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authorStefani Seibold <stefani@seibold.net>2009-12-21 14:37:32 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-22 14:17:56 -0800
commit86d4880313603810901f639ccb5c88ff13d4ad3c (patch)
treec182d890b5c96a1143b70b00b93e3fc4a9263555 /kernel
parenta121f24accac1600bf5b6fb1e12eeabdfed7cb1a (diff)
downloadvexpress-lsk-86d4880313603810901f639ccb5c88ff13d4ad3c.tar.gz
kfifo: add record handling functions
Add kfifo_in_rec() - puts some record data into the FIFO Add kfifo_out_rec() - gets some record data from the FIFO Add kfifo_from_user_rec() - puts some data from user space into the FIFO Add kfifo_to_user_rec() - gets data from the FIFO and write it to user space Add kfifo_peek_rec() - gets the size of the next FIFO record field Add kfifo_skip_rec() - skip the next fifo out record Add kfifo_avail_rec() - determinate the number of bytes available in a record FIFO Signed-off-by: Stefani Seibold <stefani@seibold.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kfifo.c286
1 files changed, 193 insertions, 93 deletions
diff --git a/kernel/kfifo.c b/kernel/kfifo.c
index 2a78425ef67..e92d519f93b 100644
--- a/kernel/kfifo.c
+++ b/kernel/kfifo.c
@@ -115,27 +115,11 @@ void kfifo_skip(struct kfifo *fifo, unsigned int len)
}
EXPORT_SYMBOL(kfifo_skip);
-/**
- * kfifo_in - puts some data into the FIFO
- * @fifo: the fifo to be used.
- * @from: the data to be added.
- * @len: the length of the data to be added.
- *
- * This function copies at most @len bytes from the @from buffer into
- * the FIFO depending on the free space, and returns the number of
- * bytes copied.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-unsigned int kfifo_in(struct kfifo *fifo,
- const unsigned char *from, unsigned int len)
+static inline void __kfifo_in_data(struct kfifo *fifo,
+ const void *from, unsigned int len, unsigned int off)
{
- unsigned int off;
unsigned int l;
- len = min(len, fifo->size - fifo->in + fifo->out);
-
/*
* Ensure that we sample the fifo->out index -before- we
* start putting bytes into the kfifo.
@@ -143,7 +127,7 @@ unsigned int kfifo_in(struct kfifo *fifo,
smp_mb();
- off = __kfifo_off(fifo, fifo->in);
+ off = __kfifo_off(fifo, fifo->in + off);
/* first put the data starting from fifo->in to buffer end */
l = min(len, fifo->size - off);
@@ -151,33 +135,13 @@ unsigned int kfifo_in(struct kfifo *fifo,
/* then put the rest (if any) at the beginning of the buffer */
memcpy(fifo->buffer, from + l, len - l);
-
- __kfifo_add_in(fifo, len);
-
- return len;
}
-EXPORT_SYMBOL(kfifo_in);
-/**
- * kfifo_out - gets some data from the FIFO
- * @fifo: the fifo to be used.
- * @to: where the data must be copied.
- * @len: the size of the destination buffer.
- *
- * This function copies at most @len bytes from the FIFO into the
- * @to buffer and returns the number of copied bytes.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-unsigned int kfifo_out(struct kfifo *fifo,
- unsigned char *to, unsigned int len)
+static inline void __kfifo_out_data(struct kfifo *fifo,
+ void *to, unsigned int len, unsigned int off)
{
- unsigned int off;
unsigned int l;
- len = min(len, fifo->in - fifo->out);
-
/*
* Ensure that we sample the fifo->in index -before- we
* start removing bytes from the kfifo.
@@ -185,7 +149,7 @@ unsigned int kfifo_out(struct kfifo *fifo,
smp_rmb();
- off = __kfifo_off(fifo, fifo->out);
+ off = __kfifo_off(fifo, fifo->out + off);
/* first get the data from fifo->out until the end of the buffer */
l = min(len, fifo->size - off);
@@ -193,34 +157,14 @@ unsigned int kfifo_out(struct kfifo *fifo,
/* then get the rest (if any) from the beginning of the buffer */
memcpy(to + l, fifo->buffer, len - l);
-
- __kfifo_add_out(fifo, len);
-
- return len;
}
-EXPORT_SYMBOL(kfifo_out);
-/**
- * kfifo_from_user - puts some data from user space into the FIFO
- * @fifo: the fifo to be used.
- * @from: pointer to the data to be added.
- * @len: the length of the data to be added.
