#include <linux/err.h>
#include <linux/kfifo.h>
#include <linux/log2.h>
+#include <linux/uaccess.h>
static void _kfifo_init(struct kfifo *fifo, unsigned char *buffer,
unsigned int size)
EXPORT_SYMBOL(kfifo_free);
/**
- * __kfifo_put - puts some data into the FIFO, no locking version
+ * kfifo_skip - skip output data
* @fifo: the fifo to be used.
- * @buffer: the data to be added.
+ * @len: number of bytes to skip
+ */
+void kfifo_skip(struct kfifo *fifo, unsigned int len)
+{
+ if (len < kfifo_len(fifo)) {
+ __kfifo_add_out(fifo, len);
+ return;
+ }
+ kfifo_reset_out(fifo);
+}
+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 @buffer into
+ * 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_put(struct kfifo *fifo,
- const unsigned char *buffer, unsigned int len)
+unsigned int kfifo_in(struct kfifo *fifo,
+ const unsigned char *from, unsigned int len)
{
+ unsigned int off;
unsigned int l;
len = min(len, fifo->size - fifo->in + fifo->out);
smp_mb();
+ off = __kfifo_off(fifo, fifo->in);
+
/* first put the data starting from fifo->in to buffer end */
- l = min(len, fifo->size - (fifo->in & (fifo->size - 1)));
- memcpy(fifo->buffer + (fifo->in & (fifo->size - 1)), buffer, l);
+ l = min(len, fifo->size - off);
+ memcpy(fifo->buffer + off, from, l);
/* then put the rest (if any) at the beginning of the buffer */
- memcpy(fifo->buffer, buffer + l, len - l);
-
- /*
- * Ensure that we add the bytes to the kfifo -before-
- * we update the fifo->in index.
- */
-
- smp_wmb();
+ memcpy(fifo->buffer, from + l, len - l);
- fifo->in += len;
+ __kfifo_add_in(fifo, len);
return len;
}
-EXPORT_SYMBOL(__kfifo_put);
+EXPORT_SYMBOL(kfifo_in);
/**
- * __kfifo_get - gets some data from the FIFO, no locking version
+ * kfifo_out - gets some data from the FIFO
* @fifo: the fifo to be used.
- * @buffer: where the data must be copied.
+ * @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
- * @buffer and returns the number of copied bytes.
+ * @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_get(struct kfifo *fifo,
- unsigned char *buffer, unsigned int len)
+unsigned int kfifo_out(struct kfifo *fifo,
+ unsigned char *to, unsigned int len)
{
+ unsigned int off;
unsigned int l;
len = min(len, fifo->in - fifo->out);
smp_rmb();
+ off = __kfifo_off(fifo, fifo->out);
+
/* first get the data from fifo->out until the end of the buffer */
- l = min(len, fifo->size - (fifo->out & (fifo->size - 1)));
- memcpy(buffer, fifo->buffer + (fifo->out & (fifo->size - 1)), l);
+ l = min(len, fifo->size - off);
+ memcpy(to, fifo->buffer + off, l);
/* then get the rest (if any) from the beginning of the buffer */
- memcpy(buffer + l, fifo->buffer, len - l);
+ 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)
+{
+ unsigned int off;
+ unsigned int l;
+ int ret;
+
+ len = min(len, fifo->size - fifo->in + fifo->out);
/*
- * Ensure that we remove the bytes from the kfifo -before-
- * we update the fifo->out index.
+ * Ensure that we sample the fifo->out index -before- we
+ * start putting bytes into the kfifo.
*/
smp_mb();
- fifo->out += len;
+ off = __kfifo_off(fifo, fifo->in);
+
+ /* 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;
+
+ /* then put the rest (if any) at the beginning of the buffer */
+ ret = copy_from_user(fifo->buffer, from + l, len - l);
+
+ if (unlikely(ret))
+ return len - ret;
+
+ __kfifo_add_in(fifo, len);
+
+ return len;
+}
+EXPORT_SYMBOL(kfifo_from_user);
+
+/**
+ * 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)
+{
+ unsigned int off;
+ unsigned int l;
+ int ret;
+
+ len = min(len, fifo->in - fifo->out);
+
+ /*
+ * Ensure that we sample the fifo->in index -before- we
+ * start removing bytes from the kfifo.
+ */
+
+ smp_rmb();
+
+ off = __kfifo_off(fifo, fifo->out);
+
+ /* 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 l - ret;
+
+ /* then get the rest (if any) from the beginning of the buffer */
+ ret = copy_to_user(to + l, fifo->buffer, len - l);
+
+ if (unlikely(ret))
+ return len - ret;
+
+ __kfifo_add_out(fifo, len);
return len;
}
-EXPORT_SYMBOL(__kfifo_get);
+EXPORT_SYMBOL(kfifo_to_user);
+
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff