Commit 98dd0e3a authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Ingo Molnar
Browse files

efi/x86: Split off some old memmap handling into separate routines 



In a subsequent patch, we will fold the prolog/epilog routines that are
part of the support code to call SetVirtualAddressMap() with a 1:1
mapping into the callers. However, the 64-bit version mostly consists
of ugly mapping code that is only used when efi=old_map is in effect,
which is extremely rare. So let's move this code out of the way so it
does not clutter the common code.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Matthew Garrett <mjg59@google.com>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20200103113953.9571-7-ardb@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 89ed4865

arch/x86/platform/efi/efi_64.c

+22 −13
Original line number Diff line number Diff line
@@ -72,7 +72,9 @@ static void __init early_code_mapping_set_exec(int executable) 
	}

}



pgd_t * __init efi_call_phys_prolog(void)

void __init efi_old_memmap_phys_epilog(pgd_t *save_pgd);



pgd_t * __init efi_old_memmap_phys_prolog(void)

{

	unsigned long vaddr, addr_pgd, addr_p4d, addr_pud;

	pgd_t *save_pgd, *pgd_k, *pgd_efi;
@@ -82,11 +84,6 @@ pgd_t * __init efi_call_phys_prolog(void) 
	int pgd;

	int n_pgds, i, j;



	if (!efi_enabled(EFI_OLD_MEMMAP)) {

		efi_switch_mm(&efi_mm);

		return efi_mm.pgd;

	}



	early_code_mapping_set_exec(1);



	n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
@@ -143,11 +140,11 @@ pgd_t * __init efi_call_phys_prolog(void) 
	__flush_tlb_all();

	return save_pgd;

out:

	efi_call_phys_epilog(save_pgd);

	efi_old_memmap_phys_epilog(save_pgd);

	return NULL;

}



void __init efi_call_phys_epilog(pgd_t *save_pgd)

void __init efi_old_memmap_phys_epilog(pgd_t *save_pgd)

{

	/*

	 * After the lock is released, the original page table is restored.
@@ -158,11 +155,6 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd) 
	p4d_t *p4d;

	pud_t *pud;



	if (!efi_enabled(EFI_OLD_MEMMAP)) {

		efi_switch_mm(efi_scratch.prev_mm);

		return;

	}



	nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);



	for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++) {
@@ -193,6 +185,23 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd) 
	early_code_mapping_set_exec(0);

}



pgd_t * __init efi_call_phys_prolog(void)

{

	if (efi_enabled(EFI_OLD_MEMMAP))

		return efi_old_memmap_phys_prolog();



	efi_switch_mm(&efi_mm);

	return efi_mm.pgd;

}



void __init efi_call_phys_epilog(pgd_t *save_pgd)

{

	if (efi_enabled(EFI_OLD_MEMMAP))

		efi_old_memmap_phys_epilog(save_pgd);

	else

		efi_switch_mm(efi_scratch.prev_mm);

}



EXPORT_SYMBOL_GPL(efi_mm);



/*

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