1 files changed, 457 insertions, 294 deletions

diff --git a/kernel/kfifo.c b/kernel/kfifo.c
index 35edbe22e9a9..01a0700e873f 100644
--- a/kernel/kfifo.c
+++ b/kernel/kfifo.c
@@ -1,8 +1,7 @@
 /*
- * 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
@@ -11,7 +10,7 @@
  *
  * 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
@@ -24,422 +23,586 @@
 #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);
+
+        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);
+EXPORT_SYMBOL(__kfifo_in_r);
 
-/**
- * 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)
-{
-        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;
+static unsigned int kfifo_out_copy_r(struct __kfifo *fifo,
+        void *buf, unsigned int len, size_t recsize, unsigned int *n)
+{
+        *n = __kfifo_peek_n(fifo, recsize);
+
+        if (len > *n)
+                len = *n;
+
+        kfifo_copy_out(fifo, buf, len, fifo->out + recsize);
+        return len;
 }
-EXPORT_SYMBOL(kfifo_from_user);
 
-unsigned int __kfifo_from_user_generic(struct kfifo *fifo,
-        const void __user *from, unsigned int len, unsigned int recsize)
+unsigned int __kfifo_out_peek_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;
+
+        return kfifo_out_copy_r(fifo, buf, len, recsize, &n);
 }
-EXPORT_SYMBOL(__kfifo_from_user_generic);
+EXPORT_SYMBOL(__kfifo_out_peek_r);
 
-unsigned int __kfifo_to_user_n(struct kfifo *fifo,
-        void __user *to, unsigned int len, unsigned int reclen,
-        unsigned int recsize)
+unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,
+                unsigned int len, size_t recsize)
 {
-        unsigned int ret, total;
+        unsigned int n;
 
-        if (kfifo_len(fifo) < reclen + recsize)
-                return len;
+        if (fifo->in == fifo->out)
+                return 0;
 
-        ret = __kfifo_to_user_data(fifo, to, reclen, recsize, &total);
+        len = kfifo_out_copy_r(fifo, buf, len, recsize, &n);
+        fifo->out += n + recsize;
+        return len;
+}
+EXPORT_SYMBOL(__kfifo_out_r);
 
-        if (likely(ret == 0))
-                __kfifo_add_out(fifo, reclen + recsize);
+void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize)
+{
+        unsigned int n;
 
-        return total;
+        n = __kfifo_peek_n(fifo, recsize);
+        fifo->out += n + recsize;
 }
-EXPORT_SYMBOL(__kfifo_to_user_n);
+EXPORT_SYMBOL(__kfifo_skip_r);
 
-/**
- * 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)
+int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,
+        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;
+
+        len = __kfifo_max_r(len, recsize);
+
+        if (len + recsize > kfifo_unused(fifo)) {
+                *copied = 0;
+                return 0;
+        }
+
+        __kfifo_poke_n(fifo, len, recsize);
+
+        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);
+EXPORT_SYMBOL(__kfifo_from_user_r);
 
-unsigned int __kfifo_to_user_generic(struct kfifo *fifo,
-        void __user *to, unsigned int len, unsigned int recsize,
-        unsigned int *total)
+int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
+        unsigned long len, unsigned int *copied, size_t recsize)
 {
-        return __kfifo_to_user_rec(fifo, to, len, recsize, total);
+        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_generic);
+EXPORT_SYMBOL(__kfifo_to_user_r);
 
-unsigned int __kfifo_peek_generic(struct kfifo *fifo, unsigned int recsize)
+unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
+        struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
 {
-        if (recsize == 0)
-                return kfifo_avail(fifo);
+        if (!nents)
+                BUG();
 
-        return __kfifo_peek_n(fifo, recsize);
+        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_peek_generic);
+EXPORT_SYMBOL(__kfifo_dma_in_prepare_r);
 
-void __kfifo_skip_generic(struct kfifo *fifo, unsigned int recsize)
+void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
+        unsigned int len, size_t recsize)
 {
-        __kfifo_skip_rec(fifo, recsize);
+        len = __kfifo_max_r(len, recsize);
+        __kfifo_poke_n(fifo, len, recsize);
+        fifo->in += len + recsize;
 }
-EXPORT_SYMBOL(__kfifo_skip_generic);
+EXPORT_SYMBOL(__kfifo_dma_in_finish_r);
 
+unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
+        struct scatterlist *sgl, int nents, unsigned int len, size_t 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_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);