Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

Pull EFI updates for v5.7 from Ard Biesheuvel:

This time, the set of changes for the EFI subsystem is much larger than
usual. The main reasons are:

 - Get things cleaned up before EFI support for RISC-V arrives, which will
   increase the size of the validation matrix, and therefore the threshold to
   making drastic changes,

 - After years of defunct maintainership, the GRUB project has finally started
   to consider changes from the distros regarding UEFI boot, some of which are
   highly specific to the way x86 does UEFI secure boot and measured boot,
   based on knowledge of both shim internals and the layout of bootparams and
   the x86 setup header. Having this maintenance burden on other architectures
   (which don't need shim in the first place) is hard to justify, so instead,
   we are introducing a generic Linux/UEFI boot protocol.

Summary of changes:

 - Boot time GDT handling changes (Arvind)

 - Simplify handling of EFI properties table on arm64

 - Generic EFI stub cleanups, to improve command line handling, file I/O,
   memory allocation, etc.

 - Introduce a generic initrd loading method based on calling back into
   the firmware, instead of relying on the x86 EFI handover protocol or
   device tree.

 - Introduce a mixed mode boot method that does not rely on the x86 EFI
   handover protocol either, and could potentially be adopted by other
   architectures (if another one ever surfaces where one execution mode
   is a superset of another)

 - Clean up the contents of struct efi, and move out everything that
   doesn't need to be stored there.

 - Incorporate support for UEFI spec v2.8A changes that permit firmware
   implementations to return EFI_UNSUPPORTED from UEFI runtime services at
   OS runtime, and expose a mask of which ones are supported or unsupported
   via a configuration table.

 - Various documentation updates and minor code cleanups (Heinrich)

 - Partial fix for the lack of by-VA cache maintenance in the decompressor
   on 32-bit ARM. Note that these patches were deliberately put at the
   beginning so they can be used as a stable branch that will be shared with
   a PR containing the complete fix, which I will send to the ARM tree.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

6 files changed, 155 insertions, 972 deletions

diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 26050ae0b27e..e51879bdc51c 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -87,10 +87,7 @@ endif
 
 vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
 
-$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
-
-vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o \
-	$(objtree)/drivers/firmware/efi/libstub/lib.a
+vmlinux-objs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
 vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
 
