xref: /openbmc/linux/arch/x86/include/asm/efi.h (revision 5fb859f7)
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  
15  extern unsigned long efi_fw_vendor, efi_config_table;
16  extern 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  /*
35   * The EFI services are called through variadic functions in many cases. These
36   * functions are implemented in assembler and support only a fixed number of
37   * arguments. The macros below allows us to check at build time that we don't
38   * try to call them with too many arguments.
39   *
40   * __efi_nargs() will return the number of arguments if it is 7 or less, and
41   * cause a BUILD_BUG otherwise. The limitations of the C preprocessor make it
42   * impossible to calculate the exact number of arguments beyond some
43   * pre-defined limit. The maximum number of arguments currently supported by
44   * any of the thunks is 7, so this is good enough for now and can be extended
45   * in the obvious way if we ever need more.
46   */
47  
48  #define __efi_nargs(...) __efi_nargs_(__VA_ARGS__)
49  #define __efi_nargs_(...) __efi_nargs__(0, ##__VA_ARGS__,	\
50  	__efi_arg_sentinel(9), __efi_arg_sentinel(8),		\
51  	__efi_arg_sentinel(7), __efi_arg_sentinel(6),		\
52  	__efi_arg_sentinel(5), __efi_arg_sentinel(4),		\
53  	__efi_arg_sentinel(3), __efi_arg_sentinel(2),		\
54  	__efi_arg_sentinel(1), __efi_arg_sentinel(0))
55  #define __efi_nargs__(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, n, ...)	\
56  	__take_second_arg(n,					\
57  		({ BUILD_BUG_ON_MSG(1, "__efi_nargs limit exceeded"); 10; }))
58  #define __efi_arg_sentinel(n) , n
59  
60  /*
61   * __efi_nargs_check(f, n, ...) will cause a BUILD_BUG if the ellipsis
62   * represents more than n arguments.
63   */
64  
65  #define __efi_nargs_check(f, n, ...)					\
66  	__efi_nargs_check_(f, __efi_nargs(__VA_ARGS__), n)
67  #define __efi_nargs_check_(f, p, n) __efi_nargs_check__(f, p, n)
68  #define __efi_nargs_check__(f, p, n) ({					\
69  	BUILD_BUG_ON_MSG(						\
70  		(p) > (n),						\
71  		#f " called with too many arguments (" #p ">" #n ")");	\
72  })
73  
74  static inline void efi_fpu_begin(void)
75  {
76  	/*
77  	 * The UEFI calling convention (UEFI spec 2.3.2 and 2.3.4) requires
78  	 * that FCW and MXCSR (64-bit) must be initialized prior to calling
79  	 * UEFI code.  (Oddly the spec does not require that the FPU stack
80  	 * be empty.)
81  	 */
82  	kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR);
83  }
84  
85  static inline void efi_fpu_end(void)
86  {
87  	kernel_fpu_end();
88  }
89  
90  #ifdef CONFIG_X86_32
91  #define arch_efi_call_virt_setup()					\
92  ({									\
93  	efi_fpu_begin();						\
94  	firmware_restrict_branch_speculation_start();			\
95  })
96  
97  #define arch_efi_call_virt_teardown()					\
98  ({									\
99  	firmware_restrict_branch_speculation_end();			\
100  	efi_fpu_end();							\
101  })
102  
103  #define arch_efi_call_virt(p, f, args...)	p->f(args)
104  
105  #else /* !CONFIG_X86_32 */
106  
107  #define EFI_LOADER_SIGNATURE	"EL64"
108  
109  extern asmlinkage u64 __efi_call(void *fp, ...);
110  
111  #define efi_call(...) ({						\
112  	__efi_nargs_check(efi_call, 7, __VA_ARGS__);			\
113  	__efi_call(__VA_ARGS__);					\
114  })
115  
116  #define arch_efi_call_virt_setup()					\
117  ({									\
118  	efi_sync_low_kernel_mappings();					\
119  	efi_fpu_begin();						\
120  	firmware_restrict_branch_speculation_start();			\
121  	efi_enter_mm();							\
122  })
123  
124  #define arch_efi_call_virt(p, f, args...) ({				\
125  	u64 ret, ibt = ibt_save();					\
126  	ret = efi_call((void *)p->f, args);				\
127  	ibt_restore(ibt);						\
128  	ret;								\
129  })
130  
131  #define arch_efi_call_virt_teardown()					\
132  ({									\
133  	efi_leave_mm();							\
134  	firmware_restrict_branch_speculation_end();			\
135  	efi_fpu_end();							\
136  })
137  
138  #ifdef CONFIG_KASAN
139  /*
140   * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
141   * only in kernel binary.  Since the EFI stub linked into a separate binary it
142   * doesn't have __memset().  So we should use standard memset from
143   * arch/x86/boot/compressed/string.c.  The same applies to memcpy and memmove.
