~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/x86/platform/efi/efi_64.c

Version: ~ [ linux-5.8-rc4 ] ~ [ linux-5.7.7 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.50 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.131 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.187 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.229 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.229 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * x86_64 specific EFI support functions
  3  * Based on Extensible Firmware Interface Specification version 1.0
  4  *
  5  * Copyright (C) 2005-2008 Intel Co.
  6  *      Fenghua Yu <fenghua.yu@intel.com>
  7  *      Bibo Mao <bibo.mao@intel.com>
  8  *      Chandramouli Narayanan <mouli@linux.intel.com>
  9  *      Huang Ying <ying.huang@intel.com>
 10  *
 11  * Code to convert EFI to E820 map has been implemented in elilo bootloader
 12  * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
 13  * is setup appropriately for EFI runtime code.
 14  * - mouli 06/14/2007.
 15  *
 16  */
 17 
 18 #include <linux/kernel.h>
 19 #include <linux/init.h>
 20 #include <linux/mm.h>
 21 #include <linux/types.h>
 22 #include <linux/spinlock.h>
 23 #include <linux/bootmem.h>
 24 #include <linux/ioport.h>
 25 #include <linux/module.h>
 26 #include <linux/efi.h>
 27 #include <linux/uaccess.h>
 28 #include <linux/io.h>
 29 #include <linux/reboot.h>
 30 #include <linux/slab.h>
 31 
 32 #include <asm/setup.h>
 33 #include <asm/page.h>
 34 #include <asm/e820.h>
 35 #include <asm/pgtable.h>
 36 #include <asm/tlbflush.h>
 37 #include <asm/proto.h>
 38 #include <asm/efi.h>
 39 #include <asm/cacheflush.h>
 40 #include <asm/fixmap.h>
 41 #include <asm/realmode.h>
 42 #include <asm/time.h>
 43 
 44 static pgd_t *save_pgd __initdata;
 45 static unsigned long efi_flags __initdata;
 46 
 47 /*
 48  * We allocate runtime services regions bottom-up, starting from -4G, i.e.
 49  * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
 50  */
 51 static u64 efi_va = EFI_VA_START;
 52 
 53 /*
 54  * Scratch space used for switching the pagetable in the EFI stub
 55  */
 56 struct efi_scratch {
 57         u64 r15;
 58         u64 prev_cr3;
 59         pgd_t *efi_pgt;
 60         bool use_pgd;
 61         u64 phys_stack;
 62 } __packed;
 63 
 64 static void __init early_code_mapping_set_exec(int executable)
 65 {
 66         efi_memory_desc_t *md;
 67         void *p;
 68 
 69         if (!(__supported_pte_mask & _PAGE_NX))
 70                 return;
 71 
 72         /* Make EFI service code area executable */
 73         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
 74                 md = p;
 75                 if (md->type == EFI_RUNTIME_SERVICES_CODE ||
 76                     md->type == EFI_BOOT_SERVICES_CODE)
 77                         efi_set_executable(md, executable);
 78         }
 79 }
 80 
 81 void __init efi_call_phys_prolog(void)
 82 {
 83         unsigned long vaddress;
 84         int pgd;
 85         int n_pgds;
 86 
 87         if (!efi_enabled(EFI_OLD_MEMMAP))
 88                 return;
 89 
 90         early_code_mapping_set_exec(1);
 91         local_irq_save(efi_flags);
 92 
 93         n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
 94         save_pgd = kmalloc(n_pgds * sizeof(pgd_t), GFP_KERNEL);
 95 
 96         for (pgd = 0; pgd < n_pgds; pgd++) {
 97                 save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE);
 98                 vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);
 99                 set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));
100         }
101         __flush_tlb_all();
102 }
103 
104 void __init efi_call_phys_epilog(void)
105 {
106         /*
107          * After the lock is released, the original page table is restored.
