efi/libstub: Move arm-stub to a common file

Most of the arm-stub code is written in an architecture independent manner.
As a result, RISC-V can reuse most of the arm-stub code.

Rename the arm-stub.c to efi-stub.c so that ARM, ARM64 and RISC-V can use it.
This patch doesn't introduce any functional changes.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Link: https://lore.kernel.org/r/20200415195422.19866-2-atish.patra@wdc.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

1 files changed, 0 insertions, 408 deletions

diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
deleted file mode 100644
index 99a5cde7c2d8..000000000000
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ /dev/null
@@ -1,408 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * EFI stub implementation that is shared by arm and arm64 architectures.
- * This should be #included by the EFI stub implementation files.
- *
- * Copyright (C) 2013,2014 Linaro Limited
- *     Roy Franz <roy.franz@linaro.org
- * Copyright (C) 2013 Red Hat, Inc.
- *     Mark Salter <msalter@redhat.com>
- */
-
-#include <linux/efi.h>
-#include <linux/libfdt.h>
-#include <asm/efi.h>
-
-#include "efistub.h"
-
-/*
- * This is the base address at which to start allocating virtual memory ranges
- * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
- * any allocation we choose, and eliminate the risk of a conflict after kexec.
- * The value chosen is the largest non-zero power of 2 suitable for this purpose
- * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
- * be mapped efficiently.
- * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split,
- * map everything below 1 GB. (512 MB is a reasonable upper bound for the
- * entire footprint of the UEFI runtime services memory regions)
- */
-#define EFI_RT_VIRTUAL_BASE	SZ_512M
-#define EFI_RT_VIRTUAL_SIZE	SZ_512M
-
-#ifdef CONFIG_ARM64
-# define EFI_RT_VIRTUAL_LIMIT	DEFAULT_MAP_WINDOW_64
-#else
-# define EFI_RT_VIRTUAL_LIMIT	TASK_SIZE
-#endif
-
-static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
-static bool __efistub_global flat_va_mapping;
-
-static efi_system_table_t *__efistub_global sys_table;
-
-__pure efi_system_table_t *efi_system_table(void)
-{
-	return sys_table;
-}
-
-static struct screen_info *setup_graphics(void)
-{
-	efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
-	efi_status_t status;
-	unsigned long size;
-	void **gop_handle = NULL;
-	struct screen_info *si = NULL;
-
-	size = 0;
-	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-			     &gop_proto, NULL, &size, gop_handle);
-	if (status == EFI_BUFFER_TOO_SMALL) {
-		si = alloc_screen_info();
-		if (!si)
-			return NULL;
-		efi_setup_gop(si, &gop_proto, size);
-	}
-	return si;
-}
-
-void install_memreserve_table(void)
-{
-	struct linux_efi_memreserve *rsv;
-	efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
-	efi_status_t status;
-
-	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv),
-			     (void **)&rsv);
-	if (status != EFI_SUCCESS) {
-		pr_efi_err("Failed to allocate memreserve entry!\n");
-		return;
-	}
-
-	rsv->next = 0;
-	rsv->size = 0;
-	atomic_set(&rsv->count, 0);
-
-	status = efi_bs_call(install_configuration_table,
-			     &memreserve_table_guid, rsv);
-	if (status != EFI_SUCCESS)
-		pr_efi_err("Failed to install memreserve config table!\n");
-}
-
-static unsigned long get_dram_base(void)
-{
-	efi_status_t status;
-	unsigned long map_size, buff_size;
-	unsigned long membase  = EFI_ERROR;
-	struct efi_memory_map map;
-	efi_memory_desc_t *md;
-	struct efi_boot_memmap boot_map;
-
-	boot_map.map		= (efi_memory_desc_t **)&map.map;
-	boot_map.map_size	= &map_size;
-	boot_map.desc_size	= &map.desc_size;
-	boot_map.desc_ver	= NULL;
-	boot_map.key_ptr	= NULL;
-	boot_map.buff_size	= &buff_size;
-
-	status = efi_get_memory_map(&boot_map);
-	if (status != EFI_SUCCESS)
-		return membase;
-
-	map.map_end = map.map + map_size;
-
-	for_each_efi_memory_desc_in_map(&map, md) {
-		if (md->attribute & EFI_MEMORY_WB) {
-			if (membase > md->phys_addr)
-				membase = md->phys_addr;
-		}
-	}
-
-	efi_bs_call(free_pool, map.map);
-
-	return membase;
-}
-
-/*
- * This function handles the architcture specific differences between arm and
- * arm64 regarding where the kernel image must be loaded and any memory that
- * must be reserved. On failure it is required to free all
- * all allocations it has made.
