From 72b56e869fa2c058969e47da101a9e7d319f6062 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Wed, 14 Nov 2012 09:42:35 +0000 Subject: [PATCH] efi: Make 'efi_enabled' a function to query EFI facilities commit 83e68189745ad931c2afd45d8ee3303929233e7f upstream. Originally 'efi_enabled' indicated whether a kernel was booted from EFI firmware. Over time its semantics have changed, and it now indicates whether or not we are booted on an EFI machine with bit-native firmware, e.g. 64-bit kernel with 64-bit firmware. The immediate motivation for this patch is the bug report at, https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557 which details how running a platform driver on an EFI machine that is designed to run under BIOS can cause the machine to become bricked. Also, the following report, https://bugzilla.kernel.org/show_bug.cgi?id=47121 details how running said driver can also cause Machine Check Exceptions. Drivers need a new means of detecting whether they're running on an EFI machine, as sadly the expression, if (!efi_enabled) hasn't been a sufficient condition for quite some time. Users actually want to query 'efi_enabled' for different reasons - what they really want access to is the list of available EFI facilities. For instance, the x86 reboot code needs to know whether it can invoke the ResetSystem() function provided by the EFI runtime services, while the ACPI OSL code wants to know whether the EFI config tables were mapped successfully. There are also checks in some of the platform driver code to simply see if they're running on an EFI machine (which would make it a bad idea to do BIOS-y things). This patch is a prereq for the samsung-laptop fix patch. Signed-off-by: Matt Fleming Cc: David Airlie Cc: Corentin Chary Cc: Matthew Garrett Cc: Dave Jiang Cc: Olof Johansson Cc: Peter Jones Cc: Colin Ian King Cc: Steve Langasek Cc: Tony Luck Cc: Konrad Rzeszutek Wilk Cc: Rafael J. Wysocki Signed-off-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/efi.h | 1 + arch/x86/kernel/reboot.c | 2 +- arch/x86/kernel/setup.c | 28 ++++++------- arch/x86/platform/efi/efi.c | 57 +++++++++++++++----------- drivers/acpi/osl.c | 2 +- drivers/firmware/dmi_scan.c | 2 +- drivers/firmware/efivars.c | 4 +- drivers/firmware/iscsi_ibft_find.c | 2 +- drivers/gpu/drm/radeon/radeon_device.c | 3 +- drivers/platform/x86/ibm_rtl.c | 2 +- drivers/scsi/isci/init.c | 2 +- include/linux/efi.h | 24 ++++++++--- init/main.c | 4 +- 13 files changed, 79 insertions(+), 54 deletions(-) diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 6e8fdf5ad113..28677c55113f 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -94,6 +94,7 @@ extern void __iomem *efi_ioremap(unsigned long addr, unsigned long size, #endif /* CONFIG_X86_32 */ extern int add_efi_memmap; +extern unsigned long x86_efi_facility; extern void efi_set_executable(efi_memory_desc_t *md, bool executable); extern int efi_memblock_x86_reserve_range(void); extern void efi_call_phys_prelog(void); diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 4e8ba39eaf0f..76fa1e9a2b39 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -584,7 +584,7 @@ static void native_machine_emergency_restart(void) break; case BOOT_EFI: - if (efi_enabled) + if (efi_enabled(EFI_RUNTIME_SERVICES)) efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD, diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 86c524c504b0..0219cf2d6c76 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -809,15 +809,15 @@ void __init setup_arch(char **cmdline_p) #ifdef CONFIG_EFI