- *
- * This function copies at most @len bytes from the @from into the
- * FIFO depending and returns the number of copied bytes.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-unsigned int kfifo_from_user(struct kfifo *fifo,
- const void __user *from, unsigned int len)
+static inline unsigned int __kfifo_from_user_data(struct kfifo *fifo,
+ const void __user *from, unsigned int len, unsigned int off)
{
- unsigned int off;
unsigned int l;
int ret;
- len = min(len, fifo->size - fifo->in + fifo->out);
-
/*
* Ensure that we sample the fifo->out index -before- we
* start putting bytes into the kfifo.
@@ -228,29 +172,101 @@ unsigned int kfifo_from_user(struct kfifo *fifo,
smp_mb();
- off = __kfifo_off(fifo, fifo->in);
+ off = __kfifo_off(fifo, fifo->in + off);
/* first put the data starting from fifo->in to buffer end */
l = min(len, fifo->size - off);
ret = copy_from_user(fifo->buffer + off, from, l);
if (unlikely(ret))
- return l - ret;
+ return ret + len - l;
/* then put the rest (if any) at the beginning of the buffer */
- ret = copy_from_user(fifo->buffer, from + l, len - l);
+ return copy_from_user(fifo->buffer, from + l, len - l);
+}
+
+static inline unsigned int __kfifo_to_user_data(struct kfifo *fifo,
+ void __user *to, unsigned int len, unsigned int off)
+{
+ unsigned int l;
+ int ret;
+
+ /*
+ * Ensure that we sample the fifo->in index -before- we
+ * start removing bytes from the kfifo.
+ */
+
+ smp_rmb();
+
+ off = __kfifo_off(fifo, fifo->out + off);
+
+ /* first get the data from fifo->out until the end of the buffer */
+ l = min(len, fifo->size - off);
+ ret = copy_to_user(to, fifo->buffer + off, l);
if (unlikely(ret))
- return len - ret;
+ return ret + len - l;
- __kfifo_add_in(fifo, len);
+ /* then get the rest (if any) from the beginning of the buffer */
+ return copy_to_user(to + l, fifo->buffer, len - l);
+}
+unsigned int __kfifo_in_n(struct kfifo *fifo,
+ const void *from, unsigned int len, unsigned int recsize)
+{
+ if (kfifo_avail(fifo) < len + recsize)
+ return len + 1;
+
+ __kfifo_in_data(fifo, from, len, recsize);
+ return 0;
+}
+EXPORT_SYMBOL(__kfifo_in_n);
+
+/**
+ * kfifo_in - puts some data into the FIFO
+ * @fifo: the fifo to be used.
+ * @from: the data to be added.
+ * @len: the length of the data to be added.
+ *
+ * This function copies at most @len bytes from the @from buffer into
+ * the FIFO depending on the free space, and returns the number of
+ * bytes copied.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these functions.
+ */
+unsigned int kfifo_in(struct kfifo *fifo, const unsigned char *from,
+ unsigned int len)
+{
+ len = min(kfifo_avail(fifo), len);
+
+ __kfifo_in_data(fifo, from, len, 0);
+ __kfifo_add_in(fifo, len);
return len;
}
-EXPORT_SYMBOL(kfifo_from_user);
+EXPORT_SYMBOL(kfifo_in);
+
+unsigned int __kfifo_in_generic(struct kfifo *fifo,
+ const void *from, unsigned int len, unsigned int recsize)
+{
+ return __kfifo_in_rec(fifo, from, len, recsize);
+}
+EXPORT_SYMBOL(__kfifo_in_generic);
+
+unsigned int __kfifo_out_n(struct kfifo *fifo,
+ void *to, unsigned int len, unsigned int recsize)
+{
+ if (kfifo_len(fifo) < len + recsize)
+ return len;
+
+ __kfifo_out_data(fifo, to, len, recsize);
+ __kfifo_add_out(fifo, len + recsize);
+ return 0;
+}
+EXPORT_SYMBOL(__kfifo_out_n);
/**
- * kfifo_to_user - gets data from the FIFO and write it to user space
+ * kfifo_out - gets some data from the FIFO
* @fifo: the fifo to be used.
* @to: where the data must be copied.
* @len: the size of the destination buffer.
@@ -261,40 +277,124 @@ EXPORT_SYMBOL(kfifo_from_user);
* Note that with only one concurrent reader and one concurrent
* writer, you don't need extra locking to use these functions.
*/
-unsigned int kfifo_to_user(struct kfifo *fifo,
- void __user *to, unsigned int len)
+unsigned int kfifo_out(struct kfifo *fifo, unsigned char *to, unsigned int len)
{
- unsigned int off;
- unsigned int l;
- int ret;
+ len = min(kfifo_len(fifo), len);
- len = min(len, fifo->in - fifo->out);
+ __kfifo_out_data(fifo, to, len, 0);
+ __kfifo_add_out(fifo, len);
- /*
- * Ensure that we sample the fifo->in index -before- we
- * start removing bytes from the kfifo.
