/*
* PowerNV OPAL asynchronous completion interfaces
*
- * Copyright 2013 IBM Corp.
+ * Copyright 2013-2017 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
#include <asm/machdep.h>
#include <asm/opal.h>
-#define N_ASYNC_COMPLETIONS 64
+enum opal_async_token_state {
+ ASYNC_TOKEN_UNALLOCATED = 0,
+ ASYNC_TOKEN_ALLOCATED,
+ ASYNC_TOKEN_DISPATCHED,
+ ASYNC_TOKEN_ABANDONED,
+ ASYNC_TOKEN_COMPLETED
+};
+
+struct opal_async_token {
+ enum opal_async_token_state state;
+ struct opal_msg response;
+};
-static DECLARE_BITMAP(opal_async_complete_map, N_ASYNC_COMPLETIONS) = {~0UL};
-static DECLARE_BITMAP(opal_async_token_map, N_ASYNC_COMPLETIONS);
static DECLARE_WAIT_QUEUE_HEAD(opal_async_wait);
static DEFINE_SPINLOCK(opal_async_comp_lock);
static struct semaphore opal_async_sem;
-static struct opal_msg *opal_async_responses;
static unsigned int opal_max_async_tokens;
+static struct opal_async_token *opal_async_tokens;
-int __opal_async_get_token(void)
+static int __opal_async_get_token(void)
{
unsigned long flags;
- int token;
+ int i, token = -EBUSY;
spin_lock_irqsave(&opal_async_comp_lock, flags);
- token = find_first_bit(opal_async_complete_map, opal_max_async_tokens);
- if (token >= opal_max_async_tokens) {
- token = -EBUSY;
- goto out;
- }
- if (__test_and_set_bit(token, opal_async_token_map)) {
- token = -EBUSY;
- goto out;
+ for (i = 0; i < opal_max_async_tokens; i++) {
+ if (opal_async_tokens[i].state == ASYNC_TOKEN_UNALLOCATED) {
+ opal_async_tokens[i].state = ASYNC_TOKEN_ALLOCATED;
+ token = i;
+ break;
+ }
}
- __clear_bit(token, opal_async_complete_map);
-
-out:
spin_unlock_irqrestore(&opal_async_comp_lock, flags);
return token;
}
+/*
+ * Note: If the returned token is used in an opal call and opal returns
+ * OPAL_ASYNC_COMPLETION you MUST call one of opal_async_wait_response() or
+ * opal_async_wait_response_interruptible() at least once before calling another
+ * opal_async_* function
+ */
int opal_async_get_token_interruptible(void)
{
int token;
}
EXPORT_SYMBOL_GPL(opal_async_get_token_interruptible);
-int __opal_async_release_token(int token)
+static int __opal_async_release_token(int token)
{
unsigned long flags;
+ int rc;
if (token < 0 || token >= opal_max_async_tokens) {
pr_err("%s: Passed token is out of range, token %d\n",
}
spin_lock_irqsave(&opal_async_comp_lock, flags);
- __set_bit(token, opal_async_complete_map);
- __clear_bit(token, opal_async_token_map);
+ switch (opal_async_tokens[token].state) {
+ case ASYNC_TOKEN_COMPLETED:
+ case ASYNC_TOKEN_ALLOCATED:
+ opal_async_tokens[token].state = ASYNC_TOKEN_UNALLOCATED;
+ rc = 0;
+ break;
+ /*
+ * DISPATCHED and ABANDONED tokens must wait for OPAL to respond.
+ * Mark a DISPATCHED token as ABANDONED so that the response handling
+ * code knows no one cares and that it can free it then.
+ */
+ case ASYNC_TOKEN_DISPATCHED:
+ opal_async_tokens[token].state = ASYNC_TOKEN_ABANDONED;
+ /* Fall through */
+ default:
+ rc = 1;
+ }
spin_unlock_irqrestore(&opal_async_comp_lock, flags);
- return 0;
+ return rc;
}
int opal_async_release_token(int token)
int ret;
ret = __opal_async_release_token(token);
- if (ret)
- return ret;
-
- up(&opal_async_sem);
+ if (!ret)
+ up(&opal_async_sem);
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(opal_async_release_token);
return -EINVAL;
}
- /* Wakeup the poller before we wait for events to speed things
+ /*
+ * There is no need to mark the token as dispatched, wait_event()
+ * will block until the token completes.
+ *
+ * Wakeup the poller before we wait for events to speed things
* up on platforms or simulators where the interrupts aren't
* functional.
