msm: ipc_logging: Add IPC event logger module

Add a logging module to log any high frequency IPC events. This will
enable any IPC drivers like message routers, multiplexers etc. to log
debug and performance data.

Change-Id: Iaed7079d4402a18b241b9957301f69a45cefa77f
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Signed-off-by: Eric Holmberg <eholmber@codeaurora.org>
diff --git a/arch/arm/mach-msm/ipc_logging.c b/arch/arm/mach-msm/ipc_logging.c
new file mode 100644
index 0000000..2cd30de
--- /dev/null
+++ b/arch/arm/mach-msm/ipc_logging.c
@@ -0,0 +1,556 @@
+/* Copyright (c) 2012, Code Aurora Forum. 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/slab.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/jiffies.h>
+#include <linux/debugfs.h>
+#include <linux/io.h>
+#include <linux/idr.h>
+#include <linux/string.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/delay.h>
+#include <linux/completion.h>
+
+#include <mach/msm_ipc_logging.h>
+
+#include "ipc_logging.h"
+
+static LIST_HEAD(ipc_log_context_list);
+DEFINE_SPINLOCK(ipc_log_context_list_lock);
+static atomic_t next_log_id = ATOMIC_INIT(0);
+
+static struct ipc_log_page *get_first_page(struct ipc_log_context *ilctxt)
+{
+	struct ipc_log_page_header *p_pghdr;
+	struct ipc_log_page *pg = NULL;
+
+	if (!ilctxt)
+		return NULL;
+	p_pghdr = list_first_entry(&ilctxt->page_list,
+				   struct ipc_log_page_header, list);
+	pg = container_of(p_pghdr, struct ipc_log_page, hdr);
+	return pg;
+}
+
+static struct ipc_log_page *get_next_page(struct ipc_log_context *ilctxt,
+					  struct ipc_log_page *cur_pg)
+{
+	struct ipc_log_page_header *p_pghdr;
+	struct ipc_log_page *pg = NULL;
+
+	if (!ilctxt || !cur_pg)
+		return NULL;
+
+	if (ilctxt->last_page == cur_pg)
+		return ilctxt->first_page;
+
+	p_pghdr = list_first_entry(&cur_pg->hdr.list,
+			struct ipc_log_page_header, list);
+	pg = container_of(p_pghdr, struct ipc_log_page, hdr);
+
+	return pg;
+}
+
+/* If data == NULL, drop the log of size data_size*/
+static void ipc_log_read(struct ipc_log_context *ilctxt,
+			 void *data, int data_size)
+{
+	int bytes_to_read;
+
+	bytes_to_read = MIN(((PAGE_SIZE - sizeof(struct ipc_log_page_header))
+				- ilctxt->read_page->hdr.read_offset),
+			      data_size);
+	if (data)
+		memcpy(data, (ilctxt->read_page->data +
+			ilctxt->read_page->hdr.read_offset), bytes_to_read);
+	if (bytes_to_read != data_size) {
+		ilctxt->read_page->hdr.read_offset = 0xFFFF;
+		ilctxt->read_page = get_next_page(ilctxt, ilctxt->read_page);
+		ilctxt->read_page->hdr.read_offset = 0;
+		if (data)
+			memcpy((data + bytes_to_read),
+			       (ilctxt->read_page->data +
+				ilctxt->read_page->hdr.read_offset),
+			       (data_size - bytes_to_read));
+		bytes_to_read = (data_size - bytes_to_read);
+	}
+	ilctxt->read_page->hdr.read_offset += bytes_to_read;
+	ilctxt->write_avail += data_size;
+}
+
+/*
+ * Reads a message.
+ *
+ * If a message is read successfully, then the the message context
+ * will be set to:
+ *     .hdr    message header .size and .type values
+ *     .offset beginning of message data
+ *
+ * @ectxt   Message context and if NULL, drops the message.
