static ssize_t subdev_read_block(struct bdev *_dev, void *buf, bnum_t block, uint count)
{
subdev_t *subdev = (subdev_t *)_dev;
return bio_read_block(subdev->parent, buf, block + subdev->offset, count);
}
static status_t memory_mapped_test(bdev_t *device)
{
status_t retcode = NO_ERROR;
uint8_t *test_buffer = memalign(DMA_ALIGNMENT, device->block_size);
if (!test_buffer) {
printf("Could not allocate %zu bytes for a temporary buffer. "
"Aborting.\n", device->block_size);
return ERR_NO_MEMORY;
}
uint8_t *reference_buffer = memalign(DMA_ALIGNMENT, device->block_size);
if (!reference_buffer) {
printf("Could not allocate %zu bytes for a temporary reference "
"buffer. Aborting.\n", device->block_size);
free(test_buffer);
return ERR_NO_MEMORY;
}
// Erase the first page of the Device.
ssize_t err = bio_erase(device, 0, device->block_size);
if (err < (ssize_t)device->block_size) {
printf("Expected to erase at least %zu bytes but only erased %ld. "
"Not continuing to test memory mapped mode.\n",
device->block_size, err);
retcode = ERR_IO;
goto finish;
}
// Write a pattern to the first page of the device.
uint8_t pattern_seed = (uint8_t)(rand() % 256);
for (size_t i = 0; i < device->block_size; i++) {
test_buffer[i] = (uint8_t)((pattern_seed + i) % 256);
}
err = bio_write_block(device, test_buffer, 0, 1);
if (err != (ssize_t)device->block_size) {
printf("Error while writing test pattern to device. Expected to write "
"%zu bytes but actually wrote %ld. Not continuing to test memory "
"mapped mode.\n", device->block_size, err);
retcode = ERR_IO;
goto finish;
}
// Put the device into linear mode if possible.
uint8_t *devaddr;
int ioctl_result = bio_ioctl(device, BIO_IOCTL_GET_MEM_MAP, (void *)&devaddr);
if (ioctl_result == ERR_NOT_SUPPORTED) {
printf("Device does not support linear mode. Aborting.\n");
retcode = ERR_NOT_SUPPORTED;
goto finish;
} else if (ioctl_result != NO_ERROR) {
printf("BIO_IOCTL_GET_MEM_MAP returned error %d. Aborting.\n",
ioctl_result);
retcode = ioctl_result;
goto finish;
}
uint8_t *testptr = test_buffer;
for (uint i = 0; i < device->block_size; i++) {
if (*testptr != *devaddr) {
printf("Data mismatch at position %d. Expected %d got %d. "
"Aborting.\n", i, *testptr, *devaddr);
goto finish;
}
testptr++;
devaddr++;
}
// Put the device back into command mode.
ioctl_result = bio_ioctl(device, BIO_IOCTL_PUT_MEM_MAP, NULL);
if (ioctl_result != NO_ERROR) {
printf("BIO_IOCTL_GET_MEM_MAP returned error %d. Aborting.\n",
ioctl_result);
retcode = ioctl_result;
goto finish;
}
// Read the first page into memory using command mode and compare it with
// what we wrote back earlier.
err = bio_read_block(device, reference_buffer, 0, 1);
if (err != (ssize_t)device->block_size) {
printf("Expected to read %zu bytes, actually read %ld. Aborting.\n",
device->block_size, err);
retcode = ERR_IO;
goto finish;
}
uint8_t *expected = test_buffer;
uint8_t *actual = reference_buffer;
for (uint i = 0; i < device->block_size; i++) {
if (*actual != *expected) {
printf("Data mismatch at position %d. Expected %d got %d. "
"Aborting.\n", i, *expected, *actual);
goto finish;
}
expected++;
actual++;
}
finish:
free(test_buffer);
free(reference_buffer);
return retcode;
}
