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, 694 insertions, 0 deletions

diff --git a/drivers/soc/qcom/smsm.c b/drivers/soc/qcom/smsm.c
new file mode 100644
index 000000000..021e9d1f6
--- /dev/null
+++ b/drivers/soc/qcom/smsm.c
@@ -0,0 +1,694 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015, Sony Mobile Communications Inc.
+ * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/mailbox_client.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/regmap.h>
+#include <linux/soc/qcom/smem.h>
+#include <linux/soc/qcom/smem_state.h>
+
+/*
+ * This driver implements the Qualcomm Shared Memory State Machine, a mechanism
+ * for communicating single bit state information to remote processors.
+ *
+ * The implementation is based on two sections of shared memory; the first
+ * holding the state bits and the second holding a matrix of subscription bits.
+ *
+ * The state bits are structured in entries of 32 bits, each belonging to one
+ * system in the SoC. The entry belonging to the local system is considered
+ * read-write, while the rest should be considered read-only.
+ *
+ * The subscription matrix consists of N bitmaps per entry, denoting interest
+ * in updates of the entry for each of the N hosts. Upon updating a state bit
+ * each host's subscription bitmap should be queried and the remote system
+ * should be interrupted if they request so.
+ *
+ * The subscription matrix is laid out in entry-major order:
+ * entry0: [host0 ... hostN]
+ *	.
+ *	.
+ * entryM: [host0 ... hostN]
+ *
+ * A third, optional, shared memory region might contain information regarding
+ * the number of entries in the state bitmap as well as number of columns in
+ * the subscription matrix.
+ */
+
+/*
+ * Shared memory identifiers, used to acquire handles to respective memory
+ * region.
+ */
+#define SMEM_SMSM_SHARED_STATE		85
+#define SMEM_SMSM_CPU_INTR_MASK		333
+#define SMEM_SMSM_SIZE_INFO		419
+
+/*
+ * Default sizes, in case SMEM_SMSM_SIZE_INFO is not found.
+ */
+#define SMSM_DEFAULT_NUM_ENTRIES	8
+#define SMSM_DEFAULT_NUM_HOSTS		3
+
+struct smsm_entry;
+struct smsm_host;
+
+/**
+ * struct qcom_smsm - smsm driver context
+ * @dev:	smsm device pointer
+ * @local_host:	column in the subscription matrix representing this system
+ * @num_hosts:	number of columns in the subscription matrix
+ * @num_entries: number of entries in the state map and rows in the subscription
+ *		matrix
+ * @local_state: pointer to the local processor's state bits
+ * @subscription: pointer to local processor's row in subscription matrix
+ * @state:	smem state handle
+ * @lock:	spinlock for read-modify-write of the outgoing state
+ * @entries:	context for each of the entries
+ * @hosts:	context for each of the hosts
+ * @mbox_client: mailbox client handle
+ */
+struct qcom_smsm {
+	struct device *dev;
+
+	u32 local_host;
+
+	u32 num_hosts;
+	u32 num_entries;
+
+	u32 *local_state;
+	u32 *subscription;
+	struct qcom_smem_state *state;
+
+	spinlock_t lock;
+
+	struct smsm_entry *entries;
+	struct smsm_host *hosts;
+
+	struct mbox_client mbox_client;
+};
+
+/**
+ * struct smsm_entry - per remote processor entry context
+ * @smsm:	back-reference to driver context
+ * @domain:	IRQ domain for this entry, if representing a remote system
+ * @irq_enabled: bitmap of which state bits IRQs are enabled
+ * @irq_rising:	bitmap tracking if rising bits should be propagated
+ * @irq_falling: bitmap tracking if falling bits should be propagated
+ * @last_value:	snapshot of state bits last time the interrupts where propagated
+ * @remote_state: pointer to this entry's state bits
+ * @subscription: pointer to a row in the subscription matrix representing this
+ *		entry
+ */
+struct smsm_entry {
+	struct qcom_smsm *smsm;
+
+	struct irq_domain *domain;
+	DECLARE_BITMAP(irq_enabled, 32);
+	DECLARE_BITMAP(irq_rising, 32);
+	DECLARE_BITMAP(irq_falling, 32);
+	unsigned long last_value;
+
+	u32 *remote_state;
+	u32 *subscription;
+};
+
+/**
+ * struct smsm_host - representation of a remote host
+ * @ipc_regmap:	regmap for outgoing interrupt
+ * @ipc_offset:	offset in @ipc_regmap for outgoing interrupt
+ * @ipc_bit:	bit in @ipc_regmap + @ipc_offset for outgoing interrupt
+ * @mbox_chan:	apcs ipc mailbox channel handle
+ */
+struct smsm_host {
+	struct regmap *ipc_regmap;
+	int ipc_offset;
+	int ipc_bit;
+
+	struct mbox_chan *mbox_chan;
+};
+
+/**
+ * smsm_update_bits() - change bit in outgoing entry and inform subscribers
+ * @data:	smsm context pointer
+ * @mask:	value mask
+ * @value:	new value
+ *
+ * Used to set and clear the bits in the outgoing/local entry and inform
+ * subscribers about the change.