 # The compressed kernel is built with -fPIC/-fPIE so that a boot loader
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
deleted file mode 100644
index 287393d725f0..000000000000
--- a/arch/x86/boot/compressed/eboot.c
+++ /dev/null
@@ -1,889 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-
-/* -----------------------------------------------------------------------
- *
- *   Copyright 2011 Intel Corporation; author Matt Fleming
- *
- * ----------------------------------------------------------------------- */
-
-#pragma GCC visibility push(hidden)
-
-#include <linux/efi.h>
-#include <linux/pci.h>
-
-#include <asm/efi.h>
-#include <asm/e820/types.h>
-#include <asm/setup.h>
-#include <asm/desc.h>
-#include <asm/boot.h>
-
-#include "../string.h"
-#include "eboot.h"
-
-static efi_system_table_t *sys_table;
-extern const bool efi_is64;
-
-__pure efi_system_table_t *efi_system_table(void)
-{
-	return sys_table;
-}
-
-__attribute_const__ bool efi_is_64bit(void)
-{
-	if (IS_ENABLED(CONFIG_EFI_MIXED))
-		return efi_is64;
-	return IS_ENABLED(CONFIG_X86_64);
-}
-
-static efi_status_t
-preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
-{
-	struct pci_setup_rom *rom = NULL;
-	efi_status_t status;
-	unsigned long size;
-	uint64_t romsize;
-	void *romimage;
-
-	/*
-	 * Some firmware images contain EFI function pointers at the place where
-	 * the romimage and romsize fields are supposed to be. Typically the EFI
-	 * code is mapped at high addresses, translating to an unrealistically
-	 * large romsize. The UEFI spec limits the size of option ROMs to 16
-	 * MiB so we reject any ROMs over 16 MiB in size to catch this.
-	 */
-	romimage = efi_table_attr(pci, romimage);
-	romsize = efi_table_attr(pci, romsize);
-	if (!romimage || !romsize || romsize > SZ_16M)
-		return EFI_INVALID_PARAMETER;
-
-	size = romsize + sizeof(*rom);
-
-	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
-			     (void **)&rom);
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to allocate memory for 'rom'\n");
-		return status;
-	}
-
-	memset(rom, 0, sizeof(*rom));
-
-	rom->data.type	= SETUP_PCI;
-	rom->data.len	= size - sizeof(struct setup_data);
-	rom->data.next	= 0;
-	rom->pcilen	= pci->romsize;
-	*__rom = rom;
-
-	status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
-				PCI_VENDOR_ID, 1, &rom->vendor);
-
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to read rom->vendor\n");
-		goto free_struct;
-	}
-
-	status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
-				PCI_DEVICE_ID, 1, &rom->devid);
-
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to read rom->devid\n");
-		goto free_struct;
-	}
-
-	status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
-				&rom->device, &rom->function);
-
-	if (status != EFI_SUCCESS)
-		goto free_struct;
-
-	memcpy(rom->romdata, romimage, romsize);
-	return status;
-
-free_struct:
-	efi_bs_call(free_pool, rom);
-	return status;
-}
-
-/*
- * There's no way to return an informative status from this function,
- * because any analysis (and printing of error messages) needs to be
- * done directly at the EFI function call-site.
- *
- * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
- * just didn't find any PCI devices, but there's no way to tell outside
- * the context of the call.
- */
-static void setup_efi_pci(struct boot_params *params)
-{
-	efi_status_t status;
-	void **pci_handle = NULL;
-	efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
-	unsigned long size = 0;
-	struct setup_data *data;
-	efi_handle_t h;
-	int i;
-
-	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-			     &pci_proto, NULL, &size, pci_handle);
-
-	if (status == EFI_BUFFER_TOO_SMALL) {
-		status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
-				     (void **)&pci_handle);
-
-		if (status != EFI_SUCCESS) {
-			efi_printk("Failed to allocate memory for 'pci_handle'\n");
-			return;
-		}
-
-		status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-				     &pci_proto, NULL, &size, pci_handle);
-	}
-
-	if (status != EFI_SUCCESS)
-		goto free_handle;
-
-	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
-
-	while (data && data->next)
-		data = (struct setup_data *)(unsigned long)data->next;
-
-	for_each_efi_handle(h, pci_handle, size, i) {
-		efi_pci_io_protocol_t *pci = NULL;
-		struct pci_setup_rom *rom;
-
-		status = efi_bs_call(handle_protocol, h, &pci_proto,
-				     (void **)&pci);
-		if (status != EFI_SUCCESS || !pci)
-			continue;
-
-		status = preserve_pci_rom_image(pci, &rom);
-		if (status != EFI_SUCCESS)
-			continue;
-
-		if (data)
-			data->next = (unsigned long)rom;
-		else
-			params->hdr.setup_data = (unsigned long)rom;
-
-		data = (struct setup_data *)rom;
-	}
-
-free_handle:
-	efi_bs_call(free_pool, pci_handle);
-}
-
-static void retrieve_apple_device_properties(struct boot_params *boot_params)
-{
-	efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
-	struct setup_data *data, *new;
-	efi_status_t status;
-	u32 size = 0;
-	apple_properties_protocol_t *p;
-
-	status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
-	if (status != EFI_SUCCESS)
-		return;
-
-	if (efi_table_attr(p, version) != 0x10000) {
-		efi_printk("Unsupported properties proto version\n");
-		return;
-	}
-
-	efi_call_proto(p, get_all, NULL, &size);
-	if (!size)
-		return;
-
-	do {
-		status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
-				     size + sizeof(struct setup_data),
-				     (void **)&new);
-		if (status != EFI_SUCCESS) {
-			efi_printk("Failed to allocate memory for 'properties'\n");
-			return;
-		}
-
-		status = efi_call_proto(p, get_all, new->data, &size);
-
-		if (status == EFI_BUFFER_TOO_SMALL)
-			efi_bs_call(free_pool, new);
-	} while (status == EFI_BUFFER_TOO_SMALL);
-
-	new->type = SETUP_APPLE_PROPERTIES;
-	new->len  = size;
-	new->next = 0;
-
-	data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
-	if (!data) {
-		boot_params->hdr.setup_data = (unsigned long)new;
-	} else {
-		while (data->next)
-			data = (struct setup_data *)(unsigned long)data->next;
-		data->next = (unsigned long)new;
-	}
-}
-
-static const efi_char16_t apple[] = L"Apple";
-
-static void setup_quirks(struct boot_params *boot_params)
-{
-	efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
-		efi_table_attr(efi_system_table(), fw_vendor);
-
-	if (!memcmp(fw_vendor, apple, sizeof(apple))) {
-		if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
-			retrieve_apple_device_properties(boot_params);
-	}
-}
-
-/*
- * See if we have Universal Graphics Adapter (UGA) protocol
- */
-static efi_status_t
-setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
-{
-	efi_status_t status;
-	u32 width, height;
-	void **uga_handle = NULL;
-	efi_uga_draw_protocol_t *uga = NULL, *first_uga;
-	efi_handle_t handle;
-	int i;
-
-	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
-			     (void **)&uga_handle);
-	if (status != EFI_SUCCESS)
-		return status;
-
-	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-			     uga_proto, NULL, &size, uga_handle);
-	if (status != EFI_SUCCESS)
-		goto free_handle;
-
-	height = 0;
-	width = 0;
-
-	first_uga = NULL;
-	for_each_efi_handle(handle, uga_handle, size, i) {
-		efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
-		u32 w, h, depth, refresh;
-		void *pciio;
-
-		status = efi_bs_call(handle_protocol, handle, uga_proto,
-				     (void **)&uga);
-		if (status != EFI_SUCCESS)
-			continue;
-
-		pciio = NULL;
-		efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
-
-		status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
-		if (status == EFI_SUCCESS && (!first_uga || pciio)) {
-			width = w;
-			height = h;
-
-			/*
-			 * Once we've found a UGA supporting PCIIO,
-			 * don't bother looking any further.
-			 */
-			if (pciio)
-				break;
-
-			first_uga = uga;
-		}
-	}
-
-	if (!width && !height)
-		goto free_handle;
-
-	/* EFI framebuffer */
-	si->orig_video_isVGA	= VIDEO_TYPE_EFI;
-
-	si->lfb_depth		= 32;
-	si->lfb_width		= width;
-	si->lfb_height		= height;
-
-	si->red_size		= 8;
-	si->red_pos		= 16;
-	si->green_size		= 8;
-	si->green_pos		= 8;
-	si->blue_size		= 8;
-	si->blue_pos		= 0;
-	si->rsvd_size		= 8;
-	si->rsvd_pos		= 24;
-