+ *
+ * @returns 0  - no message available
+ *          1  - message read
+ */
+int msg_read(struct ipc_log_context *ilctxt,
+	     struct encode_context *ectxt)
+{
+	struct tsv_header hdr;
+
+	ipc_log_read(ilctxt, &hdr, sizeof(hdr));
+	if (ectxt) {
+		ectxt->hdr.type = hdr.type;
+		ectxt->hdr.size = hdr.size;
+		ectxt->offset = sizeof(hdr);
+		ipc_log_read(ilctxt, (ectxt->buff + ectxt->offset),
+			     (int)hdr.size);
+	} else {
+		ipc_log_read(ilctxt, NULL, (int)hdr.size);
+	}
+	return sizeof(hdr) + (int)hdr.size;
+}
+
+/*
+ * Commits messages to the FIFO.  If the FIFO is full, then enough
+ * messages are dropped to create space for the new message.
+ */
+void ipc_log_write(void *ctxt, struct encode_context *ectxt)
+{
+	struct ipc_log_context *ilctxt = (struct ipc_log_context *)ctxt;
+	int bytes_to_write;
+	unsigned long flags;
+
+	if (!ilctxt || !ectxt) {
+		pr_err("%s: Invalid ipc_log or encode context\n", __func__);
+		return;
+	}
+
+	spin_lock_irqsave(&ipc_log_context_list_lock, flags);
+	spin_lock(&ilctxt->ipc_log_context_lock);
+	while (ilctxt->write_avail < ectxt->offset)
+		msg_read(ilctxt, NULL);
+
+	bytes_to_write = MIN(((PAGE_SIZE - sizeof(struct ipc_log_page_header))
+				- ilctxt->write_page->hdr.write_offset),
+				ectxt->offset);
+	memcpy((ilctxt->write_page->data +
+		ilctxt->write_page->hdr.write_offset),
+		ectxt->buff, bytes_to_write);
+	if (bytes_to_write != ectxt->offset) {
+		ilctxt->write_page->hdr.write_offset = 0xFFFF;
+		ilctxt->write_page = get_next_page(ilctxt, ilctxt->write_page);
+		ilctxt->write_page->hdr.write_offset = 0;
+		memcpy((ilctxt->write_page->data +
+			ilctxt->write_page->hdr.write_offset),
+		       (ectxt->buff + bytes_to_write),
+		       (ectxt->offset - bytes_to_write));
+		bytes_to_write = (ectxt->offset - bytes_to_write);
+	}
+	ilctxt->write_page->hdr.write_offset += bytes_to_write;
+	ilctxt->write_avail -= ectxt->offset;
+	complete(&ilctxt->read_avail);
+	spin_unlock(&ilctxt->ipc_log_context_lock);
+	spin_unlock_irqrestore(&ipc_log_context_list_lock, flags);
+}
+EXPORT_SYMBOL(ipc_log_write);
+
+/*
+ * Starts a new message after which you can add serialized data and
+ * then complete the message by calling msg_encode_end().
+ */
+void msg_encode_start(struct encode_context *ectxt, uint32_t type)
+{
+	if (!ectxt) {
+		pr_err("%s: Invalid encode context\n", __func__);
+		return;
+	}
+
+	ectxt->hdr.type = type;
+	ectxt->hdr.size = 0;
+	ectxt->offset = sizeof(ectxt->hdr);
+}
+EXPORT_SYMBOL(msg_encode_start);
+
+/*
+ * Completes the message
+ */
+void msg_encode_end(struct encode_context *ectxt)
+{
+	if (!ectxt) {
+		pr_err("%s: Invalid encode context\n", __func__);
+		return;
+	}
+
+	/* finalize data size */
+	ectxt->hdr.size = ectxt->offset - sizeof(ectxt->hdr);
+	BUG_ON(ectxt->hdr.size > MAX_MSG_SIZE);
+	memcpy(ectxt->buff, &ectxt->hdr, sizeof(ectxt->hdr));
+}
+EXPORT_SYMBOL(msg_encode_end);
+
+/*
+ * Helper funtion used to write data to a message context.
+ *
+ * @ectxt context initialized by calling msg_encode_start()
+ * @data  data to write
+ * @size  number of bytes of data to write
+ */
+static inline int tsv_write_data(struct encode_context *ectxt,
+				 void *data, uint32_t size)
+{
+	if (!ectxt) {
+		pr_err("%s: Invalid encode context\n", __func__);
+		return -EINVAL;
+	}
+	if ((ectxt->offset + size) > MAX_MSG_SIZE) {
+		pr_err("%s: No space to encode further\n", __func__);
+		return -EINVAL;
+	}
+
+	memcpy((void *)(ectxt->buff + ectxt->offset), data, size);
+	ectxt->offset += size;
+	return 0;
+}
+
+/*
+ * Helper function that writes a type to the context.
