static int __init testfunc(void)
{
	unsigned char	buf[6];
	unsigned char	i, j;
	unsigned int	ret;

	printk(KERN_INFO "[fifo]byte stream fifo test start\n");

	/* put string into the fifo */
	kfifo_in(&test, "hello", 5);

	/* put values into the fifo */
	for (i = 0; i != 10; i++)
		kfifo_put(&test, &i);

	/* show the number of used elements */
	printk(KERN_INFO "[fifo]fifo len: %u\n", kfifo_len(&test));

	/* get max of 5 bytes from the fifo */
	i = kfifo_out(&test, buf, 5);
	printk(KERN_INFO "[fifo]buf: %.*s\n", i, buf);

	/* get max of 2 elements from the fifo */
	ret = kfifo_out(&test, buf, 2);
	printk(KERN_INFO "[fifo]ret: %d\n", ret);
	/* and put it back to the end of the fifo */
	ret = kfifo_in(&test, buf, ret);
	printk(KERN_INFO "[fifo]ret: %d\n", ret);

	/* skip first element of the fifo */
	printk(KERN_INFO "[fifo]skip 1st element\n");
	kfifo_skip(&test);

	/* put values into the fifo until is full */
	for (i = 20; kfifo_put(&test, &i); i++)
		;

	printk(KERN_INFO "[fifo]queue len: %u\n", kfifo_len(&test));

	/* show the first value without removing from the fifo */
	if (kfifo_peek(&test, &i))
		printk(KERN_INFO "[fifo]%d\n", i);

	/* check the correctness of all values in the fifo */
	j = 0;
	while (kfifo_get(&test, &i)) {
		printk(KERN_INFO "item = %d\n", i);
		if (i != expected_result[j++]) {
			printk(KERN_WARNING "value mismatch: test failed\n");
			return -EIO;
		}
	}
	if (j != ARRAY_SIZE(expected_result)) {
		printk(KERN_WARNING "size mismatch: test failed\n");
		return -EIO;
	}
	printk(KERN_INFO "[fifo]test passed\n");

	return 0;
}
static int __init testfunc(void)
{
	int		buf[6];
	int		i, j;
	unsigned int	ret;

	printk(KERN_INFO "int fifo test start\n");

	
	for (i = 0; i != 10; i++)
		kfifo_put(&test, &i);

	
	printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test));

	
	ret = kfifo_out(&test, buf, 2);
	printk(KERN_INFO "ret: %d\n", ret);
	
	ret = kfifo_in(&test, buf, ret);
	printk(KERN_INFO "ret: %d\n", ret);

	
	printk(KERN_INFO "skip 1st element\n");
	kfifo_skip(&test);

	
	for (i = 20; kfifo_put(&test, &i); i++)
		;

	printk(KERN_INFO "queue len: %u\n", kfifo_len(&test));

	
	if (kfifo_peek(&test, &i))
		printk(KERN_INFO "%d\n", i);

	
	j = 0;
	while (kfifo_get(&test, &i)) {
		printk(KERN_INFO "item = %d\n", i);
		if (i != expected_result[j++]) {
			printk(KERN_WARNING "value mismatch: test failed\n");
			return -EIO;
		}
	}
	if (j != ARRAY_SIZE(expected_result)) {
		printk(KERN_WARNING "size mismatch: test failed\n");
		return -EIO;
	}
	printk(KERN_INFO "test passed\n");

	return 0;
}
Beispiel #3
0
static int __init example_init(void)
{
	int			i;
	unsigned int		ret;
	unsigned int		nents;
	struct scatterlist	sg[10];

	printk(KERN_INFO "DMA fifo test start\n");

	if (kfifo_alloc(&fifo, FIFO_SIZE, GFP_KERNEL)) {
		printk(KERN_WARNING "error kfifo_alloc\n");
		return -ENOMEM;
	}

	printk(KERN_INFO "queue size: %u\n", kfifo_size(&fifo));

	kfifo_in(&fifo, "test", 4);

	for (i = 0; i != 9; i++)
		kfifo_put(&fifo, i);

	/* kick away first byte */
	kfifo_skip(&fifo);

	printk(KERN_INFO "queue len: %u\n", kfifo_len(&fifo));

	/*
	 * Configure the kfifo buffer to receive data from DMA input.
	 *
	 *  .--------------------------------------.
	 *  | 0 | 1 | 2 | ... | 12 | 13 | ... | 31 |
	 *  |---|------------------|---------------|
	 *   \_/ \________________/ \_____________/
	 *    \          \                  \
	 *     \          \_allocated data   \
	 *      \_*free space*                \_*free space*
	 *
	 * We need two different SG entries: one for the free space area at the
	 * end of the kfifo buffer (19 bytes) and another for the first free
	 * byte at the beginning, after the kfifo_skip().
	 */
	sg_init_table(sg, ARRAY_SIZE(sg));
	nents = kfifo_dma_in_prepare(&fifo, sg, ARRAY_SIZE(sg), FIFO_SIZE);
	printk(KERN_INFO "DMA sgl entries: %d\n", nents);
	if (!nents) {
		/* fifo is full and no sgl was created */
		printk(KERN_WARNING "error kfifo_dma_in_prepare\n");
		return -EIO;
	}

	/* receive data */
	printk(KERN_INFO "scatterlist for receive:\n");
	for (i = 0; i < nents; i++) {
		printk(KERN_INFO
		"sg[%d] -> "
		"page_link 0x%.8lx offset 0x%.8x length 0x%.8x\n",
			i, sg[i].page_link, sg[i].offset, sg[i].length);

		if (sg_is_last(&sg[i]))
			break;
	}

	/* put here your code to setup and exectute the dma operation */
	/* ... */

	/* example: zero bytes received */
	ret = 0;

	/* finish the dma operation and update the received data */
	kfifo_dma_in_finish(&fifo, ret);

	/* Prepare to transmit data, example: 8 bytes */
	nents = kfifo_dma_out_prepare(&fifo, sg, ARRAY_SIZE(sg), 8);
	printk(KERN_INFO "DMA sgl entries: %d\n", nents);
	if (!nents) {
		/* no data was available and no sgl was created */
		printk(KERN_WARNING "error kfifo_dma_out_prepare\n");
		return -EIO;
	}

	printk(KERN_INFO "scatterlist for transmit:\n");
	for (i = 0; i < nents; i++) {
		printk(KERN_INFO
		"sg[%d] -> "
		"page_link 0x%.8lx offset 0x%.8x length 0x%.8x\n",
			i, sg[i].page_link, sg[i].offset, sg[i].length);

		if (sg_is_last(&sg[i]))
			break;
	}

	/* put here your code to setup and exectute the dma operation */
	/* ... */

	/* example: 5 bytes transmitted */
	ret = 5;

	/* finish the dma operation and update the transmitted data */
	kfifo_dma_out_finish(&fifo, ret);

	ret = kfifo_len(&fifo);
	printk(KERN_INFO "queue len: %u\n", kfifo_len(&fifo));

	if (ret != 7) {
		printk(KERN_WARNING "size mismatch: test failed");
		return -EIO;
	}
	printk(KERN_INFO "test passed\n");

	return 0;
}