Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 941 insertions, 0 deletions

diff --git a/drivers/firmware/tegra/bpmp.c b/drivers/firmware/tegra/bpmp.c
new file mode 100644
index 000000000..753472b53
--- /dev/null
+++ b/drivers/firmware/tegra/bpmp.c
@@ -0,0 +1,941 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#include <linux/clk/tegra.h>
+#include <linux/genalloc.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/semaphore.h>
+#include <linux/sched/clock.h>
+
+#include <soc/tegra/bpmp.h>
+#include <soc/tegra/bpmp-abi.h>
+#include <soc/tegra/ivc.h>
+
+#include "bpmp-private.h"
+
+#define MSG_ACK		BIT(0)
+#define MSG_RING	BIT(1)
+#define TAG_SZ		32
+
+static inline const struct tegra_bpmp_ops *
+channel_to_ops(struct tegra_bpmp_channel *channel)
+{
+	struct tegra_bpmp *bpmp = channel->bpmp;
+
+	return bpmp->soc->ops;
+}
+
+struct tegra_bpmp *tegra_bpmp_get_with_id(struct device *dev, unsigned int *id)
+{
+	struct platform_device *pdev;
+	struct of_phandle_args args;
+	struct tegra_bpmp *bpmp;
+	int err;
+
+	err = __of_parse_phandle_with_args(dev->of_node, "nvidia,bpmp", NULL,
+					   1, 0, &args);
+	if (err < 0)
+		return ERR_PTR(err);
+
+	pdev = of_find_device_by_node(args.np);
+	if (!pdev) {
+		bpmp = ERR_PTR(-ENODEV);
+		goto put;
+	}
+
+	bpmp = platform_get_drvdata(pdev);
+	if (!bpmp) {
+		bpmp = ERR_PTR(-EPROBE_DEFER);
+		put_device(&pdev->dev);
+		goto put;
+	}
+
+	if (id)
+		*id = args.args[0];
+
+put:
+	of_node_put(args.np);
+	return bpmp;
+}
+EXPORT_SYMBOL_GPL(tegra_bpmp_get_with_id);
+
+struct tegra_bpmp *tegra_bpmp_get(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct tegra_bpmp *bpmp;
+	struct device_node *np;
+
+	np = of_parse_phandle(dev->of_node, "nvidia,bpmp", 0);
+	if (!np)
+		return ERR_PTR(-ENOENT);
+
+	pdev = of_find_device_by_node(np);
+	if (!pdev) {
+		bpmp = ERR_PTR(-ENODEV);
+		goto put;
+	}
+
+	bpmp = platform_get_drvdata(pdev);
+	if (!bpmp) {
+		bpmp = ERR_PTR(-EPROBE_DEFER);
+		put_device(&pdev->dev);
+		goto put;
+	}
+
+put:
+	of_node_put(np);
+	return bpmp;
+}
+EXPORT_SYMBOL_GPL(tegra_bpmp_get);
+
+void tegra_bpmp_put(struct tegra_bpmp *bpmp)
+{
+	if (bpmp)
+		put_device(bpmp->dev);
+}
+EXPORT_SYMBOL_GPL(tegra_bpmp_put);
+
+static int
+tegra_bpmp_channel_get_thread_index(struct tegra_bpmp_channel *channel)
+{
+	struct tegra_bpmp *bpmp = channel->bpmp;
+	unsigned int count;
+	int index;
+
+	count = bpmp->soc->channels.thread.count;
+
+	index = channel - channel->bpmp->threaded_channels;
+	if (index < 0 || index >= count)
+		return -EINVAL;
+
+	return index;
+}
+
+static bool tegra_bpmp_message_valid(const struct tegra_bpmp_message *msg)
+{
+	return (msg->tx.size <= MSG_DATA_MIN_SZ) &&
+	       (msg->rx.size <= MSG_DATA_MIN_SZ) &&
+	       (msg->tx.size == 0 || msg->tx.data) &&