-free_handle:
-	efi_bs_call(free_pool, uga_handle);
-
-	return status;
-}
-
-void setup_graphics(struct boot_params *boot_params)
-{
-	efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
-	struct screen_info *si;
-	efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
-	efi_status_t status;
-	unsigned long size;
-	void **gop_handle = NULL;
-	void **uga_handle = NULL;
-
-	si = &boot_params->screen_info;
-	memset(si, 0, sizeof(*si));
-
-	size = 0;
-	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-			     &graphics_proto, NULL, &size, gop_handle);
-	if (status == EFI_BUFFER_TOO_SMALL)
-		status = efi_setup_gop(si, &graphics_proto, size);
-
-	if (status != EFI_SUCCESS) {
-		size = 0;
-		status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-				     &uga_proto, NULL, &size, uga_handle);
-		if (status == EFI_BUFFER_TOO_SMALL)
-			setup_uga(si, &uga_proto, size);
-	}
-}
-
-void startup_32(struct boot_params *boot_params);
-
-void __noreturn efi_stub_entry(efi_handle_t handle,
-			       efi_system_table_t *sys_table_arg,
-			       struct boot_params *boot_params);
-
-/*
- * Because the x86 boot code expects to be passed a boot_params we
- * need to create one ourselves (usually the bootloader would create
- * one for us).
- */
-efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
-				   efi_system_table_t *sys_table_arg)
-{
-	struct boot_params *boot_params;
-	struct apm_bios_info *bi;
-	struct setup_header *hdr;
-	efi_loaded_image_t *image;
-	efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
-	int options_size = 0;
-	efi_status_t status;
-	char *cmdline_ptr;
-	unsigned long ramdisk_addr;
-	unsigned long ramdisk_size;
-
-	sys_table = sys_table_arg;
-
-	/* Check if we were booted by the EFI firmware */
-	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
-		return EFI_INVALID_PARAMETER;
-
-	status = efi_bs_call(handle_protocol, handle, &proto, (void *)&image);
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
-		return status;
-	}
-
-	status = efi_low_alloc(0x4000, 1, (unsigned long *)&boot_params);
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to allocate lowmem for boot params\n");
-		return status;
-	}
-
-	memset(boot_params, 0x0, 0x4000);
-
-	hdr = &boot_params->hdr;
-	bi = &boot_params->apm_bios_info;
-
-	/* Copy the second sector to boot_params */
-	memcpy(&hdr->jump, image->image_base + 512, 512);
-
-	/*
-	 * Fill out some of the header fields ourselves because the
-	 * EFI firmware loader doesn't load the first sector.
-	 */
-	hdr->root_flags	= 1;
-	hdr->vid_mode	= 0xffff;
-	hdr->boot_flag	= 0xAA55;
-
-	hdr->type_of_loader = 0x21;
-
-	/* Convert unicode cmdline to ascii */
-	cmdline_ptr = efi_convert_cmdline(image, &options_size);
-	if (!cmdline_ptr)
-		goto fail;
-
-	hdr->cmd_line_ptr = (unsigned long)cmdline_ptr;
-	/* Fill in upper bits of command line address, NOP on 32 bit  */
-	boot_params->ext_cmd_line_ptr = (u64)(unsigned long)cmdline_ptr >> 32;
-
-	hdr->ramdisk_image = 0;
-	hdr->ramdisk_size = 0;
-
-	/* Clear APM BIOS info */
-	memset(bi, 0, sizeof(*bi));
-
-	status = efi_parse_options(cmdline_ptr);
-	if (status != EFI_SUCCESS)
-		goto fail2;
-
-	status = handle_cmdline_files(image,
-				      (char *)(unsigned long)hdr->cmd_line_ptr,
-				      "initrd=", hdr->initrd_addr_max,
-				      &ramdisk_addr, &ramdisk_size);
-
-	if (status != EFI_SUCCESS &&
-	    hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G) {
-		efi_printk("Trying to load files to higher address\n");
-		status = handle_cmdline_files(image,
-				      (char *)(unsigned long)hdr->cmd_line_ptr,
-				      "initrd=", -1UL,
-				      &ramdisk_addr, &ramdisk_size);
-	}
-
-	if (status != EFI_SUCCESS)
-		goto fail2;
-	hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
-	hdr->ramdisk_size  = ramdisk_size & 0xffffffff;
-	boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;
-	boot_params->ext_ramdisk_size  = (u64)ramdisk_size >> 32;
-
-	hdr->code32_start = (u32)(unsigned long)startup_32;
-
-	efi_stub_entry(handle, sys_table, boot_params);
-	/* not reached */
-
-fail2:
-	efi_free(options_size, hdr->cmd_line_ptr);
-fail:
-	efi_free(0x4000, (unsigned long)boot_params);
-
-	return status;
-}
-
-static void add_e820ext(struct boot_params *params,
-			struct setup_data *e820ext, u32 nr_entries)
-{
-	struct setup_data *data;
-
-	e820ext->type = SETUP_E820_EXT;
-	e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
-	e820ext->next = 0;
-
-	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
-
-	while (data && data->next)
-		data = (struct setup_data *)(unsigned long)data->next;
-
-	if (data)
-		data->next = (unsigned long)e820ext;
-	else
-		params->hdr.setup_data = (unsigned long)e820ext;
-}
-
-static efi_status_t
-setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
-{
-	struct boot_e820_entry *entry = params->e820_table;
-	struct efi_info *efi = &params->efi_info;
-	struct boot_e820_entry *prev = NULL;
-	u32 nr_entries;
-	u32 nr_desc;
-	int i;
-
-	nr_entries = 0;
-	nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
-
-	for (i = 0; i < nr_desc; i++) {
-		efi_memory_desc_t *d;
-		unsigned int e820_type = 0;
-		unsigned long m = efi->efi_memmap;
-
-#ifdef CONFIG_X86_64
-		m |= (u64)efi->efi_memmap_hi << 32;
-#endif
-
-		d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
-		switch (d->type) {
-		case EFI_RESERVED_TYPE:
-		case EFI_RUNTIME_SERVICES_CODE:
-		case EFI_RUNTIME_SERVICES_DATA:
-		case EFI_MEMORY_MAPPED_IO:
-		case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
-		case EFI_PAL_CODE:
-			e820_type = E820_TYPE_RESERVED;
-			break;
-
-		case EFI_UNUSABLE_MEMORY:
-			e820_type = E820_TYPE_UNUSABLE;
-			break;
-
-		case EFI_ACPI_RECLAIM_MEMORY:
-			e820_type = E820_TYPE_ACPI;
-			break;
-
-		case EFI_LOADER_CODE:
-		case EFI_LOADER_DATA:
-		case EFI_BOOT_SERVICES_CODE:
-		case EFI_BOOT_SERVICES_DATA:
-		case EFI_CONVENTIONAL_MEMORY:
-			if (efi_soft_reserve_enabled() &&
-			    (d->attribute & EFI_MEMORY_SP))
-				e820_type = E820_TYPE_SOFT_RESERVED;
-			else
-				e820_type = E820_TYPE_RAM;
-			break;
-
-		case EFI_ACPI_MEMORY_NVS:
-			e820_type = E820_TYPE_NVS;
-			break;
-
-		case EFI_PERSISTENT_MEMORY:
-			e820_type = E820_TYPE_PMEM;
-			break;
-
-		default:
-			continue;
-		}
-
-		/* Merge adjacent mappings */
-		if (prev && prev->type == e820_type &&
-		    (prev->addr + prev->size) == d->phys_addr) {
-			prev->size += d->num_pages << 12;
-			continue;
-		}
-
-		if (nr_entries == ARRAY_SIZE(params->e820_table)) {
-			u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
-				   sizeof(struct setup_data);
-
-			if (!e820ext || e820ext_size < need)
-				return EFI_BUFFER_TOO_SMALL;
-
-			/* boot_params map full, switch to e820 extended */
-			entry = (struct boot_e820_entry *)e820ext->data;
-		}
-
-		entry->addr = d->phys_addr;
-		entry->size = d->num_pages << PAGE_SHIFT;
-		entry->type = e820_type;
-		prev = entry++;
-		nr_entries++;
-	}
-
-	if (nr_entries > ARRAY_SIZE(params->e820_table)) {
-		u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
-
-		add_e820ext(params, e820ext, nr_e820ext);
-		nr_entries -= nr_e820ext;
-	}
-
-	params->e820_entries = (u8)nr_entries;
-
-	return EFI_SUCCESS;
-}
-
-static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
-				  u32 *e820ext_size)
-{
-	efi_status_t status;
-	unsigned long size;
-
-	size = sizeof(struct setup_data) +
-		sizeof(struct e820_entry) * nr_desc;
-
-	if (*e820ext) {
-		efi_bs_call(free_pool, *e820ext);
-		*e820ext = NULL;
-		*e820ext_size = 0;
-	}
-
-	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
-			     (void **)e820ext);
-	if (status == EFI_SUCCESS)
-		*e820ext_size = size;
-
-	return status;
-}
-
-static efi_status_t allocate_e820(struct boot_params *params,
-				  struct setup_data **e820ext,
-				  u32 *e820ext_size)
-{
-	unsigned long map_size, desc_size, buff_size;
-	struct efi_boot_memmap boot_map;
-	efi_memory_desc_t *map;
-	efi_status_t status;
-	__u32 nr_desc;
-
-	boot_map.map		= &map;
-	boot_map.map_size	= &map_size;
-	boot_map.desc_size	= &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 status;
-
-	nr_desc = buff_size / desc_size;
-
-	if (nr_desc > ARRAY_SIZE(params->e820_table)) {