108          */
109         int pgd;
110         int n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
111 
112         if (!efi_enabled(EFI_OLD_MEMMAP))
113                 return;
114 
115         for (pgd = 0; pgd < n_pgds; pgd++)
116                 set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]);
117         kfree(save_pgd);
118         __flush_tlb_all();
119         local_irq_restore(efi_flags);
120         early_code_mapping_set_exec(0);
121 }
122 
123 /*
124  * Add low kernel mappings for passing arguments to EFI functions.
125  */
126 void efi_sync_low_kernel_mappings(void)
127 {
128         unsigned num_pgds;
129         pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
130 
131         if (efi_enabled(EFI_OLD_MEMMAP))
132                 return;
133 
134         num_pgds = pgd_index(MODULES_END - 1) - pgd_index(PAGE_OFFSET);
135 
136         memcpy(pgd + pgd_index(PAGE_OFFSET),
137                 init_mm.pgd + pgd_index(PAGE_OFFSET),
138                 sizeof(pgd_t) * num_pgds);
139 }
140 
141 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
142 {
143         unsigned long text;
144         struct page *page;
145         unsigned npages;
146         pgd_t *pgd;
147 
148         if (efi_enabled(EFI_OLD_MEMMAP))
149                 return 0;
150 
151         efi_scratch.efi_pgt = (pgd_t *)(unsigned long)real_mode_header->trampoline_pgd;
152         pgd = __va(efi_scratch.efi_pgt);
153 
154         /*
155          * It can happen that the physical address of new_memmap lands in memory
156          * which is not mapped in the EFI page table. Therefore we need to go
157          * and ident-map those pages containing the map before calling
158          * phys_efi_set_virtual_address_map().
159          */
160         if (kernel_map_pages_in_pgd(pgd, pa_memmap, pa_memmap, num_pages, _PAGE_NX)) {
161                 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
162                 return 1;
163         }
164 
165         efi_scratch.use_pgd = true;
166 
167         /*
168          * When making calls to the firmware everything needs to be 1:1
169          * mapped and addressable with 32-bit pointers. Map the kernel
170          * text and allocate a new stack because we can't rely on the
171          * stack pointer being < 4GB.
172          */
173         if (!IS_ENABLED(CONFIG_EFI_MIXED))
174                 return 0;
175 
176         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
177         if (!page)
178                 panic("Unable to allocate EFI runtime stack < 4GB\n");
179 
180         efi_scratch.phys_stack = virt_to_phys(page_address(page));
181         efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */
182 
183         npages = (_end - _text) >> PAGE_SHIFT;
184         text = __pa(_text);
185 
186         if (kernel_map_pages_in_pgd(pgd, text >> PAGE_SHIFT, text, npages, 0)) {
187                 pr_err("Failed to map kernel text 1:1\n");
188                 return 1;
189         }
190 
191         return 0;
192 }
193 
194 void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages)
195 {
196         pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
197 
198         kernel_unmap_pages_in_pgd(pgd, pa_memmap, num_pages);
199 }
200 
201 static void __init __map_region(efi_memory_desc_t *md, u64 va)
202 {
203         pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
204         unsigned long pf = 0;
205 
206         if (!(md->attribute & EFI_MEMORY_WB))
207                 pf |= _PAGE_PCD;
208 
209         if (kernel_map_pages_in_pgd(pgd, md->phys_addr, va, md->num_pages, pf))
210                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
211                            md->phys_addr, va);
212 }
213 
214 void __init efi_map_region(efi_memory_desc_t *md)
215 {
216         unsigned long size = md->num_pages << PAGE_SHIFT;
217         u64 pa = md->phys_addr;
218 
219         if (efi_enabled(EFI_OLD_MEMMAP))
220                 return old_map_region(md);
221 
222         /*
223          * Make sure the 1:1 mappings are present as a catch-all for b0rked
224          * firmware which doesn't update all internal pointers after switching
225          * to virtual mode and would otherwise crap on us.
