efi.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_X86_EFI_H
  3#define _ASM_X86_EFI_H
  4
  5#include <asm/fpu/api.h>
  6#include <asm/processor-flags.h>
  7#include <asm/tlb.h>
  8#include <asm/nospec-branch.h>
  9#include <asm/mmu_context.h>
 10#include <asm/ibt.h>
 11#include <linux/build_bug.h>
 12#include <linux/kernel.h>
 13#include <linux/pgtable.h>
 14
 15extern unsigned long efi_fw_vendor, efi_config_table;
 16extern unsigned long efi_mixed_mode_stack_pa;
 17
 18/*
 19 * We map the EFI regions needed for runtime services non-contiguously,
 20 * with preserved alignment on virtual addresses starting from -4G down
 21 * for a total max space of 64G. This way, we provide for stable runtime
 22 * services addresses across kernels so that a kexec'd kernel can still
 23 * use them.
 24 *
 25 * This is the main reason why we're doing stable VA mappings for RT
 26 * services.
 27 */
 28
 29#define EFI32_LOADER_SIGNATURE	"EL32"
 30#define EFI64_LOADER_SIGNATURE	"EL64"
 31
 32#define ARCH_EFI_IRQ_FLAGS_MASK	X86_EFLAGS_IF
 33
 34#define EFI_UNACCEPTED_UNIT_SIZE PMD_SIZE
 35
 36/*
 37 * The EFI services are called through variadic functions in many cases. These
 38 * functions are implemented in assembler and support only a fixed number of
 39 * arguments. The macros below allows us to check at build time that we don't
 40 * try to call them with too many arguments.
 41 *
 42 * __efi_nargs() will return the number of arguments if it is 7 or less, and
 43 * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it
 44 * impossible to calculate the exact number of arguments beyond some
 45 * pre-defined limit. The maximum number of arguments currently supported by
 46 * any of the thunks is 7, so this is good enough for now and can be extended
 47 * in the obvious way if we ever need more.
 48 */
 49
 50#define __efi_nargs(...) __efi_nargs_(__VA_ARGS__)
 51#define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__,	\
 52	__efi_arg_sentinel(9), __efi_arg_sentinel(8),		\
 53	__efi_arg_sentinel(7), __efi_arg_sentinel(6),		\
 54	__efi_arg_sentinel(5), __efi_arg_sentinel(4),		\
 55	__efi_arg_sentinel(3), __efi_arg_sentinel(2),		\
 56	__efi_arg_sentinel(1), __efi_arg_sentinel(0))
 57#define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, n, ...)	\
 58	__take_second_arg(n,					\
 59		({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 10; }))
 60#define __efi_arg_sentinel(n) , n
 61
 62/*
 63 * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis
 64 * represents more than n arguments.
 65 */
 66
 67#define __efi_nargs_check(f, n, ...)					\
 68	__efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n)
 69#define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n)
 70#define __efi_nargs_check__(f, p, n) ({					\
 71	BUILD_BUG_ON_MSG(						\
 72		(p) > (n),						\
 73		#f " called with too many arguments (" #p ">" #n ")");	\
 74})
 75
 76static inline void efi_fpu_begin(void)
 77{
 78	/*
 79	 * The UEFI calling convention (UEFI spec 2.3.2 and 2.3.4) requires
 80	 * that FCW and MXCSR (64-bit) must be initialized prior to calling
 81	 * UEFI code.  (Oddly the spec does not require that the FPU stack
 82	 * be empty.)