-		u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
-
-		status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
-		if (status != EFI_SUCCESS)
-			return status;
-	}
-
-	return EFI_SUCCESS;
-}
-
-struct exit_boot_struct {
-	struct boot_params	*boot_params;
-	struct efi_info		*efi;
-};
-
-static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
-				   void *priv)
-{
-	const char *signature;
-	struct exit_boot_struct *p = priv;
-
-	signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
-				   : EFI32_LOADER_SIGNATURE;
-	memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
-
-	p->efi->efi_systab		= (unsigned long)efi_system_table();
-	p->efi->efi_memdesc_size	= *map->desc_size;
-	p->efi->efi_memdesc_version	= *map->desc_ver;
-	p->efi->efi_memmap		= (unsigned long)*map->map;
-	p->efi->efi_memmap_size		= *map->map_size;
-
-#ifdef CONFIG_X86_64
-	p->efi->efi_systab_hi		= (unsigned long)efi_system_table() >> 32;
-	p->efi->efi_memmap_hi		= (unsigned long)*map->map >> 32;
-#endif
-
-	return EFI_SUCCESS;
-}
-
-static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
-{
-	unsigned long map_sz, key, desc_size, buff_size;
-	efi_memory_desc_t *mem_map;
-	struct setup_data *e820ext = NULL;
-	__u32 e820ext_size = 0;
-	efi_status_t status;
-	__u32 desc_version;
-	struct efi_boot_memmap map;
-	struct exit_boot_struct priv;
-
-	map.map			= &mem_map;
-	map.map_size		= &map_sz;
-	map.desc_size		= &desc_size;
-	map.desc_ver		= &desc_version;
-	map.key_ptr		= &key;
-	map.buff_size		= &buff_size;
-	priv.boot_params	= boot_params;
-	priv.efi		= &boot_params->efi_info;
-
-	status = allocate_e820(boot_params, &e820ext, &e820ext_size);
-	if (status != EFI_SUCCESS)
-		return status;
-
-	/* Might as well exit boot services now */
-	status = efi_exit_boot_services(handle, &map, &priv, exit_boot_func);
-	if (status != EFI_SUCCESS)
-		return status;
-
-	/* Historic? */
-	boot_params->alt_mem_k	= 32 * 1024;
-
-	status = setup_e820(boot_params, e820ext, e820ext_size);
-	if (status != EFI_SUCCESS)
-		return status;
-
-	return EFI_SUCCESS;
-}
-
-/*
- * On success we return a pointer to a boot_params structure, and NULL
- * on failure.
- */
-struct boot_params *efi_main(efi_handle_t handle,
-			     efi_system_table_t *sys_table_arg,
-			     struct boot_params *boot_params)
-{
-	struct desc_ptr *gdt = NULL;
-	struct setup_header *hdr = &boot_params->hdr;
-	efi_status_t status;
-	struct desc_struct *desc;
-	unsigned long cmdline_paddr;
-
-	sys_table = sys_table_arg;
-
-	/* Check if we were booted by the EFI firmware */
-	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
-		goto fail;
-
-	/*
-	 * make_boot_params() may have been called before efi_main(), in which
-	 * case this is the second time we parse the cmdline. This is ok,
-	 * parsing the cmdline multiple times does not have side-effects.
-	 */
-	cmdline_paddr = ((u64)hdr->cmd_line_ptr |
-			 ((u64)boot_params->ext_cmd_line_ptr << 32));
-	efi_parse_options((char *)cmdline_paddr);
-
-	/*
-	 * If the boot loader gave us a value for secure_boot then we use that,
-	 * otherwise we ask the BIOS.
-	 */
-	if (boot_params->secure_boot == efi_secureboot_mode_unset)
-		boot_params->secure_boot = efi_get_secureboot();
-
-	/* Ask the firmware to clear memory on unclean shutdown */
-	efi_enable_reset_attack_mitigation();
-
-	efi_random_get_seed();
-
-	efi_retrieve_tpm2_eventlog();
-
-	setup_graphics(boot_params);
-
-	setup_efi_pci(boot_params);
-
-	setup_quirks(boot_params);
-
-	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(*gdt),
-			     (void **)&gdt);
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to allocate memory for 'gdt' structure\n");
-		goto fail;
-	}
-
-	gdt->size = 0x800;
-	status = efi_low_alloc(gdt->size, 8, (unsigned long *)&gdt->address);
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to allocate memory for 'gdt'\n");
-		goto fail;
-	}
-
-	/*
-	 * If the kernel isn't already loaded at the preferred load
-	 * address, relocate it.
-	 */
-	if (hdr->pref_address != hdr->code32_start) {
-		unsigned long bzimage_addr = hdr->code32_start;
-		status = efi_relocate_kernel(&bzimage_addr,
-					     hdr->init_size, hdr->init_size,
-					     hdr->pref_address,
-					     hdr->kernel_alignment,
-					     LOAD_PHYSICAL_ADDR);
-		if (status != EFI_SUCCESS) {
-			efi_printk("efi_relocate_kernel() failed!\n");
-			goto fail;
-		}
-
-		hdr->pref_address = hdr->code32_start;
-		hdr->code32_start = bzimage_addr;
-	}
-
-	status = exit_boot(boot_params, handle);
-	if (status != EFI_SUCCESS) {
-		efi_printk("exit_boot() failed!\n");
-		goto fail;
-	}
-
-	memset((char *)gdt->address, 0x0, gdt->size);
-	desc = (struct desc_struct *)gdt->address;
-
-	/* The first GDT is a dummy. */
-	desc++;
-
-	if (IS_ENABLED(CONFIG_X86_64)) {
-		/* __KERNEL32_CS */
-		desc->limit0	= 0xffff;
-		desc->base0	= 0x0000;
-		desc->base1	= 0x0000;
-		desc->type	= SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
-		desc->s		= DESC_TYPE_CODE_DATA;
-		desc->dpl	= 0;
-		desc->p		= 1;
-		desc->limit1	= 0xf;
-		desc->avl	= 0;
-		desc->l		= 0;
-		desc->d		= SEG_OP_SIZE_32BIT;
-		desc->g		= SEG_GRANULARITY_4KB;
-		desc->base2	= 0x00;
-
-		desc++;
-	} else {
-		/* Second entry is unused on 32-bit */
-		desc++;
-	}
-
-	/* __KERNEL_CS */
-	desc->limit0	= 0xffff;
-	desc->base0	= 0x0000;
-	desc->base1	= 0x0000;
-	desc->type	= SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
-	desc->s		= DESC_TYPE_CODE_DATA;
-	desc->dpl	= 0;
-	desc->p		= 1;
-	desc->limit1	= 0xf;
-	desc->avl	= 0;
-
-	if (IS_ENABLED(CONFIG_X86_64)) {
-		desc->l = 1;
-		desc->d = 0;
-	} else {
-		desc->l = 0;
-		desc->d = SEG_OP_SIZE_32BIT;
-	}
-	desc->g		= SEG_GRANULARITY_4KB;
-	desc->base2	= 0x00;
-	desc++;
-
-	/* __KERNEL_DS */
-	desc->limit0	= 0xffff;
-	desc->base0	= 0x0000;
-	desc->base1	= 0x0000;
-	desc->type	= SEG_TYPE_DATA | SEG_TYPE_READ_WRITE;
-	desc->s		= DESC_TYPE_CODE_DATA;
-	desc->dpl	= 0;
-	desc->p		= 1;
-	desc->limit1	= 0xf;
-	desc->avl	= 0;
-	desc->l		= 0;
-	desc->d		= SEG_OP_SIZE_32BIT;
-	desc->g		= SEG_GRANULARITY_4KB;
-	desc->base2	= 0x00;
-	desc++;
-
-	if (IS_ENABLED(CONFIG_X86_64)) {
-		/* Task segment value */
-		desc->limit0	= 0x0000;
-		desc->base0	= 0x0000;
-		desc->base1	= 0x0000;
-		desc->type	= SEG_TYPE_TSS;
-		desc->s		= 0;
-		desc->dpl	= 0;
-		desc->p		= 1;
-		desc->limit1	= 0x0;
-		desc->avl	= 0;
-		desc->l		= 0;
-		desc->d		= 0;
-		desc->g		= SEG_GRANULARITY_4KB;
-		desc->base2	= 0x00;
-		desc++;
-	}
-
-	asm volatile("cli");
-	asm volatile ("lgdt %0" : : "m" (*gdt));
-
-	return boot_params;
-fail:
-	efi_printk("efi_main() failed!\n");
-
-	for (;;)
-		asm("hlt");
-}
diff --git a/arch/x86/boot/compressed/eboot.h b/arch/x86/boot/compressed/eboot.h
deleted file mode 100644
index 99f35343d443..000000000000
--- a/arch/x86/boot/compressed/eboot.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef BOOT_COMPRESSED_EBOOT_H
-#define BOOT_COMPRESSED_EBOOT_H
-
-#define SEG_TYPE_DATA		(0 << 3)
-#define SEG_TYPE_READ_WRITE	(1 << 1)
-#define SEG_TYPE_CODE		(1 << 3)
-#define SEG_TYPE_EXEC_READ	(1 << 1)
-#define SEG_TYPE_TSS		((1 << 3) | (1 << 0))
-#define SEG_OP_SIZE_32BIT	(1 << 0)
-#define SEG_GRANULARITY_4KB	(1 << 0)
-
-#define DESC_TYPE_CODE_DATA	(1 << 0)
-
-typedef union efi_uga_draw_protocol efi_uga_draw_protocol_t;
-
-union efi_uga_draw_protocol {
-	struct {
-		efi_status_t (__efiapi *get_mode)(efi_uga_draw_protocol_t *,
-						  u32*, u32*, u32*, u32*);
-		void *set_mode;
-		void *blt;
-	};
-	struct {
-		u32 get_mode;
-		u32 set_mode;
-		u32 blt;
-	} mixed_mode;
-};
-
-#endif /* BOOT_COMPRESSED_EBOOT_H */
diff --git a/arch/x86/boot/compressed/efi_thunk_64.S b/arch/x86/boot/compressed/efi_thunk_64.S
index 8fb7f6799c52..2b2049259619 100644
--- a/arch/x86/boot/compressed/efi_thunk_64.S
+++ b/arch/x86/boot/compressed/efi_thunk_64.S
@@ -54,11 +54,16 @@ SYM_FUNC_START(__efi64_thunk)
 	 * Switch to gdt with 32-bit segments. This is the firmware GDT
 	 * that was installed when the kernel started executing. This
 	 * pointer was saved at the EFI stub entry point in head_64.S.
+	 *
+	 * Pass the saved DS selector to the 32-bit code, and use far return to
+	 * restore the saved CS selector.
 	 */
 	leaq	efi32_boot_gdt(%rip), %rax
 	lgdt	(%rax)
 