226          */
227         __map_region(md, md->phys_addr);
228 
229         /*
230          * Enforce the 1:1 mapping as the default virtual address when
231          * booting in EFI mixed mode, because even though we may be
232          * running a 64-bit kernel, the firmware may only be 32-bit.
233          */
234         if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
235                 md->virt_addr = md->phys_addr;
236                 return;
237         }
238 
239         efi_va -= size;
240 
241         /* Is PA 2M-aligned? */
242         if (!(pa & (PMD_SIZE - 1))) {
243                 efi_va &= PMD_MASK;
244         } else {
245                 u64 pa_offset = pa & (PMD_SIZE - 1);
246                 u64 prev_va = efi_va;
247 
248                 /* get us the same offset within this 2M page */
249                 efi_va = (efi_va & PMD_MASK) + pa_offset;
250 
251                 if (efi_va > prev_va)
252                         efi_va -= PMD_SIZE;
253         }
254 
255         if (efi_va < EFI_VA_END) {
256                 pr_warn(FW_WARN "VA address range overflow!\n");
257                 return;
258         }
259 
260         /* Do the VA map */
261         __map_region(md, efi_va);
262         md->virt_addr = efi_va;
263 }
264 
265 /*
266  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
267  * md->virt_addr is the original virtual address which had been mapped in kexec
268  * 1st kernel.
269  */
270 void __init efi_map_region_fixed(efi_memory_desc_t *md)
271 {
272         __map_region(md, md->virt_addr);
273 }
274 
275 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
276                                  u32 type, u64 attribute)
277 {
278         unsigned long last_map_pfn;
279 
280         if (type == EFI_MEMORY_MAPPED_IO)
281                 return ioremap(phys_addr, size);
282 
283         last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
284         if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
285                 unsigned long top = last_map_pfn << PAGE_SHIFT;
286                 efi_ioremap(top, size - (top - phys_addr), type, attribute);
287         }
288 
289         if (!(attribute & EFI_MEMORY_WB))
290                 efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
291 
292         return (void __iomem *)__va(phys_addr);
293 }
294 
295 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
296 {
297         efi_setup = phys_addr + sizeof(struct setup_data);
298 }
299 
300 void __init efi_runtime_mkexec(void)
301 {
302         if (!efi_enabled(EFI_OLD_MEMMAP))
303                 return;
304 
305         if (__supported_pte_mask & _PAGE_NX)
306                 runtime_code_page_mkexec();
307 }
308 
309 void __init efi_dump_pagetable(void)
310 {
311 #ifdef CONFIG_EFI_PGT_DUMP
312         pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
313 
314         ptdump_walk_pgd_level(NULL, pgd);
315 #endif
316 }
317 
318 #ifdef CONFIG_EFI_MIXED
319 extern efi_status_t efi64_thunk(u32, ...);
320 
321 #define runtime_service32(func)                                          \
322 ({                                                                       \
323         u32 table = (u32)(unsigned long)efi.systab;                      \
324         u32 *rt, *___f;                                                  \
325                                                                          \
326         rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime));  \
327         ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
328         *___f;                                                           \
329 })
330 
331 /*
332  * Switch to the EFI page tables early so that we can access the 1:1
333  * runtime services mappings which are not mapped in any other page
334  * tables. This function must be called before runtime_service32().
335  *
336  * Also, disable interrupts because the IDT points to 64-bit handlers,
337  * which aren't going to function correctly when we switch to 32-bit.