+	       (msg->rx.size == 0 || msg->rx.data);
+}
+
+static bool tegra_bpmp_is_response_ready(struct tegra_bpmp_channel *channel)
+{
+	const struct tegra_bpmp_ops *ops = channel_to_ops(channel);
+
+	return ops->is_response_ready(channel);
+}
+
+static bool tegra_bpmp_is_request_ready(struct tegra_bpmp_channel *channel)
+{
+	const struct tegra_bpmp_ops *ops = channel_to_ops(channel);
+
+	return ops->is_request_ready(channel);
+}
+
+static int tegra_bpmp_wait_response(struct tegra_bpmp_channel *channel)
+{
+	unsigned long timeout = channel->bpmp->soc->channels.cpu_tx.timeout;
+	ktime_t end;
+
+	end = ktime_add_us(ktime_get(), timeout);
+
+	do {
+		if (tegra_bpmp_is_response_ready(channel))
+			return 0;
+	} while (ktime_before(ktime_get(), end));
+
+	return -ETIMEDOUT;
+}
+
+static int tegra_bpmp_ack_response(struct tegra_bpmp_channel *channel)
+{
+	const struct tegra_bpmp_ops *ops = channel_to_ops(channel);
+
+	return ops->ack_response(channel);
+}
+
+static int tegra_bpmp_ack_request(struct tegra_bpmp_channel *channel)
+{
+	const struct tegra_bpmp_ops *ops = channel_to_ops(channel);
+
+	return ops->ack_request(channel);
+}
+
+static bool
+tegra_bpmp_is_request_channel_free(struct tegra_bpmp_channel *channel)
+{
+	const struct tegra_bpmp_ops *ops = channel_to_ops(channel);
+
+	return ops->is_request_channel_free(channel);
+}
+
+static bool
+tegra_bpmp_is_response_channel_free(struct tegra_bpmp_channel *channel)
+{
+	const struct tegra_bpmp_ops *ops = channel_to_ops(channel);
+
+	return ops->is_response_channel_free(channel);
+}
+
+static int
+tegra_bpmp_wait_request_channel_free(struct tegra_bpmp_channel *channel)
+{
+	unsigned long timeout = channel->bpmp->soc->channels.cpu_tx.timeout;
+	ktime_t start, now;
+
+	start = ns_to_ktime(local_clock());
+
+	do {
+		if (tegra_bpmp_is_request_channel_free(channel))
+			return 0;
+
+		now = ns_to_ktime(local_clock());
+	} while (ktime_us_delta(now, start) < timeout);
+
+	return -ETIMEDOUT;
+}
+
+static int tegra_bpmp_post_request(struct tegra_bpmp_channel *channel)
+{
+	const struct tegra_bpmp_ops *ops = channel_to_ops(channel);
+
+	return ops->post_request(channel);
+}
+
+static int tegra_bpmp_post_response(struct tegra_bpmp_channel *channel)
+{
+	const struct tegra_bpmp_ops *ops = channel_to_ops(channel);
+
+	return ops->post_response(channel);
+}
+
+static int tegra_bpmp_ring_doorbell(struct tegra_bpmp *bpmp)
+{
+	return bpmp->soc->ops->ring_doorbell(bpmp);
+}
+
+static ssize_t __tegra_bpmp_channel_read(struct tegra_bpmp_channel *channel,
+					 void *data, size_t size, int *ret)
+{
+	int err;
+
+	if (data && size > 0)
+		tegra_bpmp_mb_read(data, &channel->ib, size);
+
+	err = tegra_bpmp_ack_response(channel);
+	if (err < 0)
+		return err;
+