144   */
145  #undef memcpy
146  #undef memset
147  #undef memmove
148  #endif
149  
150  #endif /* CONFIG_X86_32 */
151  
152  extern int __init efi_memblock_x86_reserve_range(void);
153  extern void __init efi_print_memmap(void);
154  extern void __init efi_map_region(efi_memory_desc_t *md);
155  extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
156  extern void efi_sync_low_kernel_mappings(void);
157  extern int __init efi_alloc_page_tables(void);
158  extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
159  extern void __init efi_runtime_update_mappings(void);
160  extern void __init efi_dump_pagetable(void);
161  extern void __init efi_apply_memmap_quirks(void);
162  extern int __init efi_reuse_config(u64 tables, int nr_tables);
163  extern void efi_delete_dummy_variable(void);
164  extern void efi_crash_gracefully_on_page_fault(unsigned long phys_addr);
165  extern void efi_free_boot_services(void);
166  
167  void efi_enter_mm(void);
168  void efi_leave_mm(void);
169  
170  /* kexec external ABI */
171  struct efi_setup_data {
172  	u64 fw_vendor;
173  	u64 __unused;
174  	u64 tables;
175  	u64 smbios;
176  	u64 reserved[8];
177  };
178  
179  extern u64 efi_setup;
180  
181  #ifdef CONFIG_EFI
182  extern efi_status_t __efi64_thunk(u32, ...);
183  
184  #define efi64_thunk(...) ({						\
185  	u64 __pad[3]; /* must have space for 3 args on the stack */	\
186  	__efi_nargs_check(efi64_thunk, 9, __VA_ARGS__);			\
187  	__efi64_thunk(__VA_ARGS__, __pad);				\
188  })
189  
190  static inline bool efi_is_mixed(void)
191  {
192  	if (!IS_ENABLED(CONFIG_EFI_MIXED))
193  		return false;
194  	return IS_ENABLED(CONFIG_X86_64) && !efi_enabled(EFI_64BIT);
195  }
196  
197  static inline bool efi_runtime_supported(void)
198  {
199  	if (IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT))
200  		return true;
201  
202  	return IS_ENABLED(CONFIG_EFI_MIXED);
203  }
204  
205  extern void parse_efi_setup(u64 phys_addr, u32 data_len);
206  
207  extern void efi_thunk_runtime_setup(void);
208  efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
209  					 unsigned long descriptor_size,
210  					 u32 descriptor_version,
211  					 efi_memory_desc_t *virtual_map,
212  					 unsigned long systab_phys);
213  
214  /* arch specific definitions used by the stub code */
215  
216  #ifdef CONFIG_EFI_MIXED
217  
218  #define ARCH_HAS_EFISTUB_WRAPPERS
219  
220  static inline bool efi_is_64bit(void)
221  {
222  	extern const bool efi_is64;
223  
224  	return efi_is64;
225  }
226  
227  static inline bool efi_is_native(void)
228  {
229  	return efi_is_64bit();
230  }
231  
232  #define efi_mixed_mode_cast(attr)					\
233  	__builtin_choose_expr(						\
234  		__builtin_types_compatible_p(u32, __typeof__(attr)),	\
235  			(unsigned long)(attr), (attr))
236  
237  #define efi_table_attr(inst, attr)					\
238  	(efi_is_native()						\
239  		? inst->attr						\
240  		: (__typeof__(inst->attr))				\
241  			efi_mixed_mode_cast(inst->mixed_mode.attr))
242  
243  /*
244   * The following macros allow translating arguments if necessary from native to
245   * mixed mode. The use case for this is to initialize the upper 32 bits of
246   * output parameters, and where the 32-bit method requires a 64-bit argument,
247   * which must be split up into two arguments to be thunked properly.
