/**
* __hwspin_lock_request() - tag an hwspinlock as used and power it up
*
* This is an internal function that prepares an hwspinlock instance
* before it is given to the user. The function assumes that
* hwspinlock_tree_lock is taken.
*
* Returns 0 or positive to indicate success, and a negative value to
* indicate an error (with the appropriate error code)
*/
static int __hwspin_lock_request(struct hwspinlock *hwlock)
{
struct device *dev = hwlock->bank->dev;
struct hwspinlock *tmp;
int ret;
/* prevent underlying implementation from being removed */
if (!try_module_get(dev->driver->owner)) {
dev_err(dev, "%s: can't get owner\n", __func__);
return -EINVAL;
}
/* notify PM core that power is now needed */
ret = pm_runtime_get_sync(dev);
if (ret < 0) {
dev_err(dev, "%s: can't power on device\n", __func__);
pm_runtime_put_noidle(dev);
module_put(dev->driver->owner);
return ret;
}
/* mark hwspinlock as used, should not fail */
tmp = radix_tree_tag_clear(&hwspinlock_tree, hwlock_to_id(hwlock),
HWSPINLOCK_UNUSED);
/* self-sanity check that should never fail */
WARN_ON(tmp != hwlock);
return ret;
}
/**
* hwspin_lock_request_specific() - request for a specific hwspinlock
* @id: index of the specific hwspinlock that is requested
*
* This function should be called by users of the hwspinlock module,
* in order to assign them a specific hwspinlock.
* Usually early board code will be calling this function in order to
* reserve specific hwspinlock ids for predefined purposes.
*
* Should be called from a process context (might sleep)
*
* Returns the address of the assigned hwspinlock, or NULL on error
*/
struct hwspinlock *hwspin_lock_request_specific(unsigned int id)
{
struct hwspinlock *hwlock;
int ret;
mutex_lock(&hwspinlock_tree_lock);
/* make sure this hwspinlock exists */
hwlock = radix_tree_lookup(&hwspinlock_tree, id);
if (!hwlock) {
pr_warn("hwspinlock %u does not exist\n", id);
goto out;
}
/* sanity check (this shouldn't happen) */
WARN_ON(hwlock_to_id(hwlock) != id);
/* make sure this hwspinlock is unused */
ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED);
if (ret == 0) {
pr_warn("hwspinlock %u is already in use\n", id);
hwlock = NULL;
goto out;
}
/* mark as used and power up */
ret = __hwspin_lock_request(hwlock);
if (ret < 0)
hwlock = NULL;
out:
mutex_unlock(&hwspinlock_tree_lock);
return hwlock;
}
/**
* hwspin_lock_get_id() - retrieve id number of a given hwspinlock
* @hwlock: a valid hwspinlock instance
*
* Returns the id number of a given @hwlock, or -EINVAL if @hwlock is invalid.
*/
int hwspin_lock_get_id(struct hwspinlock *hwlock)
{
if (!hwlock) {
pr_err("invalid hwlock\n");
return -EINVAL;
}
return hwlock_to_id(hwlock);
}
/**
* hwspin_lock_free() - free a specific hwspinlock
* @hwlock: the specific hwspinlock to free
*
* This function mark @hwlock as free again.
* Should only be called with an @hwlock that was retrieved from
* an earlier call to omap_hwspin_lock_request{_specific}.