+	*ret = tegra_bpmp_mb_read_field(&channel->ib, code);
+
+	return 0;
+}
+
+static ssize_t tegra_bpmp_channel_read(struct tegra_bpmp_channel *channel,
+				       void *data, size_t size, int *ret)
+{
+	struct tegra_bpmp *bpmp = channel->bpmp;
+	unsigned long flags;
+	ssize_t err;
+	int index;
+
+	index = tegra_bpmp_channel_get_thread_index(channel);
+	if (index < 0) {
+		err = index;
+		goto unlock;
+	}
+
+	spin_lock_irqsave(&bpmp->lock, flags);
+	err = __tegra_bpmp_channel_read(channel, data, size, ret);
+	clear_bit(index, bpmp->threaded.allocated);
+	spin_unlock_irqrestore(&bpmp->lock, flags);
+
+unlock:
+	up(&bpmp->threaded.lock);
+
+	return err;
+}
+
+static ssize_t __tegra_bpmp_channel_write(struct tegra_bpmp_channel *channel,
+					  unsigned int mrq, unsigned long flags,
+					  const void *data, size_t size)
+{
+	tegra_bpmp_mb_write_field(&channel->ob, code, mrq);
+	tegra_bpmp_mb_write_field(&channel->ob, flags, flags);
+
+	if (data && size > 0)
+		tegra_bpmp_mb_write(&channel->ob, data, size);
+
+	return tegra_bpmp_post_request(channel);
+}
+
+static struct tegra_bpmp_channel *
+tegra_bpmp_write_threaded(struct tegra_bpmp *bpmp, unsigned int mrq,
+			  const void *data, size_t size)
+{
+	unsigned long timeout = bpmp->soc->channels.thread.timeout;
+	unsigned int count = bpmp->soc->channels.thread.count;
+	struct tegra_bpmp_channel *channel;
+	unsigned long flags;
+	unsigned int index;
+	int err;
+
+	err = down_timeout(&bpmp->threaded.lock, usecs_to_jiffies(timeout));
+	if (err < 0)
+		return ERR_PTR(err);
+
+	spin_lock_irqsave(&bpmp->lock, flags);
+
+	index = find_first_zero_bit(bpmp->threaded.allocated, count);
+	if (index == count) {
+		err = -EBUSY;
+		goto unlock;
+	}
+
+	channel = &bpmp->threaded_channels[index];
+
+	if (!tegra_bpmp_is_request_channel_free(channel)) {
+		err = -EBUSY;
+		goto unlock;
+	}
+
+	set_bit(index, bpmp->threaded.allocated);
+
+	err = __tegra_bpmp_channel_write(channel, mrq, MSG_ACK | MSG_RING,
+					 data, size);
+	if (err < 0)
+		goto clear_allocated;
+
+	set_bit(index, bpmp->threaded.busy);
+
+	spin_unlock_irqrestore(&bpmp->lock, flags);
+	return channel;
+
+clear_allocated:
+	clear_bit(index, bpmp->threaded.allocated);
+unlock:
+	spin_unlock_irqrestore(&bpmp->lock, flags);
+	up(&bpmp->threaded.lock);
+
+	return ERR_PTR(err);
+}
+
+static ssize_t tegra_bpmp_channel_write(struct tegra_bpmp_channel *channel,
+					unsigned int mrq, unsigned long flags,
+					const void *data, size_t size)
+{
+	int err;
+
+	err = tegra_bpmp_wait_request_channel_free(channel);
+	if (err < 0)
+		return err;
+
+	return __tegra_bpmp_channel_write(channel, mrq, flags, data, size);
+}
+
+static int __maybe_unused tegra_bpmp_resume(struct device *dev);
+
+int tegra_bpmp_transfer_atomic(struct tegra_bpmp *bpmp,
