Commit 60305db9 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Catalin Marinas
Browse files

arm64/efi: move virtmap init to early initcall 



Now that the create_mapping() code in mm/mmu.c is able to support
setting up kernel page tables at initcall time, we can move the whole
virtmap creation to arm64_enable_runtime_services() instead of having
a distinct stage during early boot. This also allows us to drop the
arm64-specific EFI_VIRTMAP flag.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent da141706

arch/arm64/include/asm/efi.h

+5 −13
Original line number Diff line number Diff line
@@ -6,10 +6,8 @@ 


#ifdef CONFIG_EFI

extern void efi_init(void);

extern void efi_virtmap_init(void);

#else

#define efi_init()

#define efi_virtmap_init()

#endif



#define efi_call_virt(f, ...)						\
@@ -53,23 +51,17 @@ extern void efi_virtmap_init(void); 
#define EFI_ALLOC_ALIGN		SZ_64K



/*

 * On ARM systems, virtually remapped UEFI runtime services are set up in three

 * On ARM systems, virtually remapped UEFI runtime services are set up in two

 * distinct stages:

 * - The stub retrieves the final version of the memory map from UEFI, populates

 *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime

 *   service to communicate the new mapping to the firmware (Note that the new

 *   mapping is not live at this time)

 * - During early boot, the page tables are allocated and populated based on the

 *   virt_addr fields in the memory map, but only if all descriptors with the

 *   EFI_MEMORY_RUNTIME attribute have a non-zero value for virt_addr. If this

 *   succeeds, the EFI_VIRTMAP flag is set to indicate that the virtual mappings

 *   have been installed successfully.

 * - During an early initcall(), the UEFI Runtime Services are enabled and the

 *   EFI_RUNTIME_SERVICES bit set if some conditions are met, i.e., we need a

 *   non-early mapping of the UEFI system table, and we need to have the virtmap

 *   installed.

 * - During an early initcall(), the EFI system table is permanently remapped

 *   and the virtual remapping of the UEFI Runtime Services regions is loaded

 *   into a private set of page tables. If this all succeeds, the Runtime

 *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.

 */

#define EFI_VIRTMAP		EFI_ARCH_1



void efi_virtmap_load(void);

void efi_virtmap_unload(void);

arch/arm64/kernel/efi.c

+53 −58
Original line number Diff line number Diff line
@@ -38,6 +38,19 @@ struct efi_memory_map memmap; 


static u64 efi_system_table;



static pgd_t efi_pgd[PTRS_PER_PGD] __page_aligned_bss;



static struct mm_struct efi_mm = {

	.mm_rb			= RB_ROOT,

	.pgd			= efi_pgd,

	.mm_users		= ATOMIC_INIT(2),

	.mm_count		= ATOMIC_INIT(1),

	.mmap_sem		= __RWSEM_INITIALIZER(efi_mm.mmap_sem),

	.page_table_lock	= __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),

	.mmlist			= LIST_HEAD_INIT(efi_mm.mmlist),

	INIT_MM_CONTEXT(efi_mm)

};



static int uefi_debug __initdata;

static int __init uefi_debug_setup(char *str)

{
@@ -213,6 +226,45 @@ void __init efi_init(void) 
		return;



	reserve_regions();

	early_memunmap(memmap.map, params.mmap_size);

}



static bool __init efi_virtmap_init(void)

{

	efi_memory_desc_t *md;



	for_each_efi_memory_desc(&memmap, md) {

		u64 paddr, npages, size;

		pgprot_t prot;



		if (!(md->attribute & EFI_MEMORY_RUNTIME))

			continue;

		if (md->virt_addr == 0)

			return false;



		paddr = md->phys_addr;

		npages = md->num_pages;

		memrange_efi_to_native(&paddr, &npages);

		size = npages << PAGE_SHIFT;



		pr_info("  EFI remap 0x%016llx => %p\n",

			md->phys_addr, (void *)md->virt_addr);



		/*

		 * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be

		 * executable, everything else can be mapped with the XN bits

		 * set.