338  */
339 #define efi_thunk(f, ...)                                               \
340 ({                                                                      \
341         efi_status_t __s;                                               \
342         unsigned long flags;                                            \
343         u32 func;                                                       \
344                                                                         \
345         efi_sync_low_kernel_mappings();                                 \
346         local_irq_save(flags);                                          \
347                                                                         \
348         efi_scratch.prev_cr3 = read_cr3();                              \
349         write_cr3((unsigned long)efi_scratch.efi_pgt);                  \
350         __flush_tlb_all();                                              \
351                                                                         \
352         func = runtime_service32(f);                                    \
353         __s = efi64_thunk(func, __VA_ARGS__);                   \
354                                                                         \
355         write_cr3(efi_scratch.prev_cr3);                                \
356         __flush_tlb_all();                                              \
357         local_irq_restore(flags);                                       \
358                                                                         \
359         __s;                                                            \
360 })
361 
362 efi_status_t efi_thunk_set_virtual_address_map(
363         void *phys_set_virtual_address_map,
364         unsigned long memory_map_size,
365         unsigned long descriptor_size,
366         u32 descriptor_version,
367         efi_memory_desc_t *virtual_map)
368 {
369         efi_status_t status;
370         unsigned long flags;
371         u32 func;
372 
373         efi_sync_low_kernel_mappings();
374         local_irq_save(flags);
375 
376         efi_scratch.prev_cr3 = read_cr3();
377         write_cr3((unsigned long)efi_scratch.efi_pgt);
378         __flush_tlb_all();
379 
380         func = (u32)(unsigned long)phys_set_virtual_address_map;
381         status = efi64_thunk(func, memory_map_size, descriptor_size,
382                              descriptor_version, virtual_map);
383 
384         write_cr3(efi_scratch.prev_cr3);
385         __flush_tlb_all();
386         local_irq_restore(flags);
387 
388         return status;
389 }
390 
391 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
392 {
393         efi_status_t status;
394         u32 phys_tm, phys_tc;
395 
396         spin_lock(&rtc_lock);
397 
398         phys_tm = virt_to_phys(tm);
399         phys_tc = virt_to_phys(tc);
400 
401         status = efi_thunk(get_time, phys_tm, phys_tc);
402 
403         spin_unlock(&rtc_lock);
404 
405         return status;
406 }
407 
408 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
409 {
410         efi_status_t status;
411         u32 phys_tm;
412 
413         spin_lock(&rtc_lock);
414 
415         phys_tm = virt_to_phys(tm);
416 
417         status = efi_thunk(set_time, phys_tm);
418 
419         spin_unlock(&rtc_lock);
420 
421         return status;
422 }
423 
424 static efi_status_t
425 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
426                           efi_time_t *tm)
427 {
428         efi_status_t status;
429         u32 phys_enabled, phys_pending, phys_tm;
430 
431         spin_lock(&rtc_lock);
432 
433         phys_enabled = virt_to_phys(enabled);
434         phys_pending = virt_to_phys(pending);
435         phys_tm = virt_to_phys(tm);
436 
437         status = efi_thunk(get_wakeup_time, phys_enabled,
438                              phys_pending, phys_tm);
439 
440         spin_unlock(&rtc_lock);
441 
442         return status;
443 }
444 
445 static efi_status_t
446 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
447 {
448         efi_status_t status;
449         u32 phys_tm;
450 
451         spin_lock(&rtc_lock);
452 
453         phys_tm = virt_to_phys(tm);
454 
455         status = efi_thunk(set_wakeup_time, enabled, phys_tm);
456 
457         spin_unlock(&rtc_lock);
458 
459         return status;
460 }
461 
462 
463 static efi_status_t
464 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
465                        u32 *attr, unsigned long *data_size, void *data)
466 {
467         efi_status_t status;
468         u32 phys_name, phys_vendor, phys_attr;
469         u32 phys_data_size, phys_data;
470 
471         phys_data_size = virt_to_phys(data_size);
