diff options
Diffstat (limited to 'arch/x86/platform/efi/efi_64.c')
-rw-r--r-- | arch/x86/platform/efi/efi_64.c | 327 |
1 files changed, 326 insertions, 1 deletions
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 1928090..7e7f195 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -39,6 +39,7 @@ #include <asm/cacheflush.h> #include <asm/fixmap.h> #include <asm/realmode.h> +#include <asm/time.h> static pgd_t *save_pgd __initdata; static unsigned long efi_flags __initdata; @@ -58,7 +59,8 @@ struct efi_scratch { u64 prev_cr3; pgd_t *efi_pgt; bool use_pgd; -}; + u64 phys_stack; +} __packed; static void __init early_code_mapping_set_exec(int executable) { @@ -139,6 +141,9 @@ void efi_sync_low_kernel_mappings(void) int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) { + unsigned long text; + struct page *page; + unsigned npages; pgd_t *pgd; if (efi_enabled(EFI_OLD_MEMMAP)) @@ -160,6 +165,29 @@ int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) efi_scratch.use_pgd = true; + /* + * When making calls to the firmware everything needs to be 1:1 + * mapped and addressable with 32-bit pointers. Map the kernel + * text and allocate a new stack because we can't rely on the + * stack pointer being < 4GB. + */ + if (!IS_ENABLED(CONFIG_EFI_MIXED)) + return 0; + + page = alloc_page(GFP_KERNEL|__GFP_DMA32); + if (!page) + panic("Unable to allocate EFI runtime stack < 4GB\n"); + + efi_scratch.phys_stack = virt_to_phys(page_address(page)); + efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */ + + npages = (_end - _text) >> PAGE_SHIFT; + text = __pa(_text); + + if (kernel_map_pages_in_pgd(pgd, text >> PAGE_SHIFT, text, npages, 0)) { + pr_err("Failed to map kernel text 1:1\n"); + return 1; + } return 0; } @@ -199,6 +227,16 @@ void __init efi_map_region(efi_memory_desc_t *md) */ __map_region(md, md->phys_addr); + /* + * Enforce the 1:1 mapping as the default virtual address when + * booting in EFI mixed mode, because even though we may be + * running a 64-bit kernel, the firmware may only be 32-bit. + */ + if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) { + md->virt_addr = md->phys_addr; + return; + } + efi_va -= size; /* Is PA 2M-aligned? */ @@ -277,3 +315,290 @@ void __init efi_dump_pagetable(void) ptdump_walk_pgd_level(NULL, pgd); #endif } + +#ifdef CONFIG_EFI_MIXED +extern efi_status_t efi64_thunk(u32, ...); + +#define runtime_service32(func) \ +({ \ + u32 table = (u32)(unsigned long)efi.systab; \ + u32 *rt, *___f; \ + \ + rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime)); \ + ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \ + *___f; \ +}) + +/* + * Switch to the EFI page tables early so that we can access the 1:1 + * runtime services mappings which are not mapped in any other page + * tables. This function must be called before runtime_service32(). + * + * Also, disable interrupts because the IDT points to 64-bit handlers, + * which aren't going to function correctly when we switch to 32-bit. + */ +#define efi_thunk(f, ...) \ +({ \ + efi_status_t __s; \ + unsigned long flags; \ + u32 func; \ + \ + efi_sync_low_kernel_mappings(); \ + local_irq_save(flags); \ + \ + efi_scratch.prev_cr3 = read_cr3(); \ + write_cr3((unsigned long)efi_scratch.efi_pgt); \ + __flush_tlb_all(); \ + \ + func = runtime_service32(f); \ + __s = efi64_thunk(func, __VA_ARGS__); \ + \ + write_cr3(efi_scratch.prev_cr3); \ + __flush_tlb_all(); \ + local_irq_restore(flags); \ + \ + __s; \ +}) + +efi_status_t efi_thunk_set_virtual_address_map( + void *phys_set_virtual_address_map, + unsigned long memory_map_size, + unsigned long descriptor_size, + u32 descriptor_version, + efi_memory_desc_t *virtual_map) +{ + efi_status_t status; + unsigned long flags; + u32 func; + + efi_sync_low_kernel_mappings(); + local_irq_save(flags); + + efi_scratch.prev_cr3 = read_cr3(); + write_cr3((unsigned long)efi_scratch.efi_pgt); + __flush_tlb_all(); + + func = (u32)(unsigned long)phys_set_virtual_address_map; + status = efi64_thunk(func, memory_map_size, descriptor_size, + descriptor_version, virtual_map); + + write_cr3(efi_scratch.prev_cr3); + __flush_tlb_all(); + local_irq_restore(flags); + + return status; +} + +static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc) +{ + efi_status_t status; + u32 phys_tm, phys_tc; + + spin_lock(&rtc_lock); + + phys_tm = virt_to_phys(tm); + phys_tc = virt_to_phys(tc); + + status = efi_thunk(get_time, phys_tm, phys_tc); + + spin_unlock(&rtc_lock); + + return status; +} + +static efi_status_t efi_thunk_set_time(efi_time_t *tm) +{ + efi_status_t status; + u32 phys_tm; + + spin_lock(&rtc_lock); + + phys_tm = virt_to_phys(tm); + + status = efi_thunk(set_time, phys_tm); + + spin_unlock(&rtc_lock); + + return status; +} + +static efi_status_t +efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending, + efi_time_t *tm) +{ + efi_status_t status; + u32 phys_enabled, phys_pending, phys_tm; + + spin_lock(&rtc_lock); + + phys_enabled = virt_to_phys(enabled); + phys_pending = virt_to_phys(pending); + phys_tm = virt_to_phys(tm); + + status = efi_thunk(get_wakeup_time, phys_enabled, + phys_pending, phys_tm); + + spin_unlock(&rtc_lock); + + return status; +} + +static efi_status_t +efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm) +{ + efi_status_t status; + u32 phys_tm; + + spin_lock(&rtc_lock); + + phys_tm = virt_to_phys(tm); + + status = efi_thunk(set_wakeup_time, enabled, phys_tm); + + spin_unlock(&rtc_lock); + + return status; +} + + +static efi_status_t +efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor, + u32 *attr, unsigned long *data_size, void *data) +{ + efi_status_t status; + u32 phys_name, phys_vendor, phys_attr; + u32 phys_data_size, phys_data; + + phys_data_size = virt_to_phys(data_size); + phys_vendor = virt_to_phys(vendor); + phys_name = virt_to_phys(name); + phys_attr = virt_to_phys(attr); + phys_data = virt_to_phys(data); + + status = efi_thunk(get_variable, phys_name, phys_vendor, + phys_attr, phys_data_size, phys_data); + + return status; +} + +static efi_status_t +efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor, + u32 attr, unsigned long data_size, void *data) +{ + u32 phys_name, phys_vendor, phys_data; + efi_status_t status; + + phys_name = virt_to_phys(name); + phys_vendor = virt_to_phys(vendor); + phys_data = virt_to_phys(data); + + /* If data_size is > sizeof(u32) we've got problems */ + status = efi_thunk(set_variable, phys_name, phys_vendor, + attr, data_size, phys_data); + + return status; +} + +static efi_status_t +efi_thunk_get_next_variable(unsigned long *name_size, + efi_char16_t *name, + efi_guid_t *vendor) +{ + efi_status_t status; + u32 phys_name_size, phys_name, phys_vendor; + + phys_name_size = virt_to_phys(name_size); + phys_vendor = virt_to_phys(vendor); + phys_name = virt_to_phys(name); + + status = efi_thunk(get_next_variable, phys_name_size, + phys_name, phys_vendor); + + return status; +} + +static efi_status_t +efi_thunk_get_next_high_mono_count(u32 *count) +{ + efi_status_t status; + u32 phys_count; + + phys_count = virt_to_phys(count); + status = efi_thunk(get_next_high_mono_count, phys_count); + + return status; +} + +static void +efi_thunk_reset_system(int reset_type, efi_status_t status, + unsigned long data_size, efi_char16_t *data) +{ + u32 phys_data; + + phys_data = virt_to_phys(data); + + efi_thunk(reset_system, reset_type, status, data_size, phys_data); +} + +static efi_status_t +efi_thunk_update_capsule(efi_capsule_header_t **capsules, + unsigned long count, unsigned long sg_list) +{ + /* + * To properly support this function we would need to repackage + * 'capsules' because the firmware doesn't understand 64-bit + * pointers. + */ + return EFI_UNSUPPORTED; +} + +static efi_status_t +efi_thunk_query_variable_info(u32 attr, u64 *storage_space, + u64 *remaining_space, + u64 *max_variable_size) +{ + efi_status_t status; + u32 phys_storage, phys_remaining, phys_max; + + if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) + return EFI_UNSUPPORTED; + + phys_storage = virt_to_phys(storage_space); + phys_remaining = virt_to_phys(remaining_space); + phys_max = virt_to_phys(max_variable_size); + + status = efi_thunk(query_variable_info, phys_storage, + phys_remaining, phys_max); + + return status; +} + +static efi_status_t +efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules, + unsigned long count, u64 *max_size, + int *reset_type) +{ + /* + * To properly support this function we would need to repackage + * 'capsules' because the firmware doesn't understand 64-bit + * pointers. + */ + return EFI_UNSUPPORTED; +} + +void efi_thunk_runtime_setup(void) +{ + efi.get_time = efi_thunk_get_time; + efi.set_time = efi_thunk_set_time; + efi.get_wakeup_time = efi_thunk_get_wakeup_time; + efi.set_wakeup_time = efi_thunk_set_wakeup_time; + efi.get_variable = efi_thunk_get_variable; + efi.get_next_variable = efi_thunk_get_next_variable; + efi.set_variable = efi_thunk_set_variable; + efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count; + efi.reset_system = efi_thunk_reset_system; + efi.query_variable_info = efi_thunk_query_variable_info; + efi.update_capsule = efi_thunk_update_capsule; + efi.query_capsule_caps = efi_thunk_query_capsule_caps; +} +#endif /* CONFIG_EFI_MIXED */ |