+ */
+static int smsm_update_bits(void *data, u32 mask, u32 value)
+{
+	struct qcom_smsm *smsm = data;
+	struct smsm_host *hostp;
+	unsigned long flags;
+	u32 changes;
+	u32 host;
+	u32 orig;
+	u32 val;
+
+	spin_lock_irqsave(&smsm->lock, flags);
+
+	/* Update the entry */
+	val = orig = readl(smsm->local_state);
+	val &= ~mask;
+	val |= value;
+
+	/* Don't signal if we didn't change the value */
+	changes = val ^ orig;
+	if (!changes) {
+		spin_unlock_irqrestore(&smsm->lock, flags);
+		goto done;
+	}
+
+	/* Write out the new value */
+	writel(val, smsm->local_state);
+	spin_unlock_irqrestore(&smsm->lock, flags);
+
+	/* Make sure the value update is ordered before any kicks */
+	wmb();
+
+	/* Iterate over all hosts to check whom wants a kick */
+	for (host = 0; host < smsm->num_hosts; host++) {
+		hostp = &smsm->hosts[host];
+
+		val = readl(smsm->subscription + host);
+		if (!(val & changes))
+			continue;
+
+		if (hostp->mbox_chan) {
+			mbox_send_message(hostp->mbox_chan, NULL);
+			mbox_client_txdone(hostp->mbox_chan, 0);
+		} else if (hostp->ipc_regmap) {
+			regmap_write(hostp->ipc_regmap,
+				     hostp->ipc_offset,
+				     BIT(hostp->ipc_bit));
+		}
+	}
+
+done:
+	return 0;
+}
+
+static const struct qcom_smem_state_ops smsm_state_ops = {
+	.update_bits = smsm_update_bits,
+};
+
+/**
+ * smsm_intr() - cascading IRQ handler for SMSM
+ * @irq:	unused
+ * @data:	entry related to this IRQ
+ *
+ * This function cascades an incoming interrupt from a remote system, based on
+ * the state bits and configuration.
+ */
+static irqreturn_t smsm_intr(int irq, void *data)
+{
+	struct smsm_entry *entry = data;
+	unsigned i;
+	int irq_pin;
+	u32 changed;
+	u32 val;
+
+	val = readl(entry->remote_state);
+	changed = val ^ xchg(&entry->last_value, val);
+
+	for_each_set_bit(i, entry->irq_enabled, 32) {
+		if (!(changed & BIT(i)))
+			continue;
+
+		if (val & BIT(i)) {
+			if (test_bit(i, entry->irq_rising)) {
+				irq_pin = irq_find_mapping(entry->domain, i);
+				handle_nested_irq(irq_pin);
+			}
+		} else {
+			if (test_bit(i, entry->irq_falling)) {
+				irq_pin = irq_find_mapping(entry->domain, i);
+				handle_nested_irq(irq_pin);
+			}
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * smsm_mask_irq() - un-subscribe from cascades of IRQs of a certain staus bit
+ * @irqd:	IRQ handle to be masked
+ *
+ * This un-subscribes the local CPU from interrupts upon changes to the defines
+ * status bit. The bit is also cleared from cascading.
