On Wed, Dec 15, 2010 at 09:34:27PM +0100, Michal Nazarewicz wrote:+unsigned long cma_reserve(unsigned long start, unsigned long size,
+ unsigned long alignment)
+{
+ pr_debug("%s(%p+%p/%p)\n", __func__, (void *)start, (void *)size,
+ (void *)alignment);
+
+ /* Sanity checks */
+ if (!size || (alignment & (alignment - 1)))
+ return (unsigned long)-EINVAL;
+
+ /* Sanitise input arguments */
+ start = PAGE_ALIGN(start);
+ size = PAGE_ALIGN(size);
+ if (alignment < PAGE_SIZE)
+ alignment = PAGE_SIZE;
+
+ /* Reserve memory */
+ if (start) {
+ if (memblock_is_region_reserved(start, size) ||
+ memblock_reserve(start, size) < 0)
+ return (unsigned long)-EBUSY;
+ } else {
+ /*
+ * Use __memblock_alloc_base() since
+ * memblock_alloc_base() panic()s.
+ */
+ u64 addr = __memblock_alloc_base(size, alignment, 0);
+ if (!addr) {
+ return (unsigned long)-ENOMEM;
+ } else if (addr + size > ~(unsigned long)0) {
+ memblock_free(addr, size);
+ return (unsigned long)-EOVERFLOW;
+ } else {
+ start = addr;
+ }
+ }
+
Reserving the areas of memory belonging to CMA using memblock_reserve,
would preclude that range from the zones, due to which it would not be
available for buddy allocations right ?
+ return start;
+}