-	pushq	$__KERNEL_CS
+	movzwl	efi32_boot_ds(%rip), %edx
+	movzwq	efi32_boot_cs(%rip), %rax
+	pushq	%rax
 	leaq	efi_enter32(%rip), %rax
 	pushq	%rax
 	lretq
@@ -73,6 +78,10 @@ SYM_FUNC_START(__efi64_thunk)
 	movl	%ebx, %es
 	pop	%rbx
 	movl	%ebx, %ds
+	/* Clear out 32-bit selector from FS and GS */
+	xorl	%ebx, %ebx
+	movl	%ebx, %fs
+	movl	%ebx, %gs
 
 	/*
 	 * Convert 32-bit status code into 64-bit.
@@ -92,10 +101,12 @@ SYM_FUNC_END(__efi64_thunk)
  * The stack should represent the 32-bit calling convention.
  */
 SYM_FUNC_START_LOCAL(efi_enter32)
-	movl	$__KERNEL_DS, %eax
-	movl	%eax, %ds
-	movl	%eax, %es
-	movl	%eax, %ss
+	/* Load firmware selector into data and stack segment registers */
+	movl	%edx, %ds
+	movl	%edx, %es
+	movl	%edx, %fs
+	movl	%edx, %gs
+	movl	%edx, %ss
 
