msm: rdbg: Add snapshot of remote debugger driver

This snapshot was taken as of msm-3.10 commit
("Merge "msm: msm_bus: Provide valid input pointer argument")

Updated source and documentation to fix checkpatch warnings.

Change-Id: I6e84fc016a7bea69bb4d5d1991d8b5500244307d
Acked-by: Vivek Iyer <viyer@qti.qualcomm.com>
Acked-by: Mahesh Rohera <mrohera@qti.qualcomm.com>
Acked-by: Jay Jayanna <jjayanna@qti.qualcomm.com>
Signed-off-by: Sathish Ambley <sathishambley@codeaurora.org>

1 files changed, 1165 insertions, 0 deletions

diff --git a/drivers/char/rdbg.c b/drivers/char/rdbg.c
new file mode 100644
index 000000000000..0823ed78485e
--- /dev/null
+++ b/drivers/char/rdbg.c
@@ -0,0 +1,1165 @@
+/*
+ * Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <soc/qcom/smsm.h>
+#include <linux/uaccess.h>
+#include <linux/interrupt.h>
+
+#define SMP2P_NUM_PROCS				8
+#define MAX_RETRIES				20
+
+#define SM_VERSION				1
+#define SM_BLOCKSIZE				128
+
+#define SMQ_MAGIC_INIT				0xFF00FF00
+#define SMQ_MAGIC_PRODUCER			(SMQ_MAGIC_INIT | 0x1)
+#define SMQ_MAGIC_CONSUMER			(SMQ_MAGIC_INIT | 0x2)
+
+enum SMQ_STATUS {
+	SMQ_SUCCESS    =  0,
+	SMQ_ENOMEMORY  = -1,
+	SMQ_EBADPARM   = -2,
+	SMQ_UNDERFLOW  = -3,
+	SMQ_OVERFLOW   = -4
+};
+
+enum smq_type {
+	PRODUCER = 1,
+	CONSUMER = 2,
+	INVALID  = 3
+};
+
+struct smq_block_map {
+	uint32_t index_read;
+	uint32_t num_blocks;
+	uint8_t *map;
+};
+
+struct smq_node {
+	uint16_t index_block;
+	uint16_t num_blocks;
+} __attribute__ ((__packed__));
+
+struct smq_hdr {
+	uint8_t producer_version;
+	uint8_t consumer_version;
+} __attribute__ ((__packed__));
+
+struct smq_out_state {
+	uint32_t init;
+	uint32_t index_check_queue_for_reset;
+	uint32_t index_sent_write;
+	uint32_t index_free_read;
+} __attribute__ ((__packed__));
+
+struct smq_out {
+	struct smq_out_state s;
+	struct smq_node sent[1];
+};
+
+struct smq_in_state {
+	uint32_t init;
+	uint32_t index_check_queue_for_reset_ack;
+	uint32_t index_sent_read;
+	uint32_t index_free_write;
+} __attribute__ ((__packed__));
+
+struct smq_in {
+	struct smq_in_state s;
+	struct smq_node free[1];
+};
+
+struct smq {
+	struct smq_hdr *hdr;
+	struct smq_out *out;
+	struct smq_in *in;
+	uint8_t *blocks;
+	uint32_t num_blocks;
+	struct mutex *lock;
+	uint32_t initialized;
+	struct smq_block_map block_map;
+	enum smq_type type;
+};
+
+struct gpio_info {
+	int gpio_base_id;
+	int irq_base_id;
+};
+
+struct rdbg_data {
+	struct device *device;
+	struct completion work;
+	struct gpio_info in;
+	struct gpio_info out;
+	bool   device_initialized;
+	int    gpio_out_offset;
+	bool   device_opened;
+	void   *smem_addr;
+	size_t smem_size;
+	struct smq    producer_smrb;
+	struct smq    consumer_smrb;
+	struct mutex  write_mutex;
+};
+
+struct rdbg_device {
+	struct cdev cdev;
+	struct class *class;
+	dev_t dev_no;
+	int num_devices;
+	struct rdbg_data *rdbg_data;
+};
+
+static struct rdbg_device g_rdbg_instance = {
+	{ {0} },
+	NULL,
+	0,
+	SMP2P_NUM_PROCS,
+	NULL
+};
+
+struct processor_specific_info {
+	char *name;
+	unsigned int smem_buffer_addr;
+	size_t smem_buffer_size;
+};
+
+static struct processor_specific_info proc_info[SMP2P_NUM_PROCS] = {
+		{0},	/*APPS*/
+		{"rdbg_modem", 0, 0},	/*MODEM*/
+		{"rdbg_adsp", SMEM_LC_DEBUGGER, 16*1024},	/*ADSP*/
+		{0},	/*SMP2P_RESERVED_PROC_1*/
+		{"rdbg_wcnss", 0, 0},		/*WCNSS*/
+		{0},	/*SMP2P_RESERVED_PROC_2*/
+		{0},	/*SMP2P_POWER_PROC*/
+		{0}		/*SMP2P_REMOTE_MOCK_PROC*/
+};
+
+static int smq_blockmap_get(struct smq_block_map *block_map,
+	uint32_t *block_index, uint32_t n)
+{
+	uint32_t start;
+	uint32_t mark = 0;
+	uint32_t found = 0;
+	uint32_t i = 0;
+
+	start = block_map->index_read;
+
+	if (n == 1) {
+		do {
+			if (!block_map->map[block_map->index_read]) {