 83	 */
 84	kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR);
 85}
 86
 87static inline void efi_fpu_end(void)
 88{
 89	kernel_fpu_end();
 90}
 91
 92#ifdef CONFIG_X86_32
 93#define EFI_X86_KERNEL_ALLOC_LIMIT		(SZ_512M - 1)
 94#else /* !CONFIG_X86_32 */
 95#define EFI_X86_KERNEL_ALLOC_LIMIT		EFI_ALLOC_LIMIT
 96
 97extern asmlinkage u64 __efi_call(void *fp, ...);
 98
 99extern bool efi_disable_ibt_for_runtime;
100
101#define efi_call(...) ({						\
102	__efi_nargs_check(efi_call, 7, __VA_ARGS__);			\
103	__efi_call(__VA_ARGS__);					\
104})
105
106#undef arch_efi_call_virt
107#define arch_efi_call_virt(p, f, args...) ({				\
108	u64 ret, ibt = ibt_save(efi_disable_ibt_for_runtime);		\
109	ret = efi_call((void *)p->f, args);				\
110	ibt_restore(ibt);						\
111	ret;								\
112})
113
114#ifdef CONFIG_KASAN
115/*
116 * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
117 * only in kernel binary.  Since the EFI stub linked into a separate binary it
118 * doesn't have __memset().  So we should use standard memset from
119 * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
120 */
121#undef memcpy
122#undef memset
123#undef memmove
124#endif
125
126#endif /* CONFIG_X86_32 */
127
128extern int __init efi_memblock_x86_reserve_range(void);
129extern void __init efi_print_memmap(void);
130extern void __init efi_map_region(efi_memory_desc_t *md);
131extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
132extern void efi_sync_low_kernel_mappings(void);
133extern int __init efi_alloc_page_tables(void);
134extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
135extern void __init efi_runtime_update_mappings(void);
136extern void __init efi_dump_pagetable(void);
137extern void __init efi_apply_memmap_quirks(void);
138extern int __init efi_reuse_config(u64 tables, int nr_tables);
139extern void efi_delete_dummy_variable(void);
140extern void efi_crash_gracefully_on_page_fault(unsigned long phys_addr);
141extern void efi_unmap_boot_services(void);
142
143void arch_efi_call_virt_setup(void);
144void arch_efi_call_virt_teardown(void);
145
146extern u64 efi_setup;
147
148#ifdef CONFIG_EFI
149extern u64 __efi64_thunk(u32, ...);
150
151#define efi64_thunk(...) ({						\
152	u64 __pad[3]; /* must have space for 3 args on the stack */	\
153	__efi_nargs_check(efi64_thunk, 9, __VA_ARGS__);			\
154	__efi64_thunk(__VA_ARGS__, __pad);				\
155})
156
157static inline bool efi_is_mixed(void)
158{
159	if (!IS_ENABLED(CONFIG_EFI_MIXED))
160		return false;
161	return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT);
162}
163
164static inline bool efi_runtime_supported(void)
165{
166	if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT))
167		return true;
168
169	return IS_ENABLED(CONFIG_EFI_MIXED);
170}
171
172extern void parse_efi_setup(u64 phys_addr, u32 data_len);
173
174extern void efi_thunk_runtime_setup(void);
175efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
176					 unsigned long descriptor_size,
177					 u32 descriptor_version,
178					 efi_memory_desc_t *virtual_map,
179					 unsigned long systab_phys);
180
181/* arch specific definitions used by the stub code */
182
183#ifdef CONFIG_EFI_MIXED
184
185#define EFI_ALLOC_LIMIT		(efi_is_64bit() ? ULONG_MAX : U32_MAX)
186
187#define ARCH_HAS_EFISTUB_WRAPPERS
188
189static inline bool efi_is_64bit(void)
190{
191	extern const bool efi_is64;
192
193	return efi_is64;
194}
195
196static inline bool efi_is_native(void)
197{
198	return efi_is_64bit();
199}
200
201#define efi_table_attr(inst, attr)					\
202	(efi_is_native() ? (inst)->attr					\
203			 : efi_mixed_table_attr((inst), attr))
204
205#define efi_mixed_table_attr(inst, attr)				\
206	(__typeof__(inst->attr))					\
207		_Generic(inst->mixed_mode.attr,				\
208		u32:		(unsigned long)(inst->mixed_mode.attr),	\
209		default:	(inst->mixed_mode.attr))
210
211/*
212 * The following macros allow translating arguments if necessary from native to
213 * mixed mode. The use case for this is to initialize the upper 32 bits of
214 * output parameters, and where the 32-bit method requires a 64-bit argument,
215 * which must be split up into two arguments to be thunked properly.
216 *
217 * As examples, the AllocatePool boot service returns the address of the
218 * allocation, but it will not set the high 32 bits of the address. To ensure
219 * that the full 64-bit address is initialized, we zero-init the address before
220 * calling the thunk.