+ */
+static void smsm_mask_irq(struct irq_data *irqd)
+{
+	struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd);
+	irq_hw_number_t irq = irqd_to_hwirq(irqd);
+	struct qcom_smsm *smsm = entry->smsm;
+	u32 val;
+
+	if (entry->subscription) {
+		val = readl(entry->subscription + smsm->local_host);
+		val &= ~BIT(irq);
+		writel(val, entry->subscription + smsm->local_host);
+	}
+
+	clear_bit(irq, entry->irq_enabled);
+}
+
+/**
+ * smsm_unmask_irq() - subscribe to cascades of IRQs of a certain status bit
+ * @irqd:	IRQ handle to be unmasked
+ *
+ * This subscribes the local CPU to interrupts upon changes to the defined
+ * status bit. The bit is also marked for cascading.
+ */
+static void smsm_unmask_irq(struct irq_data *irqd)
+{
+	struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd);
+	irq_hw_number_t irq = irqd_to_hwirq(irqd);
+	struct qcom_smsm *smsm = entry->smsm;
+	u32 val;
+
+	/* Make sure our last cached state is up-to-date */
+	if (readl(entry->remote_state) & BIT(irq))
+		set_bit(irq, &entry->last_value);
+	else
+		clear_bit(irq, &entry->last_value);
+
+	set_bit(irq, entry->irq_enabled);
+
+	if (entry->subscription) {
+		val = readl(entry->subscription + smsm->local_host);
+		val |= BIT(irq);
+		writel(val, entry->subscription + smsm->local_host);
+	}
+}
+
+/**
+ * smsm_set_irq_type() - updates the requested IRQ type for the cascading
+ * @irqd:	consumer interrupt handle
+ * @type:	requested flags
+ */
+static int smsm_set_irq_type(struct irq_data *irqd, unsigned int type)
+{
+	struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd);
+	irq_hw_number_t irq = irqd_to_hwirq(irqd);
+
+	if (!(type & IRQ_TYPE_EDGE_BOTH))
+		return -EINVAL;
+
+	if (type & IRQ_TYPE_EDGE_RISING)
+		set_bit(irq, entry->irq_rising);
+	else
+		clear_bit(irq, entry->irq_rising);
+
+	if (type & IRQ_TYPE_EDGE_FALLING)
+		set_bit(irq, entry->irq_falling);
+	else
+		clear_bit(irq, entry->irq_falling);
+
+	return 0;
+}
+
+static int smsm_get_irqchip_state(struct irq_data *irqd,
+				  enum irqchip_irq_state which, bool *state)
+{
+	struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd);
+	irq_hw_number_t irq = irqd_to_hwirq(irqd);
+	u32 val;
+
+	if (which != IRQCHIP_STATE_LINE_LEVEL)
+		return -EINVAL;
+
+	val = readl(entry->remote_state);
+	*state = !!(val & BIT(irq));
+
+	return 0;
+}
+
+static struct irq_chip smsm_irq_chip = {
+	.name           = "smsm",
+	.irq_mask       = smsm_mask_irq,
+	.irq_unmask     = smsm_unmask_irq,
+	.irq_set_type	= smsm_set_irq_type,
+	.irq_get_irqchip_state = smsm_get_irqchip_state,
+};
+
+/**
+ * smsm_irq_map() - sets up a mapping for a cascaded IRQ
+ * @d:		IRQ domain representing an entry
+ * @irq:	IRQ to set up
+ * @hw:		unused
+ */
+static int smsm_irq_map(struct irq_domain *d,
+			unsigned int irq,
+			irq_hw_number_t hw)
+{
+	struct smsm_entry *entry = d->host_data;
+
+	irq_set_chip_and_handler(irq, &smsm_irq_chip, handle_level_irq);
+	irq_set_chip_data(irq, entry);
+	irq_set_nested_thread(irq, 1);
+
+	return 0;
+}
+
+static const struct irq_domain_ops smsm_irq_ops = {
+	.map = smsm_irq_map,
+	.xlate = irq_domain_xlate_twocell,
+};
+
+/**
+ * smsm_parse_mbox() - requests an mbox channel
+ * @smsm:	smsm driver context
+ * @host_id:	index of the remote host to be resolved
+ *
+ * Requests the desired channel using the mbox interface which is needed for
+ * sending the outgoing interrupts to a remove hosts - identified by @host_id.