*
* Should be called from a process context (might sleep)
*
* Returns 0 on success, or an appropriate error code on failure
*/
int hwspin_lock_free(struct hwspinlock *hwlock)
{
struct device *dev = hwlock->bank->dev;
struct hwspinlock *tmp;
int ret;
if (!hwlock) {
pr_err("invalid hwlock\n");
return -EINVAL;
}
mutex_lock(&hwspinlock_tree_lock);
/* make sure the hwspinlock is used */
ret = radix_tree_tag_get(&hwspinlock_tree, hwlock_to_id(hwlock),
HWSPINLOCK_UNUSED);
if (ret == 1) {
dev_err(dev, "%s: hwlock is already free\n", __func__);
dump_stack();
ret = -EINVAL;
goto out;
}
/* notify the underlying device that power is not needed */
ret = pm_runtime_put(dev);
if (ret < 0)
goto out;
/* mark this hwspinlock as available */
tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock_to_id(hwlock),
HWSPINLOCK_UNUSED);
/* sanity check (this shouldn't happen) */
WARN_ON(tmp != hwlock);
module_put(dev->driver->owner);
out:
mutex_unlock(&hwspinlock_tree_lock);
return ret;
}
static int debugfs_hwspinlock_lock_free(struct hwspinlock *_hwlock)
{
int ret;
ret = hwspin_lock_free(_hwlock);
if (ret)
pr_err("[debug] hwspinlock free fail, ret = [%d]\n", ret);
else
pr_info("[debug] hwspinlock free %d sucess!\n", hwlock_to_id(_hwlock));
return ret;
}
/**
* __hwspin_lock_reset() - reset/unlock a specific hwspinlock
* @id: index of the specific hwspinlock that needs to be reset
*
* This function resets a specific hwspinlock. This _should_
* only be called in very special circumstances to unlock and
* to avoid a deadlock by an user who would want to acquire the
* lock but cannot.
*
* An example would be a case where a remote processor has crashed
* holding a lock.
*/
void __hwspin_lock_reset(int id)
{
struct hwspinlock *hwlock;
mutex_lock(&hwspinlock_tree_lock);
/* make sure this hwspinlock exists */
hwlock = radix_tree_lookup(&hwspinlock_tree, id);
if (!hwlock) {
pr_warn("hwspinlock %u does not exist\n", id);
goto out;
}
/* sanity check (this shouldn't happen) */
if (hwlock_to_id(hwlock) != id) {
pr_warn("id %u does not match hwspinlock id %u\n", id,
hwlock_to_id(hwlock));
goto out;
}
/*
* We must make sure that memory operations (both reads and writes),
* done before unlocking the hwspinlock, will not be reordered
* after the lock is released.
*
* That's the purpose of this explicit memory barrier.
*/
mb();
pr_warn("hwspinlock %u forced to unlock\n", id);
hwlock->bank->ops->unlock(hwlock);
out:
mutex_unlock(&hwspinlock_tree_lock);
}
/* try to lock the hardware spinlock */
static int sprd_hwspinlock_trylock(struct hwspinlock *lock)
{
struct sprd_hwspinlock_dev *sprd_hwlock =
dev_get_drvdata(lock->bank->dev);
void __iomem *addr = lock->priv;
int user_id, lock_id;
if (!readl(addr))
return 1;
lock_id = hwlock_to_id(lock);
/* get the hardware spinlock master/user id */
user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));
dev_warn(sprd_hwlock->bank.dev,
"hwspinlock [%d] lock failed and master/user id = %d!\n",
lock_id, user_id);
return 0;
}
static ssize_t
debugfs_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos)
{
struct hwspinlock *__hwlock;
char buf[128];
char *cmd = NULL;
char *_cmd = NULL;
int id;
int timeout;
int unlock;
int ret ;
if (NULL == ubuf || 0 == cnt){
