/*
- * A generic kernel FIFO implementation.
+ * A generic kernel FIFO implementation
*
- * Copyright (C) 2009 Stefani Seibold <stefani@seibold.net>
- * Copyright (C) 2004 Stelian Pop <stelian@popies.net>
+ * Copyright (C) 2009/2010 Stefani Seibold <stefani@seibold.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
*
* 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/err.h>
-#include <linux/kfifo.h>
#include <linux/log2.h>
#include <linux/uaccess.h>
+#include <linux/kfifo.h>
-static void _kfifo_init(struct kfifo *fifo, void *buffer,
- unsigned int size)
-{
- fifo->buffer = buffer;
- fifo->size = size;
-
- kfifo_reset(fifo);
-}
-
-/**
- * kfifo_init - initialize a FIFO using a preallocated buffer
- * @fifo: the fifo to assign the buffer
- * @buffer: the preallocated buffer to be used.
- * @size: the size of the internal buffer, this has to be a power of 2.
- *
+/*
+ * internal helper to calculate the unused elements in a fifo
*/
-void kfifo_init(struct kfifo *fifo, void *buffer, unsigned int size)
+static inline unsigned int kfifo_unused(struct __kfifo *fifo)
{
- /* size must be a power of 2 */
- BUG_ON(!is_power_of_2(size));
-
- _kfifo_init(fifo, buffer, size);
+ return (fifo->mask + 1) - (fifo->in - fifo->out);
}
-EXPORT_SYMBOL(kfifo_init);
-/**
- * kfifo_alloc - allocates a new FIFO internal buffer
- * @fifo: the fifo to assign then new buffer
- * @size: the size of the buffer to be allocated, this have to be a power of 2.
- * @gfp_mask: get_free_pages mask, passed to kmalloc()
- *
- * This function dynamically allocates a new fifo internal buffer
- *
- * The size will be rounded-up to a power of 2.
- * The buffer will be release with kfifo_free().
- * Return 0 if no error, otherwise the an error code
- */
-int kfifo_alloc(struct kfifo *fifo, unsigned int size, gfp_t gfp_mask)
+int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
+ size_t esize, gfp_t gfp_mask)
{
- unsigned char *buffer;
-
/*
- * round up to the next power of 2, since our 'let the indices
+ * round down to the next power of 2, since our 'let the indices
* wrap' technique works only in this case.
*/
- if (!is_power_of_2(size)) {
- BUG_ON(size > 0x80000000);
- size = roundup_pow_of_two(size);
+ if (!is_power_of_2(size))
+ size = rounddown_pow_of_two(size);
+
+ fifo->in = 0;
+ fifo->out = 0;
+ fifo->esize = esize;
+
+ if (size < 2) {
+ fifo->data = NULL;
+ fifo->mask = 0;
+ return -EINVAL;
}
- buffer = kmalloc(size, gfp_mask);
- if (!buffer) {
- _kfifo_init(fifo, NULL, 0);
+ fifo->data = kmalloc(size * esize, gfp_mask);
+
+ if (!fifo->data) {
+ fifo->mask = 0;
return -ENOMEM;
}
-
- _kfifo_init(fifo, buffer, size);
+ fifo->mask = size - 1;
return 0;
}
-EXPORT_SYMBOL(kfifo_alloc);
+EXPORT_SYMBOL(__kfifo_alloc);
-/**
- * kfifo_free - frees the FIFO internal buffer
- * @fifo: the fifo to be freed.
- */
-void kfifo_free(struct kfifo *fifo)
+void __kfifo_free(struct __kfifo *fifo)
{
- kfree(fifo->buffer);
- _kfifo_init(fifo, NULL, 0);
+ kfree(fifo->data);
+ fifo->in = 0;
+ fifo->out = 0;
+ fifo->esize = 0;
+ fifo->data = NULL;
+ fifo->mask = 0;
}
-EXPORT_SYMBOL(kfifo_free);
+EXPORT_SYMBOL(__kfifo_free);
-/**
- * kfifo_skip - skip output data
- * @fifo: the fifo to be used.
