Commit a25effa4 authored by Andrea Righi's avatar Andrea Righi Committed by Linus Torvalds

kfifo: add explicit error checking in all the examples

Provide a check in all the kfifo examples to validate the correct
execution of each testcase.
Signed-off-by: default avatarAndrea Righi <arighi@develer.com>
Acked-by: default avatarStefani Seibold <stefani@seibold.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d83a71c4
......@@ -44,7 +44,7 @@ static struct kfifo test;
static DECLARE_KFIFO(test, unsigned char, FIFO_SIZE);
#endif
static unsigned char expected_result[FIFO_SIZE] = {
static const unsigned char expected_result[FIFO_SIZE] = {
3, 4, 5, 6, 7, 8, 9, 0,
1, 20, 21, 22, 23, 24, 25, 26,
27, 28, 29, 30, 31, 32, 33, 34,
......@@ -90,9 +90,14 @@ static int __init testfunc(void)
printk(KERN_INFO "queue len: %u\n", kfifo_len(&test));
/* show the first value without removing from the fifo */
if (kfifo_peek(&test, &i))
printk(KERN_INFO "%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;
......
......@@ -29,8 +29,8 @@ static int __init example_init(void)
printk(KERN_INFO "DMA fifo test start\n");
if (kfifo_alloc(&fifo, FIFO_SIZE, GFP_KERNEL)) {
printk(KERN_ERR "error kfifo_alloc\n");
return 1;
printk(KERN_WARNING "error kfifo_alloc\n");
return -ENOMEM;
}
printk(KERN_INFO "queue size: %u\n", kfifo_size(&fifo));
......@@ -41,65 +41,93 @@ static int __init example_init(void)
kfifo_put(&fifo, &i);
/* kick away first byte */
ret = kfifo_get(&fifo, &i);
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));
ret = kfifo_dma_in_prepare(&fifo, sg, ARRAY_SIZE(sg), FIFO_SIZE);
printk(KERN_INFO "DMA sgl entries: %d\n", ret);
if (!ret) {
/* fifo is full and no sgl was created */
printk(KERN_WARNING "error kfifo_dma_in_prepare\n");
return -EIO;
}
/* if 0 was returned, fifo is full and no sgl was created */
if (ret) {
printk(KERN_INFO "scatterlist for receive:\n");
for (i = 0; i < ARRAY_SIZE(sg); 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);
/* receive data */
printk(KERN_INFO "scatterlist for receive:\n");
for (i = 0; i < ARRAY_SIZE(sg); 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;
}
if (sg_is_last(&sg[i]))
break;
}
/* but here your code to setup and exectute the dma operation */
/* ... */
/* put here your code to setup and exectute the dma operation */
/* ... */
/* example: zero bytes received */
ret = 0;
/* example: zero bytes received */
ret = 0;
/* finish the dma operation and update the received data */
kfifo_dma_in_finish(&fifo, ret);
}
/* finish the dma operation and update the received data */
kfifo_dma_in_finish(&fifo, ret);
/* Prepare to transmit data, example: 8 bytes */
ret = kfifo_dma_out_prepare(&fifo, sg, ARRAY_SIZE(sg), 8);
printk(KERN_INFO "DMA sgl entries: %d\n", ret);
if (!ret) {
/* no data was available and no sgl was created */
printk(KERN_WARNING "error kfifo_dma_out_prepare\n");
return -EIO;
}
/* if 0 was returned, no data was available and no sgl was created */
if (ret) {
printk(KERN_INFO "scatterlist for transmit:\n");
for (i = 0; i < ARRAY_SIZE(sg); 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);
printk(KERN_INFO "scatterlist for transmit:\n");
for (i = 0; i < ARRAY_SIZE(sg); 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;
}
if (sg_is_last(&sg[i]))
break;
}
/* but here your code to setup and exectute the dma operation */
/* ... */
/* put here your code to setup and exectute the dma operation */
/* ... */
/* example: 5 bytes transmitted */
ret = 5;
/* example: 5 bytes transmitted */
ret = 5;
/* finish the dma operation and update the transmitted data */
kfifo_dma_out_finish(&fifo, ret);
}
/* 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;
}
......
