From 185034e72d591f9465e5e18f937ed642e7ea0070 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 7 Sep 2012 18:28:04 +0100 Subject: x86, efi: 1:1 pagetable mapping for virtual EFI calls MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some firmware still needs a 1:1 (virt->phys) mapping even after we've called SetVirtualAddressMap(). So install the mapping alongside our existing kernel mapping whenever we make EFI calls in virtual mode. This bug was discovered on ASUS machines where the firmware implementation of GetTime() accesses the RTC device via physical addresses, even though that's bogus per the UEFI spec since we've informed the firmware via SetVirtualAddressMap() that the boottime memory map is no longer valid. This bug seems to be present in a lot of consumer devices, so there's not a lot we can do about this spec violation apart from workaround it. Cc: JérômeCarretero Cc: Vasco Dias Acked-by: Jan Beulich Signed-off-by: Matt Fleming --- arch/x86/platform/efi/efi_64.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'arch/x86/platform') diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index ac3aa54e2654..ddb0174cf093 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -58,6 +58,21 @@ static void __init early_code_mapping_set_exec(int executable) } } +unsigned long efi_call_virt_prelog(void) +{ + unsigned long saved; + + saved = read_cr3(); + write_cr3(real_mode_header->trampoline_pgd); + + return saved; +} + +void efi_call_virt_epilog(unsigned long saved) +{ + write_cr3(saved); +} + void __init efi_call_phys_prelog(void) { unsigned long vaddress; -- cgit v1.2.3 From bd52276fa1d420c3a504b76ffaaa1642cc79d4c4 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 25 May 2012 16:20:31 +0100 Subject: 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 Tested-by: Matt Fleming Acked-by: Matthew Garrett Cc: Ingo Molnar Cc: Peter Zijlstra Cc: H. Peter Anvin Signed-off-by: Matt Fleming [added commit history] --- 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(-) (limited to 'arch/x86/platform') diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index a718e0d23503..931930a96160 100644 --- 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 aded2a91162a..757834434e59 100644 --- 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 337aefbfb003..5e2308d9c6be 100644 --- 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 9cf77ab138a6..ae70b647b4d9 100644 --- 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); -- cgit v1.2.3 From 5d6d578c170bb280db5d4779f666e456f4f82ec5 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Wed, 7 Nov 2012 16:46:08 +0000 Subject: x86, efi: Check table header length in efi_bgrt_init() Header length should be validated for all ACPI tables before accessing any non-header field. Signed-off-by: Jan Beulich Link: http://lkml.kernel.org/r/509A9E6002000078000A7079@nat28.tlf.novell.com Acked-by: Matt Fleming Signed-off-by: H. Peter Anvin --- arch/x86/platform/efi/efi-bgrt.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/platform') diff --git a/arch/x86/platform/efi/efi-bgrt.c b/arch/x86/platform/efi/efi-bgrt.c index f6a0c1b8e518..d9c1b95af17c 100644 --- a/arch/x86/platform/efi/efi-bgrt.c +++ b/arch/x86/platform/efi/efi-bgrt.c @@ -39,6 +39,8 @@ void efi_bgrt_init(void) if (ACPI_FAILURE(status)) return; + if (bgrt_tab->header.length < sizeof(*bgrt_tab)) + return; if (bgrt_tab->version != 1) return; if (bgrt_tab->image_type != 0 || !bgrt_tab->image_address) -- cgit v1.2.3