From eeb9db09f738993c63ecb5aedf950a1e4fe4bd3f Mon Sep 17 00:00:00 2001 From: Saurabh Tangri Date: Mon, 2 Jun 2014 05:18:35 -0700 Subject: x86/efi: Move all workarounds to a separate file quirks.c Currently, it's difficult to find all the workarounds that are applied when running on EFI, because they're littered throughout various code paths. This change moves all of them into a separate file with the hope that it will be come the single location for all our well documented quirks. Signed-off-by: Saurabh Tangri Signed-off-by: Matt Fleming --- arch/x86/platform/efi/quirks.c | 267 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 267 insertions(+) create mode 100644 arch/x86/platform/efi/quirks.c (limited to 'arch/x86/platform/efi/quirks.c') diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c new file mode 100644 index 00000000000..7e3099c610d --- /dev/null +++ b/arch/x86/platform/efi/quirks.c @@ -0,0 +1,267 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define EFI_MIN_RESERVE 5120 + +#define EFI_DUMMY_GUID \ + EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9) + +static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 }; + +static bool efi_no_storage_paranoia; + +/* + * Some firmware implementations refuse to boot if there's insufficient + * space in the variable store. The implementation of garbage collection + * in some FW versions causes stale (deleted) variables to take up space + * longer than intended and space is only freed once the store becomes + * almost completely full. + * + * Enabling this option disables the space checks in + * efi_query_variable_store() and forces garbage collection. + * + * Only enable this option if deleting EFI variables does not free up + * space in your variable store, e.g. if despite deleting variables + * you're unable to create new ones. + */ +static int __init setup_storage_paranoia(char *arg) +{ + efi_no_storage_paranoia = true; + return 0; +} +early_param("efi_no_storage_paranoia", setup_storage_paranoia); + +/* + * Deleting the dummy variable which kicks off garbage collection +*/ +void efi_delete_dummy_variable(void) +{ + efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID, + EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS, + 0, NULL); +} + +/* + * Some firmware implementations refuse to boot if there's insufficient space + * in the variable store. Ensure that we never use more than a safe limit. + * + * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable + * store. + */ +efi_status_t efi_query_variable_store(u32 attributes, unsigned long size) +{ + efi_status_t status; + u64 storage_size, remaining_size, max_size; + + if (!(attributes & EFI_VARIABLE_NON_VOLATILE)) + return 0; + + status = efi.query_variable_info(attributes, &storage_size, + &remaining_size, &max_size); + if (status != EFI_SUCCESS) + return status; + + /* + * We account for that by refusing the write if permitting it would + * reduce the available space to under 5KB. This figure was provided by + * Samsung, so should be safe. + */ + if ((remaining_size - size < EFI_MIN_RESERVE) && + !efi_no_storage_paranoia) { + + /* + * Triggering garbage collection may require that the firmware + * generate a real EFI_OUT_OF_RESOURCES error. We can force + * that by attempting to use more space than is available. + */ + unsigned long dummy_size = remaining_size + 1024; + void *dummy = kzalloc(dummy_size, GFP_ATOMIC); + + if (!dummy) + return EFI_OUT_OF_RESOURCES; + + status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID, + EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS, + dummy_size, dummy); + + if (status == EFI_SUCCESS) { + /* + * This should have failed, so if it didn't make sure + * that we delete it... + */ + efi_delete_dummy_variable(); + } + + kfree(dummy); + + /* + * The runtime code may now have triggered a garbage collection + * run, so check the variable info again + */ + status = efi.query_variable_info(attributes, &storage_size, + &remaining_size, &max_size); + + if (status != EFI_SUCCESS) + return status; + + /* + * There still isn't enough room, so return an error + */ + if (remaining_size - size < EFI_MIN_RESERVE) + return EFI_OUT_OF_RESOURCES; + } + + return EFI_SUCCESS; +} +EXPORT_SYMBOL_GPL(efi_query_variable_store); + +/* + * The UEFI specification makes it clear that the operating system is free to do + * whatever it wants with boot services code after ExitBootServices() has been + * called. Ignoring this recommendation a significant bunch of EFI implementations + * continue calling into boot services code (SetVirtualAddressMap). In order to + * work around such buggy implementations we reserve boot services region during + * EFI init and make sure it stays executable. Then, after SetVirtualAddressMap(), it +* is discarded. +*/ +void __init efi_reserve_boot_services(void) +{ + void *p; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + efi_memory_desc_t *md = p; + u64 start = md->phys_addr; + u64 size = md->num_pages << EFI_PAGE_SHIFT; + + if (md->type != EFI_BOOT_SERVICES_CODE && + md->type != EFI_BOOT_SERVICES_DATA) + continue; + /* Only reserve where possible: + * - Not within any already allocated areas + * - Not over any memory area (really needed, if above?) + * - Not within any part of the kernel + * - Not the bios reserved area + */ + if ((start + size > __pa_symbol(_text) + && start <= __pa_symbol(_end)) || + !e820_all_mapped(start, start+size, E820_RAM) || + memblock_is_region_reserved(start, size)) { + /* Could not reserve, skip it */ + md->num_pages = 0; + memblock_dbg("Could not reserve boot range [0x%010llx-0x%010llx]\n", + start, start+size-1); + } else + memblock_reserve(start, size); + } +} + +void __init efi_free_boot_services(void) +{ + void *p; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + efi_memory_desc_t *md = p; + unsigned long long start = md->phys_addr; + unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; + + if (md->type != EFI_BOOT_SERVICES_CODE && + md->type != EFI_BOOT_SERVICES_DATA) + continue; + + /* Could not reserve boot area */ + if (!size) + continue; + + free_bootmem_late(start, size); + } + + efi_unmap_memmap(); +} + +/* + * A number of config table entries get remapped to virtual addresses + * after entering EFI virtual mode. However, the kexec kernel requires + * their physical addresses therefore we pass them via setup_data and + * correct those entries to their respective physical addresses here. + * + * Currently only handles smbios which is necessary for some firmware + * implementation. + */ +int __init efi_reuse_config(u64 tables, int nr_tables) +{ + int i, sz, ret = 0; + void *p, *tablep; + struct efi_setup_data *data; + + if (!efi_setup) + return 0; + + if (!efi_enabled(EFI_64BIT)) + return 0; + + data = early_memremap(efi_setup, sizeof(*data)); + if (!data) { + ret = -ENOMEM; + goto out; + } + + if (!data->smbios) + goto out_memremap; + + sz = sizeof(efi_config_table_64_t); + + p = tablep = early_memremap(tables, nr_tables * sz); + if (!p) { + pr_err("Could not map Configuration table!\n"); + ret = -ENOMEM; + goto out_memremap; + } + + for (i = 0; i < efi.systab->nr_tables; i++) { + efi_guid_t guid; + + guid = ((efi_config_table_64_t *)p)->guid; + + if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID)) + ((efi_config_table_64_t *)p)->table = data->smbios; + p += sz; + } + early_iounmap(tablep, nr_tables * sz); + +out_memremap: + early_iounmap(data, sizeof(*data)); +out: + return ret; +} + +void __init efi_apply_memmap_quirks(void) +{ + /* + * Once setup is done earlier, unmap the EFI memory map on mismatched + * firmware/kernel architectures since there is no support for runtime + * services. + */ + if (!efi_runtime_supported()) { + pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n"); + efi_unmap_memmap(); + } + + /* + * UV doesn't support the new EFI pagetable mapping yet. + */ + if (is_uv_system()) + set_bit(EFI_OLD_MEMMAP, &efi.flags); +} -- cgit v1.2.3-70-g09d2 From 98a716b66cab993e15001c7ec06f637ca6f1079b Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Mon, 9 Jun 2014 13:41:26 +0100 Subject: x86/efi: Use early_memunmap() to squelch sparse errors The kbuild reports the following sparse errors, >> arch/x86/platform/efi/quirks.c:242:23: sparse: incorrect type in >> argument 1 (different address spaces) arch/x86/platform/efi/quirks.c:242:23: expected void [noderef] *addr arch/x86/platform/efi/quirks.c:242:23: got void *[assigned] tablep >> arch/x86/platform/efi/quirks.c:245:23: sparse: incorrect type in >> argument 1 (different address spaces) arch/x86/platform/efi/quirks.c:245:23: expected void [noderef] *addr arch/x86/platform/efi/quirks.c:245:23: got struct efi_setup_data *[assigned] data Dave Young had made previous attempts to convert the early_iounmap() calls to early_memunmap() but ran into merge conflicts with commit 9e5c33d7aeee ("mm: create generic early_ioremap() support"). Now that we've got that commit in place we can switch to using early_memunmap() since we're already using early_memremap() in efi_reuse_config(). Cc: Dave Young Cc: Saurabh Tangri Signed-off-by: Matt Fleming --- arch/x86/platform/efi/quirks.