6 Mar
2012
6 Mar
'12
10:48 p.m.
+struct dma_iommu_mapping * +arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size,
int order)+{
unsigned int count = (size >> PAGE_SHIFT) - order;unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
The count calculation doesn't seem correct. "order" is log2 number and size >> PAGE_SHIFT is number of pages.
If size is passed as 64*4096(256KB) and order is 6(allocation granularity is 2^6 pages=256KB), just 1 bit is enough to manage allocations. So it should be 4 bytes or one long.
But the calculation gives count = 64 - 6 = 58 and Bitmap_size gets set to (58/(4*8)) * 4 = 8 bytes, which is incorrect.
It should be as follows. unsigned int count = 1 << get_order(size) - order; unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long) * BITS_PER_BYTE;
-KR
--nvpublic