200 lines
4.6 KiB
C
200 lines
4.6 KiB
C
#ifndef _FIFO_H_
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#define _FIFO_H_
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#include "include.h"
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#include "generic.h"
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#include "mem_pub.h"
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#include "mem_pub.h"
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typedef struct kfifo
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{
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unsigned int in;
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unsigned int out;
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unsigned int mask;
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unsigned int size;
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unsigned char *buffer;
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}KFIFO_T, *KFIFO_PTR;
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/**
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* kfifo_init - allocates a new FIFO using a preallocated buffer
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* @buffer: the preallocated buffer to be used.
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* @size: the size of the internal buffer, this have to be a power of 2.
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* @gfp_mask: get_free_pages mask, passed to ke_malloc()
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* @lock: the lock to be used to protect the fifo buffer
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*
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* Do NOT pass the kfifo to kfifo_free() after use ! Simply free the
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* struct kfifo with ke_free().
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*/
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__INLINE struct kfifo *kfifo_init(unsigned char *buffer, unsigned int size)
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{
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struct kfifo *fifo;
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/* size must be a power of 2 */
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BUG_ON(size & (size - 1));
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fifo = os_malloc(sizeof(struct kfifo));
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if (!fifo)
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return NULLPTR;
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fifo->buffer = buffer;
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fifo->size = size;
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fifo->in = 0;
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fifo->out = 0;
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fifo->mask = fifo->size - 1;
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return fifo;
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}
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/**
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* kfifo_alloc - allocates a new FIFO and its internal buffer
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* @size: the size of the internal buffer to be allocated.
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* @gfp_mask: get_free_pages mask, passed to ke_malloc()
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* @lock: the lock to be used to protect the fifo buffer
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*
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* The size will be rounded-up to a power of 2.
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*/
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__INLINE struct kfifo *kfifo_alloc(unsigned int size)
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{
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unsigned char *buffer;
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struct kfifo *ret;
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buffer = os_malloc(size);
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if (!buffer)
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return 0;
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ret = kfifo_init(buffer, size);
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if (!(ret))
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os_free(buffer);
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return ret;
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}
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/**
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* kfifo_free - frees the FIFO
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* @fifo: the fifo to be freed.
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*/
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__INLINE void kfifo_free(struct kfifo *fifo)
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{
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os_free(fifo->buffer);
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fifo->buffer = 0;
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os_free(fifo);
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}
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/**
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* __kfifo_put - puts some data into the FIFO, no locking version
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* @fifo: the fifo to be used.
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* @buffer: the data to be added.
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* @len: the length of the data to be added.
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*
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* This function copies at most 'len' bytes from the 'buffer' into
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* the FIFO depending on the free space, and returns the number of
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* bytes copied.
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*
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* Note that with only one concurrent reader and one concurrent
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* writer, you don't need extra locking to use these functions.
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*/
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__INLINE unsigned int kfifo_put(struct kfifo *fifo,
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unsigned char *buffer, unsigned int len)
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{
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unsigned int l;
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GLOBAL_INT_DECLARATION();
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GLOBAL_INT_DISABLE();
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len = _min(len, fifo->size - fifo->in + fifo->out);
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/* first put the data starting from fifo->in to buffer end */
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l = _min(len, fifo->size - (fifo->in & (fifo->size - 1)));
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os_memcpy(fifo->buffer + (fifo->in & (fifo->size - 1)), buffer, l);
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/* then put the rest (if any) at the beginning of the buffer */
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os_memcpy(fifo->buffer, buffer + l, len - l);
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fifo->in += len;
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GLOBAL_INT_RESTORE();
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return len;
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}
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/**
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* __kfifo_get - gets some data from the FIFO, no locking version
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* @fifo: the fifo to be used.
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* @buffer: where the data must be copied.
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* @len: the size of the destination buffer.
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*
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* This function copies at most 'len' bytes from the FIFO into the
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* 'buffer' and returns the number of copied bytes.
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*
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* Note that with only one concurrent reader and one concurrent
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* writer, you don't need extra locking to use these functions.
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*/
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__INLINE unsigned int kfifo_get(struct kfifo *fifo,
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unsigned char *buffer, unsigned int len)
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{
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unsigned int l;
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GLOBAL_INT_DECLARATION();
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GLOBAL_INT_DISABLE();
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len = _min(len, fifo->in - fifo->out);
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/* first get the data from fifo->out until the end of the buffer */
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l = _min(len, fifo->size - (fifo->out & (fifo->size - 1)));
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os_memcpy(buffer, fifo->buffer + (fifo->out & (fifo->size - 1)), l);
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/* then get the rest (if any) from the beginning of the buffer */
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os_memcpy(buffer + l, fifo->buffer, len - l);
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fifo->out += len;
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GLOBAL_INT_RESTORE();
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return len;
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}
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__INLINE unsigned int kfifo_data_size(struct kfifo *fifo)
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{
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return (fifo->in - fifo->out);
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}
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__INLINE unsigned int kfifo_unused(struct kfifo *fifo)
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{
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return (fifo->mask + 1) - (fifo->in - fifo->out);
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}
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__INLINE void kfifo_copy_out(struct kfifo *fifo, void *dst,
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unsigned int len, unsigned int off)
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{
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unsigned int size = fifo->mask + 1;
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unsigned int l;
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off &= fifo->mask;
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l = _min(len, size - off);
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os_memcpy(dst, (void *)(fifo->buffer + off), l);
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os_memcpy((void *)((unsigned int)dst + l), (void *)fifo->buffer, len - l);
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/*
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* make sure that the data is copied before
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* incrementing the fifo->out index counter
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*/
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}
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__INLINE unsigned int kfifo_out_peek(struct kfifo *fifo,
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unsigned char *buffer, unsigned int len)
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{
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unsigned int l;
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l = fifo->in - fifo->out;
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if (len > l)
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len = l;
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kfifo_copy_out(fifo, buffer, len, fifo->out);
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return len;
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}
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#endif // _FIFO_H_
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// eof
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