diff options
Diffstat (limited to 'kernel/kfifo.c')
-rw-r--r-- | kernel/kfifo.c | 609 |
1 files changed, 0 insertions, 609 deletions
diff --git a/kernel/kfifo.c b/kernel/kfifo.c deleted file mode 100644 index 59dcf5b81d24..000000000000 --- 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); |