/* * arch/arm/include/asm/cache.h */ #ifndef __ASMARM_CACHE_H #define __ASMARM_CACHE_H #define L1_CACHE_SHIFT CONFIG_ARM_L1_CACHE_SHIFT #define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT) /* * Set the prefetch distance in units of L1_CACHE_BYTES based on the * cache line size. The prefetch distance is used by the memcpy, * copy_from_user, copy_to_user versions that are optimized * for ARM v6 and v7 platforms, as well as the copy_page function * on ARM v5, v6 and v7 platforms. */ #if L1_CACHE_BYTES == 64 /* * This value was calibrated on a Cortex A8-based SOC with a 32-bit * DDR3 interface. Other Cortex cores and architectures may benefit * from a different setting. */ #define PREFETCH_DISTANCE 3 #else /* * This value was calibrated on the ARM v6-based SOC used in the Raspbery * Pi. Other architectures may benefit from a different setting. */ #define PREFETCH_DISTANCE 3 #endif /* * Memory returned by kmalloc() may be used for DMA, so we must make * sure that all such allocations are cache aligned. Otherwise, * unrelated code may cause parts of the buffer to be read into the * cache before the transfer is done, causing old data to be seen by * the CPU. */ #define ARCH_DMA_MINALIGN L1_CACHE_BYTES /* * With EABI on ARMv5 and above we must have 64-bit aligned slab pointers. */ #if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5) #define ARCH_SLAB_MINALIGN 8 #endif #define __read_mostly __attribute__((__section__(".data..read_mostly"))) #endif