Fixed MTP to work with TWRP

arch/powerpc/platforms/powernv/opal-async.c

@@ -0,0 +1,205 @@
+/*
+ * PowerNV OPAL asynchronous completion interfaces
+ *
+ * Copyright 2013 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/semaphore.h>
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+#include <linux/gfp.h>
+#include <linux/of.h>
+#include <asm/machdep.h>
+#include <asm/opal.h>
+
+#define N_ASYNC_COMPLETIONS	64
+
+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;
+
+int __opal_async_get_token(void)
+{
+	unsigned long flags;
+	int token;
+
+	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;
+	}
+
+	__clear_bit(token, opal_async_complete_map);
+
+out:
+	spin_unlock_irqrestore(&opal_async_comp_lock, flags);
+	return token;
+}
+
+int opal_async_get_token_interruptible(void)
+{
+	int token;
+
+	/* Wait until a token is available */
+	if (down_interruptible(&opal_async_sem))
+		return -ERESTARTSYS;
+
+	token = __opal_async_get_token();
+	if (token < 0)
+		up(&opal_async_sem);
+
+	return token;
+}
+
+int __opal_async_release_token(int token)
+{
+	unsigned long flags;
+
+	if (token < 0 || token >= opal_max_async_tokens) {
+		pr_err("%s: Passed token is out of range, token %d\n",
+				__func__, token);
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&opal_async_comp_lock, flags);
+	__set_bit(token, opal_async_complete_map);
+	__clear_bit(token, opal_async_token_map);
+	spin_unlock_irqrestore(&opal_async_comp_lock, flags);
+
+	return 0;
+}
+
+int opal_async_release_token(int token)
+{
+	int ret;
+
+	ret = __opal_async_release_token(token);
+	if (ret)
+		return ret;
+
+	up(&opal_async_sem);
+
+	return 0;
+}
+
+int opal_async_wait_response(uint64_t token, struct opal_msg *msg)
+{
+	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;
+	}
+
+	wait_event(opal_async_wait, test_bit(token, opal_async_complete_map));
+	memcpy(msg, &opal_async_responses[token], sizeof(*msg));
+
+	return 0;
+}
+
+static int opal_async_comp_event(struct notifier_block *nb,
+		unsigned long msg_type, void *msg)
+{
+	struct opal_msg *comp_msg = msg;
+	unsigned long flags;
+	uint64_t token;
+
+	if (msg_type != OPAL_MSG_ASYNC_COMP)
+		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);
+	spin_unlock_irqrestore(&opal_async_comp_lock, flags);
+
+	wake_up(&opal_async_wait);
+
+	return 0;
+}
+
+static struct notifier_block opal_async_comp_nb = {
+		.notifier_call	= opal_async_comp_event,
+		.next		= NULL,
+		.priority	= 0,
+};
+
+static int __init opal_async_comp_init(void)
+{
+	struct device_node *opal_node;
+	const __be32 *async;
+	int err;
+
+	opal_node = of_find_node_by_path("/ibm,opal");
+	if (!opal_node) {
+		pr_err("%s: Opal node not found\n", __func__);
+		err = -ENOENT;
+		goto out;
+	}
+
+	async = of_get_property(opal_node, "opal-msg-async-num", NULL);
+	if (!async) {
+		pr_err("%s: %s has no opal-msg-async-num\n",
+				__func__, opal_node->full_name);
+		err = -ENOENT;
+		goto out_opal_node;
+	}
+
+	opal_max_async_tokens = be32_to_cpup(async);
+	if (opal_max_async_tokens > N_ASYNC_COMPLETIONS)
+		opal_max_async_tokens = N_ASYNC_COMPLETIONS;
+
+	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);
+		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);
+
+out_opal_node:
+	of_node_put(opal_node);
+out:
+	return err;
+}
+machine_subsys_initcall(powernv, opal_async_comp_init);