diff options
Diffstat (limited to 'arch/x86/platform/efi/efi_64.c')
| -rw-r--r-- | arch/x86/platform/efi/efi_64.c | 60 |
1 files changed, 33 insertions, 27 deletions
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 7f443bd1411d..bed7e7f4e44c 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -34,6 +34,7 @@ #include <linux/slab.h> #include <linux/ucs2_string.h> #include <linux/mem_encrypt.h> +#include <linux/sched/task.h> #include <asm/setup.h> #include <asm/page.h> @@ -82,9 +83,8 @@ pgd_t * __init efi_call_phys_prolog(void) int n_pgds, i, j; if (!efi_enabled(EFI_OLD_MEMMAP)) { - save_pgd = (pgd_t *)__read_cr3(); - write_cr3((unsigned long)efi_scratch.efi_pgt); - goto out; + efi_switch_mm(&efi_mm); + return NULL; } early_code_mapping_set_exec(1); @@ -156,8 +156,7 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd) pud_t *pud; if (!efi_enabled(EFI_OLD_MEMMAP)) { - write_cr3((unsigned long)save_pgd); - __flush_tlb_all(); + efi_switch_mm(efi_scratch.prev_mm); return; } @@ -191,8 +190,7 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd) early_code_mapping_set_exec(0); } -pgd_t *efi_pgd; -EXPORT_SYMBOL_GPL(efi_pgd); +EXPORT_SYMBOL_GPL(efi_mm); /* * We need our own copy of the higher levels of the page tables @@ -205,7 +203,7 @@ EXPORT_SYMBOL_GPL(efi_pgd); */ int __init efi_alloc_page_tables(void) { - pgd_t *pgd; + pgd_t *pgd, *efi_pgd; p4d_t *p4d; pud_t *pud; gfp_t gfp_mask; @@ -233,6 +231,10 @@ int __init efi_alloc_page_tables(void) return -ENOMEM; } + efi_mm.pgd = efi_pgd; + mm_init_cpumask(&efi_mm); + init_new_context(NULL, &efi_mm); + return 0; } @@ -245,6 +247,7 @@ void efi_sync_low_kernel_mappings(void) pgd_t *pgd_k, *pgd_efi; p4d_t *p4d_k, *p4d_efi; pud_t *pud_k, *pud_efi; + pgd_t *efi_pgd = efi_mm.pgd; if (efi_enabled(EFI_OLD_MEMMAP)) return; @@ -338,20 +341,12 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) unsigned long pfn, text, pf; struct page *page; unsigned npages; - pgd_t *pgd; + pgd_t *pgd = efi_mm.pgd; if (efi_enabled(EFI_OLD_MEMMAP)) return 0; /* - * Since the PGD is encrypted, set the encryption mask so that when - * this value is loaded into cr3 the PGD will be decrypted during - * the pagetable walk. - */ - efi_scratch.efi_pgt = (pgd_t *)__sme_pa(efi_pgd); - pgd = efi_pgd; - - /* * It can happen that the physical address of new_memmap lands in memory * which is not mapped in the EFI page table. Therefore we need to go * and ident-map those pages containing the map before calling @@ -364,8 +359,6 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) return 1; } - efi_scratch.use_pgd = true; - /* * Certain firmware versions are way too sentimential and still believe * they are exclusive and unquestionable owners of the first physical page, @@ -419,7 +412,7 @@ static void __init __map_region(efi_memory_desc_t *md, u64 va) { unsigned long flags = _PAGE_RW; unsigned long pfn; - pgd_t *pgd = efi_pgd; + pgd_t *pgd = efi_mm.pgd; if (!(md->attribute & EFI_MEMORY_WB)) flags |= _PAGE_PCD; @@ -523,7 +516,7 @@ void __init parse_efi_setup(u64 phys_addr, u32 data_len) static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf) { unsigned long pfn; - pgd_t *pgd = efi_pgd; + pgd_t *pgd = efi_mm.pgd; int err1, err2; /* Update the 1:1 mapping */ @@ -620,10 +613,26 @@ void __init efi_dump_pagetable(void) if (efi_enabled(EFI_OLD_MEMMAP)) ptdump_walk_pgd_level(NULL, swapper_pg_dir); else - ptdump_walk_pgd_level(NULL, efi_pgd); + ptdump_walk_pgd_level(NULL, efi_mm.pgd); #endif } +/* + * Makes the calling thread switch to/from efi_mm context. Can be used + * for SetVirtualAddressMap() i.e. current->active_mm == init_mm as well + * as during efi runtime calls i.e current->active_mm == current_mm. + * We are not mm_dropping()/mm_grabbing() any mm, because we are not + * losing/creating any references. + */ +void efi_switch_mm(struct mm_struct *mm) +{ + task_lock(current); + efi_scratch.prev_mm = current->active_mm; + current->active_mm = mm; + switch_mm(efi_scratch.prev_mm, mm, NULL); + task_unlock(current); +} + #ifdef CONFIG_EFI_MIXED extern efi_status_t efi64_thunk(u32, ...); @@ -677,16 +686,13 @@ efi_status_t efi_thunk_set_virtual_address_map( 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(); + efi_switch_mm(&efi_mm); 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(); + efi_switch_mm(efi_scratch.prev_mm); local_irq_restore(flags); return status; |