x86/efi: Build our own EFI services pointer table

It's not possible to dereference the EFI System table directly when
booting a 64-bit kernel on a 32-bit EFI firmware because the size of
pointers don't match.

In preparation for supporting the above use case, build a list of
function pointers on boot so that callers don't have to worry about
converting pointer sizes through multiple levels of indirection.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

arch/x86/boot/compressed/eboot.h

@@ -103,4 +103,20 @@ struct efi_uga_draw_protocol {
 	void *blt;
 };
 
+struct efi_config {
+	u64 image_handle;
+	u64 table;
+	u64 allocate_pool;
+	u64 allocate_pages;
+	u64 get_memory_map;
+	u64 free_pool;
+	u64 free_pages;
+	u64 locate_handle;
+	u64 handle_protocol;
+	u64 exit_boot_services;
+	u64 text_output;
+	efi_status_t (*call)(unsigned long, ...);
+	bool is64;
+} __packed;
+
 #endif /* BOOT_COMPRESSED_EBOOT_H */

arch/x86/boot/compressed/head_32.S

@@ -42,26 +42,53 @@ ENTRY(startup_32)
 ENTRY(efi_pe_entry)
 	add	$0x4, %esp
 
+	call	1f
+1:	popl	%esi
+	subl	$1b, %esi
+
+	popl	%ecx
+	movl	%ecx, efi32_config(%esi)	/* Handle */
+	popl	%ecx
+	movl	%ecx, efi32_config+8(%esi)	/* EFI System table pointer */
+
+	/* Relocate efi_config->call() */
+	leal	efi32_config(%esi), %eax
+	add	%esi, 88(%eax)
+	pushl	%eax
+
 	call	make_boot_params
 	cmpl	$0, %eax
-	je	1f
-	movl	0x4(%esp), %esi
-	movl	(%esp), %ecx
+	je	fail
+	popl	%ecx
 	pushl	%eax
-	pushl	%esi
 	pushl	%ecx
-	sub	$0x4, %esp
+	jmp	2f		/* Skip efi_config initialization */
 
 ENTRY(efi_stub_entry)
 	add	$0x4, %esp
+	popl	%ecx
+	popl	%edx
+
+	call	1f
+1:	popl	%esi
+	subl	$1b, %esi
+
+	movl	%ecx, efi32_config(%esi)	/* Handle */
+	movl	%edx, efi32_config+8(%esi)	/* EFI System table pointer */
+
+	/* Relocate efi_config->call() */
+	leal	efi32_config(%esi), %eax
+	add	%esi, 88(%eax)
+	pushl	%eax
+2:
 	call	efi_main
 	cmpl	$0, %eax
 	movl	%eax, %esi
 	jne	2f
-1:
+fail:
 	/* EFI init failed, so hang. */
 	hlt
-	jmp	1b
+	jmp	fail
 2:
 	call	3f
 3:
@@ -202,6 +229,13 @@ relocated:
 	xorl	%ebx, %ebx
 	jmp	*%eax
 
+	.data
+efi32_config:
+	.fill 11,8,0
+	.long efi_call_phys
+	.long 0
+	.byte 0
+
 /*
  * Stack and heap for uncompression
  */

arch/x86/boot/compressed/head_64.S

@@ -209,26 +209,55 @@ ENTRY(startup_64)
 	jmp	preferred_addr
 
 ENTRY(efi_pe_entry)
-	mov	%rcx, %rdi
-	mov	%rdx, %rsi
-	pushq	%rdi
-	pushq	%rsi
+	movq	%rcx, efi64_config(%rip)	/* Handle */
+	movq	%rdx, efi64_config+8(%rip) /* EFI System table pointer */
+
+	leaq	efi64_config(%rip), %rax
+	movq	%rax, efi_config(%rip)
+
+	call	1f
+1:	popq	%rbp
+	subq	$1b, %rbp
+
+	/*
+	 * Relocate efi_config->call().
+	 */
+	addq	%rbp, efi64_config+88(%rip)
+
+	movq	%rax, %rdi
 	call	make_boot_params
 	cmpq	$0,%rax
-	je	1f
-	mov	%rax, %rdx
-	popq	%rsi
-	popq	%rdi
+	je	fail
+	mov	%rax, %rsi
+	jmp	2f		/* Skip the relocation */
 
 ENTRY(efi_stub_entry)
+	movq	%rdi, efi64_config(%rip)	/* Handle */
+	movq	%rsi, efi64_config+8(%rip) /* EFI System table pointer */
+
+	leaq	efi64_config(%rip), %rax
+	movq	%rax, efi_config(%rip)
+
+	call	1f
+1:	popq	%rbp
+	subq	$1b, %rbp
+
+	/*
+	 * Relocate efi_config->call().
+	 */
+	movq	efi_config(%rip), %rax
+	addq	%rbp, 88(%rax)
+	movq	%rdx, %rsi
+2:
+	movq	efi_config(%rip), %rdi
 	call	efi_main
 	movq	%rax,%rsi
 	cmpq	$0,%rax
 	jne	2f
-1:
+fail:
 	/* EFI init failed, so hang. */
 	hlt
-	jmp	1b
+	jmp	fail
 2:
 	call	3f
 3:
@@ -372,6 +401,14 @@ gdt:
 	.quad   0x0000000000000000	/* TS continued */
 gdt_end:
 
+efi_config:
+	.quad	0
+
+	.global efi64_config
+efi64_config:
+	.fill	11,8,0
+	.quad	efi_call6
+	.byte	1
 /*
  * Stack and heap for uncompression
  */

drivers/firmware/efi/efi-stub-helper.c

@@ -16,18 +16,6 @@ struct file_info {
 	u64 size;
 };
 
-
-
-
-static void efi_char16_printk(efi_system_table_t *sys_table_arg,
-			      efi_char16_t *str)
-{
-	struct efi_simple_text_output_protocol *out;
-
-	out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
-	efi_call_phys2(out->output_string, out, str);
-}
-
 static void efi_printk(efi_system_table_t *sys_table_arg, char *str)
 {
 	char *s8;
@@ -65,20 +53,23 @@ static efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg,
 	 * allocation which may be in a new descriptor region.
 	 */
 	*map_size += sizeof(*m);
-	status = efi_call_phys3(sys_table_arg->boottime->allocate_pool,
-				EFI_LOADER_DATA, *map_size, (void **)&m);
+	status = efi_early->call(efi_early->allocate_pool, EFI_LOADER_DATA,
+				 *map_size, (void **)&m);
 	if (status != EFI_SUCCESS)
 		goto fail;
 
-	status = efi_call_phys5(sys_table_arg->boottime->get_memory_map,
-				map_size, m, &key, desc_size, &desc_version);
+	*desc_size = 0;
+	key = 0;
+	status = efi_early->call(efi_early->get_memory_map, map_size, m,
+				 &key, desc_size, &desc_version);
 	if (status == EFI_BUFFER_TOO_SMALL) {
-		efi_call_phys1(sys_table_arg->boottime->free_pool, m);
+		efi_early->call(efi_early->free_pool, m);
 		goto again;
 	}
 
 	if (status != EFI_SUCCESS)
-		efi_call_phys1(sys_table_arg->boottime->free_pool, m);
+		efi_early->call(efi_early->free_pool, m);
+
 	if (key_ptr && status == EFI_SUCCESS)
 		*key_ptr = key;
 	if (desc_ver && status == EFI_SUCCESS)
@@ -158,7 +149,7 @@ static efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
 	if (!max_addr)
 		status = EFI_NOT_FOUND;
 	else {
-		status = efi_call_phys4(sys_table_arg->boottime->allocate_pages,
+		status = efi_early->call(efi_early->allocate_pages,
 					 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
 					 nr_pages, &max_addr);
 		if (status != EFI_SUCCESS) {
@@ -170,8 +161,7 @@ static efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
 		*addr = max_addr;
 	}
 
-	efi_call_phys1(sys_table_arg->boottime->free_pool, map);
-
+	efi_early->call(efi_early->free_pool, map);
 fail:
 	return status;
 }
@@ -231,7 +221,7 @@ static efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
 		if ((start + size) > end)
 			continue;
 
-		status = efi_call_phys4(sys_table_arg->boottime->allocate_pages,
+		status = efi_early->call(efi_early->allocate_pages,
 					 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
 					 nr_pages, &start);
 		if (status == EFI_SUCCESS) {
@@ -243,7 +233,7 @@ static efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
 	if (i == map_size / desc_size)
 		status = EFI_NOT_FOUND;
 
-	efi_call_phys1(sys_table_arg->boottime->free_pool, map);
+	efi_early->call(efi_early->free_pool, map);
 fail:
 	return status;
 }
@@ -257,7 +247,7 @@ static void efi_free(efi_system_table_t *sys_table_arg, unsigned long size,
 		return;
 
 	nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
-	efi_call_phys2(sys_table_arg->boottime->free_pages, addr, nr_pages);
+	efi_early->call(efi_early->free_pages, addr, nr_pages);
 }
 
 
@@ -276,9 +266,7 @@ static efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 {
 	struct file_info *files;
 	unsigned long file_addr;
-	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
 	u64 file_size_total;
-	efi_file_io_interface_t *io;
 	efi_file_handle_t *fh;
 	efi_status_t status;
 	int nr_files;
@@ -319,10 +307,8 @@ static efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 	if (!nr_files)
 		return EFI_SUCCESS;
 