+				*block_index = block_map->index_read;
+				block_map->map[block_map->index_read] = 1;
+				block_map->index_read++;
+				block_map->index_read %= block_map->num_blocks;
+				return SMQ_SUCCESS;
+			}
+			block_map->index_read++;
+		} while (start != (block_map->index_read %=
+			block_map->num_blocks));
+	} else {
+		mark = block_map->num_blocks;
+
+		do {
+			if (!block_map->map[block_map->index_read]) {
+				if (mark > block_map->index_read) {
+					mark = block_map->index_read;
+					start = block_map->index_read;
+					found = 0;
+				}
+
+				found++;
+				if (found == n) {
+					*block_index = mark;
+					for (i = 0; i < n; i++)
+						block_map->map[mark + i] =
+							(uint8_t)(n - i);
+					block_map->index_read += block_map->map
+						[block_map->index_read] - 1;
+					return SMQ_SUCCESS;
+				}
+			} else {
+				found = 0;
+				block_map->index_read += block_map->map
+					[block_map->index_read] - 1;
+				mark = block_map->num_blocks;
+			}
+			block_map->index_read++;
+		} while (start != (block_map->index_read %=
+			block_map->num_blocks));
+	}
+
+	return SMQ_ENOMEMORY;
+}
+
+static void smq_blockmap_put(struct smq_block_map *block_map, uint32_t i)
+{
+	uint32_t num_blocks = block_map->map[i];
+
+	while (num_blocks--) {
+		block_map->map[i] = 0;
+		i++;
+	}
+}
+
+static int smq_blockmap_reset(struct smq_block_map *block_map)
+{
+	if (!block_map->map)
+		return SMQ_ENOMEMORY;
+	memset(block_map->map, 0, block_map->num_blocks + 1);
+	block_map->index_read = 0;
+
+	return SMQ_SUCCESS;
+}
+
+static int smq_blockmap_ctor(struct smq_block_map *block_map,
+	uint32_t num_blocks)
+{
+	if (num_blocks <= 1)
+		return SMQ_ENOMEMORY;
+
+	block_map->map = kcalloc(num_blocks, sizeof(uint8_t), GFP_KERNEL);
+	if (!block_map->map)
+		return SMQ_ENOMEMORY;
+
+	block_map->num_blocks = num_blocks - 1;
+	smq_blockmap_reset(block_map);
+
+	return SMQ_SUCCESS;
+}
+
+static void smq_blockmap_dtor(struct smq_block_map *block_map)
+{
+	kfree(block_map->map);
+	block_map->map = NULL;
+}
+
+static int smq_free(struct smq *smq, void *data)
+{
+	struct smq_node node;
+	uint32_t index_block;
+	int err = SMQ_SUCCESS;
+
+	if (smq->lock)
+		mutex_lock(smq->lock);
+
+	if ((smq->hdr->producer_version != SM_VERSION) &&
+		(smq->out->s.init != SMQ_MAGIC_PRODUCER)) {
+		err = SMQ_UNDERFLOW;
+		goto bail;
+	}
+
+	index_block = ((uint8_t *)data - smq->blocks) / SM_BLOCKSIZE;
+	if (index_block >= smq->num_blocks) {
+		err = SMQ_EBADPARM;
+		goto bail;
+	}
+
+	node.index_block = (uint16_t)index_block;
+	node.num_blocks = 0;
+	*((struct smq_node *)(smq->in->free + smq->in->
+		s.index_free_write)) = node;
+
+	smq->in->s.index_free_write = (smq->in->s.index_free_write + 1)
+		% smq->num_blocks;
+
+bail:
+	if (smq->lock)
+		mutex_unlock(smq->lock);
+	return err;
+}
+
+static int smq_receive(struct smq *smq, void **pp, int *pnsize, int *pbmore)
+{
+	struct smq_node *node;
+	int err = SMQ_SUCCESS;
+	int more = 0;
+
+	if ((smq->hdr->producer_version != SM_VERSION) &&
+		(smq->out->s.init != SMQ_MAGIC_PRODUCER))
+		return SMQ_UNDERFLOW;
+
+	if (smq->in->s.index_sent_read == smq->out->s.index_sent_write) {
+		err = SMQ_UNDERFLOW;
+		goto bail;
+	}
+
+	node = (struct smq_node *)(smq->out->sent + smq->in->s.index_sent_read);
+	if (node->index_block >= smq->num_blocks) {
+		err = SMQ_EBADPARM;
+		goto bail;
+	}
+
+	smq->in->s.index_sent_read = (smq->in->s.index_sent_read + 1)
+		% smq->num_blocks;
+
+	*pp = smq->blocks + (node->index_block * SM_BLOCKSIZE);
+	*pnsize = SM_BLOCKSIZE * node->num_blocks;
+
+	/* Ensure that the reads and writes are updated in the memory
+	* when they are done and not cached. Also, ensure that the reads
+	* and writes are not reordered as they are shared between two cores.
