Re: [ 105/128] efi: Make efi_enabled a function to query EFI facilities

Ben Hutchings
2013-02-03T15:16:44Z

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On Sun, 2013-02-03 at 15:48 +0100, Ben Hutchings wrote:
> 3.2-stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: Matt Fleming <matt.fleming@intel.com>
>
> commit 83e68189745ad931c2afd45d8ee3303929233e7f upstream.
[...]
> [bwh: Backported to 3.2:
> - Adjust context (a lot)
> - Add efi_is_native() function from commit 5189c2a7c776
> ('x86: efi: Turn off efi_enabled after setup on mixed fw/kernel')
> - Make efi_init() bail out when booted non-native, as it would previously
> not be called in this case
> - Drop inapplicable changes to start_kernel()]
> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

As you can see this needed quite a lot of work to backport, and I
haven't been able to test it yet. So I would particularly appreciate
careful review of this.

Ben.

> ---
> --- a/arch/x86/include/asm/efi.h
> +++ b/arch/x86/include/asm/efi.h
> @@ -90,6 +90,7 @@ extern void __iomem *efi_ioremap(unsigne
> #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 void efi_memblock_x86_reserve_range(void);
> extern void efi_call_phys_prelog(void);
> --- a/arch/x86/kernel/reboot.c
> +++ b/arch/x86/kernel/reboot.c
> @@ -603,7 +603,7 @@ static void native_machine_emergency_res
> break;
>
> case BOOT_EFI:
> - if (efi_enabled)
> + if (efi_enabled(EFI_RUNTIME_SERVICES))
> efi.reset_system(reboot_mode ?
> EFI_RESET_WARM :
> EFI_RESET_COLD,
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -750,15 +750,16 @@ void __init setup_arch(char **cmdline_p)
> #endif
> #ifdef CONFIG_EFI
> if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
> -#ifdef CONFIG_X86_32
> - "EL32",
> -#else
> - "EL64",
> -#endif
> - 4)) {
> - efi_enabled = 1;
> - efi_memblock_x86_reserve_range();
> + "EL32", 4)) {
> + set_bit(EFI_BOOT, &x86_efi_facility);
> + } else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
> + "EL64", 4)) {
> + set_bit(EFI_BOOT, &x86_efi_facility);
> + set_bit(EFI_64BIT, &x86_efi_facility);
> }
> +
> + if (efi_enabled(EFI_BOOT))
> + efi_memblock_x86_reserve_range();
> #endif
>
> x86_init.oem.arch_setup();
> @@ -831,7 +832,7 @@ void __init setup_arch(char **cmdline_p)
>
> finish_e820_parsing();
>
> - if (efi_enabled)
> + if (efi_enabled(EFI_BOOT))
> efi_init();
>
> dmi_scan_machine();
> @@ -914,7 +915,7 @@ 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 */
> @@ -1048,7 +1049,7 @@ 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;
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -49,9 +49,6 @@
> #define EFI_DEBUG 1
> #define PFX "EFI: "
>
> -int efi_enabled;
> -EXPORT_SYMBOL(efi_enabled);
> -
> struct efi __read_mostly efi = {
> .mps = EFI_INVALID_TABLE_ADDR,
> .acpi = EFI_INVALID_TABLE_ADDR,
> @@ -70,9 +67,25 @@ struct efi_memory_map memmap;
> 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_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);
> @@ -440,6 +453,9 @@ void __init efi_init(void)
> int i = 0;
> void *tmp;
>
> + if (!efi_is_native())
> + return;
> +
> #ifdef CONFIG_X86_32
> efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
> #else
> @@ -467,6 +483,8 @@ void __init efi_init(void)
> efi.systab->hdr.revision >> 16,
> efi.systab->hdr.revision & 0xffff);
>
> + set_bit(EFI_SYSTEM_TABLES, &x86_efi_facility);
> +
> /*
> * Show what we know for posterity
> */
> @@ -529,6 +547,8 @@ void __init efi_init(void)
> early_iounmap(config_tables,
> efi.systab->nr_tables * sizeof(efi_config_table_t));
>
> + set_bit(EFI_CONFIG_TABLES, &x86_efi_facility);
> +
> /*
> * Check out the runtime services table. We need to map
> * the runtime services table so that we can grab the physical
> @@ -552,6 +572,8 @@ void __init efi_init(void)
> * virtual mode.
> */
> efi.get_time = phys_efi_get_time;
> +
> + set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
> } else
> printk(KERN_ERR "Could not map the EFI runtime service "
> "table!\n");
> @@ -571,6 +593,8 @@ void __init efi_init(void)
> if (add_efi_memmap)
> do_add_efi_memmap();
>
> + set_bit(EFI_MEMMAP, &x86_efi_facility);
> +
> #ifdef CONFIG_X86_32
> x86_platform.get_wallclock = efi_get_time;
> x86_platform.set_wallclock = efi_set_rtc_mmss;
> @@ -747,6 +771,7 @@ void __init efi_enter_virtual_mode(void)
> efi.query_capsule_caps = virt_efi_query_capsule_caps;
> if (__supported_pte_mask & _PAGE_NX)
> runtime_code_page_mkexec();
> + clear_bit(EFI_MEMMAP, &x86_efi_facility);
> early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
> memmap.map = NULL;
> kfree(new_memmap);
> @@ -760,6 +785,9 @@ 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) &&
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -255,7 +255,7 @@ acpi_physical_address __init acpi_os_get
> 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)
> --- a/drivers/firmware/dmi_scan.c
> +++ b/drivers/firmware/dmi_scan.c
> @@ -432,7 +432,7 @@ 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;
>
> --- a/drivers/firmware/efivars.c
> +++ b/drivers/firmware/efivars.c
> @@ -1222,7 +1222,7 @@ 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 */
> @@ -1260,7 +1260,7 @@ err_put:
> static void __exit
> efivars_exit(void)
> {
> - if (efi_enabled) {
> + if (efi_enabled(EFI_RUNTIME_SERVICES)) {
> unregister_efivars(&__efivars);
> kobject_put(efi_kobj);
> }
> --- a/drivers/firmware/iscsi_ibft_find.c
> +++ b/drivers/firmware/iscsi_ibft_find.c
> @@ -99,7 +99,7 @@ unsigned long __init find_ibft_region(un
> /* 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) {
> --- a/drivers/gpu/drm/radeon/radeon_device.c
> +++ b/drivers/gpu/drm/radeon/radeon_device.c
> @@ -354,7 +354,8 @@ bool radeon_card_posted(struct radeon_de
> {
> 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 */
> --- a/drivers/platform/x86/ibm_rtl.c
> +++ b/drivers/platform/x86/ibm_rtl.c
> @@ -255,7 +255,7 @@ 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 */
> --- a/drivers/scsi/isci/init.c
> +++ b/drivers/scsi/isci/init.c
> @@ -459,7 +459,7 @@ static int __devinit isci_pci_probe(stru
> 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)
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -364,17 +364,30 @@ extern int __init efi_setup_pcdp_console
> #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 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
>
> /*
> --- a/init/main.c
> +++ b/init/main.c
> @@ -606,7 +606,7 @@ 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();
>
>
> --
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>

--
Ben Hutchings
Everything should be made as simple as possible, but not simpler.
- Albert Einstein

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