- */
-efi_status_t handle_kernel_image(unsigned long *image_addr,
-				 unsigned long *image_size,
-				 unsigned long *reserve_addr,
-				 unsigned long *reserve_size,
-				 unsigned long dram_base,
-				 efi_loaded_image_t *image);
-
-asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
-					    unsigned long fdt_addr,
-					    unsigned long fdt_size);
-
-/*
- * EFI entry point for the arm/arm64 EFI stubs.  This is the entrypoint
- * that is described in the PE/COFF header.  Most of the code is the same
- * for both archictectures, with the arch-specific code provided in the
- * handle_kernel_image() function.
- */
-efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
-{
-	efi_loaded_image_t *image;
-	efi_status_t status;
-	unsigned long image_addr;
-	unsigned long image_size = 0;
-	unsigned long dram_base;
-	/* addr/point and size pairs for memory management*/
-	unsigned long initrd_addr = 0;
-	unsigned long initrd_size = 0;
-	unsigned long fdt_addr = 0;  /* Original DTB */
-	unsigned long fdt_size = 0;
-	char *cmdline_ptr = NULL;
-	int cmdline_size = 0;
-	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
-	unsigned long reserve_addr = 0;
-	unsigned long reserve_size = 0;
-	enum efi_secureboot_mode secure_boot;
-	struct screen_info *si;
-	efi_properties_table_t *prop_tbl;
-	unsigned long max_addr;
-
-	sys_table = sys_table_arg;
-
-	/* Check if we were booted by the EFI firmware */
-	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
-		status = EFI_INVALID_PARAMETER;
-		goto fail;
-	}
-
-	status = check_platform_features();
-	if (status != EFI_SUCCESS)
-		goto fail;
-
-	/*
-	 * Get a handle to the loaded image protocol.  This is used to get
-	 * information about the running image, such as size and the command
-	 * line.
-	 */
-	status = sys_table->boottime->handle_protocol(handle,
-					&loaded_image_proto, (void *)&image);
-	if (status != EFI_SUCCESS) {
-		pr_efi_err("Failed to get loaded image protocol\n");
-		goto fail;
-	}
-
-	dram_base = get_dram_base();
-	if (dram_base == EFI_ERROR) {
-		pr_efi_err("Failed to find DRAM base\n");
-		status = EFI_LOAD_ERROR;
-		goto fail;
-	}
-
-	/*
-	 * Get the command line from EFI, using the LOADED_IMAGE
-	 * protocol. We are going to copy the command line into the
-	 * device tree, so this can be allocated anywhere.
-	 */
-	cmdline_ptr = efi_convert_cmdline(image, &cmdline_size, ULONG_MAX);
-	if (!cmdline_ptr) {
-		pr_efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");
-		status = EFI_OUT_OF_RESOURCES;
-		goto fail;
-	}
-
-	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
-	    IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
-	    cmdline_size == 0)
-		efi_parse_options(CONFIG_CMDLINE);
-
-	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0)
-		efi_parse_options(cmdline_ptr);
-
-	pr_efi("Booting Linux Kernel...\n");
-
-	si = setup_graphics();
-
-	status = handle_kernel_image(&image_addr, &image_size,
-				     &reserve_addr,
-				     &reserve_size,
-				     dram_base, image);
-	if (status != EFI_SUCCESS) {
-		pr_efi_err("Failed to relocate kernel\n");
-		goto fail_free_cmdline;
-	}
-
-	efi_retrieve_tpm2_eventlog();
-
-	/* Ask the firmware to clear memory on unclean shutdown */
-	efi_enable_reset_attack_mitigation();
-
-	secure_boot = efi_get_secureboot();
-
-	/*
-	 * Unauthenticated device tree data is a security hazard, so ignore
-	 * 'dtb=' unless UEFI Secure Boot is disabled.  We assume that secure
-	 * boot is enabled if we can't determine its state.
-	 */
-	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
-	     secure_boot != efi_secureboot_mode_disabled) {
-		if (strstr(cmdline_ptr, "dtb="))
-			pr_efi("Ignoring DTB from command line.\n");
-	} else {
-		status = efi_load_dtb(image, &fdt_addr, &fdt_size);
-
-		if (status != EFI_SUCCESS) {
-			pr_efi_err("Failed to load device tree!\n");
-			goto fail_free_image;
-		}
-	}
-
-	if (fdt_addr) {
-		pr_efi("Using DTB from command line\n");
-	} else {
-		/* Look for a device tree configuration table entry. */
-		fdt_addr = (uintptr_t)get_fdt(&fdt_size);
-		if (fdt_addr)
-			pr_efi("Using DTB from configuration table\n");
-	}
-
-	if (!fdt_addr)
-		pr_efi("Generating empty DTB\n");
-
-	if (!noinitrd()) {
-		max_addr = efi_get_max_initrd_addr(dram_base, image_addr);
-		status = efi_load_initrd_dev_path(&initrd_addr, &initrd_size,
-						  max_addr);
-		if (status == EFI_SUCCESS) {
-			pr_efi("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n");
-		} else if (status == EFI_NOT_FOUND) {
-			status = efi_load_initrd(image, &initrd_addr, &initrd_size,
-						 ULONG_MAX, max_addr);
-			if (status == EFI_SUCCESS && initrd_size > 0)
-				pr_efi("Loaded initrd from command line option\n");
-		}
-		if (status != EFI_SUCCESS)
-			pr_efi_err("Failed to load initrd!\n");
-	}
-
-	efi_random_get_seed();
-
-	/*
-	 * If the NX PE data feature is enabled in the properties table, we
-	 * should take care not to create a virtual mapping that changes the
-	 * relative placement of runtime services code and data regions, as
-	 * they may belong to the same PE/COFF executable image in memory.