+ */
+static int smsm_parse_mbox(struct qcom_smsm *smsm, unsigned int host_id)
+{
+	struct smsm_host *host = &smsm->hosts[host_id];
+	int ret = 0;
+
+	host->mbox_chan = mbox_request_channel(&smsm->mbox_client, host_id);
+	if (IS_ERR(host->mbox_chan)) {
+		ret = PTR_ERR(host->mbox_chan);
+		host->mbox_chan = NULL;
+	}
+
+	return ret;
+}
+
+/**
+ * smsm_parse_ipc() - parses a qcom,ipc-%d device tree property
+ * @smsm:	smsm driver context
+ * @host_id:	index of the remote host to be resolved
+ *
+ * Parses device tree to acquire the information needed for sending the
+ * outgoing interrupts to a remote host - identified by @host_id.
+ */
+static int smsm_parse_ipc(struct qcom_smsm *smsm, unsigned host_id)
+{
+	struct device_node *syscon;
+	struct device_node *node = smsm->dev->of_node;
+	struct smsm_host *host = &smsm->hosts[host_id];
+	char key[16];
+	int ret;
+
+	snprintf(key, sizeof(key), "qcom,ipc-%d", host_id);
+	syscon = of_parse_phandle(node, key, 0);
+	if (!syscon)
+		return 0;
+
+	host->ipc_regmap = syscon_node_to_regmap(syscon);
+	of_node_put(syscon);
+	if (IS_ERR(host->ipc_regmap))
+		return PTR_ERR(host->ipc_regmap);
+
+	ret = of_property_read_u32_index(node, key, 1, &host->ipc_offset);
+	if (ret < 0) {
+		dev_err(smsm->dev, "no offset in %s\n", key);
+		return -EINVAL;
+	}
+
+	ret = of_property_read_u32_index(node, key, 2, &host->ipc_bit);
+	if (ret < 0) {
+		dev_err(smsm->dev, "no bit in %s\n", key);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * smsm_inbound_entry() - parse DT and set up an entry representing a remote system
+ * @smsm:	smsm driver context
+ * @entry:	entry context to be set up
+ * @node:	dt node containing the entry's properties
+ */
+static int smsm_inbound_entry(struct qcom_smsm *smsm,
+			      struct smsm_entry *entry,
+			      struct device_node *node)
+{
+	int ret;
+	int irq;
+
+	irq = irq_of_parse_and_map(node, 0);
+	if (!irq) {
+		dev_err(smsm->dev, "failed to parse smsm interrupt\n");
+		return -EINVAL;
+	}
+
+	ret = devm_request_threaded_irq(smsm->dev, irq,
+					NULL, smsm_intr,
+					IRQF_ONESHOT,
+					"smsm", (void *)entry);
+	if (ret) {
+		dev_err(smsm->dev, "failed to request interrupt\n");
+		return ret;
+	}
+
+	entry->domain = irq_domain_create_linear(of_fwnode_handle(node), 32, &smsm_irq_ops, entry);
+	if (!entry->domain) {
+		dev_err(smsm->dev, "failed to add irq_domain\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/**
+ * smsm_get_size_info() - parse the optional memory segment for sizes
+ * @smsm:	smsm driver context
+ *
+ * Attempt to acquire the number of hosts and entries from the optional shared
+ * memory location. Not being able to find this segment should indicate that
+ * we're on a older system where these values was hard coded to
+ * SMSM_DEFAULT_NUM_ENTRIES and SMSM_DEFAULT_NUM_HOSTS.