221 *
222 * The FreePages boot service takes a 64-bit physical address even in 32-bit
223 * mode. For the thunk to work correctly, a native 64-bit call of
224 * 	free_pages(addr, size)
225 * must be translated to
226 * 	efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size)
227 * so that the two 32-bit halves of addr get pushed onto the stack separately.
228 */
229
230static inline void *efi64_zero_upper(void *p)
231{
232	if (p)
233		((u32 *)p)[1] = 0;
234	return p;
235}
236
237static inline u32 efi64_convert_status(efi_status_t status)
238{
239	return (u32)(status | (u64)status >> 32);
240}
241
242#define __efi64_split(val)		(val) & U32_MAX, (u64)(val) >> 32
243
244#define __efi64_argmap_free_pages(addr, size)				\
245	((addr), 0, (size))
246
247#define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver)	\
248	((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver))
249
250#define __efi64_argmap_allocate_pool(type, size, buffer)		\
251	((type), (size), efi64_zero_upper(buffer))
252
253#define __efi64_argmap_locate_handle_buffer(type, proto, key, num, buf)	\
254	((type), (proto), (key), efi64_zero_upper(num), efi64_zero_upper(buf))
255
256#define __efi64_argmap_create_event(type, tpl, f, c, event)		\
257	((type), (tpl), (f), (c), efi64_zero_upper(event))
258
259#define __efi64_argmap_set_timer(event, type, time)			\
260	((event), (type), lower_32_bits(time), upper_32_bits(time))
261
262#define __efi64_argmap_wait_for_event(num, event, index)		\
263	((num), (event), efi64_zero_upper(index))
264
265#define __efi64_argmap_handle_protocol(handle, protocol, interface)	\
266	((handle), (protocol), efi64_zero_upper(interface))
267
268#define __efi64_argmap_locate_protocol(protocol, reg, interface)	\
269	((protocol), (reg), efi64_zero_upper(interface))
270
271#define __efi64_argmap_locate_device_path(protocol, path, handle)	\
272	((protocol), (path), efi64_zero_upper(handle))
273
274#define __efi64_argmap_exit(handle, status, size, data)			\
275	((handle), efi64_convert_status(status), (size), (data))
276
277/* PCI I/O */
278#define __efi64_argmap_get_location(protocol, seg, bus, dev, func)	\
279	((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus),	\
280	 efi64_zero_upper(dev), efi64_zero_upper(func))
281
282/* LoadFile */
283#define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf)	\
284	((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf))
285
286/* Graphics Output Protocol */
287#define __efi64_argmap_query_mode(gop, mode, size, info)		\
288	((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info))
289
290/* TCG2 protocol */
291#define __efi64_argmap_hash_log_extend_event(prot, fl, addr, size, ev)	\
292	((prot), (fl), 0ULL, (u64)(addr), 0ULL, (u64)(size), 0ULL, ev)
293
294/* DXE services */
295#define __efi64_argmap_get_memory_space_descriptor(phys, desc) \
296	(__efi64_split(phys), (desc))
297
298#define __efi64_argmap_set_memory_space_attributes(phys, size, flags) \
299	(__efi64_split(phys), __efi64_split(size), __efi64_split(flags))
300
301/* file protocol */
302#define __efi64_argmap_open(prot, newh, fname, mode, attr) \
303	((prot), efi64_zero_upper(newh), (fname), __efi64_split(mode), \
304	 __efi64_split(attr))
305
306#define __efi64_argmap_set_position(pos) (__efi64_split(pos))
307
308/* file system protocol */
309#define __efi64_argmap_open_volume(prot, file) \
310	((prot), efi64_zero_upper(file))
311
312/* Memory Attribute Protocol */
313#define __efi64_argmap_get_memory_attributes(protocol, phys, size, flags) \
314	((protocol), __efi64_split(phys), __efi64_split(size), (flags))
315
316#define __efi64_argmap_set_memory_attributes(protocol, phys, size, flags) \
317	((protocol), __efi64_split(phys), __efi64_split(size), __efi64_split(flags))
318
319#define __efi64_argmap_clear_memory_attributes(protocol, phys, size, flags) \
320	((protocol), __efi64_split(phys), __efi64_split(size), __efi64_split(flags))
321
322/* EFI SMBIOS protocol */
323#define __efi64_argmap_get_next(protocol, smbioshandle, type, record, phandle) \
324	((protocol), (smbioshandle), (type), efi64_zero_upper(record), \
325	 efi64_zero_upper(phandle))
326/*
327 * The macros below handle the plumbing for the argument mapping. To add a
328 * mapping for a specific EFI method, simply define a macro
329 * __efi64_argmap_<method name>, following the examples above.
