NUM_DMA_SEGS
((((NUM_DMA_SEGS * BCM_SDHCI_BUFFER_SIZE) - 1) / PAGE_SIZE) + 1)
#define ALLOCATED_DMA_SEGS (NUM_DMA_SEGS + NUM_DMA_SPILL_SEGS)
#define BCM_DMA_MAXSIZE (NUM_DMA_SEGS * BCM_SDHCI_BUFFER_SIZE)