- * @len: number of bytes to skip
- */
-void kfifo_skip(struct kfifo *fifo, unsigned int len)
+int __kfifo_init(struct __kfifo *fifo, void *buffer,
+ unsigned int size, size_t esize)
{
- if (len < kfifo_len(fifo)) {
- __kfifo_add_out(fifo, len);
- return;
+ size /= esize;
+
+ if (!is_power_of_2(size))
+ size = rounddown_pow_of_two(size);
+
+ fifo->in = 0;
+ fifo->out = 0;
+ fifo->esize = esize;
+ fifo->data = buffer;
+
+ if (size < 2) {
+ fifo->mask = 0;
+ return -EINVAL;
}
- kfifo_reset_out(fifo);
+ fifo->mask = size - 1;
+
+ return 0;
}
-EXPORT_SYMBOL(kfifo_skip);
+EXPORT_SYMBOL(__kfifo_init);
-static inline void __kfifo_in_data(struct kfifo *fifo,
- const void *from, unsigned int len, unsigned int off)
+static void kfifo_copy_in(struct __kfifo *fifo, const void *src,
+ unsigned int len, unsigned int off)
{
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
unsigned int l;
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ memcpy(fifo->data + off, src, l);
+ memcpy(fifo->data, src + l, len - l);
/*
- * Ensure that we sample the fifo->out index -before- we
- * start putting bytes into the kfifo.
+ * make sure that the data in the fifo is up to date before
+ * incrementing the fifo->in index counter
*/
+ smp_wmb();
+}
- smp_mb();
-
- off = __kfifo_off(fifo, fifo->in + off);
+unsigned int __kfifo_in(struct __kfifo *fifo,
+ const void *buf, unsigned int len)
+{
+ unsigned int l;
- /* first put the data starting from fifo->in to buffer end */
- l = min(len, fifo->size - off);
- memcpy(fifo->buffer + off, from, l);
+ l = kfifo_unused(fifo);
+ if (len > l)
+ len = l;
- /* then put the rest (if any) at the beginning of the buffer */
- memcpy(fifo->buffer, from + l, len - l);
+ kfifo_copy_in(fifo, buf, len, fifo->in);
+ fifo->in += len;
+ return len;
}
+EXPORT_SYMBOL(__kfifo_in);
-static inline void __kfifo_out_data(struct kfifo *fifo,
- void *to, unsigned int len, unsigned int off)
+static void kfifo_copy_out(struct __kfifo *fifo, void *dst,
+ unsigned int len, unsigned int off)
{
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
unsigned int l;
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ memcpy(dst, fifo->data + off, l);
+ memcpy(dst + l, fifo->data, len - l);
/*
- * Ensure that we sample the fifo->in index -before- we
- * start removing bytes from the kfifo.
+ * make sure that the data is copied before
+ * incrementing the fifo->out index counter
*/
+ smp_wmb();
+}
- smp_rmb();
+unsigned int __kfifo_out_peek(struct __kfifo *fifo,
+ void *buf, unsigned int len)
+{
+ unsigned int l;
- off = __kfifo_off(fifo, fifo->out + off);
+ l = fifo->in - fifo->out;
+ if (len > l)
+ len = l;
- /* first get the data from fifo->out until the end of the buffer */
- l = min(len, fifo->size - off);
- memcpy(to, fifo->buffer + off, l);
+ kfifo_copy_out(fifo, buf, len, fifo->out);
+ return len;
+}
+EXPORT_SYMBOL(__kfifo_out_peek);
- /* then get the rest (if any) from the beginning of the buffer */
- memcpy(to + l, fifo->buffer, len - l);
+unsigned int __kfifo_out(struct __kfifo *fifo,
+ void *buf, unsigned int len)
+{
+ len = __kfifo_out_peek(fifo, buf, len);
+ fifo->out += len;
+ return len;
}
+EXPORT_SYMBOL(__kfifo_out);
-static inline int __kfifo_from_user_data(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned int off,
- unsigned *lenout)
+static unsigned long kfifo_copy_from_user(struct __kfifo *fifo,
+ const void __user *from, unsigned int len, unsigned int off,
+ unsigned int *copied)
{
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
unsigned int l;
- int ret;
+ unsigned long ret;
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ ret = copy_from_user(fifo->data + off, from, l);
+ if (unlikely(ret))
+ ret = DIV_ROUND_UP(ret + len - l, esize);
+ else {
+ ret = copy_from_user(fifo->data, from + l, len - l);
+ if (unlikely(ret))
+ ret = DIV_ROUND_UP(ret, esize);
+ }
/*
- * Ensure that we sample the fifo->out index -before- we
- * start putting bytes into the kfifo.