		 */

		if (!is_normal_ram(md))

			prot = __pgprot(PROT_DEVICE_nGnRE);

		else if (md->type == EFI_RUNTIME_SERVICES_CODE)

			prot = PAGE_KERNEL_EXEC;

		else

			prot = PAGE_KERNEL;



		create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size, prot);

	}

	return true;

}



/*
@@ -254,7 +306,7 @@ static int __init arm64_enable_runtime_services(void) 
	}

	set_bit(EFI_SYSTEM_TABLES, &efi.flags);



	if (!efi_enabled(EFI_VIRTMAP)) {

	if (!efi_virtmap_init()) {

		pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");

		return -1;

	}
@@ -283,19 +335,6 @@ static int __init arm64_dmi_init(void) 
}

core_initcall(arm64_dmi_init);



static pgd_t efi_pgd[PTRS_PER_PGD] __page_aligned_bss;



static struct mm_struct efi_mm = {

	.mm_rb			= RB_ROOT,

	.pgd			= efi_pgd,

	.mm_users		= ATOMIC_INIT(2),

	.mm_count		= ATOMIC_INIT(1),

	.mmap_sem		= __RWSEM_INITIALIZER(efi_mm.mmap_sem),

	.page_table_lock	= __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),

	.mmlist			= LIST_HEAD_INIT(efi_mm.mmlist),

	INIT_MM_CONTEXT(efi_mm)

};



static void efi_set_pgd(struct mm_struct *mm)

{

	cpu_switch_mm(mm->pgd, mm);
@@ -315,47 +354,3 @@ void efi_virtmap_unload(void) 
	efi_set_pgd(current->active_mm);

	preempt_enable();

}
 


void __init efi_virtmap_init(void)

{

	efi_memory_desc_t *md;



	if (!efi_enabled(EFI_BOOT))

		return;



	for_each_efi_memory_desc(&memmap, md) {

		u64 paddr, npages, size;

		pgprot_t prot;



		if (!(md->attribute & EFI_MEMORY_RUNTIME))

			continue;

		if (WARN(md->virt_addr == 0,

			 "UEFI virtual mapping incomplete or missing -- no entry found for 0x%llx\n",

			 md->phys_addr))

			return;



		paddr = md->phys_addr;

		npages = md->num_pages;

		memrange_efi_to_native(&paddr, &npages);

		size = npages << PAGE_SHIFT;



		pr_info("  EFI remap 0x%016llx => %p\n",

			md->phys_addr, (void *)md->virt_addr);



		/*

		 * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be

		 * executable, everything else can be mapped with the XN bits

		 * set.

		 */

		if (!is_normal_ram(md))

			prot = __pgprot(PROT_DEVICE_nGnRE);

		else if (md->type == EFI_RUNTIME_SERVICES_CODE)

			prot = PAGE_KERNEL_EXEC;

		else

			prot = PAGE_KERNEL;



		create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size, prot);

	}

	set_bit(EFI_VIRTMAP, &efi.flags);

	early_memunmap(memmap.map, memmap.map_end - memmap.map);

}

arch/arm64/kernel/setup.c

+0 −1
Original line number Diff line number Diff line
@@ -382,7 +382,6 @@ void __init setup_arch(char **cmdline_p) 
	paging_init();

	request_standard_resources();



	efi_virtmap_init();

	early_ioremap_reset();



	unflatten_device_tree();

arch/arm64/mm/mmu.c

+1 −1
Original line number Diff line number Diff line
@@ -269,7 +269,7 @@ void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, 
			       pgprot_t prot)

{

	__create_mapping(mm, pgd_offset(mm, virt), phys, virt, size, prot,

				early_alloc);

				late_alloc);

}



static void create_mapping_late(phys_addr_t phys, unsigned long virt,

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