+			       struct tegra_bpmp_message *msg)
+{
+	struct tegra_bpmp_channel *channel;
+	int err;
+
+	if (WARN_ON(!irqs_disabled()))
+		return -EPERM;
+
+	if (!tegra_bpmp_message_valid(msg))
+		return -EINVAL;
+
+	if (bpmp->suspended) {
+		/* Reset BPMP IPC channels during resume based on flags passed */
+		if (msg->flags & TEGRA_BPMP_MESSAGE_RESET)
+			tegra_bpmp_resume(bpmp->dev);
+		else
+			return -EAGAIN;
+	}
+
+	channel = bpmp->tx_channel;
+
+	spin_lock(&bpmp->atomic_tx_lock);
+
+	err = tegra_bpmp_channel_write(channel, msg->mrq, MSG_ACK,
+				       msg->tx.data, msg->tx.size);
+	if (err < 0) {
+		spin_unlock(&bpmp->atomic_tx_lock);
+		return err;
+	}
+
+	spin_unlock(&bpmp->atomic_tx_lock);
+
+	err = tegra_bpmp_ring_doorbell(bpmp);
+	if (err < 0)
+		return err;
+
+	err = tegra_bpmp_wait_response(channel);
+	if (err < 0)
+		return err;
+
+	return __tegra_bpmp_channel_read(channel, msg->rx.data, msg->rx.size,
+					 &msg->rx.ret);
+}
+EXPORT_SYMBOL_GPL(tegra_bpmp_transfer_atomic);
+
+int tegra_bpmp_transfer(struct tegra_bpmp *bpmp,
+			struct tegra_bpmp_message *msg)
+{
+	struct tegra_bpmp_channel *channel;
+	unsigned long timeout;
+	int err;
+
+	if (WARN_ON(irqs_disabled()))
+		return -EPERM;
+
+	if (!tegra_bpmp_message_valid(msg))
+		return -EINVAL;
+
+	if (bpmp->suspended) {
+		/* Reset BPMP IPC channels during resume based on flags passed */
+		if (msg->flags & TEGRA_BPMP_MESSAGE_RESET)
+			tegra_bpmp_resume(bpmp->dev);
+		else
+			return -EAGAIN;
+	}
+
+	channel = tegra_bpmp_write_threaded(bpmp, msg->mrq, msg->tx.data,
+					    msg->tx.size);
+	if (IS_ERR(channel))
+		return PTR_ERR(channel);
+
+	err = tegra_bpmp_ring_doorbell(bpmp);
+	if (err < 0)
+		return err;
+
+	timeout = usecs_to_jiffies(bpmp->soc->channels.thread.timeout);
+
+	err = wait_for_completion_timeout(&channel->completion, timeout);
+	if (err == 0)
+		return -ETIMEDOUT;
+
+	return tegra_bpmp_channel_read(channel, msg->rx.data, msg->rx.size,
+				       &msg->rx.ret);
+}
+EXPORT_SYMBOL_GPL(tegra_bpmp_transfer);
+
+static struct tegra_bpmp_mrq *tegra_bpmp_find_mrq(struct tegra_bpmp *bpmp,
+						  unsigned int mrq)
+{
+	struct tegra_bpmp_mrq *entry;
+
+	list_for_each_entry(entry, &bpmp->mrqs, list)
+		if (entry->mrq == mrq)
+			return entry;
+
+	return NULL;
+}
+
+void tegra_bpmp_mrq_return(struct tegra_bpmp_channel *channel, int code,
+			   const void *data, size_t size)
+{
+	unsigned long flags = tegra_bpmp_mb_read_field(&channel->ib, flags);
+	struct tegra_bpmp *bpmp = channel->bpmp;
+	int err;
+
+	if (WARN_ON(size > MSG_DATA_MIN_SZ))
+		return;
+
+	err = tegra_bpmp_ack_request(channel);
+	if (WARN_ON(err < 0))
+		return;
+
+	if ((flags & MSG_ACK) == 0)
+		return;
+
+	if (WARN_ON(!tegra_bpmp_is_response_channel_free(channel)))
+		return;
+