 	/* Reload pgtables */
 	movl	%cr3, %eax
@@ -157,6 +168,14 @@ SYM_DATA_START(efi32_boot_gdt)
 	.quad	0
 SYM_DATA_END(efi32_boot_gdt)
 
+SYM_DATA_START(efi32_boot_cs)
+	.word	0
+SYM_DATA_END(efi32_boot_cs)
+
+SYM_DATA_START(efi32_boot_ds)
+	.word	0
+SYM_DATA_END(efi32_boot_ds)
+
 SYM_DATA_START(efi_gdt64)
 	.word	efi_gdt64_end - efi_gdt64
 	.long	0			/* Filled out by user */
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 73f17d0544dd..356060c5332c 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -63,21 +63,7 @@
 	__HEAD
 SYM_FUNC_START(startup_32)
 	cld
-	/*
-	 * Test KEEP_SEGMENTS flag to see if the bootloader is asking
-	 * us to not reload segments
-	 */
-	testb	$KEEP_SEGMENTS, BP_loadflags(%esi)
-	jnz	1f
-
 	cli
-	movl	$__BOOT_DS, %eax
-	movl	%eax, %ds
-	movl	%eax, %es
-	movl	%eax, %fs
-	movl	%eax, %gs
-	movl	%eax, %ss
-1:
 