+ * make sure that the data in the fifo is up to date before
+ * incrementing the fifo->in index counter
*/
+ smp_wmb();
+ *copied = len - ret;
+ /* return the number of elements which are not copied */
+ return ret;
+}
- smp_mb();
+int __kfifo_from_user(struct __kfifo *fifo, const void __user *from,
+ unsigned long len, unsigned int *copied)
+{
+ unsigned int l;
+ unsigned long ret;
+ unsigned int esize = fifo->esize;
+ int err;
- off = __kfifo_off(fifo, fifo->in + off);
+ if (esize != 1)
+ len /= esize;
- /* 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)) {
- *lenout = ret;
- return -EFAULT;
- }
- *lenout = l;
+ l = kfifo_unused(fifo);
+ if (len > l)
+ len = l;
- /* then put the rest (if any) at the beginning of the buffer */
- ret = copy_from_user(fifo->buffer, from + l, len - l);
- *lenout += ret ? ret : len - l;
- return ret ? -EFAULT : 0;
+ ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied);
+ if (unlikely(ret)) {
+ len -= ret;
+ err = -EFAULT;
+ } else
+ err = 0;
+ fifo->in += len;
+ return err;
}
+EXPORT_SYMBOL(__kfifo_from_user);
-static inline int __kfifo_to_user_data(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned int off, unsigned *lenout)
+static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to,
+ unsigned int len, unsigned int off, unsigned int *copied)
{
unsigned int l;
- int ret;
-
+ unsigned long ret;
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
+
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ ret = copy_to_user(to, fifo->data + off, l);
+ if (unlikely(ret))
+ ret = DIV_ROUND_UP(ret + len - l, esize);
+ else {
+ ret = copy_to_user(to + l, fifo->data, len - l);
+ if (unlikely(ret))
+ ret = DIV_ROUND_UP(ret, esize);
+ }
/*
- * Ensure that we sample the fifo->in index -before- we
- * start removing bytes from the kfifo.
+ * make sure that the data is copied before
+ * incrementing the fifo->out index counter
*/
+ smp_wmb();
+ *copied = len - ret;
+ /* return the number of elements which are not copied */
+ return ret;
+}
- smp_rmb();
+int __kfifo_to_user(struct __kfifo *fifo, void __user *to,
+ unsigned long len, unsigned int *copied)
+{
+ unsigned int l;
+ unsigned long ret;
+ unsigned int esize = fifo->esize;
+ int err;
- off = __kfifo_off(fifo, fifo->out + off);
+ if (esize != 1)
+ len /= esize;
- /* 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);
- *lenout = l;
+ l = fifo->in - fifo->out;
+ if (len > l)
+ len = l;
+ ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);
if (unlikely(ret)) {
- *lenout -= ret;
- return -EFAULT;
- }
+ len -= ret;
+ err = -EFAULT;
+ } else
+ err = 0;
+ fifo->out += len;
+ return err;
+}
+EXPORT_SYMBOL(__kfifo_to_user);
- /* then get the rest (if any) from the beginning of the buffer */
- len -= l;
- ret = copy_to_user(to + l, fifo->buffer, len);
- if (unlikely(ret)) {
- *lenout += len - ret;
- return -EFAULT;
+static int setup_sgl_buf(struct scatterlist *sgl, void *buf,
+ int nents, unsigned int len)
+{
+ int n;
+ unsigned int l;
+ unsigned int off;
+ struct page *page;
+
+ if (!nents)
+ return 0;
+
+ if (!len)
+ return 0;
+
+ n = 0;
+ page = virt_to_page(buf);
+ off = offset_in_page(buf);
+ l = 0;
+
+ while (len >= l + PAGE_SIZE - off) {
+ struct page *npage;
+
+ l += PAGE_SIZE;
+ buf += PAGE_SIZE;
+ npage = virt_to_page(buf);
