From 9e5e66d15e2a7280fdba2ecbd9f583c8485e21bf Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Sat, 9 Jun 2012 10:52:39 +0200
Subject: [PATCH] 	Use ITC on IA64 rather than broken routine based on
 daytime.

	* grub-core/kern/efi/efi.c (grub_rtc_get_time_ms) [__ia64__]: Remove on
	ia64.
	(grub_get_rtc) [__ia64__]: Likewise.
	* grub-core/kern/ia64/efi/init.c (divisor): New variable.
	(get_itc): New function.
	(grub_rtc_get_time_ms): Likewise.
	(grub_machine_init): Calibrate ITC.
	* include/grub/efi/time.h (grub_get_rtc), (GRUB_TICKS_PER_SECOND):
	Keep only on non-ia64. Don't export since it's broken and used only
	if TSC is unavailable.
---
 ChangeLog                      | 15 +++++++++++++++
 grub-core/kern/efi/efi.c       |  2 ++
 grub-core/kern/ia64/efi/init.c | 33 +++++++++++++++++++++++++++++++++
 include/grub/efi/time.h        |  4 +++-
 4 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 8fd093457..4c4d5336c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2012-06-09  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	Use ITC on IA64 rather than broken routine based on daytime.
+
+	* grub-core/kern/efi/efi.c (grub_rtc_get_time_ms) [__ia64__]: Remove on
+	ia64.
+	(grub_get_rtc) [__ia64__]: Likewise.
+	* grub-core/kern/ia64/efi/init.c (divisor): New variable.
+	(get_itc): New function.
+	(grub_rtc_get_time_ms): Likewise.
+	(grub_machine_init): Calibrate ITC.
+	* include/grub/efi/time.h (grub_get_rtc), (GRUB_TICKS_PER_SECOND):
+	Keep only on non-ia64. Don't export since it's broken and used only
+	if TSC is unavailable.
+
 2012-06-09  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	* grub-core/disk/efi/efidisk.c (find_parent_device): Return the parent
diff --git a/grub-core/kern/efi/efi.c b/grub-core/kern/efi/efi.c
index 6f12c7618..a59a6edbc 100644
--- a/grub-core/kern/efi/efi.c
+++ b/grub-core/kern/efi/efi.c
@@ -230,6 +230,7 @@ grub_efi_get_variable (const char *var, const grub_efi_guid_t *guid,
   return NULL;
 }
 
+#ifndef __ia64__
 grub_uint64_t
 grub_rtc_get_time_ms (void)
 {
@@ -250,6 +251,7 @@ grub_get_rtc (void)
 {
   return grub_rtc_get_time_ms ();
 }
+#endif
 
 #pragma GCC diagnostic ignored "-Wcast-align"
 
diff --git a/grub-core/kern/ia64/efi/init.c b/grub-core/kern/ia64/efi/init.c
index e2fa58090..7fa6fbf71 100644
--- a/grub-core/kern/ia64/efi/init.c
+++ b/grub-core/kern/ia64/efi/init.c
@@ -27,10 +27,43 @@
 #include <grub/kernel.h>
 #include <grub/efi/efi.h>
 
+static grub_uint64_t divisor = 1;
+
+static grub_uint64_t
+get_itc (void)
+{
+  grub_uint64_t ret;
+  asm volatile ("mov %0=ar.itc" : "=r" (ret));
+  return ret;
+}
+
+grub_uint64_t
+grub_rtc_get_time_ms (void)
+{
+  return get_itc () / divisor;
+}
+
 void
 grub_machine_init (void)
 {
+  grub_efi_event_t event;
+  grub_uint64_t before, after;
+  grub_efi_uintn_t idx;
   grub_efi_init ();
+
+  efi_call_5 (grub_efi_system_table->boot_services->create_event,
+	      GRUB_EFI_EVT_TIMER, GRUB_EFI_TPL_CALLBACK, 0, 0, &event);
+
+  before = get_itc ();
+  efi_call_3 (grub_efi_system_table->boot_services->set_timer, event,
+	      GRUB_EFI_TIMER_RELATIVE, 200000);
+  efi_call_3 (grub_efi_system_table->boot_services->wait_for_event, 1,
+	      &event, &idx);
+  after = get_itc ();
+  efi_call_1 (grub_efi_system_table->boot_services->close_event, event);
+  divisor = (after - before + 5) / 20;
+  if (divisor == 0)
+    divisor = 800000;
   grub_install_get_time_ms (grub_rtc_get_time_ms);
 }
 
diff --git a/include/grub/efi/time.h b/include/grub/efi/time.h
index 51b337309..1c38ac0e7 100644
--- a/include/grub/efi/time.h
+++ b/include/grub/efi/time.h
@@ -21,9 +21,11 @@
 
 #include <grub/symbol.h>
 
+#ifndef __ia64__
 #define GRUB_TICKS_PER_SECOND	1000
 
 /* Return the real time in ticks.  */
-grub_uint32_t EXPORT_FUNC (grub_get_rtc) (void);
+grub_uint32_t grub_get_rtc (void);
+#endif
 
 #endif /* ! GRUB_EFI_TIME_HEADER */