if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature, "EL32", 4)) { - efi_enabled = 1; - efi_64bit = false; + set_bit(EFI_BOOT, &x86_efi_facility); } else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature, "EL64", 4)) { - efi_enabled = 1; - efi_64bit = true; + set_bit(EFI_BOOT, &x86_efi_facility); + set_bit(EFI_64BIT, &x86_efi_facility); } - if (efi_enabled && efi_memblock_x86_reserve_range()) - efi_enabled = 0; + + if (efi_enabled(EFI_BOOT)) + efi_memblock_x86_reserve_range(); #endif x86_init.oem.arch_setup(); @@ -890,7 +890,7 @@ void __init setup_arch(char **cmdline_p) finish_e820_parsing(); - if (efi_enabled) + if (efi_enabled(EFI_BOOT)) efi_init(); dmi_scan_machine(); @@ -973,7 +973,7 @@ void __init setup_arch(char **cmdline_p) * The EFI specification says that boot service code won't be called * after ExitBootServices(). This is, in fact, a lie. */ - if (efi_enabled) + if (efi_enabled(EFI_MEMMAP)) efi_reserve_boot_services(); /* preallocate 4k for mptable mpc */ @@ -1112,7 +1112,7 @@ void __init setup_arch(char **cmdline_p) #ifdef CONFIG_VT #if defined(CONFIG_VGA_CONSOLE) - if (!efi_enabled || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY)) + if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY)) conswitchp = &vga_con; #elif defined(CONFIG_DUMMY_CONSOLE) conswitchp = &dummy_con; @@ -1129,14 +1129,14 @@ void __init setup_arch(char **cmdline_p) register_refined_jiffies(CLOCK_TICK_RATE); #ifdef CONFIG_EFI - /* Once setup is done above, disable efi_enabled on mismatched - * firmware/kernel archtectures since there is no support for - * runtime services. + /* Once setup is done above, unmap the EFI memory map on + * mismatched firmware/kernel archtectures since there is no + * support for runtime services. */ - if (efi_enabled && IS_ENABLED(CONFIG_X86_64) != efi_64bit) { + if (efi_enabled(EFI_BOOT) && + IS_ENABLED(CONFIG_X86_64) != efi_enabled(EFI_64BIT)) { pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n"); efi_unmap_memmap(); - efi_enabled = 0; } #endif } diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index ad4439145f85..5426e482db6e 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -51,9 +51,6 @@ #define EFI_DEBUG 1 -int efi_enabled; -EXPORT_SYMBOL(efi_enabled); - struct efi __read_mostly efi = { .mps = EFI_INVALID_TABLE_ADDR, .acpi = EFI_INVALID_TABLE_ADDR, @@ -69,19 +66,28 @@ EXPORT_SYMBOL(efi); struct efi_memory_map memmap; -bool efi_64bit; - static struct efi efi_phys __initdata; static efi_system_table_t efi_systab __initdata; static inline bool efi_is_native(void) { - return IS_ENABLED(CONFIG_X86_64) == efi_64bit; + return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT); +} + +unsigned long x86_efi_facility; + +/* + * Returns 1 if 'facility' is enabled, 0 otherwise. + */ +int efi_enabled(int facility) +{ + return test_bit(facility, &x86_efi_facility) != 0; } +EXPORT_SYMBOL(efi_enabled); static int __init setup_noefi(char *arg) { - efi_enabled = 0; + clear_bit(EFI_BOOT, &x86_efi_facility); return 0; } early_param("noefi", setup_noefi); @@ -426,6 +432,7 @@ void __init efi_reserve_boot_services(void) void __init efi_unmap_memmap(void) { + clear_bit(EFI_MEMMAP, &x86_efi_facility); if (memmap.map) { early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size); memmap.map = NULL; @@ -460,7 +467,7 @@ void __init efi_free_boot_services(void) static int __init efi_systab_init(void *phys) { - if (efi_64bit) { + if (efi_enabled(EFI_64BIT)) { efi_system_table_64_t *systab64; u64 tmp = 0; @@ -552,7 +559,7 @@ static int __init efi_config_init(u64 tables, int nr_tables) void *config_tables, *tablep; int i, sz; - if (efi_64bit) + if (efi_enabled(EFI_64BIT)) sz = sizeof(efi_config_table_64_t); else sz = sizeof(efi_config_table_32_t); @@ -572,7 +579,7 @@ static int __init efi_config_init(u64 tables, int nr_tables) efi_guid_t guid; unsigned long table; - if (efi_64bit) { + if (efi_enabled(EFI_64BIT)) { u64 table64; guid = ((efi_config_table_64_t *)tablep)->guid; table64 = ((efi_config_table_64_t *)tablep)->table; @@ -684,7 +691,6 @@ void __init efi_init(void) if (boot_params.efi_info.efi_systab_hi || boot_params.efi_info.efi_memmap_hi) { pr_info("Table located above 4GB, disabling EFI.\n"); - efi_enabled = 0; return; } efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab; @@ -694,10 +700,10 @@ void __init efi_init(void) ((__u64)boot_params.efi_info.efi_systab_hi<<32)); #endif - if (efi_systab_init(efi_phys.systab)) { - efi_enabled = 0; + if (efi_systab_init(efi_phys.systab)) return; - } + + set_bit(EFI_SYSTEM_TABLES, &x86_efi_facility); /* * Show what we know for posterity @@ -715,10 +721,10 @@ void __init efi_init(void) efi.systab->hdr.revision >> 16, efi.systab->hdr.revision & 0xffff, vendor); - if (efi_config_init(efi.systab->tables, efi.systab->nr_tables)) { - efi_enabled = 0; + if (efi_config_init(efi.systab->tables, efi.systab->nr_tables)) return; - } + + set_bit(EFI_CONFIG_TABLES, &x86_efi_facility); /* * Note: We currently don't support runtime services on an EFI @@ -727,15 +733,17 @@ void __init efi_init(void) if (!efi_is_native()) pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n"); - else if (efi_runtime_init()) { - efi_enabled = 0; - return; + else { + if (efi_runtime_init()) + return; + set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility); } - if (efi_memmap_init()) { - efi_enabled = 0; + if (efi_memmap_init()) return; - } + + set_bit(EFI_MEMMAP, &x86_efi_facility); + #ifdef CONFIG_X86_32 if (efi_is_native()) { x86_platform.get_wallclock = efi_get_time; @@ -969,6 +977,9 @@ u32 efi_mem_type(unsigned long phys_addr) efi_memory_desc_t *md; void *p; + if (!efi_enabled(EFI_MEMMAP)) + return 0; + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { md = p; if ((md->phys_addr <= phys_addr) && diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 9eaf708f5885..251435a78aef 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -250,7 +250,7 @@ acpi_physical_address __init acpi_os_get_root_pointer(void) return acpi_rsdp; #endif - if (efi_enabled) { + if (efi_enabled(EFI_CONFIG_TABLES)) { if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) return efi.acpi20; else if (efi.acpi != EFI_INVALID_TABLE_ADDR) diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index fd3ae6290d71..982f1f5f5742 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -471,7 +471,7 @@ void __init dmi_scan_machine(void) char __iomem *p, *q; int rc; - if (efi_enabled) { + if (efi_enabled(EFI_CONFIG_TABLES)) { if (efi.smbios == EFI_INVALID_TABLE_ADDR) goto error; diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index d10c9873dd9a..bfd8f4392492 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1224,7 +1224,7 @@ efivars_init(void) printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, EFIVARS_DATE); - if (!efi_enabled) + if (!efi_enabled(EFI_RUNTIME_SERVICES)) return 0; /* For now we'll register the efi directory at /sys/firmware/efi */ @@ -1262,7 +1262,7 @@ err_put: static void __exit efivars_exit(void) { - if (efi_enabled) { + if (efi_enabled(EFI_RUNTIME_SERVICES)) { unregister_efivars(&__efivars); kobject_put(efi_kobj); } diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c