cpu_to_be32()/be32_to_cpu()/cpu_to_le32()/le32_to_cpu() include/asm/byteorder.h

The cpu_to_be32() family (where the "32" can be replaced by 64 or 16, and the "be" can be replaced by "le") are the general way to do endian conversions in the kernel: they return the converted value. All variations supply the reverse as well: be32_to_cpu(), etc.

There are two major variations of these functions: the pointer variation, such as cpu_to_be32p(), which take a pointer to the given type, and return the converted value. The other variation is the "in-situ" family, such as cpu_to_be32s(), which convert value referred to by the pointer, and return void.