248   *
249   * As examples, the AllocatePool boot service returns the address of the
250   * allocation, but it will not set the high 32 bits of the address. To ensure
251   * that the full 64-bit address is initialized, we zero-init the address before
252   * calling the thunk.
253   *
254   * The FreePages boot service takes a 64-bit physical address even in 32-bit
255   * mode. For the thunk to work correctly, a native 64-bit call of
256   * 	free_pages(addr, size)
257   * must be translated to
258   * 	efi64_thunk(free_pages, addr & U32_MAX, addr >> 32, size)
259   * so that the two 32-bit halves of addr get pushed onto the stack separately.
260   */
261  
262  static inline void *efi64_zero_upper(void *p)
263  {
264  	((u32 *)p)[1] = 0;
265  	return p;
266  }
267  
268  static inline u32 efi64_convert_status(efi_status_t status)
269  {
270  	return (u32)(status | (u64)status >> 32);
271  }
272  
273  #define __efi64_split(val)		(val) & U32_MAX, (u64)(val) >> 32
274  
275  #define __efi64_argmap_free_pages(addr, size)				\
276  	((addr), 0, (size))
277  
278  #define __efi64_argmap_get_memory_map(mm_size, mm, key, size, ver)	\
279  	((mm_size), (mm), efi64_zero_upper(key), efi64_zero_upper(size), (ver))
280  
281  #define __efi64_argmap_allocate_pool(type, size, buffer)		\
282  	((type), (size), efi64_zero_upper(buffer))
283  
284  #define __efi64_argmap_create_event(type, tpl, f, c, event)		\
285  	((type), (tpl), (f), (c), efi64_zero_upper(event))
286  
287  #define __efi64_argmap_set_timer(event, type, time)			\
288  	((event), (type), lower_32_bits(time), upper_32_bits(time))
289  
290  #define __efi64_argmap_wait_for_event(num, event, index)		\
291  	((num), (event), efi64_zero_upper(index))
292  
293  #define __efi64_argmap_handle_protocol(handle, protocol, interface)	\
294  	((handle), (protocol), efi64_zero_upper(interface))
295  
296  #define __efi64_argmap_locate_protocol(protocol, reg, interface)	\
297  	((protocol), (reg), efi64_zero_upper(interface))
298  
299  #define __efi64_argmap_locate_device_path(protocol, path, handle)	\
300  	((protocol), (path), efi64_zero_upper(handle))
301  
302  #define __efi64_argmap_exit(handle, status, size, data)			\
303  	((handle), efi64_convert_status(status), (size), (data))
304  
305  /* PCI I/O */
306  #define __efi64_argmap_get_location(protocol, seg, bus, dev, func)	\
307  	((protocol), efi64_zero_upper(seg), efi64_zero_upper(bus),	\
308  	 efi64_zero_upper(dev), efi64_zero_upper(func))
309  
310  /* LoadFile */
311  #define __efi64_argmap_load_file(protocol, path, policy, bufsize, buf)	\
312  	((protocol), (path), (policy), efi64_zero_upper(bufsize), (buf))
313  
314  /* Graphics Output Protocol */
315  #define __efi64_argmap_query_mode(gop, mode, size, info)		\
316  	((gop), (mode), efi64_zero_upper(size), efi64_zero_upper(info))
317  
318  /* TCG2 protocol */
319  #define __efi64_argmap_hash_log_extend_event(prot, fl, addr, size, ev)	\
320  	((prot), (fl), 0ULL, (u64)(addr), 0ULL, (u64)(size), 0ULL, ev)
321  
322  /* DXE services */
323  #define __efi64_argmap_get_memory_space_descriptor(phys, desc) \
324  	(__efi64_split(phys), (desc))
325  
326  #define __efi64_argmap_set_memory_space_attributes(phys, size, flags) \
327  	(__efi64_split(phys), __efi64_split(size), __efi64_split(flags))
328  
329  /*
330   * The macros below handle the plumbing for the argument mapping. To add a
331   * mapping for a specific EFI method, simply define a macro
332   * __efi64_argmap_<method name>, following the examples above.