index 4da4eb9ae926..2224f1dc074b 100644 --- a/drivers/firmware/iscsi_ibft_find.c +++ b/drivers/firmware/iscsi_ibft_find.c @@ -99,7 +99,7 @@ unsigned long __init find_ibft_region(unsigned long *sizep) /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will * only use ACPI for this */ - if (!efi_enabled) + if (!efi_enabled(EFI_BOOT)) find_ibft_in_mem(); if (ibft_addr) { diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c index ad4c97345a6f..008d64598324 100644 --- a/drivers/gpu/drm/radeon/radeon_device.c +++ b/drivers/gpu/drm/radeon/radeon_device.c @@ -429,7 +429,8 @@ bool radeon_card_posted(struct radeon_device *rdev) { uint32_t reg; - if (efi_enabled && rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE) + if (efi_enabled(EFI_BOOT) && + rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE) return false; /* first check CRTCs */ diff --git a/drivers/platform/x86/ibm_rtl.c b/drivers/platform/x86/ibm_rtl.c index 7481146a5b47..97c2be195efc 100644 --- a/drivers/platform/x86/ibm_rtl.c +++ b/drivers/platform/x86/ibm_rtl.c @@ -244,7 +244,7 @@ static int __init ibm_rtl_init(void) { if (force) pr_warn("module loaded by force\n"); /* first ensure that we are running on IBM HW */ - else if (efi_enabled || !dmi_check_system(ibm_rtl_dmi_table)) + else if (efi_enabled(EFI_BOOT) || !dmi_check_system(ibm_rtl_dmi_table)) return -ENODEV; /* Get the address for the Extended BIOS Data Area */ diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c index b74050b95d6a..9ac1e9dfa89c 100644 --- a/drivers/scsi/isci/init.c +++ b/drivers/scsi/isci/init.c @@ -633,7 +633,7 @@ static int __devinit isci_pci_probe(struct pci_dev *pdev, const struct pci_devic return -ENOMEM; pci_set_drvdata(pdev, pci_info); - if (efi_enabled) + if (efi_enabled(EFI_RUNTIME_SERVICES)) orom = isci_get_efi_var(pdev); if (!orom) diff --git a/include/linux/efi.h b/include/linux/efi.h index 8670eb1eb8cd..b424f64cae4b 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -542,18 +542,30 @@ extern int __init efi_setup_pcdp_console(char *); #endif /* - * We play games with efi_enabled so that the compiler will, if possible, remove - * EFI-related code altogether. + * We play games with efi_enabled so that the compiler will, if + * possible, remove EFI-related code altogether. */ +#define EFI_BOOT 0 /* Were we booted from EFI? */ +#define EFI_SYSTEM_TABLES 1 /* Can we use EFI system tables? */ +#define EFI_CONFIG_TABLES 2 /* Can we use EFI config tables? */ +#define EFI_RUNTIME_SERVICES 3 /* Can we use runtime services? */ +#define EFI_MEMMAP 4 /* Can we use EFI memory map? */ +#define EFI_64BIT 5 /* Is the firmware 64-bit? */ + #ifdef CONFIG_EFI # ifdef CONFIG_X86 - extern int efi_enabled; - extern bool efi_64bit; +extern int efi_enabled(int facility); # else -# define efi_enabled 1 +static inline int efi_enabled(int facility) +{ + return 1; +} # endif #else -# define efi_enabled 0 +static inline int efi_enabled(int facility) +{ + return 0; +} #endif /* diff --git a/init/main.c b/init/main.c index cd147a918786..857166fb9f31 100644 --- a/init/main.c +++ b/init/main.c @@ -604,7 +604,7 @@ asmlinkage void __init start_kernel(void) pidmap_init(); anon_vma_init(); #ifdef CONFIG_X86 - if (efi_enabled) + if (efi_enabled(EFI_RUNTIME_SERVICES)) efi_enter_virtual_mode(); #endif thread_info_cache_init(); @@ -632,7 +632,7 @@ asmlinkage void __init start_kernel(void) acpi_early_init(); /* before LAPIC and SMP init */ sfi_init_late(); - if (efi_enabled) { + if (efi_enabled(EFI_RUNTIME_SERVICES)) { efi_late_init(); efi_free_boot_services(); } -- 2.39.5