+ if (page_to_phys(page) != page_to_phys(npage) - l) {
+ sg_set_page(sgl, page, l - off, off);
+ sgl = sg_next(sgl);
+ if (++n == nents || sgl == NULL)
+ return n;
+ page = npage;
+ len -= l - off;
+ l = off = 0;
+ }
}
- *lenout += len;
- return 0;
+ sg_set_page(sgl, page, len, off);
+ return n + 1;
}
-unsigned int __kfifo_in_n(struct kfifo *fifo,
- const void *from, unsigned int len, unsigned int recsize)
+static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,
+ int nents, unsigned int len, unsigned int off)
{
- if (kfifo_avail(fifo) < len + recsize)
- return len + 1;
+ unsigned int size = fifo->mask + 1;
+ unsigned int esize = fifo->esize;
+ unsigned int l;
+ unsigned int n;
- __kfifo_in_data(fifo, from, len, recsize);
- return 0;
+ off &= fifo->mask;
+ if (esize != 1) {
+ off *= esize;
+ size *= esize;
+ len *= esize;
+ }
+ l = min(len, size - off);
+
+ n = setup_sgl_buf(sgl, fifo->data + off, nents, l);
+ n += setup_sgl_buf(sgl + n, fifo->data, nents - n, len - l);
+
+ if (n)
+ sg_mark_end(sgl + n - 1);
+ return n;
}
-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 void *from,
- unsigned int len)
+unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len)
{
- len = min(kfifo_avail(fifo), len);
+ unsigned int l;
- __kfifo_in_data(fifo, from, len, 0);
- __kfifo_add_in(fifo, len);
- return len;
+ l = kfifo_unused(fifo);
+ if (len > l)
+ len = l;
+
+ return setup_sgl(fifo, sgl, nents, len, fifo->in);
}
-EXPORT_SYMBOL(kfifo_in);
+EXPORT_SYMBOL(__kfifo_dma_in_prepare);
-unsigned int __kfifo_in_generic(struct kfifo *fifo,
- const void *from, unsigned int len, unsigned int recsize)
+unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len)
{
- return __kfifo_in_rec(fifo, from, len, recsize);
+ unsigned int l;
+
+ l = fifo->in - fifo->out;
+ if (len > l)
+ len = l;
+
+ return setup_sgl(fifo, sgl, nents, len, fifo->out);
}
-EXPORT_SYMBOL(__kfifo_in_generic);
+EXPORT_SYMBOL(__kfifo_dma_out_prepare);
-unsigned int __kfifo_out_n(struct kfifo *fifo,
- void *to, unsigned int len, unsigned int recsize)
+unsigned int __kfifo_max_r(unsigned int len, size_t recsize)
{
- if (kfifo_len(fifo) < len + recsize)
- return len;
+ unsigned int max = (1 << (recsize << 3)) - 1;
- __kfifo_out_data(fifo, to, len, recsize);
- __kfifo_add_out(fifo, len + recsize);
- return 0;
+ if (len > max)
+ return max;
+ return len;
}
-EXPORT_SYMBOL(__kfifo_out_n);
-/**
- * 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.
+#define __KFIFO_PEEK(data, out, mask) \
+ ((data)[(out) & (mask)])
+/*
+ * __kfifo_peek_n internal helper function for determinate the length of
+ * the next record in the fifo
*/
-unsigned int kfifo_out(struct kfifo *fifo, void *to, unsigned int len)
+static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)
{
- len = min(kfifo_len(fifo), len);
+ unsigned int l;
+ unsigned int mask = fifo->mask;
+ unsigned char *data = fifo->data;
- __kfifo_out_data(fifo, to, len, 0);
- __kfifo_add_out(fifo, len);
+ l = __KFIFO_PEEK(data, fifo->out, mask);
- return len;
+ if (--recsize)
+ l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;
+
+ return l;
}
-EXPORT_SYMBOL(kfifo_out);
-
-/**
- * kfifo_out_peek - copy some data from the FIFO, but do not remove it
- * @fifo: the fifo to be used.
- * @to: where the data must be copied.