 /*
  * Calculate the delta between where we were compiled to run
@@ -92,6 +78,19 @@ SYM_FUNC_START(startup_32)
 1:	popl	%ebp
 	subl	$1b, %ebp
 
+	/* Load new GDT */
+	leal	gdt(%ebp), %eax
+	movl	%eax, 2(%eax)
+	lgdt	(%eax)
+
+	/* Load segment registers with our descriptors */
+	movl	$__BOOT_DS, %eax
+	movl	%eax, %ds
+	movl	%eax, %es
+	movl	%eax, %fs
+	movl	%eax, %gs
+	movl	%eax, %ss
+
 /*
  * %ebp contains the address we are loaded at by the boot loader and %ebx
  * contains the address where we should move the kernel image temporarily
@@ -137,6 +136,16 @@ SYM_FUNC_START(startup_32)
 	cld
 	popl	%esi
 
+	/*
+	 * The GDT may get overwritten either during the copy we just did or
+	 * during extract_kernel below. To avoid any issues, repoint the GDTR
+	 * to the new copy of the GDT. EAX still contains the previously
+	 * calculated relocation offset of init_size - _end.
+	 */
+	leal	gdt(%ebx), %edx
+	addl	%eax, 2(%edx)
+	lgdt	(%edx)
+
 /*
  * Jump to the relocated address.
  */
@@ -209,6 +218,17 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated)
 	jmp	*%eax
 SYM_FUNC_END(.Lrelocated)
 
+	.data
+	.balign	8
+SYM_DATA_START_LOCAL(gdt)
+	.word	gdt_end - gdt - 1
+	.long	0
+	.word	0
+	.quad	0x0000000000000000	/* Reserved */
+	.quad	0x00cf9a000000ffff	/* __KERNEL_CS */
+	.quad	0x00cf92000000ffff	/* __KERNEL_DS */
+SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
+
 /*
  * Stack and heap for uncompression
  */
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 1f1f6c8139b3..f7bacc4c1494 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -53,19 +53,7 @@ SYM_FUNC_START(startup_32)
 	 * all need to be under the 4G limit.
 	 */
 	cld
-	/*
-	 * Test KEEP_SEGMENTS flag to see if the bootloader is asking
-	 * us to not reload segments
-	 */
-	testb $KEEP_SEGMENTS, BP_loadflags(%esi)
-	jnz 1f
-
 	cli
-	movl	$(__BOOT_DS), %eax
-	movl	%eax, %ds
-	movl	%eax, %es
-	movl	%eax, %ss
-1:
 
 /*
  * Calculate the delta between where we were compiled to run
@@ -80,10 +68,21 @@ SYM_FUNC_START(startup_32)
 1:	popl	%ebp
 	subl	$1b, %ebp
 
+	/* Load new GDT with the 64bit segments using 32bit descriptor */
+	leal	gdt(%ebp), %eax
+	movl	%eax, 2(%eax)
+	lgdt	(%eax)
+
+	/* Load segment registers with our descriptors */
+	movl	$__BOOT_DS, %eax
+	movl	%eax, %ds
+	movl	%eax, %es
+	movl	%eax, %fs
+	movl	%eax, %gs
+	movl	%eax, %ss
+
 /* setup a stack and make sure cpu supports long mode. */
-	movl	$boot_stack_end, %eax
-	addl	%ebp, %eax
-	movl	%eax, %esp
+	leal	boot_stack_end(%ebp), %esp
 
 	call	verify_cpu
 	testl	%eax, %eax
@@ -120,10 +119,6 @@ SYM_FUNC_START(startup_32)
  * Prepare for entering 64 bit mode
  */
 
-	/* Load new GDT with the 64bit segments using 32bit descriptor */
-	addl	%ebp, gdt+2(%ebp)
-	lgdt	gdt(%ebp)
-
 	/* Enable PAE mode */
 	movl	%cr4, %eax
 	orl	$X86_CR4_PAE, %eax
@@ -212,8 +207,13 @@ SYM_FUNC_START(startup_32)
 	cmp	$0, %edi
 	jz	1f
 	leal	efi64_stub_entry(%ebp), %eax
-	movl	%esi, %edx
 	movl	efi32_boot_args+4(%ebp), %esi
+	movl	efi32_boot_args+8(%ebp), %edx	// saved bootparams pointer
+	cmpl	$0, %edx
+	jnz	1f
+	leal	efi_pe_entry(%ebp), %eax
+	movl	%edi, %ecx			// MS calling convention
+	movl	%esi, %edx
 1:
 #endif
 	pushl	%eax
@@ -238,11 +238,17 @@ SYM_FUNC_START(efi32_stub_entry)
 1:	pop	%ebp
 	subl	$1b, %ebp
 