330 */
331
332#define __efi64_thunk_map(inst, func, ...)				\
333	efi64_thunk(inst->mixed_mode.func,				\
334		__efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__),	\
335			       (__VA_ARGS__)))
336
337#define __efi64_argmap(mapped, args)					\
338	__PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args)
339#define __efi64_argmap__0(mapped, args) __efi_eval mapped
340#define __efi64_argmap__1(mapped, args) __efi_eval args
341
342#define __efi_eat(...)
343#define __efi_eval(...) __VA_ARGS__
344
345static inline efi_status_t __efi64_widen_efi_status(u64 status)
346{
347	/* use rotate to move the value of bit #31 into position #63 */
348	return ror64(rol32(status, 1), 1);
349}
350
351/* The macro below handles dispatching via the thunk if needed */
352
353#define efi_fn_call(inst, func, ...)					\
354	(efi_is_native() ? (inst)->func(__VA_ARGS__)			\
355			 : efi_mixed_call((inst), func, ##__VA_ARGS__))
356
357#define efi_mixed_call(inst, func, ...)					\
358	_Generic(inst->func(__VA_ARGS__),				\
359	efi_status_t:							\
360		__efi64_widen_efi_status(				\
361			__efi64_thunk_map(inst, func, ##__VA_ARGS__)),	\
362	u64: ({ BUILD_BUG(); ULONG_MAX; }),				\
363	default:							\
364		(__typeof__(inst->func(__VA_ARGS__)))			\
365			__efi64_thunk_map(inst, func, ##__VA_ARGS__))
366
367#else /* CONFIG_EFI_MIXED */
368
369static inline bool efi_is_64bit(void)
370{
371	return IS_ENABLED(CONFIG_X86_64);
372}
373
374#endif /* CONFIG_EFI_MIXED */
375
376extern bool efi_reboot_required(void);
377extern bool efi_is_table_address(unsigned long phys_addr);
378
379extern void efi_reserve_boot_services(void);
380#else
381static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
382static inline bool efi_reboot_required(void)
383{
384	return false;
385}
386static inline  bool efi_is_table_address(unsigned long phys_addr)
387{
388	return false;
389}
390static inline void efi_reserve_boot_services(void)
391{
392}
393#endif /* CONFIG_EFI */
394
395extern int __init efi_memmap_alloc(unsigned int num_entries,
396				   struct efi_memory_map_data *data);
397
398extern int __init efi_memmap_install(struct efi_memory_map_data *data);
399extern int __init efi_memmap_split_count(efi_memory_desc_t *md,
400					 struct range *range);
401extern void __init efi_memmap_insert(struct efi_memory_map *old_memmap,
402				     void *buf, struct efi_mem_range *mem);
403
404extern enum efi_secureboot_mode __x86_ima_efi_boot_mode(void);
405
406#define arch_ima_efi_boot_mode	__x86_ima_efi_boot_mode()
407
408#ifdef CONFIG_EFI_RUNTIME_MAP
409int efi_get_runtime_map_size(void);
410int efi_get_runtime_map_desc_size(void);
411int efi_runtime_map_copy(void *buf, size_t bufsz);
412#else
413static inline int efi_get_runtime_map_size(void)
414{
415	return 0;
416}
417
418static inline int efi_get_runtime_map_desc_size(void)
419{
420	return 0;
421}
422
423static inline int efi_runtime_map_copy(void *buf, size_t bufsz)
424{
425	return 0;
426}
427
428#endif
429
430#endif /* _ASM_X86_EFI_H */