+ *
+ * @ectxt context initialized by calling msg_encode_start()
+ * @type  primitive type
+ * @size  size of primitive in bytes
+ */
+static inline int tsv_write_header(struct encode_context *ectxt,
+				   uint32_t type, uint32_t size)
+{
+	struct tsv_header hdr;
+
+	hdr.type = (unsigned char)type;
+	hdr.size = (unsigned char)size;
+	return tsv_write_data(ectxt, &hdr, sizeof(hdr));
+}
+
+/*
+ * Writes the current timestamp count.
+ *
+ * @ectxt   context initialized by calling msg_encode_start()
+ */
+int tsv_timestamp_write(struct encode_context *ectxt)
+{
+	int ret;
+	unsigned long long t_now = sched_clock();
+
+	ret = tsv_write_header(ectxt, TSV_TYPE_TIMESTAMP, sizeof(t_now));
+	if (ret)
+		return ret;
+	return tsv_write_data(ectxt, &t_now, sizeof(t_now));
+}
+EXPORT_SYMBOL(tsv_timestamp_write);
+
+/*
+ * Writes a data pointer.
+ *
+ * @ectxt   context initialized by calling msg_encode_start()
+ * @pointer pointer value to write
+ */
+int tsv_pointer_write(struct encode_context *ectxt, void *pointer)
+{
+	int ret;
+	ret = tsv_write_header(ectxt, TSV_TYPE_POINTER, sizeof(pointer));
+	if (ret)
+		return ret;
+	return tsv_write_data(ectxt, &pointer, sizeof(pointer));
+}
+EXPORT_SYMBOL(tsv_pointer_write);
+
+/*
+ * Writes a 32-bit integer value.
+ *
+ * @ectxt context initialized by calling msg_encode_start()
+ * @n     integer to write
+ */
+int tsv_int32_write(struct encode_context *ectxt, int32_t n)
+{
+	int ret;
+	ret = tsv_write_header(ectxt, TSV_TYPE_INT32, sizeof(n));
+	if (ret)
+		return ret;
+	return tsv_write_data(ectxt, &n, sizeof(n));
+}
+EXPORT_SYMBOL(tsv_int32_write);
+
+/*
+ * Writes a byte array.
+ *
+ * @ectxt context initialized by calling msg_write_start()
+ * @data  Beginning address of data
+ * @data_size Size of data to be written
+ */
+int tsv_byte_array_write(struct encode_context *ectxt,
+			 void *data, int data_size)
+{
+	int ret;
+	ret = tsv_write_header(ectxt, TSV_TYPE_BYTE_ARRAY, data_size);
+	if (ret)
+		return ret;
+	return tsv_write_data(ectxt, data, data_size);
+}
+EXPORT_SYMBOL(tsv_byte_array_write);
+
+/*
+ * Helper function to log a string
+ *
+ * @ilctxt ipc_log_context created using ipc_log_context_create()
+ * @fmt Data specified using format specifiers
+ */
+int ipc_log_string(void *ilctxt, const char *fmt, ...)
+{
+	struct encode_context ectxt;
+	int avail_size, data_size, hdr_size = sizeof(struct tsv_header);
+	va_list arg_list;
+
+	if (!ilctxt)
+		return -EINVAL;
+
+	msg_encode_start(&ectxt, TSV_TYPE_STRING);
+	tsv_timestamp_write(&ectxt);
+	avail_size = (MAX_MSG_SIZE - (ectxt.offset + hdr_size));
+	va_start(arg_list, fmt);
+	data_size = vsnprintf((ectxt.buff + ectxt.offset + hdr_size),
+			      avail_size, fmt, arg_list);
+	va_end(arg_list);
+	tsv_write_header(&ectxt, TSV_TYPE_BYTE_ARRAY, data_size);
+	ectxt.offset += data_size;
+	msg_encode_end(&ectxt);
+	ipc_log_write(ilctxt, &ectxt);
+	return 0;
+}
+
+/*
+ * Helper funtion used to read data from a message context.
