131 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2015-2021, Linaro Limited4 */5 6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt7 8#include <linux/arm-smccc.h>9#include <linux/errno.h>10#include <linux/slab.h>11#include <linux/spinlock.h>12#include <linux/tee_core.h>13#include "optee_private.h"14 15struct notif_entry {16 struct list_head link;17 struct completion c;18 u_int key;19};20 21static bool have_key(struct optee *optee, u_int key)22{23 struct notif_entry *entry;24 25 list_for_each_entry(entry, &optee->notif.db, link)26 if (entry->key == key)27 return true;28 29 return false;30}31 32int optee_notif_wait(struct optee *optee, u_int key, u32 timeout)33{34 unsigned long flags;35 struct notif_entry *entry;36 int rc = 0;37 38 if (key > optee->notif.max_key)39 return -EINVAL;40 41 entry = kmalloc(sizeof(*entry), GFP_KERNEL);42 if (!entry)43 return -ENOMEM;44 init_completion(&entry->c);45 entry->key = key;46 47 spin_lock_irqsave(&optee->notif.lock, flags);48 49 /*50 * If the bit is already set it means that the key has already51 * been posted and we must not wait.52 */53 if (test_bit(key, optee->notif.bitmap)) {54 clear_bit(key, optee->notif.bitmap);55 goto out;56 }57 58 /*59 * Check if someone is already waiting for this key. If there is60 * it's a programming error.61 */62 if (have_key(optee, key)) {63 rc = -EBUSY;64 goto out;65 }66 67 list_add_tail(&entry->link, &optee->notif.db);68 69 /*70 * Unlock temporarily and wait for completion.71 */72 spin_unlock_irqrestore(&optee->notif.lock, flags);73 if (timeout != 0) {74 if (!wait_for_completion_timeout(&entry->c, timeout))75 rc = -ETIMEDOUT;76 } else {77 wait_for_completion(&entry->c);78 }79 spin_lock_irqsave(&optee->notif.lock, flags);80 81 list_del(&entry->link);82out:83 spin_unlock_irqrestore(&optee->notif.lock, flags);84 85 kfree(entry);86 87 return rc;88}89 90int optee_notif_send(struct optee *optee, u_int key)91{92 unsigned long flags;93 struct notif_entry *entry;94 95 if (key > optee->notif.max_key)96 return -EINVAL;97 98 spin_lock_irqsave(&optee->notif.lock, flags);99 100 list_for_each_entry(entry, &optee->notif.db, link)101 if (entry->key == key) {102 complete(&entry->c);103 goto out;104 }105 106 /* Only set the bit in case there where nobody waiting */107 set_bit(key, optee->notif.bitmap);108out:109 spin_unlock_irqrestore(&optee->notif.lock, flags);110 111 return 0;112}113 114int optee_notif_init(struct optee *optee, u_int max_key)115{116 spin_lock_init(&optee->notif.lock);117 INIT_LIST_HEAD(&optee->notif.db);118 optee->notif.bitmap = bitmap_zalloc(max_key, GFP_KERNEL);119 if (!optee->notif.bitmap)120 return -ENOMEM;121 122 optee->notif.max_key = max_key;123 124 return 0;125}126 127void optee_notif_uninit(struct optee *optee)128{129 bitmap_free(optee->notif.bitmap);130}131