+	*/
+	rmb();
+	if (smq->in->s.index_sent_read != smq->out->s.index_sent_write)
+		more = 1;
+
+bail:
+	*pbmore = more;
+	return err;
+}
+
+static int smq_alloc_send(struct smq *smq, const uint8_t *pcb, int nsize)
+{
+	void *pv = 0;
+	int num_blocks;
+	uint32_t index_block = 0;
+	int err = SMQ_SUCCESS;
+	struct smq_node *node = NULL;
+
+	mutex_lock(smq->lock);
+
+	if ((smq->in->s.init == SMQ_MAGIC_CONSUMER) &&
+	 (smq->hdr->consumer_version == SM_VERSION)) {
+		if (smq->out->s.index_check_queue_for_reset ==
+			smq->in->s.index_check_queue_for_reset_ack) {
+			while (smq->out->s.index_free_read !=
+				smq->in->s.index_free_write) {
+				node = (struct smq_node *)(
+					smq->in->free +
+					smq->out->s.index_free_read);
+				if (node->index_block >= smq->num_blocks) {
+					err = SMQ_EBADPARM;
+					goto bail;
+				}
+
+				smq->out->s.index_free_read =
+					(smq->out->s.index_free_read + 1)
+						% smq->num_blocks;
+
+				smq_blockmap_put(&smq->block_map,
+					node->index_block);
+				/* Ensure that the reads and writes are
+				* updated in the memory when they are done
+				* and not cached. Also, ensure that the reads
+				* and writes are not reordered as they are
+				* shared between two cores.
+				*/
+				rmb();
+			}
+		}
+	}
+
+	num_blocks = ALIGN(nsize, SM_BLOCKSIZE)/SM_BLOCKSIZE;
+	err = smq_blockmap_get(&smq->block_map, &index_block, num_blocks);
+	if (err != SMQ_SUCCESS)
+		goto bail;
+
+	pv = smq->blocks + (SM_BLOCKSIZE * index_block);
+
+	err = copy_from_user((void *)pv, (void *)pcb, nsize);
+	if (err != 0)
+		goto bail;
+
+	((struct smq_node *)(smq->out->sent +
+		smq->out->s.index_sent_write))->index_block
+			= (uint16_t)index_block;
+	((struct smq_node *)(smq->out->sent +
+		smq->out->s.index_sent_write))->num_blocks
+			= (uint16_t)num_blocks;
+
+	smq->out->s.index_sent_write = (smq->out->s.index_sent_write + 1)
+		% smq->num_blocks;
+
+bail:
+	if (err != SMQ_SUCCESS) {
+		if (pv)
+			smq_blockmap_put(&smq->block_map, index_block);
+	}
+	mutex_unlock(smq->lock);
+	return err;
+}
+
+static int smq_reset_producer_queue_internal(struct smq *smq,
+	uint32_t reset_num)
+{
+	int retval = 0;
+	uint32_t i;
+
+	if (smq->type != PRODUCER)
+		goto bail;
+
+	mutex_lock(smq->lock);
+	if (smq->out->s.index_check_queue_for_reset != reset_num) {
+		smq->out->s.index_check_queue_for_reset = reset_num;
+		for (i = 0; i < smq->num_blocks; i++)
+			(smq->out->sent + i)->index_block = 0xFFFF;
+
+		smq_blockmap_reset(&smq->block_map);
+		smq->out->s.index_sent_write = 0;
+		smq->out->s.index_free_read = 0;
+		retval = 1;
+	}
+	mutex_unlock(smq->lock);
+
+bail:
+	return retval;
+}
+
+static int smq_check_queue_reset(struct smq *p_cons, struct smq *p_prod)
+{
+	int retval = 0;
+	uint32_t reset_num, i;
+
+	if ((p_cons->type != CONSUMER) ||
+		(p_cons->out->s.init != SMQ_MAGIC_PRODUCER) ||
+		(p_cons->hdr->producer_version != SM_VERSION))
+		goto bail;
+
+	reset_num = p_cons->out->s.index_check_queue_for_reset;
+	if (p_cons->in->s.index_check_queue_for_reset_ack != reset_num) {
+		p_cons->in->s.index_check_queue_for_reset_ack = reset_num;
+		for (i = 0; i < p_cons->num_blocks; i++)
+			(p_cons->in->free + i)->index_block = 0xFFFF;
+
+		p_cons->in->s.index_sent_read = 0;
+		p_cons->in->s.index_free_write = 0;
+
+		retval = smq_reset_producer_queue_internal(p_prod, reset_num);
+	}
+
+bail:
+	return retval;
+}
+
+static int check_subsystem_debug_enabled(void *base_addr, int size)
+{
+	int num_blocks;
+	uint8_t *pb_orig;
+	uint8_t *pb;
+	struct smq smq;
+	int err = 0;
+
+	pb = pb_orig = (uint8_t *)base_addr;
+	pb += sizeof(struct smq_hdr);
+	pb = PTR_ALIGN(pb, 8);
+	size -= pb - (uint8_t *)pb_orig;
+	num_blocks = (int)((size - sizeof(struct smq_out_state) -
+		sizeof(struct smq_in_state))/(SM_BLOCKSIZE +
+		sizeof(struct smq_node) * 2));
+	if (num_blocks <= 0) {
+		err = SMQ_EBADPARM;
+		goto bail;
+	}
+
+	pb += num_blocks * SM_BLOCKSIZE;
+	smq.out = (struct smq_out *)pb;
+	pb += sizeof(struct smq_out_state) + (num_blocks *
+		sizeof(struct smq_node));
+	smq.in = (struct smq_in *)pb;
+
+	if (smq.in->s.init != SMQ_MAGIC_CONSUMER) {
+		pr_err("%s, smq in consumer not initialized", __func__);
+		err = -ECOMM;
+	}
+
+bail:
+	return err;
+}
+
+static void smq_dtor(struct smq *smq)
+{
+	if (smq->initialized == SMQ_MAGIC_INIT) {
+		switch (smq->type) {
+		case PRODUCER:
+			smq->out->s.init = 0;
+			smq_blockmap_dtor(&smq->block_map);
+			break;
+		case CONSUMER:
+			smq->in->s.init = 0;
+			break;
+		default:
+		case INVALID:
+			break;
+		}
+
+		smq->initialized = 0;
+	}
+}
+
+/*
+ * The shared memory is used as a circular ring buffer in each direction.
+ * Thus we have a bi-directional shared memory channel between the AP
+ * and a subsystem. We call this SMQ. Each memory channel contains a header,
+ * data and a control mechanism that is used to synchronize read and write
+ * of data between the AP and the remote subsystem.
+ *
+ * Overall SMQ memory view:
+ *
+ *    +------------------------------------------------+
+ *    | SMEM buffer                                    |
+ *    |-----------------------+------------------------|
+ *    |Producer: LA           | Producer: Remote       |
+ *    |Consumer: Remote       |           subsystem    |
+ *    |          subsystem    | Consumer: LA           |
+ *    |                       |                        |
+ *    |               Producer|                Consumer|
+ *    +-----------------------+------------------------+
+ *    |                       |
+ *    |                       |
+ *    |                       +--------------------------------------+
+ *    |                                                              |
+ *    |                                                              |
+ *    v                                                              v
+ *    +--------------------------------------------------------------+
+ *    |   Header  |       Data      |            Control             |
+ *    +-----------+---+---+---+-----+----+--+--+-----+---+--+--+-----+
+ *    |           | b | b | b |     | S  |n |n |     | S |n |n |     |
+ *    |  Producer | l | l | l |     | M  |o |o |     | M |o |o |     |
+ *    |    Ver    | o | o | o |     | Q  |d |d |     | Q |d |d |     |
+ *    |-----------| c | c | c | ... |    |e |e | ... |   |e |e | ... |
+ *    |           | k | k | k |     | O  |  |  |     | I |  |  |     |
+ *    |  Consumer |   |   |   |     | u  |0 |1 |     | n |0 |1 |     |
+ *    |    Ver    | 0 | 1 | 2 |     | t  |  |  |     |   |  |  |     |
+ *    +-----------+---+---+---+-----+----+--+--+-----+---+--+--+-----+
+ *                                       |           |
+ *                                       +           |
+ *                                                   |
+ *                          +------------------------+
+ *                          |
+ *                          v
+ *                        +----+----+----+----+
+ *                        | SMQ Nodes         |
+ *                        |----|----|----|----|
+ *                 Node # |  0 |  1 |  2 | ...|
+ *                        |----|----|----|----|
+ * Starting Block Index # |  0 |  3 |  8 | ...|
+ *                        |----|----|----|----|
+ *            # of blocks |  3 |  5 |  1 | ...|
+ *                        +----+----+----+----+
+ *
+ * Header: Contains version numbers for software compatibility to ensure
+ * that both producers and consumers on the AP and subsystems know how to
+ * read from and write to the queue.
+ * Both the producer and consumer versions are 1.
+ *     +---------+-------------------+
+ *     | Size    | Field             |
+ *     +---------+-------------------+
+ *     | 1 byte  | Producer Version  |
+ *     +---------+-------------------+
+ *     | 1 byte  | Consumer Version  |
+ *     +---------+-------------------+
+ *
+ * Data: The data portion contains multiple blocks [0..N] of a fixed size.
+ * The block size SM_BLOCKSIZE is fixed to 128 bytes for header version #1.
+ * Payload sent from the debug agent app is split (if necessary) and placed
+ * in these blocks. The first data block is placed at the next 8 byte aligned
+ * address after the header.
+ *
+ * The number of blocks for a given SMEM allocation is derived as follows:
+ *   Number of Blocks = ((Total Size - Alignment - Size of Header
+ *		- Size of SMQIn - Size of SMQOut)/(SM_BLOCKSIZE))
+ *
+ * The producer maintains a private block map of each of these blocks to
+ * determine which of these blocks in the queue is available and which are free.
+ *
+ * Control:
+ * The control portion contains a list of nodes [0..N] where N is number
+ * of available data blocks. Each node identifies the data
+ * block indexes that contain a particular debug message to be transferred,
+ * and the number of blocks it took to hold the contents of the message.
+ *
+ * Each node has the following structure:
+ *     +---------+-------------------+
+ *     | Size    | Field             |
+ *     +---------+-------------------+
+ *     | 2 bytes |Staring Block Index|
+ *     +---------+-------------------+
+ *     | 2 bytes |Number of Blocks   |
+ *     +---------+-------------------+
+ *
+ * The producer and the consumer update different parts of the control channel
+ * (SMQOut / SMQIn) respectively. Each of these control data structures contains
+ * information about the last node that was written / read, and the actual nodes
+ * that were written/read.
+ *
+ * SMQOut Structure (R/W by producer, R by consumer):
+ *     +---------+-------------------+
+ *     | Size    | Field             |
+ *     +---------+-------------------+
+ *     | 4 bytes | Magic Init Number |
+ *     +---------+-------------------+
+ *     | 4 bytes | Reset             |
+ *     +---------+-------------------+
+ *     | 4 bytes | Last Sent Index   |
+ *     +---------+-------------------+
+ *     | 4 bytes | Index Free Read   |
+ *     +---------+-------------------+
+ *
+ * SMQIn Structure (R/W by consumer, R by producer):
+ *     +---------+-------------------+
+ *     | Size    | Field             |
+ *     +---------+-------------------+
+ *     | 4 bytes | Magic Init Number |
+ *     +---------+-------------------+
+ *     | 4 bytes | Reset ACK         |
+ *     +---------+-------------------+
+ *     | 4 bytes | Last Read Index   |
+ *     +---------+-------------------+
+ *     | 4 bytes | Index Free Write  |
+ *     +---------+-------------------+
+ *
+ * Magic Init Number:
+ * Both SMQ Out and SMQ In initialize this field with a predefined magic
+ * number so as to make sure that both the consumer and producer blocks
+ * have fully initialized and have valid data in the shared memory control area.
+ *	Producer Magic #: 0xFF00FF01
+ *	Consumer Magic #: 0xFF00FF02
+ */
+static int smq_ctor(struct smq *smq, void *base_addr, int size,
+	enum smq_type type, struct mutex *lock_ptr)
+{
+	int num_blocks;
+	uint8_t *pb_orig;
+	uint8_t *pb;
+	uint32_t i;
+	int err;
+
+	if (smq->initialized == SMQ_MAGIC_INIT) {
+		err = SMQ_EBADPARM;
+		goto bail;
+	}
+
+	if (!base_addr || !size) {
+		err = SMQ_EBADPARM;
+		goto bail;
+	}
+
+	if (type == PRODUCER)
+		smq->lock = lock_ptr;
+
+	pb_orig = (uint8_t *)base_addr;
+	smq->hdr = (struct smq_hdr *)pb_orig;
+	pb = pb_orig;
+	pb += sizeof(struct smq_hdr);
+	pb = PTR_ALIGN(pb, 8);
+	size -= pb - (uint8_t *)pb_orig;
+	num_blocks = (int)((size - sizeof(struct smq_out_state) -
+		sizeof(struct smq_in_state))/(SM_BLOCKSIZE +
+		sizeof(struct smq_node) * 2));
+	if (num_blocks <= 0) {
+		err = SMQ_ENOMEMORY;
+		goto bail;
+	}
+
+	smq->blocks = pb;
+	smq->num_blocks = num_blocks;
+	pb += num_blocks * SM_BLOCKSIZE;
+	smq->out = (struct smq_out *)pb;
+	pb += sizeof(struct smq_out_state) + (num_blocks *
+		sizeof(struct smq_node));
+	smq->in = (struct smq_in *)pb;
+	smq->type = type;
+	if (type == PRODUCER) {
+		smq->hdr->producer_version = SM_VERSION;
+		for (i = 0; i < smq->num_blocks; i++)
+			(smq->out->sent + i)->index_block = 0xFFFF;
+
+		err = smq_blockmap_ctor(&smq->block_map, smq->num_blocks);
+		if (err != SMQ_SUCCESS)
+			goto bail;
+
+		smq->out->s.index_sent_write = 0;
+		smq->out->s.index_free_read = 0;
+		if (smq->out->s.init == SMQ_MAGIC_PRODUCER) {
+			smq->out->s.index_check_queue_for_reset += 1;
+		} else {
+			smq->out->s.index_check_queue_for_reset = 1;
+			smq->out->s.init = SMQ_MAGIC_PRODUCER;
+		}
+	} else {
+		smq->hdr->consumer_version = SM_VERSION;
+		for (i = 0; i < smq->num_blocks; i++)
+			(smq->in->free + i)->index_block = 0xFFFF;
+
+		smq->in->s.index_sent_read = 0;
+		smq->in->s.index_free_write = 0;
+		if (smq->out->s.init == SMQ_MAGIC_PRODUCER) {
+			smq->in->s.index_check_queue_for_reset_ack =
+				smq->out->s.index_check_queue_for_reset;
+		} else {
+			smq->in->s.index_check_queue_for_reset_ack = 0;
+		}
+
+		smq->in->s.init = SMQ_MAGIC_CONSUMER;
+	}
+	smq->initialized = SMQ_MAGIC_INIT;
+	err = SMQ_SUCCESS;
+
+bail:
+	return err;
+}
+
+static void send_interrupt_to_subsystem(struct rdbg_data *rdbgdata)
+{
+	int offset = rdbgdata->gpio_out_offset;
+	int val = 1 ^ gpio_get_value(rdbgdata->out.gpio_base_id + offset);
+
+	gpio_set_value(rdbgdata->out.gpio_base_id + offset, val);
+	rdbgdata->gpio_out_offset = (offset + 1) % 32;
+
+	dev_dbg(rdbgdata->device, "%s: sent interrupt %d to subsystem",
+		__func__, val);
+}
+
+static irqreturn_t on_interrupt_from(int irq, void *ptr)
+{
+	struct rdbg_data *rdbgdata = (struct rdbg_data *) ptr;
+
+	dev_dbg(rdbgdata->device, "%s: Received interrupt %d from subsystem",