472         phys_vendor = virt_to_phys(vendor);
473         phys_name = virt_to_phys(name);
474         phys_attr = virt_to_phys(attr);
475         phys_data = virt_to_phys(data);
476 
477         status = efi_thunk(get_variable, phys_name, phys_vendor,
478                            phys_attr, phys_data_size, phys_data);
479 
480         return status;
481 }
482 
483 static efi_status_t
484 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
485                        u32 attr, unsigned long data_size, void *data)
486 {
487         u32 phys_name, phys_vendor, phys_data;
488         efi_status_t status;
489 
490         phys_name = virt_to_phys(name);
491         phys_vendor = virt_to_phys(vendor);
492         phys_data = virt_to_phys(data);
493 
494         /* If data_size is > sizeof(u32) we've got problems */
495         status = efi_thunk(set_variable, phys_name, phys_vendor,
496                            attr, data_size, phys_data);
497 
498         return status;
499 }
500 
501 static efi_status_t
502 efi_thunk_get_next_variable(unsigned long *name_size,
503                             efi_char16_t *name,
504                             efi_guid_t *vendor)
505 {
506         efi_status_t status;
507         u32 phys_name_size, phys_name, phys_vendor;
508 
509         phys_name_size = virt_to_phys(name_size);
510         phys_vendor = virt_to_phys(vendor);
511         phys_name = virt_to_phys(name);
512 
513         status = efi_thunk(get_next_variable, phys_name_size,
514                            phys_name, phys_vendor);
515 
516         return status;
517 }
518 
519 static efi_status_t
520 efi_thunk_get_next_high_mono_count(u32 *count)
521 {
522         efi_status_t status;
523         u32 phys_count;
524 
525         phys_count = virt_to_phys(count);
526         status = efi_thunk(get_next_high_mono_count, phys_count);
527 
528         return status;
529 }
530 
531 static void
532 efi_thunk_reset_system(int reset_type, efi_status_t status,
533                        unsigned long data_size, efi_char16_t *data)
534 {
535         u32 phys_data;
536 
537         phys_data = virt_to_phys(data);
538 
539         efi_thunk(reset_system, reset_type, status, data_size, phys_data);
540 }
541 
542 static efi_status_t
543 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
544                          unsigned long count, unsigned long sg_list)
545 {
546         /*
547          * To properly support this function we would need to repackage
548          * 'capsules' because the firmware doesn't understand 64-bit
549          * pointers.
550          */
551         return EFI_UNSUPPORTED;
552 }
553 
554 static efi_status_t
555 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
556                               u64 *remaining_space,
557                               u64 *max_variable_size)
558 {
559         efi_status_t status;
560         u32 phys_storage, phys_remaining, phys_max;
561 
562         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
563                 return EFI_UNSUPPORTED;
564 
565         phys_storage = virt_to_phys(storage_space);
566         phys_remaining = virt_to_phys(remaining_space);
567         phys_max = virt_to_phys(max_variable_size);
568 
569         status = efi_thunk(query_variable_info, attr, phys_storage,
570                            phys_remaining, phys_max);
571 
572         return status;
573 }
574 
575 static efi_status_t
576 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
577                              unsigned long count, u64 *max_size,
578                              int *reset_type)
579 {
580         /*
581          * To properly support this function we would need to repackage
582          * 'capsules' because the firmware doesn't understand 64-bit
583          * pointers.
584          */
585         return EFI_UNSUPPORTED;
586 }
587 
588 void efi_thunk_runtime_setup(void)
589 {
590         efi.get_time = efi_thunk_get_time;
591         efi.set_time = efi_thunk_set_time;
592         efi.get_wakeup_time = efi_thunk_get_wakeup_time;
593         efi.set_wakeup_time = efi_thunk_set_wakeup_time;
594         efi.get_variable = efi_thunk_get_variable;
595         efi.get_next_variable = efi_thunk_get_next_variable;
596         efi.set_variable = efi_thunk_set_variable;
597         efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
598         efi.reset_system = efi_thunk_reset_system;
599         efi.query_variable_info = efi_thunk_query_variable_info;
600         efi.update_capsule = efi_thunk_update_capsule;
601         efi.query_capsule_caps = efi_thunk_query_capsule_caps;
602 }
603 #endif /* CONFIG_EFI_MIXED */
604 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp