trace: Add snapshot of ipc_logging driver

This snapshot is taken as of msm-3.18 commit e70ad0cd (Promotion of
kernel.lnx.3.18-151201.)

Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>

1 files changed, 184 insertions, 0 deletions

diff --git a/kernel/trace/ipc_logging_debug.c b/kernel/trace/ipc_logging_debug.c
new file mode 100644
index 000000000000..a54538798f2b
--- /dev/null
+++ b/kernel/trace/ipc_logging_debug.c
@@ -0,0 +1,184 @@
+/* Copyright (c) 2012-2015, 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/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 <linux/ipc_logging.h>
+
+#include "ipc_logging_private.h"
+
+static DEFINE_MUTEX(ipc_log_debugfs_init_lock);
+static struct dentry *root_dent;
+
+static int debug_log(struct ipc_log_context *ilctxt,
+		     char *buff, int size, int cont)
+{
+	int i = 0;
+	int ret;
+
+	if (size < MAX_MSG_DECODED_SIZE) {
+		pr_err("%s: buffer size %d < %d\n", __func__, size,
+			MAX_MSG_DECODED_SIZE);
+		return -ENOMEM;
+	}
+	do {
+		i = ipc_log_extract(ilctxt, buff, size - 1);
+		if (cont && i == 0) {
+			ret = wait_for_completion_interruptible(
+				&ilctxt->read_avail);
+			if (ret < 0)
+				return ret;
+		}
+	} while (cont && i == 0);
+
+	return i;
+}
+
+/*
+ * VFS Read operation helper which dispatches the call to the debugfs
+ * read command stored in file->private_data.
+ *
+ * @file  File structure
+ * @buff   user buffer
+ * @count size of user buffer
+ * @ppos  file position to read from (only a value of 0 is accepted)
+ * @cont  1 = continuous mode (don't return 0 to signal end-of-file)
+ *
+ * @returns ==0 end of file
+ *           >0 number of bytes read
+ *           <0 error
+ */
+static ssize_t debug_read_helper(struct file *file, char __user *buff,
+				 size_t count, loff_t *ppos, int cont)
+{
+	struct ipc_log_context *ilctxt = file->private_data;
+	char *buffer;
+	int bsize;
+
+	buffer = kmalloc(count, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	bsize = debug_log(ilctxt, buffer, count, cont);
+	if (bsize > 0) {
+		if (copy_to_user(buff, buffer, bsize)) {
+			kfree(buffer);
+			return -EFAULT;
+		}
+		*ppos += bsize;
+	}
+	kfree(buffer);
+	return bsize;
+}
+
+static ssize_t debug_read(struct file *file, char __user *buff,
+			  size_t count, loff_t *ppos)
+{
+	return debug_read_helper(file, buff, count, ppos, 0);
+}
+
+static ssize_t debug_read_cont(struct file *file, char __user *buff,
+			       size_t count, loff_t *ppos)
+{
+	return debug_read_helper(file, buff, count, ppos, 1);
+}
+
+static int debug_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+static const struct file_operations debug_ops = {
+	.read = debug_read,
+	.open = debug_open,
+};
+
+static const struct file_operations debug_ops_cont = {
+	.read = debug_read_cont,
+	.open = debug_open,
+};
+
+static void debug_create(const char *name, mode_t mode,
+			 struct dentry *dent,
+			 struct ipc_log_context *ilctxt,
+			 const struct file_operations *fops)
+{
+	debugfs_create_file(name, mode, dent, ilctxt, fops);
+}
+
+static void dfunc_string(struct encode_context *ectxt,
+			 struct decode_context *dctxt)
+{
+	tsv_timestamp_read(ectxt, dctxt, "");
+	tsv_qtimer_read(ectxt, dctxt, " ");
+	tsv_byte_array_read(ectxt, dctxt, "");
+
+	/* add trailing \n if necessary */
+	if (*(dctxt->buff - 1) != '\n') {
+		if (dctxt->size) {
+			++dctxt->buff;
+			--dctxt->size;
+		}
+		*(dctxt->buff - 1) = '\n';
+	}
+}
+
+void check_and_create_debugfs(void)
+{
+	mutex_lock(&ipc_log_debugfs_init_lock);
+	if (!root_dent) {
+		root_dent = debugfs_create_dir("ipc_logging", 0);
+
+		if (IS_ERR(root_dent)) {
+			pr_err("%s: unable to create debugfs %ld\n",
+				__func__, PTR_ERR(root_dent));
+			root_dent = NULL;
+		}
+	}
+	mutex_unlock(&ipc_log_debugfs_init_lock);
+}
+EXPORT_SYMBOL(check_and_create_debugfs);
+
+void create_ctx_debugfs(struct ipc_log_context *ctxt,
+			const char *mod_name)
+{
+	if (!root_dent)
+		check_and_create_debugfs();
+
+	if (root_dent) {
+		ctxt->dent = debugfs_create_dir(mod_name, root_dent);
+		if (!IS_ERR(ctxt->dent)) {
+			debug_create("log", 0444, ctxt->dent,
+				     ctxt, &debug_ops);
+			debug_create("log_cont", 0444, ctxt->dent,
+				     ctxt, &debug_ops_cont);
+		}
+	}
+	add_deserialization_func((void *)ctxt,
+				 TSV_TYPE_STRING, dfunc_string);
+}
+EXPORT_SYMBOL(create_ctx_debugfs);