+	tegra_bpmp_mb_write_field(&channel->ob, code, code);
+
+	if (data && size > 0)
+		tegra_bpmp_mb_write(&channel->ob, data, size);
+
+	err = tegra_bpmp_post_response(channel);
+	if (WARN_ON(err < 0))
+		return;
+
+	if (flags & MSG_RING) {
+		err = tegra_bpmp_ring_doorbell(bpmp);
+		if (WARN_ON(err < 0))
+			return;
+	}
+}
+EXPORT_SYMBOL_GPL(tegra_bpmp_mrq_return);
+
+static void tegra_bpmp_handle_mrq(struct tegra_bpmp *bpmp,
+				  unsigned int mrq,
+				  struct tegra_bpmp_channel *channel)
+{
+	struct tegra_bpmp_mrq *entry;
+	u32 zero = 0;
+
+	spin_lock(&bpmp->lock);
+
+	entry = tegra_bpmp_find_mrq(bpmp, mrq);
+	if (!entry) {
+		spin_unlock(&bpmp->lock);
+		tegra_bpmp_mrq_return(channel, -EINVAL, &zero, sizeof(zero));
+		return;
+	}
+
+	entry->handler(mrq, channel, entry->data);
+
+	spin_unlock(&bpmp->lock);
+}
+
+int tegra_bpmp_request_mrq(struct tegra_bpmp *bpmp, unsigned int mrq,
+			   tegra_bpmp_mrq_handler_t handler, void *data)
+{
+	struct tegra_bpmp_mrq *entry;
+	unsigned long flags;
+
+	if (!handler)
+		return -EINVAL;
+
+	entry = devm_kzalloc(bpmp->dev, sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&bpmp->lock, flags);
+
+	entry->mrq = mrq;
+	entry->handler = handler;
+	entry->data = data;
+	list_add(&entry->list, &bpmp->mrqs);
+
+	spin_unlock_irqrestore(&bpmp->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tegra_bpmp_request_mrq);
+
+void tegra_bpmp_free_mrq(struct tegra_bpmp *bpmp, unsigned int mrq, void *data)
+{
+	struct tegra_bpmp_mrq *entry;
+	unsigned long flags;
+
+	spin_lock_irqsave(&bpmp->lock, flags);
+
+	entry = tegra_bpmp_find_mrq(bpmp, mrq);
+	if (!entry)
+		goto unlock;
+
+	list_del(&entry->list);
+	devm_kfree(bpmp->dev, entry);
+
+unlock:
+	spin_unlock_irqrestore(&bpmp->lock, flags);
+}
+EXPORT_SYMBOL_GPL(tegra_bpmp_free_mrq);
+
+bool tegra_bpmp_mrq_is_supported(struct tegra_bpmp *bpmp, unsigned int mrq)
+{
+	struct mrq_query_abi_request req = { .mrq = mrq };
+	struct mrq_query_abi_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_QUERY_ABI,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	int err;
+
+	err = tegra_bpmp_transfer(bpmp, &msg);
+	if (err || msg.rx.ret)
+		return false;
+
+	return resp.status == 0;
+}
+EXPORT_SYMBOL_GPL(tegra_bpmp_mrq_is_supported);
+
+static void tegra_bpmp_mrq_handle_ping(unsigned int mrq,
+				       struct tegra_bpmp_channel *channel,
+				       void *data)
+{
+	struct mrq_ping_request request;
+	struct mrq_ping_response response;
+
+	tegra_bpmp_mb_read(&request, &channel->ib, sizeof(request));
+
+	memset(&response, 0, sizeof(response));
+	response.reply = request.challenge << 1;
+
+	tegra_bpmp_mrq_return(channel, 0, &response, sizeof(response));
+}
+
+static int tegra_bpmp_ping(struct tegra_bpmp *bpmp)
+{
+	struct mrq_ping_response response;