+		__func__, irq);
+
+	complete(&(rdbgdata->work));
+	return IRQ_HANDLED;
+}
+
+static int initialize_smq(struct rdbg_data *rdbgdata)
+{
+	int err = 0;
+	unsigned char *smem_consumer_buffer = rdbgdata->smem_addr;
+
+	smem_consumer_buffer += (rdbgdata->smem_size/2);
+
+	if (smq_ctor(&(rdbgdata->producer_smrb), (void *)(rdbgdata->smem_addr),
+		((rdbgdata->smem_size)/2), PRODUCER, &rdbgdata->write_mutex)) {
+		dev_err(rdbgdata->device, "%s: smq producer allocation failed",
+			__func__);
+		err = -ENOMEM;
+		goto bail;
+	}
+
+	if (smq_ctor(&(rdbgdata->consumer_smrb), (void *)smem_consumer_buffer,
+		((rdbgdata->smem_size)/2), CONSUMER, NULL)) {
+		dev_err(rdbgdata->device, "%s: smq conmsumer allocation failed",
+			__func__);
+		err = -ENOMEM;
+	}
+
+bail:
+	return err;
+
+}
+
+static int rdbg_open(struct inode *inode, struct file *filp)
+{
+	int device_id = -1;
+	struct rdbg_device *device = &g_rdbg_instance;
+	struct rdbg_data *rdbgdata = NULL;
+	int err = 0;
+
+	if (!inode || !device->rdbg_data) {
+		pr_err("Memory not allocated yet");
+		err = -ENODEV;
+		goto bail;
+	}
+
+	device_id = MINOR(inode->i_rdev);
+	rdbgdata = &device->rdbg_data[device_id];
+
+	if (rdbgdata->device_opened) {
+		dev_err(rdbgdata->device, "%s: Device already opened",
+			__func__);
+		err = -EEXIST;
+		goto bail;
+	}
+
+	rdbgdata->smem_size = proc_info[device_id].smem_buffer_size;
+	if (!rdbgdata->smem_size) {
+		dev_err(rdbgdata->device, "%s: smem not initialized", __func__);
+		err = -ENOMEM;
+		goto bail;
+	}
+
+	rdbgdata->smem_addr = smem_find(proc_info[device_id].smem_buffer_addr,
+		rdbgdata->smem_size, 0, SMEM_ANY_HOST_FLAG);
+	if (!rdbgdata->smem_addr) {
+		dev_err(rdbgdata->device, "%s: Could not allocate smem memory",
+			__func__);
+		err = -ENOMEM;
+		goto bail;
+	}
+	dev_dbg(rdbgdata->device, "%s: SMEM address=0x%lx smem_size=%d",
+		__func__, (unsigned long)rdbgdata->smem_addr,
+		(unsigned int)rdbgdata->smem_size);
+
+	if (check_subsystem_debug_enabled(rdbgdata->smem_addr,
+		rdbgdata->smem_size/2)) {
+		dev_err(rdbgdata->device, "%s: Subsystem %s is not debug enabled",
+			__func__, proc_info[device_id].name);
+		err = -ECOMM;
+		goto bail;
+	}
+
+	init_completion(&rdbgdata->work);
+
+	err = request_irq(rdbgdata->in.irq_base_id, on_interrupt_from,
+			IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+			proc_info[device_id].name,
+			(void *)&device->rdbg_data[device_id]);
+	if (err) {
+		dev_err(rdbgdata->device,
+			"%s: Failed to register interrupt.Err=%d,irqid=%d.",
+			__func__, err, rdbgdata->in.irq_base_id);
+		goto irq_bail;
+	}
+
+	err = enable_irq_wake(rdbgdata->in.irq_base_id);
+	if (err < 0) {
+		dev_dbg(rdbgdata->device, "enable_irq_wake() failed with err=%d",
+			err);
+		err = 0;
+	}
+
+	mutex_init(&rdbgdata->write_mutex);
+
+	err = initialize_smq(rdbgdata);
+	if (err) {
+		dev_err(rdbgdata->device, "Error initializing smq. Err=%d",
+			err);
+		goto smq_bail;
+	}
+
+	rdbgdata->device_opened = 1;
+
+	filp->private_data = (void *)rdbgdata;
+
+	return 0;
+
+smq_bail:
+	smq_dtor(&(rdbgdata->producer_smrb));
+	smq_dtor(&(rdbgdata->consumer_smrb));
+	mutex_destroy(&rdbgdata->write_mutex);
+irq_bail:
+	free_irq(rdbgdata->in.irq_base_id, (void *)
+		&device->rdbg_data[device_id]);
+bail:
+	return err;
+}
+
+static int rdbg_release(struct inode *inode, struct file *filp)
+{
+	int device_id = -1;
+	struct rdbg_device *rdbgdevice = &g_rdbg_instance;
+	struct rdbg_data *rdbgdata = NULL;
+	int err = 0;
+
+	if (!inode || !rdbgdevice->rdbg_data) {
+		pr_err("Memory not allocated yet");
+		err = -ENODEV;
+		goto bail;
+	}
+
+	device_id = MINOR(inode->i_rdev);
+	rdbgdata = &rdbgdevice->rdbg_data[device_id];
+
+	if (rdbgdata->device_opened == 1) {
+		dev_dbg(rdbgdata->device, "%s: Destroying %s.", __func__,
+			proc_info[device_id].name);
+		rdbgdata->device_opened = 0;
+		complete(&(rdbgdata->work));
+		free_irq(rdbgdata->in.irq_base_id, (void *)
+			&rdbgdevice->rdbg_data[device_id]);
+		if (rdbgdevice->rdbg_data[device_id].producer_smrb.initialized)
+			smq_dtor(&(rdbgdevice->rdbg_data[device_id].