- */
+ return len;
+}
+EXPORT_SYMBOL(kfifo_out);
- smp_rmb();
+unsigned int __kfifo_out_generic(struct kfifo *fifo,
+ void *to, unsigned int len, unsigned int recsize,
+ unsigned int *total)
+{
+ return __kfifo_out_rec(fifo, to, len, recsize, total);
+}
+EXPORT_SYMBOL(__kfifo_out_generic);
- off = __kfifo_off(fifo, fifo->out);
+unsigned int __kfifo_from_user_n(struct kfifo *fifo,
+ const void __user *from, unsigned int len, unsigned int recsize)
+{
+ if (kfifo_avail(fifo) < len + recsize)
+ return len + 1;
- /* first get the data from fifo->out until the end of the buffer */
- l = min(len, fifo->size - off);
- ret = copy_to_user(to, fifo->buffer + off, l);
+ return __kfifo_from_user_data(fifo, from, len, recsize);
+}
+EXPORT_SYMBOL(__kfifo_from_user_n);
- if (unlikely(ret))
- return l - ret;
+/**
+ * kfifo_from_user - puts some data from user space into the FIFO
+ * @fifo: the fifo to be used.
+ * @from: pointer to the data to be added.
+ * @len: the length of the data to be added.
+ *
+ * This function copies at most @len bytes from the @from into the
+ * FIFO depending and returns the number of copied bytes.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these functions.
+ */
+unsigned int kfifo_from_user(struct kfifo *fifo,
+ const void __user *from, unsigned int len)
+{
+ len = min(kfifo_avail(fifo), len);
+ len -= __kfifo_from_user_data(fifo, from, len, 0);
+ __kfifo_add_in(fifo, len);
+ return len;
+}
+EXPORT_SYMBOL(kfifo_from_user);
- /* then get the rest (if any) from the beginning of the buffer */
- ret = copy_to_user(to + l, fifo->buffer, len - l);
+unsigned int __kfifo_from_user_generic(struct kfifo *fifo,
+ const void __user *from, unsigned int len, unsigned int recsize)
+{
+ return __kfifo_from_user_rec(fifo, from, len, recsize);
+}
+EXPORT_SYMBOL(__kfifo_from_user_generic);
- if (unlikely(ret))
- return len - ret;
+unsigned int __kfifo_to_user_n(struct kfifo *fifo,
+ void __user *to, unsigned int len, unsigned int reclen,
+ unsigned int recsize)
+{
+ unsigned int ret;
- __kfifo_add_out(fifo, len);
+ if (kfifo_len(fifo) < reclen + recsize)
+ return len;
+ ret = __kfifo_to_user_data(fifo, to, reclen, recsize);
+
+ if (likely(ret == 0))
+ __kfifo_add_out(fifo, reclen + recsize);
+
+ return ret;
+}
+EXPORT_SYMBOL(__kfifo_to_user_n);
+
+/**
+ * kfifo_to_user - gets data from the FIFO and write it to user space
+ * @fifo: the fifo to be used.
+ * @to: where the data must be copied.
+ * @len: the size of the destination buffer.
+ *
+ * This function copies at most @len bytes from the FIFO into the
+ * @to buffer and returns the number of copied bytes.
+ *
+ * Note that with only one concurrent reader and one concurrent
+ * writer, you don't need extra locking to use these functions.
+ */
+unsigned int kfifo_to_user(struct kfifo *fifo,
+ void __user *to, unsigned int len)
+{
+ len = min(kfifo_len(fifo), len);
+ len -= __kfifo_to_user_data(fifo, to, len, 0);
+ __kfifo_add_out(fifo, len);
return len;
}
EXPORT_SYMBOL(kfifo_to_user);
+unsigned int __kfifo_to_user_generic(struct kfifo *fifo,
+ void __user *to, unsigned int len, unsigned int recsize,
+ unsigned int *total)
+{
+ return __kfifo_to_user_rec(fifo, to, len, recsize, total);
+}
+EXPORT_SYMBOL(__kfifo_to_user_generic);
+
+unsigned int __kfifo_peek_generic(struct kfifo *fifo, unsigned int recsize)
+{
+ if (recsize == 0)
+ return kfifo_avail(fifo);
+
+ return __kfifo_peek_n(fifo, recsize);
+}
+EXPORT_SYMBOL(__kfifo_peek_generic);
+
+void __kfifo_skip_generic(struct kfifo *fifo, unsigned int recsize)
+{
+ __kfifo_skip_rec(fifo, recsize);
+}
+EXPORT_SYMBOL(__kfifo_skip_generic);
+