From 7216a1bff3a513549525787b67bd365e8f788569 Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Sun, 8 May 2011 17:05:47 +0200
Subject: [PATCH] Set EFI ticks to 1000Hz simplifying much of the code and
 avoiding cotsly division

---
 grub-core/Makefile.core.def |  1 -
 grub-core/kern/efi/efi.c    | 16 +++++++++++-----
 include/grub/efi/time.h     |  3 +--
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 7bb51adfe..bc7ce5fbe 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -83,7 +83,6 @@ kernel = {
   noemu_nodist = symlist.c;
 
   i386_pc = kern/generic/rtc_get_time_ms.c;
-  efi = kern/generic/rtc_get_time_ms.c;
   i386_qemu = kern/generic/rtc_get_time_ms.c;
   i386_coreboot = kern/generic/rtc_get_time_ms.c;
   i386_multiboot = kern/generic/rtc_get_time_ms.c;
diff --git a/grub-core/kern/efi/efi.c b/grub-core/kern/efi/efi.c
index fa1d0c730..c95058733 100644
--- a/grub-core/kern/efi/efi.c
+++ b/grub-core/kern/efi/efi.c
@@ -24,6 +24,7 @@
 #include <grub/efi/console_control.h>
 #include <grub/efi/pe32.h>
 #include <grub/machine/time.h>
+#include <grub/time.h>
 #include <grub/term.h>
 #include <grub/kernel.h>
 #include <grub/mm.h>
@@ -193,8 +194,8 @@ grub_efi_set_virtual_address_map (grub_efi_uintn_t memory_map_size,
   return grub_error (GRUB_ERR_IO, "set_virtual_address_map failed");
 }
 
-grub_uint32_t
-grub_get_rtc (void)
+grub_uint64_t
+grub_rtc_get_time_ms (void)
 {
   grub_efi_time_t time;
   grub_efi_runtime_services_t *r;
@@ -204,9 +205,14 @@ grub_get_rtc (void)
     /* What is possible in this case?  */
     return 0;
 
-  return (((time.minute * 60 + time.second) * 1000
-	   + time.nanosecond / 1000000)
-	  * GRUB_TICKS_PER_SECOND / 1000);
+  return ((time.minute * 60 + time.second) * 1000
+	   + time.nanosecond / 1000000);
+}
+
+grub_uint32_t
+grub_get_rtc (void)
+{
+  return grub_rtc_get_time_ms ();
 }
 
 /* Search the mods section from the PE32/PE32+ image. This code uses
diff --git a/include/grub/efi/time.h b/include/grub/efi/time.h
index 540f6fc04..51b337309 100644
--- a/include/grub/efi/time.h
+++ b/include/grub/efi/time.h
@@ -21,8 +21,7 @@
 
 #include <grub/symbol.h>
 
-/* This is destined to overflow when one hour passes by.  */
-#define GRUB_TICKS_PER_SECOND	((1UL << 31) / 60 / 60 * 2)
+#define GRUB_TICKS_PER_SECOND	1000
 
 /* Return the real time in ticks.  */
 grub_uint32_t EXPORT_FUNC (grub_get_rtc) (void);