-	 * The easiest way to achieve that is to simply use a 1:1 mapping.
-	 */
-	prop_tbl = get_efi_config_table(EFI_PROPERTIES_TABLE_GUID);
-	flat_va_mapping = prop_tbl &&
-			  (prop_tbl->memory_protection_attribute &
-			   EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA);
-
-	/* hibernation expects the runtime regions to stay in the same place */
-	if (!IS_ENABLED(CONFIG_HIBERNATION) && !nokaslr() && !flat_va_mapping) {
-		/*
-		 * Randomize the base of the UEFI runtime services region.
-		 * Preserve the 2 MB alignment of the region by taking a
-		 * shift of 21 bit positions into account when scaling
-		 * the headroom value using a 32-bit random value.
-		 */
-		static const u64 headroom = EFI_RT_VIRTUAL_LIMIT -
-					    EFI_RT_VIRTUAL_BASE -
-					    EFI_RT_VIRTUAL_SIZE;
-		u32 rnd;
-
-		status = efi_get_random_bytes(sizeof(rnd), (u8 *)&rnd);
-		if (status == EFI_SUCCESS) {
-			virtmap_base = EFI_RT_VIRTUAL_BASE +
-				       (((headroom >> 21) * rnd) >> (32 - 21));
-		}
-	}
-
-	install_memreserve_table();
-
-	status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr,
-						efi_get_max_fdt_addr(dram_base),
-						initrd_addr, initrd_size,
-						cmdline_ptr, fdt_addr, fdt_size);
-	if (status != EFI_SUCCESS)
-		goto fail_free_initrd;
-
-	efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
-	/* not reached */
-
-fail_free_initrd:
-	pr_efi_err("Failed to update FDT and exit boot services\n");
-
-	efi_free(initrd_size, initrd_addr);
-	efi_free(fdt_size, fdt_addr);
-
-fail_free_image:
-	efi_free(image_size, image_addr);
-	efi_free(reserve_size, reserve_addr);
-fail_free_cmdline:
-	free_screen_info(si);
-	efi_free(cmdline_size, (unsigned long)cmdline_ptr);
-fail:
-	return status;
-}
-
-/*
- * efi_get_virtmap() - create a virtual mapping for the EFI memory map
- *
- * This function populates the virt_addr fields of all memory region descriptors
- * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
- * are also copied to @runtime_map, and their total count is returned in @count.
- */
-void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
-		     unsigned long desc_size, efi_memory_desc_t *runtime_map,
-		     int *count)
-{
-	u64 efi_virt_base = virtmap_base;
-	efi_memory_desc_t *in, *out = runtime_map;
-	int l;
-
-	for (l = 0; l < map_size; l += desc_size) {
-		u64 paddr, size;
-
-		in = (void *)memory_map + l;
-		if (!(in->attribute & EFI_MEMORY_RUNTIME))
-			continue;
-
-		paddr = in->phys_addr;
-		size = in->num_pages * EFI_PAGE_SIZE;
-
-		in->virt_addr = in->phys_addr;
-		if (novamap()) {
-			continue;
-		}
-
-		/*
-		 * Make the mapping compatible with 64k pages: this allows
-		 * a 4k page size kernel to kexec a 64k page size kernel and
-		 * vice versa.
-		 */
-		if (!flat_va_mapping) {
-
-			paddr = round_down(in->phys_addr, SZ_64K);
-			size += in->phys_addr - paddr;
-
-			/*
-			 * Avoid wasting memory on PTEs by choosing a virtual
-			 * base that is compatible with section mappings if this
-			 * region has the appropriate size and physical
-			 * alignment. (Sections are 2 MB on 4k granule kernels)
-			 */
-			if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
-				efi_virt_base = round_up(efi_virt_base, SZ_2M);
-			else
-				efi_virt_base = round_up(efi_virt_base, SZ_64K);
-
-			in->virt_addr += efi_virt_base - paddr;
-			efi_virt_base += size;
-		}
-
-		memcpy(out, in, desc_size);
-		out = (void *)out + desc_size;
-		++*count;
-	}
-}