static void *xnpipe_default_alloc_ibuf(size_t size, void *xstate)
{
void *buf;
buf = xnmalloc(size);
if (likely(buf != NULL))
return buf;
if (size > xnheap_max_contiguous(&kheap))
/* Request will never succeed. */
return (struct xnpipe_mh *)-1;
return NULL;
}
/**
* Truncate a file or shared memory object to a specified length.
*
* When used in kernel-space, this service set to @a len the size of a shared
* memory object opened with the shm_open() service. In user-space this service
* falls back to Linux regular ftruncate service for file descriptors not
* obtained with shm_open(). When this service is used to increase the size of a
* shared memory object, the added space is zero-filled.
*
* Shared memory are suitable for direct memory access (allocated in physically
* contiguous memory) if O_DIRECT was passed to shm_open.
*
* Shared memory objects may only be resized if they are not currently mapped.
*
* @param fd file descriptor;
*
* @param len new length of the underlying file or shared memory object.
*
* @retval 0 on success;
* @retval -1 with @a errno set if:
* - EBADF, @a fd is not a valid file descriptor;
* - EPERM, the caller context is invalid;
* - EINVAL, the specified length is invalid;
* - EINVAL, the architecture can not honour the O_DIRECT flag;
* - EINTR, this service was interrupted by a signal;
* - EBUSY, @a fd is a shared memory object descriptor and the underlying shared
* memory is currently mapped;
* - EFBIG, allocation of system memory failed.
*
* @par Valid contexts:
* - kernel module initialization or cleanup routine;
* - user-space thread (Xenomai threads switch to secondary mode).
*
* @see
* <a href="http://www.opengroup.org/onlinepubs/000095399/functions/ftruncate.html">
* Specification.</a>
*
*/
int ftruncate(int fd, off_t len)
{
unsigned desc_flags;
pse51_desc_t *desc;
pse51_shm_t *shm;
int err;
spl_t s;
xnlock_get_irqsave(&nklock, s);
shm = pse51_shm_get(&desc, fd, 1);
if (IS_ERR(shm)) {
err = -PTR_ERR(shm);
xnlock_put_irqrestore(&nklock, s);
goto error;
}
if (xnpod_asynch_p() || !xnpod_root_p()) {
err = EPERM;
xnlock_put_irqrestore(&nklock, s);
goto err_shm_put;
}
if (len < 0) {
err = EINVAL;
xnlock_put_irqrestore(&nklock, s);
goto err_shm_put;
}
desc_flags = pse51_desc_getflags(desc);
xnlock_put_irqrestore(&nklock, s);
if (down_interruptible(&shm->maplock)) {
err = EINTR;
goto err_shm_put;
}
/* Allocate one more page for alignment (the address returned by mmap
must be aligned on a page boundary). */
if (len)
#ifdef CONFIG_XENO_OPT_PERVASIVE
len = xnheap_rounded_size(len + PAGE_SIZE, PAGE_SIZE);
#else /* !CONFIG_XENO_OPT_PERVASIVE */
len = xnheap_rounded_size(len + PAGE_SIZE, XNHEAP_PAGE_SIZE);
#endif /* !CONFIG_XENO_OPT_PERVASIVE */
err = 0;
if (emptyq_p(&shm->mappings)) {
/* Temporary storage, in order to preserve the memory contents upon
resizing, if possible. */
void *addr = NULL;
size_t size = 0;
if (shm->addr) {
if (len == xnheap_extentsize(&shm->heapbase)) {
/* Size unchanged, skip copy and reinit. */
err = 0;
goto err_up;
}
size = xnheap_max_contiguous(&shm->heapbase);
addr = xnarch_alloc_host_mem(size);
if (!addr) {
err = ENOMEM;
goto err_up;
}
memcpy(addr, shm->addr, size);
xnheap_free(&shm->heapbase, shm->addr);
xnheap_destroy_mapped(&shm->heapbase, NULL, NULL);
shm->addr = NULL;
shm->size = 0;
}
if (len) {
int flags = XNARCH_SHARED_HEAP_FLAGS |
((desc_flags & O_DIRECT) ? GFP_DMA : 0);
err = -xnheap_init_mapped(&shm->heapbase, len, flags);
if (err)
goto err_up;
xnheap_set_label(&shm->heapbase,
"posix shm: %s", shm->nodebase.name);
shm->size = xnheap_max_contiguous(&shm->heapbase);
shm->addr = xnheap_alloc(&shm->heapbase, shm->size);
/* Required. */
memset(shm->addr, '\0', shm->size);
/* Copy the previous contents. */
if (addr)
memcpy(shm->addr, addr,
shm->size < size ? shm->size : size);
shm->size -= PAGE_SIZE;
}
if (addr)
xnarch_free_host_mem(addr, size);
} else if (len != xnheap_extentsize(&shm->heapbase))
err = EBUSY;
err_up:
up(&shm->maplock);
err_shm_put:
pse51_shm_put(shm, 1);
if (!err)
return 0;
error:
thread_set_errno(err == ENOMEM ? EFBIG : err);
return -1;
}
int rt_heap_alloc(RT_HEAP *heap, size_t size, RTIME timeout, void **blockp)
{
void *block = NULL;
xnthread_t *thread;
xnflags_t info;
int err = 0;
spl_t s;
xnlock_get_irqsave(&nklock, s);
heap = xeno_h2obj_validate(heap, XENO_HEAP_MAGIC, RT_HEAP);
if (!heap) {
err = xeno_handle_error(heap, XENO_HEAP_MAGIC, RT_HEAP);
goto unlock_and_exit;
}
/* In single-block mode, there is only a single allocation
returning the whole addressable heap space to the user. All
users referring to this heap are then returned the same
block. */
if (heap->mode & H_SINGLE) {
block = heap->sba;
if (!block) {
/* It's ok to pass zero for size here, since the requested
size is implicitely the whole heap space; but if
non-zero is given, it must match the original heap
size. */
if (size > 0 && size != heap->csize) {
err = -EINVAL;
goto unlock_and_exit;
}
block = heap->sba = xnheap_alloc(&heap->heap_base,
xnheap_max_contiguous
(&heap->heap_base));
}
if (block)
goto unlock_and_exit;
err = -ENOMEM; /* This should never happen. Paranoid. */
goto unlock_and_exit;
}
block = xnheap_alloc(&heap->heap_base, size);
if (block)
goto unlock_and_exit;
if (timeout == TM_NONBLOCK) {
err = -EWOULDBLOCK;
goto unlock_and_exit;
}
if (xnpod_unblockable_p()) {
err = -EPERM;
goto unlock_and_exit;
}
thread = xnpod_current_thread();
thread->wait_u.buffer.size = size;
thread->wait_u.buffer.ptr = NULL;
info = xnsynch_sleep_on(&heap->synch_base, timeout, XN_RELATIVE);
if (info & XNRMID)
err = -EIDRM; /* Heap deleted while pending. */
else if (info & XNTIMEO)
err = -ETIMEDOUT; /* Timeout. */
else if (info & XNBREAK)
err = -EINTR; /* Unblocked. */
else
block = thread->wait_u.buffer.ptr;
unlock_and_exit:
*blockp = block;
xnlock_put_irqrestore(&nklock, s);
return err;
}
