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Commit e981316f authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar
Browse files

x86/efi: Add 5-level paging support 



Allocate additional page table level and ajdust efi_sync_low_kernel_mappings()
to work with additional page table level.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: default avatarMatt Fleming <matt@codeblueprint.co.uk>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170317185515.8636-3-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 7f689041

arch/x86/platform/efi/efi_64.c

+26 −10
Original line number Diff line number Diff line
@@ -135,6 +135,7 @@ static pgd_t *efi_pgd; 
int __init efi_alloc_page_tables(void)

{

	pgd_t *pgd;

	p4d_t *p4d;

	pud_t *pud;

	gfp_t gfp_mask;
@@ -147,15 +148,20 @@ int __init efi_alloc_page_tables(void) 
		return -ENOMEM;



	pgd = efi_pgd + pgd_index(EFI_VA_END);

	p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);

	if (!p4d) {

		free_page((unsigned long)efi_pgd);

		return -ENOMEM;

	}



	pud = pud_alloc_one(NULL, 0);

	pud = pud_alloc(&init_mm, p4d, EFI_VA_END);

	if (!pud) {

		if (CONFIG_PGTABLE_LEVELS > 4)

			free_page((unsigned long) pgd_page_vaddr(*pgd));

		free_page((unsigned long)efi_pgd);

		return -ENOMEM;

	}



	pgd_populate(NULL, pgd, pud);



	return 0;

}
@@ -190,6 +196,21 @@ void efi_sync_low_kernel_mappings(void) 
	num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);

	memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);



	/*

	 * As with PGDs, we share all P4D entries apart from the one entry

	 * that covers the EFI runtime mapping space.

	 */

	BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END));

	BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK));



	pgd_efi = efi_pgd + pgd_index(EFI_VA_END);

	pgd_k = pgd_offset_k(EFI_VA_END);

	p4d_efi = p4d_offset(pgd_efi, 0);

	p4d_k = p4d_offset(pgd_k, 0);



	num_entries = p4d_index(EFI_VA_END);

	memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);



	/*

	 * We share all the PUD entries apart from those that map the

	 * EFI regions. Copy around them.
@@ -197,20 +218,15 @@ void efi_sync_low_kernel_mappings(void) 
	BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);

	BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);



	pgd_efi = efi_pgd + pgd_index(EFI_VA_END);

	p4d_efi = p4d_offset(pgd_efi, 0);

	p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);

	p4d_k = p4d_offset(pgd_k, EFI_VA_END);

	pud_efi = pud_offset(p4d_efi, 0);



	pgd_k = pgd_offset_k(EFI_VA_END);

	p4d_k = p4d_offset(pgd_k, 0);

	pud_k = pud_offset(p4d_k, 0);



	num_entries = pud_index(EFI_VA_END);

	memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);



	p4d_efi = p4d_offset(pgd_efi, EFI_VA_START);

	pud_efi = pud_offset(p4d_efi, EFI_VA_START);

	p4d_k = p4d_offset(pgd_k, EFI_VA_START);

	pud_k = pud_offset(p4d_k, EFI_VA_START);



	num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);