+ *
+ * @ectxt  context initialized by calling msg_read()
+ * @data  data to read
+ * @size  number of bytes of data to read
+ */
+static void tsv_read_data(struct encode_context *ectxt,
+			  void *data, uint32_t size)
+{
+	BUG_ON((ectxt->offset + size) > MAX_MSG_SIZE);
+	memcpy(data, (ectxt->buff + ectxt->offset), size);
+	ectxt->offset += size;
+}
+
+/*
+ * Helper function that reads a type from the context and updates the
+ * context pointers.
+ *
+ * @ectxt  context initialized by calling msg_read()
+ * @hdr   type header
+ */
+static void tsv_read_header(struct encode_context *ectxt,
+			    struct tsv_header *hdr)
+{
+	BUG_ON((ectxt->offset + sizeof(*hdr)) > MAX_MSG_SIZE);
+	memcpy(hdr, (ectxt->buff + ectxt->offset), sizeof(*hdr));
+	ectxt->offset += sizeof(*hdr);
+}
+
+/*
+ * Reads a timestamp.
+ *
+ * @ectxt   context initialized by calling msg_read()
+ * @dctxt   deserialization context
+ * @format output format (appended to %6u.%09u timestamp format)
+ */
+void tsv_timestamp_read(struct encode_context *ectxt,
+			struct decode_context *dctxt, const char *format)
+{
+	struct tsv_header hdr;
+	unsigned long long val;
+	unsigned long nanosec_rem;
+
+	tsv_read_header(ectxt, &hdr);
+	BUG_ON(hdr.type != TSV_TYPE_TIMESTAMP);
+	tsv_read_data(ectxt, &val, sizeof(val));
+	nanosec_rem = do_div(val, 1000000000U);
+	IPC_SPRINTF_DECODE(dctxt, "[%6u.%09lu]%s",
+			(unsigned)val, nanosec_rem, format);
+}
+EXPORT_SYMBOL(tsv_timestamp_read);
+
+/*
+ * Reads a data pointer.
+ *
+ * @ectxt   context initialized by calling msg_read()
+ * @dctxt   deserialization context
+ * @format output format
+ */
+void tsv_pointer_read(struct encode_context *ectxt,
+		      struct decode_context *dctxt, const char *format)
+{
+	struct tsv_header hdr;
+	void *val;
+
+	tsv_read_header(ectxt, &hdr);
+	BUG_ON(hdr.type != TSV_TYPE_POINTER);
+	tsv_read_data(ectxt, &val, sizeof(val));
+
+	IPC_SPRINTF_DECODE(dctxt, format, val);
+}
+EXPORT_SYMBOL(tsv_pointer_read);
+
+/*
+ * Reads a 32-bit integer value.
+ *
+ * @ectxt   context initialized by calling msg_read()
+ * @dctxt   deserialization context
+ * @format output format
+ */
+int32_t tsv_int32_read(struct encode_context *ectxt,
+		       struct decode_context *dctxt, const char *format)
+{
+	struct tsv_header hdr;
+	int32_t val;
+
+	tsv_read_header(ectxt, &hdr);
+	BUG_ON(hdr.type != TSV_TYPE_INT32);
+	tsv_read_data(ectxt, &val, sizeof(val));
+
+	IPC_SPRINTF_DECODE(dctxt, format, val);
+	return val;
+}
+EXPORT_SYMBOL(tsv_int32_read);
+
+/*
+ * Reads a byte array/string.
