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-rw-r--r--kernel/kfifo.c609
1 files changed, 0 insertions, 609 deletions
diff --git a/kernel/kfifo.c b/kernel/kfifo.c
deleted file mode 100644
index 59dcf5b..0000000
--- a/kernel/kfifo.c
+++ /dev/null
@@ -1,609 +0,0 @@
-/*
- * A generic kernel FIFO implementation
- *
- * 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
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- */
-
-#include <linux/kernel.h>
-#include <linux/export.h>
-#include <linux/slab.h>
-#include <linux/err.h>
-#include <linux/log2.h>
-#include <linux/uaccess.h>
-#include <linux/kfifo.h>
-
-/*
- * internal helper to calculate the unused elements in a fifo
- */
-static inline unsigned int kfifo_unused(struct __kfifo *fifo)
-{
- return (fifo->mask + 1) - (fifo->in - fifo->out);
-}
-
-int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
- size_t esize, gfp_t gfp_mask)
-{
- /*
- * 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))
- 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;
- }
-
- fifo->data = kmalloc(size * esize, gfp_mask);
-
- if (!fifo->data) {
- fifo->mask = 0;
- return -ENOMEM;
- }
- fifo->mask = size - 1;
-
- return 0;
-}
-EXPORT_SYMBOL(__kfifo_alloc);
-
-void __kfifo_free(struct __kfifo *fifo)
-{
- kfree(fifo->data);
- fifo->in = 0;
- fifo->out = 0;
- fifo->esize = 0;
- fifo->data = NULL;
- fifo->mask = 0;
-}
-EXPORT_SYMBOL(__kfifo_free);
-
-int __kfifo_init(struct __kfifo *fifo, void *buffer,
- unsigned int size, size_t esize)
-{
- 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;
- }
- fifo->mask = size - 1;
-
- return 0;
-}
-EXPORT_SYMBOL(__kfifo_init);
-
-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);
- /*
- * make sure that the data in the fifo is up to date before
- * incrementing the fifo->in index counter
- */
- smp_wmb();
-}
-
-unsigned int __kfifo_in(struct __kfifo *fifo,
- const void *buf, unsigned int len)
-{
- unsigned int l;
-
- l = kfifo_unused(fifo);
- if (len > l)
- len = l;
-
- kfifo_copy_in(fifo, buf, len, fifo->in);
- fifo->in += len;
- return len;
-}
-EXPORT_SYMBOL(__kfifo_in);
-
-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);
- /*
- * make sure that the data is copied before
- * incrementing the fifo->out index counter
- */
- smp_wmb();
-}
-
-unsigned int __kfifo_out_peek(struct __kfifo *fifo,
- void *buf, unsigned int len)
-{
- unsigned int l;
-
- l = fifo->in - fifo->out;
- if (len > l)
- len = l;
-
- kfifo_copy_out(fifo, buf, len, fifo->out);
- return len;
-}
-EXPORT_SYMBOL(__kfifo_out_peek);
-
-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 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;
- 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);
- }
- /*
- * 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;
-}
-
-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;
-
- if (esize != 1)
- len /= esize;
-
- l = kfifo_unused(fifo);
- if (len > l)
- len = l;
-
- 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 unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to,
- unsigned int len, unsigned int off, unsigned int *copied)
-{
- unsigned int l;
- 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);
- }
- /*
- * 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;
-}
-
-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;
-
- if (esize != 1)
- len /= esize;
-
- l = fifo->in - fifo->out;
- if (len > l)
- len = l;
- ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);
- if (unlikely(ret)) {
- len -= ret;
- err = -EFAULT;
- } else
- err = 0;
- fifo->out += len;
- return err;
-}
-EXPORT_SYMBOL(__kfifo_to_user);
-
-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;
- }
- }
- sg_set_page(sgl, page, len, off);
- return n + 1;
-}
-
-static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,
- int nents, unsigned int len, unsigned int off)
-{
- unsigned int size = fifo->mask + 1;
- unsigned int esize = fifo->esize;
- unsigned int l;
- unsigned int n;
-
- 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;
-}
-
-unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
- struct scatterlist *sgl, int nents, unsigned int len)
-{
- unsigned int l;
-
- l = kfifo_unused(fifo);
- if (len > l)
- len = l;
-
- return setup_sgl(fifo, sgl, nents, len, fifo->in);
-}
-EXPORT_SYMBOL(__kfifo_dma_in_prepare);
-
-unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
- struct scatterlist *sgl, int nents, unsigned int len)
-{
- 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_dma_out_prepare);
-
-unsigned int __kfifo_max_r(unsigned int len, size_t recsize)
-{
- unsigned int max = (1 << (recsize << 3)) - 1;
-
- if (len > max)
- return max;
- return len;
-}
-EXPORT_SYMBOL(__kfifo_max_r);
-
-#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
- */
-static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)
-{
- unsigned int l;
- unsigned int mask = fifo->mask;
- unsigned char *data = fifo->data;
-
- l = __KFIFO_PEEK(data, fifo->out, mask);
-
- if (--recsize)
- l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;
-
- return l;
-}
-
-#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
- */
-static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)
-{
- unsigned int mask = fifo->mask;
- unsigned char *data = fifo->data;
-
- __KFIFO_POKE(data, fifo->in, mask, n);
-
- if (recsize > 1)
- __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);
-}
-
-unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)
-{
- return __kfifo_peek_n(fifo, recsize);
-}
-EXPORT_SYMBOL(__kfifo_len_r);
-
-unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,
- unsigned int len, size_t recsize)
-{
- if (len + recsize > kfifo_unused(fifo))
- return 0;
-
- __kfifo_poke_n(fifo, len, recsize);
-
- kfifo_copy_in(fifo, buf, len, fifo->in + recsize);
- fifo->in += len + recsize;
- return len;
-}
-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)
-{
- *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_out_peek_r);
-
-unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,
- unsigned int len, size_t 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_out_r);
-
-void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize)
-{
- unsigned int n;
-
- n = __kfifo_peek_n(fifo, recsize);
- fifo->out += n + recsize;
-}
-EXPORT_SYMBOL(__kfifo_skip_r);
-
-int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,
- unsigned long len, unsigned int *copied, size_t recsize)
-{
- 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_from_user_r);
-
-int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
- unsigned long len, unsigned int *copied, size_t recsize)
-{
- 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_r);
-
-unsigned int __kfifo_dma_in_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 > kfifo_unused(fifo))
- return 0;
-
- return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize);
-}
-EXPORT_SYMBOL(__kfifo_dma_in_prepare_r);
-
-void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
- unsigned int len, size_t recsize)
-{
- len = __kfifo_max_r(len, recsize);
- __kfifo_poke_n(fifo, len, recsize);
- fifo->in += len + recsize;
-}
-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);