On 20/11/2016 15:57, Andre Przywara wrote:
The sunxi DRAM setup code needs an sdelay() implementation, which
wasn't defined for armv8 so far.
Shamelessly copy the armv7 version and adjust it to work in AArch64.
Signed-off-by: Andre Przywara <[email protected]>
I don't think it hurts to write this in C - and I also doubt that
inlining has any negative effect.
Something along the lines of
static inline void sdelay(...) {
for (; loops; loops--)
asm volatile("");
}
inside a header should do the trick as well and is much more readable.
Alex
---
arch/arm/cpu/armv8/cpu.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/arm/cpu/armv8/cpu.c b/arch/arm/cpu/armv8/cpu.c
index e06c3cc..e82e9cf 100644
--- a/arch/arm/cpu/armv8/cpu.c
+++ b/arch/arm/cpu/armv8/cpu.c
@@ -16,6 +16,19 @@
#include <asm/system.h>
#include <linux/compiler.h>
+/************************************************************
+ * sdelay() - simple spin loop. Will be constant time as
+ * its generally used in bypass conditions only. This
+ * is necessary until timers are accessible.
+ *
+ * not inline to increase chances its in cache when called
+ *************************************************************/
+void sdelay(unsigned long loops)
+{
+ __asm__ volatile ("1:\n" "subs %0, %1, #1\n"
+ "b.ne 1b":"=r" (loops):"0"(loops));
+}
+
int cleanup_before_linux(void)
{
/*
_______________________________________________
U-Boot mailing list
[email protected]
http://lists.denx.de/mailman/listinfo/u-boot