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/platform/efi/quirks.c') diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index 7e3099c610d..b4cb9182f15 100644 --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -239,10 +239,10 @@ int __init efi_reuse_config(u64 tables, int nr_tables) ((efi_config_table_64_t *)p)->table = data->smbios; p += sz; } - early_iounmap(tablep, nr_tables * sz); + early_memunmap(tablep, nr_tables * sz); out_memremap: - early_iounmap(data, sizeof(*data)); + early_memunmap(data, sizeof(*data)); out: return ret; } -- cgit v1.2.3-70-g09d2 From 44be28e9dd9880dca3e2cbf7a844f2114e67f2cb Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 13 Jun 2014 12:39:55 +0100 Subject: x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag It appears that the BayTrail-T class of hardware requires EFI in order to powerdown and reboot and no other reliable method exists. This quirk is generally applicable to all hardware that has the ACPI Hardware Reduced bit set, since usually ACPI would be the preferred method. Cc: Len Brown Cc: Mark Salter Cc: "Rafael J. Wysocki" Signed-off-by: Matt Fleming --- arch/x86/include/asm/efi.h | 6 ++++++ arch/x86/kernel/reboot.c | 18 ++++++++++++++++-- arch/x86/platform/efi/quirks.c | 23 +++++++++++++++++++++++ drivers/firmware/efi/reboot.c | 8 ++++++++ include/linux/efi.h | 1 + 5 files changed, 54 insertions(+), 2 deletions(-) (limited to 'arch/x86/platform/efi/quirks.c') diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 9043f365ebf..044a2fd3c5f 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -183,6 +183,8 @@ extern struct efi_config *efi_early; #define efi_call_early(f, ...) \ efi_early->call(efi_early->f, __VA_ARGS__); +extern bool efi_reboot_required(void); + #else /* * IF EFI is not configured, have the EFI calls return -ENOSYS. @@ -195,6 +197,10 @@ extern struct efi_config *efi_early; #define efi_call5(_f, _a1, _a2, _a3, _a4, _a5) (-ENOSYS) #define efi_call6(_f, _a1, _a2, _a3, _a4, _a5, _a6) (-ENOSYS) static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} +static inline bool efi_reboot_required(void) +{ + return false; +} #endif /* CONFIG_EFI */ #endif /* _ASM_X86_EFI_H */ diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 09e709fd183..17962e667a9 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -28,6 +28,7 @@ #include #include #include +#include /* * Power off function, if any @@ -401,12 +402,25 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = { static int __init reboot_init(void) { + int rv; + /* * Only do the DMI check if reboot_type hasn't been overridden * on the command line */ - if (reboot_default) - dmi_check_system(reboot_dmi_table); + if (!reboot_default) + return 0; + + /* + * The DMI quirks table takes precedence. If no quirks entry + * matches and the ACPI Hardware Reduced bit is set, force EFI + * reboot. + */ + rv = dmi_check_system(reboot_dmi_table); + + if (!rv && efi_reboot_required()) + reboot_type = BOOT_EFI; + return 0; } core_initcall(reboot_init); diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index b4cb9182f15..1c7380da65f 100644 --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include @@ -265,3 +266,25 @@ void __init efi_apply_memmap_quirks(void) if (is_uv_system()) set_bit(EFI_OLD_MEMMAP, &efi.flags); } + +/* + * For most modern platforms the preferred method of powering off is via + * ACPI. However, there are some that are known to require the use of + * EFI runtime services and for which ACPI does not work at all. + * + * Using EFI is a last resort, to be used only if no other option + * exists. + */ +bool efi_reboot_required(void) +{ + if (!acpi_gbl_reduced_hardware) + return false; + + efi_reboot_quirk_mode = EFI_RESET_WARM; + return true; +} + +bool efi_poweroff_required(void) +{ + return !!acpi_gbl_reduced_hardware; +} diff --git a/drivers/firmware/efi/reboot.c b/drivers/firmware/efi/reboot.c index e9eeeb3c634..9c59d1c795d 100644 --- a/drivers/firmware/efi/reboot.c +++ b/drivers/firmware/efi/reboot.c @@ -5,6 +5,8 @@ #include #include +int efi_reboot_quirk_mode = -1; + void efi_reboot(enum reboot_mode reboot_mode, const char *__unused) { int efi_mode; @@ -22,6 +24,12 @@ void efi_reboot(enum reboot_mode reboot_mode, const char *__unused) break; } + /* + * If a quirk forced an EFI reset mode, always use that. + */ + if (efi_reboot_quirk_mode != -1) + efi_mode = efi_reboot_quirk_mode; + efi.reset_system(efi_mode, EFI_SUCCESS, 0, NULL); } diff --git a/include/linux/efi.h b/include/linux/efi.h index 9917f58ee83..bac0f93dc47 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -878,6 +878,7 @@ extern void efi_reserve_boot_services(void); extern int efi_get_fdt_params(struct efi_fdt_params *params, int verbose); extern struct efi_memory_map memmap; +extern int efi_reboot_quirk_mode; extern bool efi_poweroff_required(void); /* Iterate through an efi_memory_map */ -- cgit v1.2.3-70-g09d2