static int _aligned_io(struct device_area *where, void *buffer,
int should_write)
{
void *bounce;
unsigned int block_size = 0;
uintptr_t mask;
struct device_area widened;
if (!(where->dev->flags & DEV_REGULAR) &&
!_get_block_size(where->dev, &block_size))
return_0;
if (!block_size)
block_size = lvm_getpagesize();
_widen_region(block_size, where, &widened);
/* Do we need to use a bounce buffer? */
mask = block_size - 1;
if (!memcmp(where, &widened, sizeof(widened)) &&
!((uintptr_t) buffer & mask))
return _io(where, buffer, should_write);
/* Allocate a bounce buffer with an extra block */
if (!(bounce = alloca((size_t) widened.size + block_size))) {
log_error("Bounce buffer alloca failed");
return 0;
}
/*
* Realign start of bounce buffer (using the extra sector)
*/
if (((uintptr_t) bounce) & mask)
bounce = (void *) ((((uintptr_t) bounce) + mask) & ~mask);
/* channel the io through the bounce buffer */
if (!_io(&widened, bounce, 0)) {
if (!should_write)
return_0;
/* FIXME pre-extend the file */
memset(bounce, '\n', widened.size);
}
if (should_write) {
memcpy(bounce + (where->start - widened.start), buffer,
(size_t) where->size);
/* ... then we write */
return _io(&widened, bounce, 1);
}
memcpy(buffer, bounce + (where->start - widened.start),
(size_t) where->size);
return 1;
}
void vpins_io(char port) {Serial.print("OK!");_io(port);}