333   */
334  
335  #define __efi64_thunk_map(inst, func, ...)				\
336  	efi64_thunk(inst->mixed_mode.func,				\
337  		__efi64_argmap(__efi64_argmap_ ## func(__VA_ARGS__),	\
338  			       (__VA_ARGS__)))
339  
340  #define __efi64_argmap(mapped, args)					\
341  	__PASTE(__efi64_argmap__, __efi_nargs(__efi_eat mapped))(mapped, args)
342  #define __efi64_argmap__0(mapped, args) __efi_eval mapped
343  #define __efi64_argmap__1(mapped, args) __efi_eval args
344  
345  #define __efi_eat(...)
346  #define __efi_eval(...) __VA_ARGS__
347  
348  /* The three macros below handle dispatching via the thunk if needed */
349  
350  #define efi_call_proto(inst, func, ...)					\
351  	(efi_is_native()						\
352  		? inst->func(inst, ##__VA_ARGS__)			\
353  		: __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__))
354  
355  #define efi_bs_call(func, ...)						\
356  	(efi_is_native()						\
357  		? efi_system_table->boottime->func(__VA_ARGS__)		\
358  		: __efi64_thunk_map(efi_table_attr(efi_system_table,	\
359  						   boottime),		\
360  				    func, __VA_ARGS__))
361  
362  #define efi_rt_call(func, ...)						\
363  	(efi_is_native()						\
364  		? efi_system_table->runtime->func(__VA_ARGS__)		\
365  		: __efi64_thunk_map(efi_table_attr(efi_system_table,	\
366  						   runtime),		\
367  				    func, __VA_ARGS__))
368  
369  #define efi_dxe_call(func, ...)						\
370  	(efi_is_native()						\
371  		? efi_dxe_table->func(__VA_ARGS__)			\
372  		: __efi64_thunk_map(efi_dxe_table, func, __VA_ARGS__))
373  
374  #else /* CONFIG_EFI_MIXED */
375  
376  static inline bool efi_is_64bit(void)
377  {
378  	return IS_ENABLED(CONFIG_X86_64);
379  }
380  
381  #endif /* CONFIG_EFI_MIXED */
382  
383  extern bool efi_reboot_required(void);
384  extern bool efi_is_table_address(unsigned long phys_addr);
385  
386  extern void efi_find_mirror(void);
387  extern void efi_reserve_boot_services(void);
388  #else
389  static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
390  static inline bool efi_reboot_required(void)
391  {
392  	return false;
393  }
394  static inline  bool efi_is_table_address(unsigned long phys_addr)
395  {
396  	return false;
397  }
398  static inline void efi_find_mirror(void)
399  {
400  }
401  static inline void efi_reserve_boot_services(void)
402  {
403  }
404  #endif /* CONFIG_EFI */
405  
406  #ifdef CONFIG_EFI_FAKE_MEMMAP
407  extern void __init efi_fake_memmap_early(void);
408  #else
409  static inline void efi_fake_memmap_early(void)
410  {
411  }
412  #endif
413  
414  #define arch_ima_efi_boot_mode	\
415  	({ extern struct boot_params boot_params; boot_params.secure_boot; })
416  
417  #endif /* _ASM_X86_EFI_H */
418