/* * 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;Lines 1–500 of 609. 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/* * 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;