+	struct mrq_ping_request request;
+	struct tegra_bpmp_message msg;
+	unsigned long flags;
+	ktime_t start, end;
+	int err;
+
+	memset(&request, 0, sizeof(request));
+	request.challenge = 1;
+
+	memset(&response, 0, sizeof(response));
+
+	memset(&msg, 0, sizeof(msg));
+	msg.mrq = MRQ_PING;
+	msg.tx.data = &request;
+	msg.tx.size = sizeof(request);
+	msg.rx.data = &response;
+	msg.rx.size = sizeof(response);
+
+	local_irq_save(flags);
+	start = ktime_get();
+	err = tegra_bpmp_transfer_atomic(bpmp, &msg);
+	end = ktime_get();
+	local_irq_restore(flags);
+
+	if (!err)
+		dev_dbg(bpmp->dev,
+			"ping ok: challenge: %u, response: %u, time: %lld\n",
+			request.challenge, response.reply,
+			ktime_to_us(ktime_sub(end, start)));
+
+	return err;
+}
+
+/* deprecated version of tag query */
+static int tegra_bpmp_get_firmware_tag_old(struct tegra_bpmp *bpmp, char *tag,
+					   size_t size)
+{
+	struct mrq_query_tag_request request;
+	struct tegra_bpmp_message msg;
+	unsigned long flags;
+	dma_addr_t phys;
+	void *virt;
+	int err;
+
+	if (size != TAG_SZ)
+		return -EINVAL;
+
+	virt = dma_alloc_coherent(bpmp->dev, TAG_SZ, &phys,
+				  GFP_KERNEL | GFP_DMA32);
+	if (!virt)
+		return -ENOMEM;
+
+	memset(&request, 0, sizeof(request));
+	request.addr = phys;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.mrq = MRQ_QUERY_TAG;
+	msg.tx.data = &request;
+	msg.tx.size = sizeof(request);
+
+	local_irq_save(flags);
+	err = tegra_bpmp_transfer_atomic(bpmp, &msg);
+	local_irq_restore(flags);
+
+	if (err == 0)
+		memcpy(tag, virt, TAG_SZ);
+
+	dma_free_coherent(bpmp->dev, TAG_SZ, virt, phys);
+
+	return err;
+}
+
+static int tegra_bpmp_get_firmware_tag(struct tegra_bpmp *bpmp, char *tag,
+				       size_t size)
+{
+	if (tegra_bpmp_mrq_is_supported(bpmp, MRQ_QUERY_FW_TAG)) {
+		struct mrq_query_fw_tag_response resp;
+		struct tegra_bpmp_message msg = {
+			.mrq = MRQ_QUERY_FW_TAG,
+			.rx = {
+				.data = &resp,
+				.size = sizeof(resp),
+			},
+		};
+		int err;
+
+		if (size != sizeof(resp.tag))
+			return -EINVAL;
+
+		err = tegra_bpmp_transfer(bpmp, &msg);
+
+		if (err)
+			return err;
+		if (msg.rx.ret < 0)
+			return -EINVAL;
+
+		memcpy(tag, resp.tag, sizeof(resp.tag));
+		return 0;
+	}
+
+	return tegra_bpmp_get_firmware_tag_old(bpmp, tag, size);
+}
+
+static void tegra_bpmp_channel_signal(struct tegra_bpmp_channel *channel)
+{
+	unsigned long flags = tegra_bpmp_mb_read_field(&channel->ob, flags);
+
+	if ((flags & MSG_RING) == 0)
+		return;
+
+	complete(&channel->completion);
+}
+
+void tegra_bpmp_handle_rx(struct tegra_bpmp *bpmp)
+{
+	struct tegra_bpmp_channel *channel;
+	unsigned int i, count;
+	unsigned long *busy;
+
+	channel = bpmp->rx_channel;
+	count = bpmp->soc->channels.thread.count;
+	busy = bpmp->threaded.busy;