- * @len: the size of the destination buffer.
- * @offset: offset into the fifo
- *
- * This function copies at most @len bytes at @offset from the FIFO
- * into the @to buffer and returns the number of copied bytes.
- * The data is not removed from the FIFO.
+
+#define __KFIFO_POKE(data, in, mask, val) \
+ ( \
+ (data)[(in) & (mask)] = (unsigned char)(val) \
+ )
+
+/*
+ * __kfifo_poke_n internal helper function for storeing the length of
+ * the record into the fifo
*/
-unsigned int kfifo_out_peek(struct kfifo *fifo, void *to, unsigned int len,
- unsigned offset)
+static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)
{
- len = min(kfifo_len(fifo), len + offset);
+ unsigned int mask = fifo->mask;
+ unsigned char *data = fifo->data;
- __kfifo_out_data(fifo, to, len, offset);
- return len;
+ __KFIFO_POKE(data, fifo->in, mask, n);
+
+ if (recsize > 1)
+ __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);
}
-EXPORT_SYMBOL(kfifo_out_peek);
-unsigned int __kfifo_out_generic(struct kfifo *fifo,
- void *to, unsigned int len, unsigned int recsize,
- unsigned int *total)
+unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)
{
- return __kfifo_out_rec(fifo, to, len, recsize, total);
+ return __kfifo_peek_n(fifo, recsize);
}
-EXPORT_SYMBOL(__kfifo_out_generic);
+EXPORT_SYMBOL(__kfifo_len_r);
-unsigned int __kfifo_from_user_n(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned int recsize)
+unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,
+ unsigned int len, size_t recsize)
{
- unsigned total;
+ if (len + recsize > kfifo_unused(fifo))
+ return 0;
- if (kfifo_avail(fifo) < len + recsize)
- return len + 1;
+ __kfifo_poke_n(fifo, len, recsize);
- __kfifo_from_user_data(fifo, from, len, recsize, &total);
- return total;
+ kfifo_copy_in(fifo, buf, len, fifo->in + recsize);
+ fifo->in += len + recsize;
+ return len;
}
-EXPORT_SYMBOL(__kfifo_from_user_n);
-
-/**
- * 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.
- * @total: the actual returned data length.
- *
- * This function copies at most @len bytes from the @from into the
- * FIFO depending and returns -EFAULT/0.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-int kfifo_from_user(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned *total)
+EXPORT_SYMBOL(__kfifo_in_r);
+
+static unsigned int kfifo_out_copy_r(struct __kfifo *fifo,
+ void *buf, unsigned int len, size_t recsize, unsigned int *n)
{
- int ret;
- len = min(kfifo_avail(fifo), len);
- ret = __kfifo_from_user_data(fifo, from, len, 0, total);
- if (ret)
- return ret;
- __kfifo_add_in(fifo, len);
- return 0;
+ *n = __kfifo_peek_n(fifo, recsize);
+
+ if (len > *n)
+ len = *n;
+
+ kfifo_copy_out(fifo, buf, len, fifo->out + recsize);
+ return len;
+}
+
+unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf,
+ unsigned int len, size_t recsize)
+{
+ unsigned int n;
+
+ if (fifo->in == fifo->out)
+ return 0;
+
+ return kfifo_out_copy_r(fifo, buf, len, recsize, &n);
}
-EXPORT_SYMBOL(kfifo_from_user);
+EXPORT_SYMBOL(__kfifo_out_peek_r);
-unsigned int __kfifo_from_user_generic(struct kfifo *fifo,
- const void __user *from, unsigned int len, unsigned int recsize)
+unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,
+ unsigned int len, size_t recsize)
{
- return __kfifo_from_user_rec(fifo, from, len, recsize);
+ unsigned int n;
+
+ if (fifo->in == fifo->out)
+ return 0;
+
+ len = kfifo_out_copy_r(fifo, buf, len, recsize, &n);
+ fifo->out += n + recsize;
+ return len;
}
-EXPORT_SYMBOL(__kfifo_from_user_generic);
+EXPORT_SYMBOL(__kfifo_out_r);
-unsigned int __kfifo_to_user_n(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned int reclen,
- unsigned int recsize)
+int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,
+ unsigned long len, unsigned int *copied, size_t recsize)
{
- unsigned int ret, total;
+ unsigned long ret;
- if (kfifo_len(fifo) < reclen + recsize)
- return len;
+ len = __kfifo_max_r(len, recsize);
- ret = __kfifo_to_user_data(fifo, to, reclen, recsize, &total);
+ if (len + recsize > kfifo_unused(fifo)) {
+ *copied = 0;
+ return 0;
+ }
- if (likely(ret == 0))
- __kfifo_add_out(fifo, reclen + recsize);
+ __kfifo_poke_n(fifo, len, recsize);
- return total;
+ ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied);
+ if (unlikely(ret)) {
+ *copied = 0;
+ return -EFAULT;
+ }
+ fifo->in += len + recsize;
+ return 0;
}
-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.
