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authorAviya Erenfeld <aviya.erenfeld@intel.com>2016-04-14 11:59:31 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-04-15 11:20:32 -0700
commit522566376a3f8373fbd5ff75bb8a7a2da701c1a7 (patch)
tree11d223946c04ca9bcdbbc8b0167297829dbb578e /drivers/base/devcoredump.c
parentc4a74f63dfd2e75e7d40a9aaa4052b0ef26e617c (diff)
devcoredump: add scatterlist support
Add scatterlist support (dev_coredumpsg) to allow drivers to avoid vmalloc() like dev_coredumpm(), while also avoiding the module reference that the latter function requires. This internally uses dev_coredumpm() with function inside the devcoredump module, requiring removing the const (which touches the driver using it.) Signed-off-by: Aviya Erenfeld <aviya.erenfeld@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/devcoredump.c')
-rw-r--r--drivers/base/devcoredump.c83
1 files changed, 74 insertions, 9 deletions
diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c
index 1bd120a0b084..240374fd1838 100644
--- a/drivers/base/devcoredump.c
+++ b/drivers/base/devcoredump.c
@@ -4,6 +4,7 @@
* GPL LICENSE SUMMARY
*
* Copyright(c) 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2015 Intel Deutschland GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
@@ -41,12 +42,12 @@ static bool devcd_disabled;
struct devcd_entry {
struct device devcd_dev;
- const void *data;
+ void *data;
size_t datalen;
struct module *owner;
ssize_t (*read)(char *buffer, loff_t offset, size_t count,
- const void *data, size_t datalen);
- void (*free)(const void *data);
+ void *data, size_t datalen);
+ void (*free)(void *data);
struct delayed_work del_wk;
struct device *failing_dev;
};
@@ -174,7 +175,7 @@ static struct class devcd_class = {
};
static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count,
- const void *data, size_t datalen)
+ void *data, size_t datalen)
{
if (offset > datalen)
return -EINVAL;
@@ -188,6 +189,11 @@ static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count,
return count;
}
+static void devcd_freev(void *data)
+{
+ vfree(data);
+}
+
/**
* dev_coredumpv - create device coredump with vmalloc data
* @dev: the struct device for the crashed device
@@ -198,10 +204,10 @@ static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count,
* This function takes ownership of the vmalloc'ed data and will free
* it when it is no longer used. See dev_coredumpm() for more information.
*/
-void dev_coredumpv(struct device *dev, const void *data, size_t datalen,
+void dev_coredumpv(struct device *dev, void *data, size_t datalen,
gfp_t gfp)
{
- dev_coredumpm(dev, NULL, data, datalen, gfp, devcd_readv, vfree);
+ dev_coredumpm(dev, NULL, data, datalen, gfp, devcd_readv, devcd_freev);
}
EXPORT_SYMBOL_GPL(dev_coredumpv);
@@ -213,6 +219,44 @@ static int devcd_match_failing(struct device *dev, const void *failing)
}
/**
+ * devcd_free_sgtable - free all the memory of the given scatterlist table
+ * (i.e. both pages and scatterlist instances)
+ * NOTE: if two tables allocated with devcd_alloc_sgtable and then chained
+ * using the sg_chain function then that function should be called only once
+ * on the chained table
+ * @table: pointer to sg_table to free
+ */
+static void devcd_free_sgtable(void *data)
+{
+ _devcd_free_sgtable(data);
+}
+
+/**
+ * devcd_read_from_table - copy data from sg_table to a given buffer
+ * and return the number of bytes read
+ * @buffer: the buffer to copy the data to it
+ * @buf_len: the length of the buffer
+ * @data: the scatterlist table to copy from
+ * @offset: start copy from @offset@ bytes from the head of the data
+ * in the given scatterlist
+ * @data_len: the length of the data in the sg_table
+ */
+static ssize_t devcd_read_from_sgtable(char *buffer, loff_t offset,
+ size_t buf_len, void *data,
+ size_t data_len)
+{
+ struct scatterlist *table = data;
+
+ if (offset > data_len)
+ return -EINVAL;
+
+ if (offset + buf_len > data_len)
+ buf_len = data_len - offset;
+ return sg_pcopy_to_buffer(table, sg_nents(table), buffer, buf_len,
+ offset);
+}
+
+/**
* dev_coredumpm - create device coredump with read/free methods
* @dev: the struct device for the crashed device
* @owner: the module that contains the read/free functions, use %THIS_MODULE
@@ -228,10 +272,10 @@ static int devcd_match_failing(struct device *dev, const void *failing)
* function will be called to free the data.
*/
void dev_coredumpm(struct device *dev, struct module *owner,
- const void *data, size_t datalen, gfp_t gfp,
+ void *data, size_t datalen, gfp_t gfp,
ssize_t (*read)(char *buffer, loff_t offset, size_t count,
- const void *data, size_t datalen),
- void (*free)(const void *data))
+ void *data, size_t datalen),
+ void (*free)(void *data))
{
static atomic_t devcd_count = ATOMIC_INIT(0);
struct devcd_entry *devcd;
@@ -291,6 +335,27 @@ void dev_coredumpm(struct device *dev, struct module *owner,
}
EXPORT_SYMBOL_GPL(dev_coredumpm);
+/**
+ * dev_coredumpmsg - create device coredump that uses scatterlist as data
+ * parameter
+ * @dev: the struct device for the crashed device
+ * @table: the dump data
+ * @datalen: length of the data
+ * @gfp: allocation flags
+ *
+ * Creates a new device coredump for the given device. If a previous one hasn't
+ * been read yet, the new coredump is discarded. The data lifetime is determined
+ * by the device coredump framework and when it is no longer needed
+ * it will free the data.
+ */
+void dev_coredumpsg(struct device *dev, struct scatterlist *table,
+ size_t datalen, gfp_t gfp)
+{
+ dev_coredumpm(dev, NULL, table, datalen, gfp, devcd_read_from_sgtable,
+ devcd_free_sgtable);
+}
+EXPORT_SYMBOL_GPL(dev_coredumpsg);
+
static int __init devcoredump_init(void)
{
return class_register(&devcd_class);