+
+	if (tegra_bpmp_is_request_ready(channel)) {
+		unsigned int mrq = tegra_bpmp_mb_read_field(&channel->ib, code);
+
+		tegra_bpmp_handle_mrq(bpmp, mrq, channel);
+	}
+
+	spin_lock(&bpmp->lock);
+
+	for_each_set_bit(i, busy, count) {
+		struct tegra_bpmp_channel *channel;
+
+		channel = &bpmp->threaded_channels[i];
+
+		if (tegra_bpmp_is_response_ready(channel)) {
+			tegra_bpmp_channel_signal(channel);
+			clear_bit(i, busy);
+		}
+	}
+
+	spin_unlock(&bpmp->lock);
+}
+
+static int tegra_bpmp_probe(struct platform_device *pdev)
+{
+	struct tegra_bpmp *bpmp;
+	char tag[TAG_SZ];
+	size_t size;
+	int err;
+
+	bpmp = devm_kzalloc(&pdev->dev, sizeof(*bpmp), GFP_KERNEL);
+	if (!bpmp)
+		return -ENOMEM;
+
+	bpmp->soc = of_device_get_match_data(&pdev->dev);
+	bpmp->dev = &pdev->dev;
+
+	INIT_LIST_HEAD(&bpmp->mrqs);
+	spin_lock_init(&bpmp->lock);
+
+	bpmp->threaded.count = bpmp->soc->channels.thread.count;
+	sema_init(&bpmp->threaded.lock, bpmp->threaded.count);
+
+	size = BITS_TO_LONGS(bpmp->threaded.count) * sizeof(long);
+
+	bpmp->threaded.allocated = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+	if (!bpmp->threaded.allocated)
+		return -ENOMEM;
+
+	bpmp->threaded.busy = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+	if (!bpmp->threaded.busy)
+		return -ENOMEM;
+
+	spin_lock_init(&bpmp->atomic_tx_lock);
+	bpmp->tx_channel = devm_kzalloc(&pdev->dev, sizeof(*bpmp->tx_channel),
+					GFP_KERNEL);
+	if (!bpmp->tx_channel)
+		return -ENOMEM;
+
+	bpmp->rx_channel = devm_kzalloc(&pdev->dev, sizeof(*bpmp->rx_channel),
+	                                GFP_KERNEL);
+	if (!bpmp->rx_channel)
+		return -ENOMEM;
+
+	bpmp->threaded_channels = devm_kcalloc(&pdev->dev, bpmp->threaded.count,
+					       sizeof(*bpmp->threaded_channels),
+					       GFP_KERNEL);
+	if (!bpmp->threaded_channels)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, bpmp);
+
+	err = bpmp->soc->ops->init(bpmp);
+	if (err < 0)
+		return err;
+
+	err = tegra_bpmp_request_mrq(bpmp, MRQ_PING,
+				     tegra_bpmp_mrq_handle_ping, bpmp);
+	if (err < 0)
+		goto deinit;
+
+	err = tegra_bpmp_ping(bpmp);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to ping BPMP: %d\n", err);
+		goto free_mrq;
+	}
+
+	err = tegra_bpmp_get_firmware_tag(bpmp, tag, sizeof(tag));
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to get firmware tag: %d\n", err);
+		goto free_mrq;
+	}
+
+	dev_info(&pdev->dev, "firmware: %.*s\n", (int)sizeof(tag), tag);
+
+	err = of_platform_default_populate(pdev->dev.of_node, NULL, &pdev->dev);
+	if (err < 0)
+		goto free_mrq;
+
+	if (of_property_present(pdev->dev.of_node, "#clock-cells")) {
+		err = tegra_bpmp_init_clocks(bpmp);
+		if (err < 0)
+			goto free_mrq;
+	}
+
+	if (of_property_present(pdev->dev.of_node, "#reset-cells")) {
