#ifndef __ASM_ARM_DIV64 #define __ASM_ARM_DIV64 #include <asm/system.h> /* * The semantics of do_div() are: * * uint32_t do_div(uint64_t *n, uint32_t base) * { * uint32_t remainder = *n % base; * *n = *n / base; * return remainder; * } * * In other words, a 64-bit dividend with a 32-bit divisor producing * a 64-bit result and a 32-bit remainder. To accomplish this optimally * we call a special __do_div64 helper with completely non standard * calling convention for arguments and results (beware). */ #ifdef __ARMEB__ #define __xh "r0" #define __xl "r1" #else #define __xl "r0" #define __xh "r1" #endif #define do_div(n,base) \ ({ \ register unsigned int __base asm("r4") = base; \ register unsigned long long __n asm("r0") = n; \ register unsigned long long __res asm("r2"); \ register unsigned int __rem asm(__xh); \ asm( __asmeq("%0", __xh) \ __asmeq("%1", "r2") \ __asmeq("%2", "r0") \ __asmeq("%3", "r4") \ "bl __do_div64" \ : "=r" (__rem), "=r" (__res) \ : "r" (__n), "r" (__base) \ : "ip", "lr", "cc"); \ n = __res; \ __rem; \ }) #endif