+ *
+ * Returns 0 on success, negative errno on failure.
+ */
+static int smsm_get_size_info(struct qcom_smsm *smsm)
+{
+	size_t size;
+	struct {
+		u32 num_hosts;
+		u32 num_entries;
+		u32 reserved0;
+		u32 reserved1;
+	} *info;
+
+	info = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SIZE_INFO, &size);
+	if (IS_ERR(info) && PTR_ERR(info) != -ENOENT)
+		return dev_err_probe(smsm->dev, PTR_ERR(info),
+				     "unable to retrieve smsm size info\n");
+	else if (IS_ERR(info) || size != sizeof(*info)) {
+		dev_warn(smsm->dev, "no smsm size info, using defaults\n");
+		smsm->num_entries = SMSM_DEFAULT_NUM_ENTRIES;
+		smsm->num_hosts = SMSM_DEFAULT_NUM_HOSTS;
+		return 0;
+	}
+
+	smsm->num_entries = info->num_entries;
+	smsm->num_hosts = info->num_hosts;
+
+	dev_dbg(smsm->dev,
+		"found custom size of smsm: %d entries %d hosts\n",
+		smsm->num_entries, smsm->num_hosts);
+
+	return 0;
+}
+
+static int qcom_smsm_probe(struct platform_device *pdev)
+{
+	struct device_node *local_node;
+	struct device_node *node;
+	struct smsm_entry *entry;
+	struct qcom_smsm *smsm;
+	u32 *intr_mask;
+	size_t size;
+	u32 *states;
+	u32 id;
+	int ret;
+
+	smsm = devm_kzalloc(&pdev->dev, sizeof(*smsm), GFP_KERNEL);
+	if (!smsm)
+		return -ENOMEM;
+	smsm->dev = &pdev->dev;
+	spin_lock_init(&smsm->lock);
+
+	ret = smsm_get_size_info(smsm);
+	if (ret)
+		return ret;
+
+	smsm->entries = devm_kcalloc(&pdev->dev,
+				     smsm->num_entries,
+				     sizeof(struct smsm_entry),
+				     GFP_KERNEL);
+	if (!smsm->entries)
+		return -ENOMEM;
+
+	smsm->hosts = devm_kcalloc(&pdev->dev,
+				   smsm->num_hosts,
+				   sizeof(struct smsm_host),
+				   GFP_KERNEL);
+	if (!smsm->hosts)
+		return -ENOMEM;
+
+	for_each_child_of_node(pdev->dev.of_node, local_node) {
+		if (of_property_present(local_node, "#qcom,smem-state-cells"))
+			break;
+	}
+	if (!local_node) {
+		dev_err(&pdev->dev, "no state entry\n");
+		return -EINVAL;
+	}
+
+	of_property_read_u32(pdev->dev.of_node,
+			     "qcom,local-host",
+			     &smsm->local_host);
+
+	smsm->mbox_client.dev = &pdev->dev;
+	smsm->mbox_client.knows_txdone = true;
+
+	/* Parse the host properties */
+	for (id = 0; id < smsm->num_hosts; id++) {
+		/* Try using mbox interface first, otherwise fall back to syscon */
+		ret = smsm_parse_mbox(smsm, id);
+		if (!ret)
+			continue;
+
+		ret = smsm_parse_ipc(smsm, id);
+		if (ret < 0)
+			goto out_put;
+	}
+
+	/* Acquire the main SMSM state vector */
+	ret = qcom_smem_alloc(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SHARED_STATE,
+			      smsm->num_entries * sizeof(u32));
+	if (ret < 0 && ret != -EEXIST) {
+		dev_err(&pdev->dev, "unable to allocate shared state entry\n");
+		goto out_put;
+	}
+
+	states = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SHARED_STATE, NULL);
+	if (IS_ERR(states)) {
+		dev_err(&pdev->dev, "Unable to acquire shared state entry\n");
+		ret = PTR_ERR(states);
+		goto out_put;
+	}
+
+	/* Acquire the list of interrupt mask vectors */
+	size = smsm->num_entries * smsm->num_hosts * sizeof(u32);