+ *
+ * @ectxt   context initialized by calling msg_read()
+ * @dctxt   deserialization context
+ * @format output format
+ */
+void tsv_byte_array_read(struct encode_context *ectxt,
+			 struct decode_context *dctxt, const char *format)
+{
+	struct tsv_header hdr;
+
+	tsv_read_header(ectxt, &hdr);
+	BUG_ON(hdr.type != TSV_TYPE_BYTE_ARRAY);
+	tsv_read_data(ectxt, dctxt->buff, hdr.size);
+	dctxt->buff += hdr.size;
+	dctxt->size -= hdr.size;
+}
+EXPORT_SYMBOL(tsv_byte_array_read);
+
+int add_deserialization_func(void *ctxt, int type,
+			void (*dfunc)(struct encode_context *,
+				      struct decode_context *))
+{
+	struct ipc_log_context *ilctxt = (struct ipc_log_context *)ctxt;
+	struct dfunc_info *df_info;
+	unsigned long flags;
+
+	if (!ilctxt || !dfunc)
+		return -EINVAL;
+
+	df_info = kmalloc(sizeof(struct dfunc_info), GFP_KERNEL);
+	if (!df_info)
+		return -ENOSPC;
+
+	spin_lock_irqsave(&ipc_log_context_list_lock, flags);
+	spin_lock(&ilctxt->ipc_log_context_lock);
+	df_info->type = type;
+	df_info->dfunc = dfunc;
+	list_add_tail(&df_info->list, &ilctxt->dfunc_info_list);
+	spin_unlock(&ilctxt->ipc_log_context_lock);
+	spin_unlock_irqrestore(&ipc_log_context_list_lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL(add_deserialization_func);
+
+void *ipc_log_context_create(int max_num_pages,
+			     const char *mod_name)
+{
+	struct ipc_log_context *ctxt;
+	struct ipc_log_page *pg = NULL;
+	int page_cnt, local_log_id;
+	unsigned long flags;
+
+	ctxt = kzalloc(sizeof(struct ipc_log_context), GFP_KERNEL);
+	if (!ctxt) {
+		pr_err("%s: cannot create ipc_log_context\n", __func__);
+		return 0;
+	}
+
+	local_log_id = atomic_add_return(1, &next_log_id);
+	init_completion(&ctxt->read_avail);
+	INIT_LIST_HEAD(&ctxt->page_list);
+	INIT_LIST_HEAD(&ctxt->dfunc_info_list);
+	spin_lock_init(&ctxt->ipc_log_context_lock);
+	for (page_cnt = 0; page_cnt < max_num_pages; page_cnt++) {
+		pg = kzalloc(sizeof(struct ipc_log_page), GFP_KERNEL);
+		if (!pg) {
+			pr_err("%s: cannot create ipc_log_page\n", __func__);
+			goto release_ipc_log_context;
+		}
+		pg->hdr.magic = IPC_LOGGING_MAGIC_NUM;
+		pg->hdr.nmagic = ~(IPC_LOGGING_MAGIC_NUM);
+		pg->hdr.log_id = (uint32_t)local_log_id;
+		pg->hdr.page_num = page_cnt;
+		pg->hdr.read_offset = 0xFFFF;
+		pg->hdr.write_offset = 0xFFFF;
+		spin_lock_irqsave(&ctxt->ipc_log_context_lock, flags);
+		list_add_tail(&pg->hdr.list, &ctxt->page_list);
+		spin_unlock_irqrestore(&ctxt->ipc_log_context_lock, flags);
+	}
+	ctxt->first_page = get_first_page(ctxt);
+	ctxt->last_page = pg;
+	ctxt->write_page = ctxt->first_page;
+	ctxt->read_page = ctxt->first_page;
+	ctxt->write_page->hdr.write_offset = 0;
+	ctxt->read_page->hdr.read_offset = 0;
+	ctxt->write_avail = max_num_pages * (PAGE_SIZE -
+					sizeof(struct ipc_log_page_header));
+
+	create_ctx_debugfs(ctxt, mod_name);
+
+	spin_lock_irqsave(&ipc_log_context_list_lock, flags);
+	list_add_tail(&ctxt->list, &ipc_log_context_list);
+	spin_unlock_irqrestore(&ipc_log_context_list_lock, flags);
+	return (void *)ctxt;
+
+release_ipc_log_context:
+	while (page_cnt-- > 0) {
+		pg = get_first_page(ctxt);
+		list_del(&pg->hdr.list);
+		kfree(pg);
+	}
+	kfree(ctxt);
+	return 0;
+}
+EXPORT_SYMBOL(ipc_log_context_create);
+
+static int __init ipc_logging_init(void)
+{
+	check_and_create_debugfs();
+	return 0;
+}
+
+module_init(ipc_logging_init);
+
+MODULE_DESCRIPTION("ipc logging");
+MODULE_LICENSE("GPL v2");