x86: explicitly use edx in const delay function.

[firefly-linux-kernel-4.4.55.git] / arch / x86 / lib / delay_64.c

diff --git a/arch/x86/lib/delay_64.c b/arch/x86/lib/delay_64.c
index d0326d07c845bb9cfe806ae5b74a4ed14058e427..ff3dfecdb6f9c49589155771c02b8359a08ae3ec 100644 (file)
--- a/arch/x86/lib/delay_64.c
+++ b/arch/x86/lib/delay_64.c
@@ -103,9 +103,16 @@ EXPORT_SYMBOL(__delay);
 
 inline void __const_udelay(unsigned long xloops)
 {
-       __delay(((xloops * HZ *
-               cpu_data(raw_smp_processor_id()).loops_per_jiffy) >> 32) + 1);
+       int d0;
+       xloops *= 4;
+       __asm__("mull %%edx"
+               :"=d" (xloops), "=&a" (d0)
+               :"1" (xloops), "0"
+               (cpu_data(raw_smp_processor_id()).loops_per_jiffy * (HZ/4)));
+
+       __delay(++xloops);
 }
+
 EXPORT_SYMBOL(__const_udelay);
 
 void __udelay(unsigned long usecs)