/* * A generic kernel FIFO implementation. * * Copyright (C) 2009 Stefani Seibold/Munich/Germany <stef...@seibold.net> * Copyright (C) 2004 Stelian Pop <stel...@popies.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/module.h> #include <linux/slab.h> #include <linux/err.h> #include <linux/uaccess.h> #include <linux/kfifo.h> #include <linux/log2.h> static void _kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size) { fifo->buffer = buffer; fifo->size = size; fifo->in = fifo->out = 0; } void kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size) { /* size must be a power of 2 */ BUG_ON(!is_power_of_2(size)); _kfifo_init(fifo, buffer, size); } EXPORT_SYMBOL(kfifo_init); int kfifo_alloc(struct kfifo *fifo, unsigned long size, gfp_t gfp_mask) { unsigned char *buffer; if (size & (size - 1)) { BUG_ON(size > 0x80000000); size = roundup_pow_of_two(size); } buffer = kmalloc(size, gfp_mask); if (!buffer) return -ENOMEM; _kfifo_init(fifo, buffer, size); return 0; } EXPORT_SYMBOL(kfifo_alloc); void kfifo_free(struct kfifo *fifo) { kfree(fifo->buffer); } EXPORT_SYMBOL(kfifo_free); static inline unsigned long __kfifo_put_data(struct kfifo *fifo, const unsigned char *from, unsigned long n, unsigned long off) { unsigned long l; /* * Ensure that we sample the fifo->out index -before- we * start putting bytes into the kfifo. */ smp_mb(); off += fifo->in; /* first put the data starting from fifo->in to buffer end */ l = min(n, fifo->size - __kfifo_off(fifo, off)); memcpy(fifo->buffer + __kfifo_off(fifo, off), from, l); /* then put the rest (if any) at the beginning of the buffer */ memcpy(fifo->buffer, from + l, n - l); return 0; } /** * kfifo_put_notrim - puts data into the FIFO without cut off a record * @fifo: the fifo to be used. * @from: the data to be added. * @n: the size of the destination buffer. * @recsize: size of record field * @total: pointer where the total number of copied bytes should stored * * This function copies @n bytes from the @from into the FIFO * * In case of an error, the function returns the number of bytes which cannot * be copied. */ unsigned long __kfifo_put_notrim(struct kfifo *fifo, const unsigned char *from, unsigned long n, unsigned long recsize, unsigned long *total) { if (kfifo_avail(fifo) < n + recsize) { *total = n + 1; return *total; } *total = n; return __kfifo_put_data(fifo, from, n, recsize); } EXPORT_SYMBOL(__kfifo_put_notrim); unsigned long __kfifo_put_trim(struct kfifo *fifo, const unsigned char *from, unsigned long n, unsigned long recsize, unsigned long *total) { unsigned long l; l = min(kfifo_avail(fifo), n + recsize); if (l < recsize) { *total = n + 1; return *total; } *total = l - recsize; return __kfifo_put_data(fifo, from, l - recsize, recsize); } EXPORT_SYMBOL(__kfifo_put_trim); unsigned long __kfifo_put_generic(struct kfifo *fifo, const unsigned char *from, unsigned long n, unsigned long recsize, unsigned long flags, unsigned long *total) { if (!recsize) return __kfifo_put(fifo, from, n, flags, total); return __kfifo_put_n(fifo, from, n, recsize, flags, total); } EXPORT_SYMBOL(__kfifo_put_generic); unsigned long kfifo_put(struct kfifo *fifo, unsigned char *from, unsigned long n) { n = min(kfifo_avail(fifo), n); __kfifo_put_data(fifo, from, n, 0); __kfifo_add_in(fifo, n); return n; } EXPORT_SYMBOL(kfifo_put); static inline unsigned long __kfifo_get_data(struct kfifo *fifo, unsigned char *to, unsigned long n, unsigned long off) { unsigned long l; /* * Ensure that we sample the fifo->in index -before- we * start removing bytes from the kfifo. */ smp_rmb(); off += fifo->out; /* first get the data from fifo->out until the end of the buffer */ l = min(n, fifo->size - __kfifo_off(fifo, off)); memcpy(to, fifo->buffer + __kfifo_off(fifo, off), l); /* then get the rest (if any) from the beginning of the buffer */ memcpy(to + l, fifo->buffer, n - l); return 0; } unsigned long __kfifo_get_notrim(struct kfifo *fifo, unsigned char *to, unsigned long n, unsigned long reclen, unsigned long recsize, unsigned long *total) { if (kfifo_used(fifo) < recsize) { *total = 0; return 0; } *total = n; if (n < reclen) return reclen; return __kfifo_get_data(fifo, to, n, recsize); } EXPORT_SYMBOL(__kfifo_get_notrim); unsigned long __kfifo_get_trim(struct kfifo *fifo, unsigned char *to, unsigned long n, unsigned long reclen, unsigned long recsize, unsigned long *total) { if (kfifo_used(fifo) < recsize) { *total = 0; return 0; } n = min(n, reclen); *total = n; return __kfifo_get_data(fifo, to, n, recsize); } EXPORT_SYMBOL(__kfifo_get_trim); unsigned long __kfifo_get_generic(struct kfifo *fifo, unsigned char *to, unsigned long n, unsigned long recsize, unsigned long flags, unsigned long *total) { if (!recsize) return __kfifo_get(fifo, to, n, flags, total); return __kfifo_get_n(fifo, to, n, recsize, flags, total); } EXPORT_SYMBOL(__kfifo_get_generic); unsigned long kfifo_get(struct kfifo *fifo, unsigned char *to, unsigned long n) { n = min(kfifo_used(fifo), n); __kfifo_get_data(fifo, to, n, 0); __kfifo_add_out(fifo, n); return n; } EXPORT_SYMBOL(kfifo_get); static inline unsigned long __kfifo_from_user_data(struct kfifo *fifo, const void __user *from, unsigned long n, unsigned long off) { unsigned long l; int ret; /* * Ensure that we sample the fifo->out index -before- we * start putting bytes into the kfifo. */ smp_mb(); off += fifo->in; /* first put the data starting from fifo->in to buffer end */ l = min(n, fifo->size - __kfifo_off(fifo, off)); ret = copy_from_user(fifo->buffer + __kfifo_off(fifo, off), from, l); if (unlikely(n)) return ret + n - l; /* then put the rest (if any) at the beginning of the buffer */ ret = copy_from_user(fifo->buffer, from + l, n - l); if (unlikely(ret)) return ret; return 0; } unsigned long __kfifo_from_user_notrim(struct kfifo *fifo, const void __user *from, unsigned long n, unsigned long recsize, unsigned long *total) { if (kfifo_avail(fifo) < n + recsize) { *total = n + 1; return *total; } *total = n; return __kfifo_from_user_data(fifo, from, n, recsize); } EXPORT_SYMBOL(__kfifo_from_user_notrim); unsigned long __kfifo_from_user_trim(struct kfifo *fifo, const void __user *from, unsigned long n, unsigned long recsize, unsigned long *total) { unsigned long l; l = min(kfifo_avail(fifo), n + recsize); if (l < recsize) { *total = n + 1; return *total; } *total = l - recsize; return __kfifo_from_user_data(fifo, from, l - recsize, recsize); } EXPORT_SYMBOL(__kfifo_from_user_trim); unsigned long __kfifo_from_user_generic(struct kfifo *fifo, const void __user *from, unsigned long n, unsigned long recsize, unsigned long flags, unsigned long *total) { if (!recsize) return __kfifo_from_user(fifo, from, n, flags, total); return __kfifo_from_user_n(fifo, from, n, recsize, flags, total); } EXPORT_SYMBOL(__kfifo_from_user_generic); static inline unsigned long __kfifo_to_user_data(struct kfifo *fifo, void __user *to, unsigned long n, unsigned long off) { unsigned long l; int ret; /* * Ensure that we sample the fifo->in index -before- we * start removing bytes from the kfifo. */ smp_rmb(); off += fifo->out; /* first get the data from fifo->out until the end of the buffer */ l = min(n, fifo->size - __kfifo_off(fifo, off)); ret = copy_to_user(to, fifo->buffer + __kfifo_off(fifo, off), l); if (unlikely(ret)) return ret + n - l; /* then get the rest (if any) from the beginning of the buffer */ ret = copy_to_user(to + l, fifo->buffer, n - l); if (unlikely(ret)) return ret; return 0; } unsigned long __kfifo_to_user_notrim(struct kfifo *fifo, void __user *to, unsigned long n, unsigned long reclen, unsigned long recsize, unsigned long *total) { if (kfifo_used(fifo) < recsize) { *total = 0; return 0; } *total = n; if (n < reclen) return reclen; return __kfifo_to_user_data(fifo, to, n, recsize); } EXPORT_SYMBOL(__kfifo_to_user_notrim); unsigned long __kfifo_to_user_trim(struct kfifo *fifo, void __user *to, unsigned long n, unsigned long reclen, unsigned long recsize, unsigned long *total) { if (kfifo_used(fifo) < recsize) { *total = 0; return 0; } n = min(n, reclen); *total = n; return __kfifo_to_user_data(fifo, to, n, recsize); } EXPORT_SYMBOL(__kfifo_to_user_trim); unsigned long __kfifo_to_user_generic(struct kfifo *fifo, void __user *to, unsigned long n, unsigned long recsize, unsigned long flags, unsigned long *total) { if (!recsize) return __kfifo_to_user(fifo, to, n, flags, total); return __kfifo_to_user_n(fifo, to, n, recsize, flags, total); } EXPORT_SYMBOL(__kfifo_to_user_generic); unsigned long __kfifo_peek_generic(struct kfifo *fifo, unsigned long recsize) { if (recsize == 0) return kfifo_avail(fifo); return __kfifo_peek_n(fifo, recsize); } EXPORT_SYMBOL(__kfifo_peek_generic); --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. 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