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 bacef661acdb ("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 f026cfa82f62. 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: Jan Beulich <jbeulich@suse.com>
Tested-by: Matt Fleming <matt.fleming@intel.com>
Acked-by: Matthew 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]

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index a718e0d..931930a 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -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);

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index aded2a9..7578344 100644 (file)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -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();

diff --git a/include/linux/efi.h b/include/linux/efi.h
index 337aefb..5e2308d 100644 (file)
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -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;
 

diff --git a/init/main.c b/init/main.c
index 9cf77ab..ae70b64 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -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);