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Date: Fri, 25 May 2012 16:20:31 +0100
From: "Jan Beulich" <JBeulich@...e.com>
To: <mingo@...e.hu>, <tglx@...utronix.de>, <hpa@...or.com>
Cc: <matt.fleming@...ux.intel.com>, <mjg@...hat.com>,
<linux-kernel@...r.kernel.org>
Subject: [PATCH] x86-64: use EFI to deal with platform wall clock
Other than ix86, x86-64 on EFI so far didn't set the {g,s}et_wallclock
accessors to the EFI routines, thus incorrectly using raw RTC accesses
instead.
Simply removing the #ifdef around the respective code isn't enough,
however: While so far early get-time calls were done in physical mode,
this doesn't work properly for x86-64, as virtual addresses would still
need to be set up for all runtime regions (which wasn't the case on the
system I have access to), so instead the patch moves the call to
efi_enter_virtual_mode() ahead (which in turn allows to drop all code
related to calling efi-get-time in physical mode).
Additionally the earlier calling of efi_set_executable() requires the
CPA code to cope, i.e. during early boot it must be avoided to call
cpa_flush_array(), as the first thing this function does is a
BUG_ON(irqs_disabled()).
Also make the two EFI functions in question here static - they're not
being referenced elsewhere.
Signed-off-by: Jan Beulich <jbeulich@...e.com>
Cc: Matt Fleming <matt.fleming@...el.com>
Cc: Matthew Garrett <mjg@...hat.com>
---
(Note that due to the lack of hardware I wasn't able to test this on
32-bit EFI - Matt offered to do so subsequently.)
---
arch/x86/mm/pageattr.c | 10 ++++++----
arch/x86/platform/efi/efi.c | 30 ++++--------------------------
include/linux/efi.h | 2 --
init/main.c | 8 ++++----
4 files changed, 14 insertions(+), 36 deletions(-)
--- 3.4/arch/x86/mm/pageattr.c
+++ 3.4-x86_64-EFI-time/arch/x86/mm/pageattr.c
@@ -919,11 +919,13 @@ static int change_page_attr_set_clr(unsi
/*
* On success we use clflush, when the CPU supports it to
- * avoid the wbindv. If the CPU does not support it and in the
- * error case we fall back to cpa_flush_all (which uses
- * wbindv):
+ * avoid the wbindv. If the CPU does not support it, in the
+ * error case, and during early boot (for EFI) we fall back
+ * to cpa_flush_all (which uses wbinvd):
*/
- if (!ret && cpu_has_clflush) {
+ if (early_boot_irqs_disabled)
+ __cpa_flush_all((void *)(long)cache);
+ else if (!ret && cpu_has_clflush) {
if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
cpa_flush_array(addr, numpages, cache,
cpa.flags, pages);
--- 3.4/arch/x86/platform/efi/efi.c
+++ 3.4-x86_64-EFI-time/arch/x86/platform/efi/efi.c
@@ -234,22 +234,7 @@ static efi_status_t __init phys_efi_set_
return status;
}
-static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
- efi_time_cap_t *tc)
-{
- unsigned long flags;
- efi_status_t status;
-
- spin_lock_irqsave(&rtc_lock, flags);
- efi_call_phys_prelog();
- status = efi_call_phys2(efi_phys.get_time, virt_to_phys(tm),
- virt_to_phys(tc));
- efi_call_phys_epilog();
- spin_unlock_irqrestore(&rtc_lock, flags);
- return status;
-}
-
-int efi_set_rtc_mmss(unsigned long nowtime)
+static int efi_set_rtc_mmss(unsigned long nowtime)
{
int real_seconds, real_minutes;
efi_status_t status;
@@ -278,7 +263,7 @@ int efi_set_rtc_mmss(unsigned long nowti
return 0;
}
-unsigned long efi_get_time(void)
+static unsigned long efi_get_time(void)
{
efi_status_t status;
efi_time_t eft;
@@ -621,18 +606,13 @@ static int __init efi_runtime_init(void)
}
/*
* We will only need *early* access to the following
- * two EFI runtime services before set_virtual_address_map
+ * EFI runtime service before set_virtual_address_map
* is invoked.
*/
- efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
efi_phys.set_virtual_address_map =
(efi_set_virtual_address_map_t *)
runtime->set_virtual_address_map;
- /*
- * Make efi_get_time can be called before entering
- * virtual mode.
- */
- efi.get_time = phys_efi_get_time;
+
early_iounmap(runtime, sizeof(efi_runtime_services_t));
return 0;
@@ -720,12 +700,10 @@ void __init efi_init(void)
efi_enabled = 0;
return;
}
-#ifdef CONFIG_X86_32
if (efi_native) {
x86_platform.get_wallclock = efi_get_time;
x86_platform.set_wallclock = efi_set_rtc_mmss;
}
-#endif
#if EFI_DEBUG
print_efi_memmap();
--- 3.4/include/linux/efi.h
+++ 3.4-x86_64-EFI-time/include/linux/efi.h
@@ -503,8 +503,6 @@ extern u64 efi_mem_attribute (unsigned l
extern int __init efi_uart_console_only (void);
extern void efi_initialize_iomem_resources(struct resource *code_resource,
struct resource *data_resource, struct resource *bss_resource);
-extern unsigned long efi_get_time(void);
-extern int efi_set_rtc_mmss(unsigned long nowtime);
extern void efi_reserve_boot_services(void);
extern struct efi_memory_map memmap;
--- 3.4/init/main.c
+++ 3.4-x86_64-EFI-time/init/main.c
@@ -460,6 +460,10 @@ static void __init mm_init(void)
percpu_init_late();
pgtable_cache_init();
vmalloc_init();
+#ifdef CONFIG_X86
+ if (efi_enabled)
+ efi_enter_virtual_mode();
+#endif
}
asmlinkage void __init start_kernel(void)
@@ -604,10 +608,6 @@ asmlinkage void __init start_kernel(void
calibrate_delay();
pidmap_init();
anon_vma_init();
-#ifdef CONFIG_X86
- if (efi_enabled)
- efi_enter_virtual_mode();
-#endif
thread_info_cache_init();
cred_init();
fork_init(totalram_pages);
--
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