+		err = tegra_bpmp_init_resets(bpmp);
+		if (err < 0)
+			goto free_mrq;
+	}
+
+	if (of_property_present(pdev->dev.of_node, "#power-domain-cells")) {
+		err = tegra_bpmp_init_powergates(bpmp);
+		if (err < 0)
+			goto free_mrq;
+	}
+
+	err = tegra_bpmp_init_debugfs(bpmp);
+	if (err < 0)
+		dev_err(&pdev->dev, "debugfs initialization failed: %d\n", err);
+
+	return 0;
+
+free_mrq:
+	tegra_bpmp_free_mrq(bpmp, MRQ_PING, bpmp);
+deinit:
+	if (bpmp->soc->ops->deinit)
+		bpmp->soc->ops->deinit(bpmp);
+
+	return err;
+}
+
+static int __maybe_unused tegra_bpmp_suspend(struct device *dev)
+{
+	struct tegra_bpmp *bpmp = dev_get_drvdata(dev);
+
+	bpmp->suspended = true;
+
+	return 0;
+}
+
+static int __maybe_unused tegra_bpmp_resume(struct device *dev)
+{
+	struct tegra_bpmp *bpmp = dev_get_drvdata(dev);
+
+	bpmp->suspended = false;
+
+	if (bpmp->soc->ops->resume)
+		return bpmp->soc->ops->resume(bpmp);
+	else
+		return 0;
+}
+
+static const struct dev_pm_ops tegra_bpmp_pm_ops = {
+	.suspend_noirq = tegra_bpmp_suspend,
+	.resume_noirq = tegra_bpmp_resume,
+};
+
+#if IS_ENABLED(CONFIG_ARCH_TEGRA_186_SOC) || \
+    IS_ENABLED(CONFIG_ARCH_TEGRA_194_SOC) || \
+    IS_ENABLED(CONFIG_ARCH_TEGRA_234_SOC) || \
+    IS_ENABLED(CONFIG_ARCH_TEGRA_264_SOC)
+static const struct tegra_bpmp_soc tegra186_soc = {
+	.channels = {
+		.cpu_tx = {
+			.offset = 3,
+			.timeout = 60 * USEC_PER_SEC,
+		},
+		.thread = {
+			.offset = 0,
+			.count = 3,
+			.timeout = 600 * USEC_PER_SEC,
+		},
+		.cpu_rx = {
+			.offset = 13,
+			.timeout = 0,
+		},
+	},
+	.ops = &tegra186_bpmp_ops,
+	.num_resets = 193,
+};
+#endif
+
+#if IS_ENABLED(CONFIG_ARCH_TEGRA_210_SOC)
+static const struct tegra_bpmp_soc tegra210_soc = {
+	.channels = {
+		.cpu_tx = {
+			.offset = 0,
+			.count = 1,
+			.timeout = 60 * USEC_PER_SEC,
+		},
+		.thread = {
+			.offset = 4,
+			.count = 1,
+			.timeout = 600 * USEC_PER_SEC,
+		},
+		.cpu_rx = {
+			.offset = 8,
+			.count = 1,
+			.timeout = 0,
+		},
+	},
+	.ops = &tegra210_bpmp_ops,
+};
+#endif
+
+static const struct of_device_id tegra_bpmp_match[] = {
+#if IS_ENABLED(CONFIG_ARCH_TEGRA_186_SOC) || \
+    IS_ENABLED(CONFIG_ARCH_TEGRA_194_SOC) || \
+    IS_ENABLED(CONFIG_ARCH_TEGRA_234_SOC) || \
+    IS_ENABLED(CONFIG_ARCH_TEGRA_264_SOC)
+	{ .compatible = "nvidia,tegra186-bpmp", .data = &tegra186_soc },
+#endif
+#if IS_ENABLED(CONFIG_ARCH_TEGRA_210_SOC)
+	{ .compatible = "nvidia,tegra210-bpmp", .data = &tegra210_soc },
+#endif
+	{ }
+};
+
+static struct platform_driver tegra_bpmp_driver = {
+	.driver = {
+		.name = "tegra-bpmp",
+		.of_match_table = tegra_bpmp_match,
+		.pm = &tegra_bpmp_pm_ops,
+		.suppress_bind_attrs = true,
+	},
+	.probe = tegra_bpmp_probe,
+};
+builtin_platform_driver(tegra_bpmp_driver);