Commit bd52276f authored by Jan Beulich's avatar Jan Beulich Committed by Matt Fleming
Browse files

x86-64/efi: Use EFI to deal with platform wall clock (again) 



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.

History:

    This commit was originally merged as bacef661 ("x86-64/efi:
    Use EFI to deal with platform wall clock") but it resulted in some
    ASUS machines no longer booting due to a firmware bug, and so was
    reverted in f026cfa8. A pre-emptive fix for the buggy ASUS
    firmware was merged in 03a1c254975e ("x86, efi: 1:1 pagetable
    mapping for virtual EFI calls") so now this patch can be
    reapplied.

Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
Tested-by: default avatarMatt Fleming <matt.fleming@intel.com>
Acked-by: default avatarMatthew Garrett <mjg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com> [added commit history]
parent da5a108d

arch/x86/mm/pageattr.c

+6 −4
Original line number Diff line number Diff line
@@ -919,11 +919,13 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, 


	/*

	 * 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);

arch/x86/platform/efi/efi.c

+4 −26
Original line number Diff line number Diff line
@@ -235,22 +235,7 @@ static efi_status_t __init phys_efi_set_virtual_address_map( 
	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;
@@ -279,7 +264,7 @@ int efi_set_rtc_mmss(unsigned long nowtime) 
	return 0;

}



unsigned long efi_get_time(void)

static unsigned long efi_get_time(void)

{

	efi_status_t status;

	efi_time_t eft;
@@ -635,18 +620,13 @@ 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;
@@ -734,12 +714,10 @@ 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();

include/linux/efi.h

+0 −2
Original line number Diff line number Diff line
@@ -516,8 +516,6 @@ extern u64 efi_mem_attribute (unsigned long phys_addr, unsigned long size); 
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;

init/main.c

+4 −4
Original line number Diff line number Diff line
@@ -461,6 +461,10 @@ 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)
@@ -601,10 +605,6 @@ 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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