- * @lenout: pointer to output variable with copied data
- *
- * This function copies at most @len bytes from the FIFO into the
- * @to buffer and 0 or -EFAULT.
- *
- * Note that with only one concurrent reader and one concurrent
- * writer, you don't need extra locking to use these functions.
- */
-int kfifo_to_user(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned *lenout)
+EXPORT_SYMBOL(__kfifo_from_user_r);
+
+int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
+ unsigned long len, unsigned int *copied, size_t recsize)
{
- int ret;
- len = min(kfifo_len(fifo), len);
- ret = __kfifo_to_user_data(fifo, to, len, 0, lenout);
- __kfifo_add_out(fifo, *lenout);
- return ret;
+ unsigned long ret;
+ unsigned int n;
+
+ if (fifo->in == fifo->out) {
+ *copied = 0;
+ return 0;
+ }
+
+ n = __kfifo_peek_n(fifo, recsize);
+ if (len > n)
+ len = n;
+
+ ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied);
+ if (unlikely(ret)) {
+ *copied = 0;
+ return -EFAULT;
+ }
+ fifo->out += n + recsize;
+ return 0;
}
-EXPORT_SYMBOL(kfifo_to_user);
+EXPORT_SYMBOL(__kfifo_to_user_r);
-unsigned int __kfifo_to_user_generic(struct kfifo *fifo,
- void __user *to, unsigned int len, unsigned int recsize,
- unsigned int *total)
+unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
{
- return __kfifo_to_user_rec(fifo, to, len, recsize, total);
+ if (!nents)
+ BUG();
+
+ len = __kfifo_max_r(len, recsize);
+
+ if (len + recsize > kfifo_unused(fifo))
+ return 0;
+
+ return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize);
}
-EXPORT_SYMBOL(__kfifo_to_user_generic);
+EXPORT_SYMBOL(__kfifo_dma_in_prepare_r);
-unsigned int __kfifo_peek_generic(struct kfifo *fifo, unsigned int recsize)
+void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
+ unsigned int len, size_t recsize)
{
- if (recsize == 0)
- return kfifo_avail(fifo);
-
- return __kfifo_peek_n(fifo, recsize);
+ len = __kfifo_max_r(len, recsize);
+ __kfifo_poke_n(fifo, len, recsize);
+ fifo->in += len + recsize;
}
-EXPORT_SYMBOL(__kfifo_peek_generic);
+EXPORT_SYMBOL(__kfifo_dma_in_finish_r);
-void __kfifo_skip_generic(struct kfifo *fifo, unsigned int recsize)
+unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
+ struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
{
- __kfifo_skip_rec(fifo, recsize);
+ if (!nents)
+ BUG();
+
+ len = __kfifo_max_r(len, recsize);
+
+ if (len + recsize > fifo->in - fifo->out)
+ return 0;
+
+ return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize);
}
-EXPORT_SYMBOL(__kfifo_skip_generic);
+EXPORT_SYMBOL(__kfifo_dma_out_prepare_r);
+
+void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize)
+{
+ unsigned int len;
+ len = __kfifo_peek_n(fifo, recsize);
+ fifo->out += len + recsize;
+}
+EXPORT_SYMBOL(__kfifo_dma_out_finish_r);
git.samba.org / sfrench / cifs-2.6.git / blobdiff