efi/libstub: Use a helper to iterate over a EFI handle array

Iterating over a EFI handle array is a bit finicky, since we have to take mixed mode into account, where handles are only 32-bit while the native efi_handle_t type is 64-bit. So introduce a helper, and replace the various occurrences of this pattern.

Ard Biesheuvel committed 6 years ago

Commit 2732ea01 parent a8147db3 files · +20 −16Browse files

Unified · Split

3 files

arch/x86/boot/compressed/eboot.c +5 −9
drivers/firmware/efi/libstub/gop.c +2 −7
include/linux/efi.h +13 −0

arch/x86/boot/compressed/eboot.c+5−9

@@ -135,6 +135,7 @@ static void setup_efi_pci(struct boot_params *params) · 134 unmodified lines
135	135	unsigned long size = 0;
136	136	unsigned long nr_pci;
137	137	struct setup_data *data;
	138	+ efi_handle_t h;
138	139	int i;
139	140
140	141	status = efi_call_early(locate_handle,
@@ -164,14 +165,11 @@ static void setup_efi_pci(struct boot_params *params) · 23 unmodified lines
164	165	while (data && data->next)
165	166	data = (struct setup_data *)(unsigned long)data->next;
166	167
167		− nr_pci = size / (efi_is_64bit() ? sizeof(u64) : sizeof(u32));
168		− for (i = 0; i < nr_pci; i++) {
	168	+ for_each_efi_handle(h, pci_handle, size, i) {
169	169	efi_pci_io_protocol_t *pci = NULL;
170	170	struct pci_setup_rom *rom;
171	171
172		− status = efi_call_early(handle_protocol,
173		− efi_is_64bit() ? ((u64 *)pci_handle)[i]
174		− : ((u32 *)pci_handle)[i],
	172	+ status = efi_call_early(handle_protocol, h,
175	173	&pci_proto, (void **)&pci);
176	174	if (status != EFI_SUCCESS \|\| !pci)
177	175	continue;
@@ -266,6 +264,7 @@ setup_uga(struct screen_info si, efi_guid_t uga_proto, unsigned long size) · 88 unmodified lines
266	264	void **uga_handle = NULL;
267	265	efi_uga_draw_protocol_t uga = NULL, first_uga;
268	266	unsigned long nr_ugas;
	267	+ efi_handle_t handle;
269	268	int i;
270	269
271	270	status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
@@ -283,13 +282,10 @@ setup_uga(struct screen_info si, efi_guid_t uga_proto, unsigned long size) · 11 unmodified lines
283	282	width = 0;
284	283
285	284	first_uga = NULL;
286		− nr_ugas = size / (efi_is_64bit() ? sizeof(u64) : sizeof(u32));
287		− for (i = 0; i < nr_ugas; i++) {
	285	+ for_each_efi_handle(handle, uga_handle, size, i) {
288	286	efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
289	287	u32 w, h, depth, refresh;
290	288	void *pciio;
291		− unsigned long handle = efi_is_64bit() ? ((u64 *)uga_handle)[i]
292		− : ((u32 *)uga_handle)[i];
293	289
294	290	status = efi_call_early(handle_protocol, handle,
295	291	uga_proto, (void **)&uga);

drivers/firmware/efi/libstub/gop.c+2−7

@@ -91,7 +91,6 @@ setup_gop(efi_system_table_t sys_table_arg, struct screen_info si, · 90 unmodified lines
91	91	efi_guid_t proto, unsigned long size, void *handles)
92	92	{
93	93	efi_graphics_output_protocol_t gop, first_gop;
94		− unsigned long nr_gops;
95	94	u16 width, height;
96	95	u32 pixels_per_scan_line;
97	96	u32 ext_lfb_base;
@@ -99,22 +98,18 @@ setup_gop(efi_system_table_t sys_table_arg, struct screen_info si, · 1 unmodified line
99	98	efi_pixel_bitmask_t pixel_info;
100	99	int pixel_format;
101	100	efi_status_t status;
	101	+ efi_handle_t h;
102	102	int i;
103		− bool is64 = efi_is_64bit();
104	103
105	104	first_gop = NULL;
106	105	gop = NULL;
107	106
108		− nr_gops = size / (is64 ? sizeof(u64) : sizeof(u32));
109		− for (i = 0; i < nr_gops; i++) {
	107	+ for_each_efi_handle(h, handles, size, i) {
110	108	efi_graphics_output_protocol_mode_t *mode;
111	109	efi_graphics_output_mode_info_t *info = NULL;
112	110	efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
113	111	bool conout_found = false;
114	112	void *dummy = NULL;
115		− efi_handle_t h = (efi_handle_t)(unsigned long)
116		− (is64 ? ((u64 *)handles)[i]
117		− : ((u32 *)handles)[i]);
118	113	efi_physical_addr_t current_fb_base;
119	114
120	115	status = efi_call_early(handle_protocol, h,

include/linux/efi.h+13−0

@@ -48,6 +48,19 @@ typedef u16 efi_char16_t; /* UNICODE character */ · 47 unmodified lines
48	48	typedef u64 efi_physical_addr_t;
49	49	typedef void *efi_handle_t;
50	50
	51	+#define efi_get_handle_at(array, idx) \
	52	+ (efi_is_64bit() ? (efi_handle_t)(unsigned long)((u64 *)(array))[idx] \
	53	+ : (efi_handle_t)(unsigned long)((u32 *)(array))[idx])
	54	+
	55	+#define efi_get_handle_num(size) \
	56	+ ((size) / (efi_is_64bit() ? sizeof(u64) : sizeof(u32)))
	57	+
	58	+#define for_each_efi_handle(handle, array, size, i) \
	59	+ for (i = 0; \
	60	+ i < efi_get_handle_num(size) && \
	61	+ ((handle = efi_get_handle_at((array), i)) \|\| true); \
	62	+ i++)
	63	+
51	64	/*
52	65	* The UEFI spec and EDK2 reference implementation both define EFI_GUID as
53	66	* struct { u32 a; u16; b; u16 c; u8 d[8]; }; and so the implied alignment