......@@ -44,10 +44,17 @@ static DECLARE_KFIFO_PTR(test, int);
static DEFINE_KFIFO(test, int, FIFO_SIZE);
#endif
static const int expected_result[FIFO_SIZE] = {
3, 4, 5, 6, 7, 8, 9, 0,
1, 20, 21, 22, 23, 24, 25, 26,
27, 28, 29, 30, 31, 32, 33, 34,
35, 36, 37, 38, 39, 40, 41, 42,
};
static int __init testfunc(void)
{
int buf[6];
int i;
int i, j;
unsigned int ret;
printk(KERN_INFO "int fifo test start\n");
......@@ -66,8 +73,13 @@ static int __init testfunc(void)
ret = kfifo_in(&test, buf, ret);
printk(KERN_INFO "ret: %d\n", ret);
for (i = 20; i != 30; i++)
kfifo_put(&test, &i);
/* skip first element of the fifo */
printk(KERN_INFO "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 "queue len: %u\n", kfifo_len(&test));
......@@ -75,10 +87,20 @@ static int __init testfunc(void)
if (kfifo_peek(&test, &i))
printk(KERN_INFO "%d\n", i);
/* print out all values in the fifo */
while (kfifo_get(&test, &i))
printk("%d ", i);
printk("\n");
/* 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 "test passed\n");
return 0;
}
......@@ -132,7 +154,12 @@ static int __init example_init(void)
return ret;
}
#endif
testfunc();
if (testfunc() < 0) {
#ifdef DYNAMIC
kfifo_free(&test);
#endif
return -EIO;
}
if (proc_create(PROC_FIFO, 0, NULL, &fifo_fops) == NULL) {
#ifdef DYNAMIC
......
......@@ -55,6 +55,19 @@ typedef STRUCT_KFIFO_REC_1(FIFO_SIZE) mytest;
static mytest test;
#endif
static const char *expected_result[] = {
"a",
"bb",
"ccc",
"dddd",
"eeeee",
"ffffff",
"ggggggg",
"hhhhhhhh",
"iiiiiiiii",
"jjjjjjjjjj",
};
static int __init testfunc(void)
{
char buf[100];
......@@ -75,6 +88,10 @@ static int __init testfunc(void)
kfifo_in(&test, buf, i + 1);
}
/* skip first element of the fifo */
printk(KERN_INFO "skip 1st element\n");
kfifo_skip(&test);
printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test));
/* show the first record without removing from the fifo */
......@@ -82,11 +99,22 @@ static int __init testfunc(void)
if (ret)
printk(KERN_INFO "%.*s\n", ret, buf);
/* print out all records in the fifo */
/* check the correctness of all values in the fifo */
i = 0;
while (!kfifo_is_empty(&test)) {
ret = kfifo_out(&test, buf, sizeof(buf));
printk(KERN_INFO "%.*s\n", ret, buf);
buf[ret] = '\0';
printk(KERN_INFO "item = %.*s\n", ret, buf);
if (strcmp(buf, expected_result[i++])) {
printk(KERN_WARNING "value mismatch: test failed\n");
return -EIO;
}
}
if (i != ARRAY_SIZE(expected_result)) {
printk(KERN_WARNING "size mismatch: test failed\n");
return -EIO;
}
printk(KERN_INFO "test passed\n");
return 0;
}
......@@ -142,7 +170,12 @@ static int __init example_init(void)
#else
INIT_KFIFO(test);
#endif
testfunc();
if (testfunc() < 0) {
#ifdef DYNAMIC
kfifo_free(&test);
#endif
return -EIO;
}
if (proc_create(PROC_FIFO, 0, NULL, &fifo_fops) == NULL) {
#ifdef DYNAMIC
......
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