-	status = efi_call_phys3(sys_table_arg->boottime->allocate_pool,
-				EFI_LOADER_DATA,
-				nr_files * sizeof(*files),
-				(void **)&files);
+	status = efi_early->call(efi_early->allocate_pool, EFI_LOADER_DATA,
+				 nr_files * sizeof(*files), (void **)&files);
 	if (status != EFI_SUCCESS) {
 		efi_printk(sys_table_arg, "Failed to alloc mem for file handle list\n");
 		goto fail;
@@ -331,13 +317,8 @@ static efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 	str = cmd_line;
 	for (i = 0; i < nr_files; i++) {
 		struct file_info *file;
-		efi_file_handle_t *h;
-		efi_file_info_t *info;
 		efi_char16_t filename_16[256];
-		unsigned long info_sz;
-		efi_guid_t info_guid = EFI_FILE_INFO_ID;
 		efi_char16_t *p;
-		u64 file_sz;
 
 		str = strstr(str, option_string);
 		if (!str)
@@ -368,71 +349,18 @@ static efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 
 		/* Only open the volume once. */
 		if (!i) {
-			efi_boot_services_t *boottime;
-
-			boottime = sys_table_arg->boottime;
-
-			status = efi_call_phys3(boottime->handle_protocol,
-					image->device_handle, &fs_proto,
-						(void **)&io);
-			if (status != EFI_SUCCESS) {
-				efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
-				goto free_files;
-			}
-
-			status = efi_call_phys2(io->open_volume, io, &fh);
-			if (status != EFI_SUCCESS) {
-				efi_printk(sys_table_arg, "Failed to open volume\n");
+			status = efi_open_volume(sys_table_arg, image,
+						 (void **)&fh);
+			if (status != EFI_SUCCESS)
 				goto free_files;
 		}
-		}
-
-		status = efi_call_phys5(fh->open, fh, &h, filename_16,
-					EFI_FILE_MODE_READ, (u64)0);
-		if (status != EFI_SUCCESS) {
-			efi_printk(sys_table_arg, "Failed to open file: ");
-			efi_char16_printk(sys_table_arg, filename_16);
-			efi_printk(sys_table_arg, "\n");
-			goto close_handles;
-		}
-
-		file->handle = h;
-
-		info_sz = 0;
-		status = efi_call_phys4(h->get_info, h, &info_guid,
-					&info_sz, NULL);
-		if (status != EFI_BUFFER_TOO_SMALL) {
-			efi_printk(sys_table_arg, "Failed to get file info size\n");
-			goto close_handles;
-		}
 
-grow:
-		status = efi_call_phys3(sys_table_arg->boottime->allocate_pool,
-					EFI_LOADER_DATA, info_sz,
-					(void **)&info);
-		if (status != EFI_SUCCESS) {
-			efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
-			goto close_handles;
-		}
-
-		status = efi_call_phys4(h->get_info, h, &info_guid,
-					&info_sz, info);
-		if (status == EFI_BUFFER_TOO_SMALL) {
-			efi_call_phys1(sys_table_arg->boottime->free_pool,
-				       info);
-			goto grow;
-		}
-
-		file_sz = info->file_size;
-		efi_call_phys1(sys_table_arg->boottime->free_pool, info);
-
-		if (status != EFI_SUCCESS) {
-			efi_printk(sys_table_arg, "Failed to get file info\n");
+		status = efi_file_size(sys_table_arg, fh, filename_16,
+				       (void **)&file->handle, &file->size);
+		if (status != EFI_SUCCESS)
 			goto close_handles;
-		}
 
-		file->size = file_sz;
-		file_size_total += file_sz;
+		file_size_total += file->size;
 	}
 
 	if (file_size_total) {
@@ -468,8 +396,8 @@ static efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 					chunksize = EFI_READ_CHUNK_SIZE;
 				else
 					chunksize = size;
-				status = efi_call_phys3(fh->read,
-							files[j].handle,
+
+				status = efi_file_read(fh, files[j].handle,
 						       &chunksize,
 						       (void *)addr);
 				if (status != EFI_SUCCESS) {
@@ -480,12 +408,12 @@ static efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 				size -= chunksize;
 			}
 
-			efi_call_phys1(fh->close, files[j].handle);
+			efi_file_close(fh, files[j].handle);
 		}
 
 	}
 
-	efi_call_phys1(sys_table_arg->boottime->free_pool, files);
+	efi_early->call(efi_early->free_pool, files);
 
 	*load_addr = file_addr;
 	*load_size = file_size_total;
@@ -497,9 +425,9 @@ static efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 
 close_handles:
 	for (k = j; k < i; k++)
-		efi_call_phys1(fh->close, files[k].handle);
+		efi_file_close(fh, files[k].handle);
 free_files:
-	efi_call_phys1(sys_table_arg->boottime->free_pool, files);
+	efi_early->call(efi_early->free_pool, files);
 fail:
 	*load_addr = 0;
 	*load_size = 0;
@@ -545,7 +473,7 @@ static efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,
 	 * as possible while respecting the required alignment.
 	 */
 	nr_pages = round_up(alloc_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
-	status = efi_call_phys4(sys_table_arg->boottime->allocate_pages,
+	status = efi_early->call(efi_early->allocate_pages,
 				 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
 				 nr_pages, &efi_addr);
 	new_addr = efi_addr;