {
  48         uint32_t ret;
  49         struct optee_msg_param params;
  50         const char *cmd_str __maybe_unused =
  51              func == OPTEE_MSG_RPC_WAIT_QUEUE_SLEEP ? "sleep" : "wake ";
  52
  53         if (fname)
  54                 DMSG("%s thread %u %p %s:%d", cmd_str, id,
  55                      sync_obj, fname, lineno);
  56         else
  57                 DMSG("%s thread %u %p", cmd_str, id, sync_obj);
  58
  59         memset(&params, 0, sizeof(params));
  60         params.attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
  61         params.u.value.a = func;
  62         params.u.value.b = id;
  63
  64         ret = thread_rpc_cmd(OPTEE_MSG_RPC_CMD_WAIT_QUEUE, 1, &params);
  65         if (ret != TEE_SUCCESS)
  66                 DMSG("%s thread %u ret 0x%x", cmd_str, id, ret);
  67 }
  68
  69 static void slist_add_tail(struct wait_queue *wq, struct wait_queue_elem *wqe)
  70 {
  71         struct wait_queue_elem *wqe_iter;
  72
  73         /* Add elem to end of wait queue */
  74         wqe_iter = SLIST_FIRST(wq);
  75         if (wqe_iter) {
  76                 while (SLIST_NEXT(wqe_iter, link))
  77                         wqe_iter = SLIST_NEXT(wqe_iter, link);
  78                 SLIST_INSERT_AFTER(wqe_iter, wqe, link);
  79         } else
  80                 SLIST_INSERT_HEAD(wq, wqe, link);
  81 }
  82
  83 void wq_wait_init_condvar(struct wait_queue *wq, struct wait_queue_elem *wqe,
  84                 struct condvar *cv)
  85 {
  86         uint32_t old_itr_status;
  87
  88         wqe->handle = thread_get_id();
  89         wqe->done = false;
  90         wqe->cv = cv;
  91
  92         old_itr_status = thread_mask_exceptions(THREAD_EXCP_ALL);
  93         cpu_spin_lock(&wq_spin_lock);
  94
  95         slist_add_tail(wq, wqe);
  96
  97         cpu_spin_unlock(&wq_spin_lock);
  98         thread_unmask_exceptions(old_itr_status);
  99 }
 100
 101 void wq_wait_final(struct wait_queue *wq, struct wait_queue_elem *wqe,
 102                         const void *sync_obj, const char *fname, int lineno)
 103 {
 104         uint32_t old_itr_status;
 105         unsigned done;
 106
 107         do {
 108                 wq_rpc(OPTEE_MSG_RPC_WAIT_QUEUE_SLEEP, wqe->handle,
 109                        sync_obj, fname, lineno);
 110
 111                 old_itr_status = thread_mask_exceptions(THREAD_EXCP_ALL);
 112                 cpu_spin_lock(&wq_spin_lock);
 113
 114                 done = wqe->done;
 115                 if (done)
 116                         SLIST_REMOVE(wq, wqe, wait_queue_elem, link);
 117
 118                 cpu_spin_unlock(&wq_spin_lock);
 119                 thread_unmask_exceptions(old_itr_status);
 120         } while (!done);
 121 }
 122
 123 void wq_wake_one(struct wait_queue *wq, const void *sync_obj,
 124                         const char *fname, int lineno)
 125 {
 126         uint32_t old_itr_status;
 127         struct wait_queue_elem *wqe;
 128         int handle = -1;
 129         bool do_wakeup = false;
 130
 131         old_itr_status = thread_mask_exceptions(THREAD_EXCP_ALL);
 132         cpu_spin_lock(&wq_spin_lock);
 133
 134         SLIST_FOREACH(wqe, wq, link) {
 135                 if (!wqe->cv) {
 136                         do_wakeup = !wqe->done;
 137                         wqe->done = true;
 138                         handle = wqe->handle;
 139                         break;
 140                 }
 141         }
 142
 143         cpu_spin_unlock(&wq_spin_lock);
 144         thread_unmask_exceptions(old_itr_status);
 145
 146         if (do_wakeup)
 147                 wq_rpc(OPTEE_MSG_RPC_WAIT_QUEUE_WAKEUP, handle,
 148                        sync_obj, fname, lineno);
 149 }
 150
 151 void wq_promote_condvar(struct wait_queue *wq, struct condvar *cv,
 152                         bool only_one, const void *sync_obj __unused,
 153                         const char *fname, int lineno __maybe_unused)
 154 {
 155         uint32_t old_itr_status;
 156         struct wait_queue_elem *wqe;
 157
 158         if (!cv)
 159                 return;
 160
 161         old_itr_status = thread_mask_exceptions(THREAD_EXCP_ALL);
 162         cpu_spin_lock(&wq_spin_lock);
 163
 164         /*
 165          * Find condvar waiter(s) and promote each to an active waiter.
 166          * This is a bit unfair to eventual other active waiters as a
 167          * condvar waiter is added the the queue when waiting for the
 168          * condvar.
 169          */
 170         SLIST_FOREACH(wqe, wq, link) {
 171                 if (wqe->cv == cv) {
 172                         if (fname)
 173                                 FMSG("promote thread %u %p %s:%d",
 174                                      wqe->handle, (void *)cv->m, fname, lineno);
 175                         else
 176                                 FMSG("promote thread %u %p",
 177                                      wqe->handle, (void *)cv->m);
 178
 179                         wqe->cv = NULL;
 180                         if (only_one)
 181                                 break;
 182                 }
 183         }
 184
 185         cpu_spin_unlock(&wq_spin_lock);
 186         thread_unmask_exceptions(old_itr_status);
 187 }
 188
 189 bool wq_have_condvar(struct wait_queue *wq, struct condvar *cv)
 190 {
 191         uint32_t old_itr_status;
 192         struct wait_queue_elem *wqe;
 193         bool rc = false;
 194
 195         old_itr_status = thread_mask_exceptions(THREAD_EXCP_ALL);
 196         cpu_spin_lock(&wq_spin_lock);
 197
 198         SLIST_FOREACH(wqe, wq, link) {
 199                 if (wqe->cv == cv) {
 200                         rc = true;
 201                         break;
 202                 }
 203         }
 204
 205         cpu_spin_unlock(&wq_spin_lock);
 206         thread_unmask_exceptions(old_itr_status);
 207
 208         return rc;
 209 }
 210
 211 bool wq_is_empty(struct wait_queue *wq)
 212 {
 213         uint32_t old_itr_status;
 214         bool ret;
 215
 216         old_itr_status = thread_mask_exceptions(THREAD_EXCP_ALL);
 217         cpu_spin_lock(&wq_spin_lock);
 218
 219         ret = SLIST_EMPTY(wq);
 220
 221         cpu_spin_unlock(&wq_spin_lock);
 222         thread_unmask_exceptions(old_itr_status);
 223
 224         return ret;
 225 }