+				producer_smrb));
+		if (rdbgdevice->rdbg_data[device_id].consumer_smrb.initialized)
+			smq_dtor(&(rdbgdevice->rdbg_data[device_id].
+				consumer_smrb));
+		mutex_destroy(&rdbgdata->write_mutex);
+	}
+
+	filp->private_data = NULL;
+
+bail:
+	return err;
+}
+
+static ssize_t rdbg_read(struct file *filp, char __user *buf, size_t size,
+	loff_t *offset)
+{
+	int err = 0;
+	struct rdbg_data *rdbgdata = filp->private_data;
+	void *p_sent_buffer = NULL;
+	int nsize = 0;
+	int more = 0;
+
+	if (!rdbgdata) {
+		pr_err("Invalid argument");
+		err = -EINVAL;
+		goto bail;
+	}
+
+	dev_dbg(rdbgdata->device, "%s: In receive", __func__);
+	err = wait_for_completion_interruptible(&(rdbgdata->work));
+	if (err) {
+		dev_err(rdbgdata->device, "%s: Error in wait", __func__);
+		goto bail;
+	}
+
+	smq_check_queue_reset(&(rdbgdata->consumer_smrb),
+		&(rdbgdata->producer_smrb));
+	if (smq_receive(&(rdbgdata->consumer_smrb), &p_sent_buffer,
+			&nsize, &more) != SMQ_SUCCESS) {
+		dev_err(rdbgdata->device, "%s: Error in smq_recv(). Err code = %d",
+			__func__, err);
+		err = -ENODATA;
+		goto bail;
+	}
+
+	size = ((size < nsize) ? size : nsize);
+	err = copy_to_user(buf, p_sent_buffer, size);
+	if (err != 0) {
+		dev_err(rdbgdata->device, "%s: Error in copy_to_user(). Err code = %d",
+			__func__, err);
+		err = -ENODATA;
+		goto bail;
+	}
+
+	smq_free(&(rdbgdata->consumer_smrb), p_sent_buffer);
+	err = size;
+	dev_dbg(rdbgdata->device, "%s: Read data to buffer with address 0x%lx",
+		__func__, (unsigned long) buf);
+
+bail:
+	return err;
+}
+
+static ssize_t rdbg_write(struct file *filp, const char __user *buf,
+	size_t size, loff_t *offset)
+{
+	int err = 0;
+	int num_retries = 0;
+	struct rdbg_data *rdbgdata = filp->private_data;
+
+	if (!rdbgdata) {
+		pr_err("Invalid argument");
+		err = -EINVAL;
+		goto bail;
+	}
+
+	do {
+		err = smq_alloc_send(&(rdbgdata->producer_smrb), buf, size);
+		dev_dbg(rdbgdata->device, "%s, smq_alloc_send returned %d.",
+			__func__, err);
+	} while (err != 0 && num_retries++ < MAX_RETRIES);
+
+	if (err != 0) {
+		err = -ECOMM;
+		goto bail;
+	}
+
+	send_interrupt_to_subsystem(rdbgdata);
+
+	err = size;
+
+bail:
+	return err;
+}
+
+
+static const struct file_operations rdbg_fops = {
+	.open = rdbg_open,
+	.read =  rdbg_read,
+	.write =  rdbg_write,
+	.release = rdbg_release,
+};
+
+static int register_smp2p(char *node_name, struct gpio_info *gpio_info_ptr)
+{
+	struct device_node *node = NULL;
+	int cnt = 0;
+	int id = 0;
+
+	node = of_find_compatible_node(NULL, NULL, node_name);
+	if (node) {
+		cnt = of_gpio_count(node);
+		if (cnt && gpio_info_ptr) {
+			id = of_get_gpio(node, 0);
+			gpio_info_ptr->gpio_base_id = id;
+			gpio_info_ptr->irq_base_id = gpio_to_irq(id);
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static int __init rdbg_init(void)
+{
+	int err = 0;
+	struct rdbg_device *rdbgdevice = &g_rdbg_instance;
+	int minor = 0;
+	int major = 0;
+	int minor_nodes_created = 0;
+
+	char *rdbg_compatible_string = "qcom,smp2pgpio_client_rdbg_";
+	int max_len = strlen(rdbg_compatible_string) + strlen("xx_out");
+
+	char *node_name = kcalloc(max_len, sizeof(char), GFP_KERNEL);
+
+	if (!node_name) {
+		err = -ENOMEM;
+		goto bail;
+	}
+
+	if (rdbgdevice->num_devices < 1 ||
+		rdbgdevice->num_devices > SMP2P_NUM_PROCS) {
+		pr_err("rgdb: invalid num_devices");
+		err = -EDOM;
+		goto name_bail;
+	}
+