*/
opal_wake_poller();
- wait_event(opal_async_wait, test_bit(token, opal_async_complete_map));
- memcpy(msg, &opal_async_responses[token], sizeof(*msg));
+ wait_event(opal_async_wait, opal_async_tokens[token].state
+ == ASYNC_TOKEN_COMPLETED);
+ memcpy(msg, &opal_async_tokens[token].response, sizeof(*msg));
return 0;
}
EXPORT_SYMBOL_GPL(opal_async_wait_response);
+int opal_async_wait_response_interruptible(uint64_t token, struct opal_msg *msg)
+{
+ unsigned long flags;
+ int ret;
+
+ if (token >= opal_max_async_tokens) {
+ pr_err("%s: Invalid token passed\n", __func__);
+ return -EINVAL;
+ }
+
+ if (!msg) {
+ pr_err("%s: Invalid message pointer passed\n", __func__);
+ return -EINVAL;
+ }
+
+ /*
+ * The first time this gets called we mark the token as DISPATCHED
+ * so that if wait_event_interruptible() returns not zero and the
+ * caller frees the token, we know not to actually free the token
+ * until the response comes.
+ *
+ * Only change if the token is ALLOCATED - it may have been
+ * completed even before the caller gets around to calling this
+ * the first time.
+ *
+ * There is also a dirty great comment at the token allocation
+ * function that if the opal call returns OPAL_ASYNC_COMPLETION to
+ * the caller then the caller *must* call this or the not
+ * interruptible version before doing anything else with the
+ * token.
+ */
+ if (opal_async_tokens[token].state == ASYNC_TOKEN_ALLOCATED) {
+ spin_lock_irqsave(&opal_async_comp_lock, flags);
+ if (opal_async_tokens[token].state == ASYNC_TOKEN_ALLOCATED)
+ opal_async_tokens[token].state = ASYNC_TOKEN_DISPATCHED;
+ spin_unlock_irqrestore(&opal_async_comp_lock, flags);
+ }
+
+ /*
+ * Wakeup the poller before we wait for events to speed things
+ * up on platforms or simulators where the interrupts aren't
+ * functional.
+ */
+ opal_wake_poller();
+ ret = wait_event_interruptible(opal_async_wait,
+ opal_async_tokens[token].state ==
+ ASYNC_TOKEN_COMPLETED);
+ if (!ret)
+ memcpy(msg, &opal_async_tokens[token].response, sizeof(*msg));
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(opal_async_wait_response_interruptible);
+
+/* Called from interrupt context */
static int opal_async_comp_event(struct notifier_block *nb,
unsigned long msg_type, void *msg)
{
struct opal_msg *comp_msg = msg;
+ enum opal_async_token_state state;
unsigned long flags;
uint64_t token;
return 0;
token = be64_to_cpu(comp_msg->params[0]);
- memcpy(&opal_async_responses[token], comp_msg, sizeof(*comp_msg));
spin_lock_irqsave(&opal_async_comp_lock, flags);
- __set_bit(token, opal_async_complete_map);
+ state = opal_async_tokens[token].state;
+ opal_async_tokens[token].state = ASYNC_TOKEN_COMPLETED;
spin_unlock_irqrestore(&opal_async_comp_lock, flags);
+ if (state == ASYNC_TOKEN_ABANDONED) {
+ /* Free the token, no one else will */
+ opal_async_release_token(token);
+ return 0;
+ }
+ memcpy(&opal_async_tokens[token].response, comp_msg, sizeof(*comp_msg));
wake_up(&opal_async_wait);
return 0;
}
opal_max_async_tokens = be32_to_cpup(async);
- if (opal_max_async_tokens > N_ASYNC_COMPLETIONS)
- opal_max_async_tokens = N_ASYNC_COMPLETIONS;
+ opal_async_tokens = kcalloc(opal_max_async_tokens,
+ sizeof(*opal_async_tokens), GFP_KERNEL);
+ if (!opal_async_tokens) {
+ err = -ENOMEM;
+ goto out_opal_node;
+ }
err = opal_message_notifier_register(OPAL_MSG_ASYNC_COMP,
&opal_async_comp_nb);
if (err) {
pr_err("%s: Can't register OPAL event notifier (%d)\n",
__func__, err);
+ kfree(opal_async_tokens);
goto out_opal_node;
}
- opal_async_responses = kzalloc(
- sizeof(*opal_async_responses) * opal_max_async_tokens,
- GFP_KERNEL);
- if (!opal_async_responses) {
- pr_err("%s: Out of memory, failed to do asynchronous "
- "completion init\n", __func__);
- err = -ENOMEM;
- goto out_opal_node;
- }
-
- /* Initialize to 1 less than the maximum tokens available, as we may
- * require to pop one during emergency through synchronous call to
- * __opal_async_get_token()
- */
- sema_init(&opal_async_sem, opal_max_async_tokens - 1);
+ sema_init(&opal_async_sem, opal_max_async_tokens);
out_opal_node:
of_node_put(opal_node);
git.samba.org / sfrench / cifs-2.6.git / blobdiff