+	ret = qcom_smem_alloc(QCOM_SMEM_HOST_ANY, SMEM_SMSM_CPU_INTR_MASK, size);
+	if (ret < 0 && ret != -EEXIST) {
+		dev_err(&pdev->dev, "unable to allocate smsm interrupt mask\n");
+		goto out_put;
+	}
+
+	intr_mask = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_CPU_INTR_MASK, NULL);
+	if (IS_ERR(intr_mask)) {
+		dev_err(&pdev->dev, "unable to acquire shared memory interrupt mask\n");
+		ret = PTR_ERR(intr_mask);
+		goto out_put;
+	}
+
+	/* Setup the reference to the local state bits */
+	smsm->local_state = states + smsm->local_host;
+	smsm->subscription = intr_mask + smsm->local_host * smsm->num_hosts;
+
+	/* Register the outgoing state */
+	smsm->state = qcom_smem_state_register(local_node, &smsm_state_ops, smsm);
+	if (IS_ERR(smsm->state)) {
+		dev_err(smsm->dev, "failed to register qcom_smem_state\n");
+		ret = PTR_ERR(smsm->state);
+		goto out_put;
+	}
+
+	/* Register handlers for remote processor entries of interest. */
+	for_each_available_child_of_node(pdev->dev.of_node, node) {
+		if (!of_property_read_bool(node, "interrupt-controller"))
+			continue;
+
+		ret = of_property_read_u32(node, "reg", &id);
+		if (ret || id >= smsm->num_entries) {
+			dev_err(&pdev->dev, "invalid reg of entry\n");
+			if (!ret)
+				ret = -EINVAL;
+			goto unwind_interfaces;
+		}
+		entry = &smsm->entries[id];
+
+		entry->smsm = smsm;
+		entry->remote_state = states + id;
+
+		/* Setup subscription pointers and unsubscribe to any kicks */
+		entry->subscription = intr_mask + id * smsm->num_hosts;
+		writel(0, entry->subscription + smsm->local_host);
+
+		ret = smsm_inbound_entry(smsm, entry, node);
+		if (ret < 0)
+			goto unwind_interfaces;
+	}
+
+	platform_set_drvdata(pdev, smsm);
+	of_node_put(local_node);
+
+	return 0;
+
+unwind_interfaces:
+	of_node_put(node);
+	for (id = 0; id < smsm->num_entries; id++)
+		if (smsm->entries[id].domain)
+			irq_domain_remove(smsm->entries[id].domain);
+
+	qcom_smem_state_unregister(smsm->state);
+out_put:
+	for (id = 0; id < smsm->num_hosts; id++)
+		mbox_free_channel(smsm->hosts[id].mbox_chan);
+
+	of_node_put(local_node);
+	return ret;
+}
+
+static void qcom_smsm_remove(struct platform_device *pdev)
+{
+	struct qcom_smsm *smsm = platform_get_drvdata(pdev);
+	unsigned id;
+
+	for (id = 0; id < smsm->num_entries; id++)
+		if (smsm->entries[id].domain)
+			irq_domain_remove(smsm->entries[id].domain);
+
+	for (id = 0; id < smsm->num_hosts; id++)
+		mbox_free_channel(smsm->hosts[id].mbox_chan);
+
+	qcom_smem_state_unregister(smsm->state);
+}
+
+static const struct of_device_id qcom_smsm_of_match[] = {
+	{ .compatible = "qcom,smsm" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_smsm_of_match);
+
+static struct platform_driver qcom_smsm_driver = {
+	.probe = qcom_smsm_probe,
+	.remove = qcom_smsm_remove,
+	.driver = {
+		.name = "qcom-smsm",
+		.of_match_table = qcom_smsm_of_match,
+	},
+};
+module_platform_driver(qcom_smsm_driver);
+
+MODULE_DESCRIPTION("Qualcomm Shared Memory State Machine driver");
+MODULE_LICENSE("GPL v2");