+	movl	%esi, efi32_boot_args+8(%ebp)
+SYM_INNER_LABEL(efi32_pe_stub_entry, SYM_L_LOCAL)
 	movl	%ecx, efi32_boot_args(%ebp)
 	movl	%edx, efi32_boot_args+4(%ebp)
-	sgdtl	efi32_boot_gdt(%ebp)
 	movb	$0, efi_is64(%ebp)
 
+	/* Save firmware GDTR and code/data selectors */
+	sgdtl	efi32_boot_gdt(%ebp)
+	movw	%cs, efi32_boot_cs(%ebp)
+	movw	%ds, efi32_boot_ds(%ebp)
+
 	/* Disable paging */
 	movl	%cr0, %eax
 	btrl	$X86_CR0_PG_BIT, %eax
@@ -266,6 +272,9 @@ SYM_CODE_START(startup_64)
 	 * and command line.
 	 */
 
+	cld
+	cli
+
 	/* Setup data segments. */
 	xorl	%eax, %eax
 	movl	%eax, %ds
@@ -354,9 +363,9 @@ SYM_CODE_START(startup_64)
 	 */
 
 	/* Make sure we have GDT with 32-bit code segment */
-	leaq	gdt(%rip), %rax
-	movq	%rax, gdt64+2(%rip)
-	lgdt	gdt64(%rip)
+	leaq	gdt64(%rip), %rax
+	addq	%rax, 2(%rax)
+	lgdt	(%rax)
 
 	/*
 	 * paging_prepare() sets up the trampoline and checks if we need to
@@ -441,6 +450,16 @@ trampoline_return:
 	cld
 	popq	%rsi
 
+	/*
+	 * The GDT may get overwritten either during the copy we just did or
+	 * during extract_kernel below. To avoid any issues, repoint the GDTR
+	 * to the new copy of the GDT.
+	 */
+	leaq	gdt64(%rbx), %rax
+	subq	%rbp, 2(%rax)
+	addq	%rbx, 2(%rax)
+	lgdt	(%rax)
+
 /*
  * Jump to the relocated address.
  */
@@ -613,13 +632,13 @@ SYM_FUNC_END(.Lno_longmode)
 
 	.data
 SYM_DATA_START_LOCAL(gdt64)
-	.word	gdt_end - gdt
-	.quad   0
+	.word	gdt_end - gdt - 1
+	.quad   gdt - gdt64
 SYM_DATA_END(gdt64)
 	.balign	8
 SYM_DATA_START_LOCAL(gdt)
-	.word	gdt_end - gdt
-	.long	gdt
+	.word	gdt_end - gdt - 1
+	.long	0
 	.word	0
 	.quad	0x00cf9a000000ffff	/* __KERNEL32_CS */
 	.quad	0x00af9a000000ffff	/* __KERNEL_CS */
@@ -629,8 +648,56 @@ SYM_DATA_START_LOCAL(gdt)
 SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
 
 #ifdef CONFIG_EFI_MIXED
-SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0)
+SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0)
 SYM_DATA(efi_is64, .byte 1)
+
+#define ST32_boottime		60 // offsetof(efi_system_table_32_t, boottime)
+#define BS32_handle_protocol	88 // offsetof(efi_boot_services_32_t, handle_protocol)
+#define LI32_image_base		32 // offsetof(efi_loaded_image_32_t, image_base)
+
+	.text
+	.code32
+SYM_FUNC_START(efi32_pe_entry)
+	pushl	%ebp
+
+	call	verify_cpu			// check for long mode support
+	testl	%eax, %eax
+	movl	$0x80000003, %eax		// EFI_UNSUPPORTED
+	jnz	3f
+
+	call	1f
+1:	pop	%ebp
+	subl	$1b, %ebp
+
+	/* Get the loaded image protocol pointer from the image handle */
+	subl	$12, %esp			// space for the loaded image pointer
+	pushl	%esp				// pass its address
+	leal	4f(%ebp), %eax
+	pushl	%eax				// pass the GUID address
+	pushl	28(%esp)			// pass the image handle
+
+	movl	36(%esp), %eax			// sys_table
+	movl	ST32_boottime(%eax), %eax	// sys_table->boottime
+	call	*BS32_handle_protocol(%eax)	// sys_table->boottime->handle_protocol
+	cmp	$0, %eax
+	jnz	2f
+
+	movl	32(%esp), %ecx			// image_handle
+	movl	36(%esp), %edx			// sys_table
+	movl	12(%esp), %esi			// loaded_image
+	movl	LI32_image_base(%esi), %esi	// loaded_image->image_base
+	jmp	efi32_pe_stub_entry
+
+2:	addl	$24, %esp
+3:	popl	%ebp
+	ret
+SYM_FUNC_END(efi32_pe_entry)
+
+	.section ".rodata"
+	/* EFI loaded image protocol GUID */
+4:	.long	0x5B1B31A1
+	.word	0x9562, 0x11d2
+	.byte	0x8E, 0x3F, 0x00, 0xA0, 0xC9, 0x69, 0x72, 0x3B
 #endif
 
 /*