[U-Boot] [PATCH 1/1] efi_loader: replace efi_div10 by div64_u64

[Heinrich Schuchardt]

We should use the existing 64bit division instead of
reinventing the wheel.

Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
The patch is based on v2017.11-rc1 with no other patches applied.

Applying it will require rebasing
[PATCH 1/1] efi_loader: provide function comments for boot services
https://patchwork.ozlabs.org/patch/817010/

But we have an open issue with the second patch anyway.
---
 lib/efi_loader/efi_boottime.c | 36 ++----------------------------------
 1 file changed, 2 insertions(+), 34 deletions(-)

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 9e741c3cf3..d63c66dd45 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -16,6 +16,7 @@
 #include <bootm.h>
 #include <inttypes.h>
 #include <watchdog.h>
+#include <linux/math64.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -128,39 +129,6 @@ const char *__efi_nesting_dec(void)
 	return indent_string(--nesting_level);
 }
 
-/* Low 32 bit */
-#define EFI_LOW32(a) (a & 0xFFFFFFFFULL)
-/* High 32 bit */
-#define EFI_HIGH32(a) (a >> 32)
-
-/*
- * 64bit division by 10 implemented as multiplication by 1 / 10
- *
- * Decimals of one tenth: 0x1 / 0xA = 0x0.19999...
- */
-#define EFI_TENTH 0x199999999999999A
-static u64 efi_div10(u64 a)
-{
-	u64 prod;
-	u64 rem;
-	u64 ret;
-
-	ret  = EFI_HIGH32(a) * EFI_HIGH32(EFI_TENTH);
-	prod = EFI_HIGH32(a) * EFI_LOW32(EFI_TENTH);
-	rem  = EFI_LOW32(prod);
-	ret += EFI_HIGH32(prod);
-	prod = EFI_LOW32(a) * EFI_HIGH32(EFI_TENTH);
-	rem += EFI_LOW32(prod);
-	ret += EFI_HIGH32(prod);
-	prod = EFI_LOW32(a) * EFI_LOW32(EFI_TENTH);
-	rem += EFI_HIGH32(prod);
-	ret += EFI_HIGH32(rem);
-	/* Round to nearest integer */
-	if (rem >= (1 << 31))
-		++ret;
-	return ret;
-}
-
 void efi_signal_event(struct efi_event *event)
 {
 	if (event->notify_function) {
@@ -364,7 +332,7 @@ efi_status_t efi_set_timer(struct efi_event *event, enum efi_timer_delay type,
 	 * The parameter defines a multiple of 100ns.
 	 * We use multiples of 1000ns. So divide by 10.
 	 */
-	trigger_time = efi_div10(trigger_time);
+	trigger_time = div64_u64(trigger_time, 10);
 
 	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
 		if (event != &efi_events[i])
-- 
2.14.1