+	rdbgdevice->rdbg_data = kcalloc(rdbgdevice->num_devices,
+		sizeof(struct rdbg_data), GFP_KERNEL);
+	if (!rdbgdevice->rdbg_data) {
+		err = -ENOMEM;
+		goto name_bail;
+	}
+
+	err = alloc_chrdev_region(&rdbgdevice->dev_no, 0,
+		rdbgdevice->num_devices, "rdbgctl");
+	if (err) {
+		pr_err("Error in alloc_chrdev_region.");
+		goto data_bail;
+	}
+	major = MAJOR(rdbgdevice->dev_no);
+
+	cdev_init(&rdbgdevice->cdev, &rdbg_fops);
+	rdbgdevice->cdev.owner = THIS_MODULE;
+	err = cdev_add(&rdbgdevice->cdev, MKDEV(major, 0),
+		rdbgdevice->num_devices);
+	if (err) {
+		pr_err("Error in cdev_add");
+		goto chrdev_bail;
+	}
+
+	rdbgdevice->class = class_create(THIS_MODULE, "rdbg");
+	if (IS_ERR(rdbgdevice->class)) {
+		err = PTR_ERR(rdbgdevice->class);
+		pr_err("Error in class_create");
+		goto cdev_bail;
+	}
+
+	for (minor = 0; minor < rdbgdevice->num_devices; minor++) {
+		if (!proc_info[minor].name)
+			continue;
+
+		if (snprintf(node_name, max_len, "%s%d_in",
+			rdbg_compatible_string, minor) <= 0) {
+			pr_err("Error in snprintf");
+			err = -ENOMEM;
+			goto device_bail;
+		}
+
+		if (register_smp2p(node_name,
+			&rdbgdevice->rdbg_data[minor].in)) {
+			pr_debug("No incoming device tree entry found for %s",
+				proc_info[minor].name);
+			continue;
+		}
+
+		if (snprintf(node_name, max_len, "%s%d_out",
+			rdbg_compatible_string, minor) <= 0) {
+			pr_err("Error in snprintf");
+			err = -ENOMEM;
+			goto device_bail;
+		}
+
+		if (register_smp2p(node_name,
+			&rdbgdevice->rdbg_data[minor].out)) {
+			pr_err("No outgoing device tree entry found for %s",
+				proc_info[minor].name);
+			err = -EINVAL;
+			goto device_bail;
+		}
+
+		rdbgdevice->rdbg_data[minor].device = device_create(
+			rdbgdevice->class, NULL, MKDEV(major, minor),
+			NULL, "%s", proc_info[minor].name);
+		if (IS_ERR(rdbgdevice->rdbg_data[minor].device)) {
+			err = PTR_ERR(rdbgdevice->rdbg_data[minor].device);
+			pr_err("Error in device_create");
+			goto device_bail;
+		}
+		rdbgdevice->rdbg_data[minor].device_initialized = 1;
+		minor_nodes_created++;
+		dev_dbg(rdbgdevice->rdbg_data[minor].device,
+			"%s: created /dev/%s c %d %d'", __func__,
+			proc_info[minor].name, major, minor);
+	}
+
+	if (!minor_nodes_created) {
+		pr_err("No device tree entries found");
+		err = -EINVAL;
+		goto class_bail;
+	}
+
+	goto name_bail;
+
+device_bail:
+	for (--minor; minor >= 0; minor--) {
+		if (rdbgdevice->rdbg_data[minor].device_initialized)
+			device_destroy(rdbgdevice->class,
+				MKDEV(MAJOR(rdbgdevice->dev_no), minor));
+	}
+class_bail:
+	class_destroy(rdbgdevice->class);
+cdev_bail:
+	cdev_del(&rdbgdevice->cdev);
+chrdev_bail:
+	unregister_chrdev_region(rdbgdevice->dev_no, rdbgdevice->num_devices);
+data_bail:
+	kfree(rdbgdevice->rdbg_data);
+name_bail:
+	kfree(node_name);
+bail:
+	return err;
+}
+
+static void __exit rdbg_exit(void)
+{
+	struct rdbg_device *rdbgdevice = &g_rdbg_instance;
+	int minor;
+
+	for (minor = 0; minor < rdbgdevice->num_devices; minor++) {
+		if (rdbgdevice->rdbg_data[minor].device_initialized) {
+			device_destroy(rdbgdevice->class,
+				MKDEV(MAJOR(rdbgdevice->dev_no), minor));
+		}
+	}
+	class_destroy(rdbgdevice->class);
+	cdev_del(&rdbgdevice->cdev);
+	unregister_chrdev_region(rdbgdevice->dev_no, 1);
+	kfree(rdbgdevice->rdbg_data);
+}
+
+module_init(rdbg_init);
+module_exit(rdbg_exit);
+
+MODULE_DESCRIPTION("rdbg module");
+MODULE_LICENSE("GPL v2");