pr_err("buf is null !\n");
return (-EINVAL);
}
if(cnt > sizeof(buf))
{
pr_err("input count larger! \n");
return (-ENOMEM);
}
if (copy_from_user(buf, ubuf, cnt - 1)) {
pr_err("[Hwspinlock Debugfs] can not copy from user\n");
cnt = -EINVAL;
goto out;
}
buf[cnt - 1] = '\0';
cmd = buf;
_cmd = buf;
pr_debug("[Hwspinlock Debugfs] [cmd: %s[cnt: %d]]\n", cmd, (int)cnt);
if (!strncmp("request ", _cmd, strlen("request "))) {
cmd = cmd + strlen("request ");
_cmd = cmd;
while ((' ' != *_cmd) && ('\0' != *_cmd))
_cmd++;
*_cmd = '\0';
if (kstrtos32(cmd, 10, &id)) {
pr_err("Hwspinlock Debugfs cmd error\n");
cnt = -EINVAL;
goto out;
}
hwlock = hwspin_lock_request_specific(id);
if (!hwlock)
pr_err("hwspinlock %u is already in use\n", id);
else
pr_info("[debug] Request hwspinlock %d sucess!",id);
} else if (!strncmp("free_lock ", _cmd, strlen("free_lock "))) {
cmd = cmd + strlen("free_lock ");
_cmd = cmd;
while ((' ' != *_cmd) && ('\0' != *_cmd))
_cmd++;
*_cmd = '\0';
if (kstrtos32(cmd, 10, &id)) {
pr_err("Hwspinlock Debugfs cmd error\n");
cnt = -EINVAL;
goto out;
}
if (!hwlock){
__hwlock = hwspin_lock_lookup(id);
if (__hwlock){
debugfs_hwspinlock_lock_free(__hwlock);
__hwlock = NULL;
}else{
pr_err("Current haven't requested the hwspinlock %d\n",id);
goto out;
}
}else if (hwlock_to_id(hwlock) == id){
debugfs_hwspinlock_lock_free(hwlock);
hwlock = NULL;
}else
pr_err("[debug] please freelock the correct lock!\n");
} else if (!strncmp("trylock ", _cmd, strlen("trylock "))) {
cmd = cmd + strlen("trylock ");
_cmd = cmd;
while ((' ' != *_cmd) && ('\0' != *_cmd))
_cmd++;
if ('\0' == *_cmd) {
pr_err("[debug] cmd error\n");
cnt = -EINVAL;
goto out;
}
*_cmd = '\0';
if (kstrtos32(cmd, 10, &id)) {
pr_err("[debug] cmd error\n");
cnt = -EINVAL;
goto out;
}
cmd = _cmd + 1;
_cmd = cmd;
while ((' ' != *_cmd) && ('\0' != *_cmd))
_cmd++;
*_cmd = '\0';
if (kstrtos32(cmd, 10, &timeout)) {
pr_err("[debug] cmd error\n");
cnt = -EINVAL;
goto out;
}
cmd = _cmd + 1;
_cmd = cmd;
while ((' ' != *_cmd) && ('\0' != *_cmd))
_cmd++;
*_cmd = '\0';
if (kstrtos32(cmd, 10, &unlock)) {
pr_err("[debug] cmd error\n");
cnt = -EINVAL;
goto out;
}
if (!hwlock){
pr_err("Current haven't requested the hwspinlock %d\n",id);
goto out;
}else if (hwlock_to_id(hwlock) == id && timeout >= 0){
ret =debugfs_hwspinlock_trylock_timeout(id, timeout, unlock);
if (!ret){
if (0 == timeout)
pr_info("[debug] hwspin_trylock %d sucess!\n",id);
else
pr_info("[debug] hwspin_trylock_timout %d sucess!\n",id);
}
}else if(timeout < 0)
pr_err("[debug] cmd err! timeout must > 0\n");
else
pr_err("[debug] please trylock the correct lock!\n");
}else if (!strncmp("unlock ", _cmd, strlen("unlock "))) {
cmd = cmd + strlen("unlock ");
_cmd = cmd;
while ((' ' != *_cmd) && ('\0' != *_cmd))
_cmd++;
*_cmd = '\0';
if (kstrtos32(cmd, 10, &id)) {
pr_err("Hwspinlock Debugfs cmd error\n");
cnt = -EINVAL;
goto out;
}
if (!hwlock){
pr_err("Current don't echo request the hwspinlock %d\n",id);
goto out;
}else if(hwlock_to_id(hwlock) == id && locked == 1){
hwspin_unlock(hwlock);
pr_info("[debug] hwspin_unlock id=%d sucess!\n",id);
}else
pr_err("[debug] please free the correct request lock!\n");
} else {
pr_err("Hwspinlock Debugfs cmd error\n");
cnt = -EINVAL;
}
out:
return cnt;
}
