arch/x86/include/asm/kexec.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_KEXEC_H
   3 #define _ASM_X86_KEXEC_H
   4
   5 #ifdef CONFIG_X86_32
   6 # define PA_CONTROL_PAGE        0
   7 # define VA_CONTROL_PAGE        1
   8 # define PA_PGD                 2
   9 # define PA_SWAP_PAGE           3
  10 # define PAGES_NR               4
  11 #else
  12 # define PA_CONTROL_PAGE        0
  13 # define VA_CONTROL_PAGE        1
  14 # define PA_TABLE_PAGE          2
  15 # define PA_SWAP_PAGE           3
  16 # define PAGES_NR               4
  17 #endif
  18
  19 # define KEXEC_CONTROL_CODE_MAX_SIZE    2048
  20
  21 #ifndef __ASSEMBLY__
  22
  23 #include <linux/string.h>
  24
  25 #include <asm/page.h>
  26 #include <asm/ptrace.h>
  27 #include <asm/bootparam.h>
  28
  29 struct kimage;
  30
  31 /*
  32  * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
  33  * I.e. Maximum page that is mapped directly into kernel memory,
  34  * and kmap is not required.
  35  *
  36  * So far x86_64 is limited to 40 physical address bits.
  37  */
  38 #ifdef CONFIG_X86_32
  39 /* Maximum physical address we can use pages from */
  40 # define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
  41 /* Maximum address we can reach in physical address mode */
  42 # define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
  43 /* Maximum address we can use for the control code buffer */
  44 # define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
  45
  46 # define KEXEC_CONTROL_PAGE_SIZE        4096
  47
  48 /* The native architecture */
  49 # define KEXEC_ARCH KEXEC_ARCH_386
  50
  51 /* We can also handle crash dumps from 64 bit kernel. */
  52 # define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
  53 #else
  54 /* Maximum physical address we can use pages from */
  55 # define KEXEC_SOURCE_MEMORY_LIMIT      (MAXMEM-1)
  56 /* Maximum address we can reach in physical address mode */
  57 # define KEXEC_DESTINATION_MEMORY_LIMIT (MAXMEM-1)
  58 /* Maximum address we can use for the control pages */
  59 # define KEXEC_CONTROL_MEMORY_LIMIT     (MAXMEM-1)
  60
  61 /* Allocate one page for the pdp and the second for the code */
  62 # define KEXEC_CONTROL_PAGE_SIZE  (4096UL + 4096UL)
  63
  64 /* The native architecture */
  65 # define KEXEC_ARCH KEXEC_ARCH_X86_64
  66 #endif
  67
  68 /* Memory to backup during crash kdump */
  69 #define KEXEC_BACKUP_SRC_START  (0UL)
  70 #define KEXEC_BACKUP_SRC_END    (640 * 1024UL)  /* 640K */
  71
  72 /*
  73  * CPU does not save ss and sp on stack if execution is already
  74  * running in kernel mode at the time of NMI occurrence. This code
  75  * fixes it.
  76  */
  77 static inline void crash_fixup_ss_esp(struct pt_regs *newregs,
  78                                       struct pt_regs *oldregs)
  79 {
  80 #ifdef CONFIG_X86_32
  81         newregs->sp = (unsigned long)&(oldregs->sp);
  82         asm volatile("xorl %%eax, %%eax\n\t"
  83                      "movw %%ss, %%ax\n\t"
  84                      :"=a"(newregs->ss));
  85 #endif
  86 }
  87
  88 /*
  89  * This function is responsible for capturing register states if coming
  90  * via panic otherwise just fix up the ss and sp if coming via kernel
  91  * mode exception.
  92  */
  93 static inline void crash_setup_regs(struct pt_regs *newregs,
  94                                     struct pt_regs *oldregs)
  95 {
  96         if (oldregs) {
  97                 memcpy(newregs, oldregs, sizeof(*newregs));
  98                 crash_fixup_ss_esp(newregs, oldregs);
  99         } else {
 100 #ifdef CONFIG_X86_32
 101                 asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
 102                 asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
 103                 asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
 104                 asm volatile("movl %%esi,%0" : "=m"(newregs->si));
 105                 asm volatile("movl %%edi,%0" : "=m"(newregs->di));
 106                 asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
 107                 asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
 108                 asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
 109                 asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
 110                 asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
 111                 asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
 112                 asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
 113                 asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
 114 #else
 115                 asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
 116                 asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
 117                 asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
 118                 asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
 119                 asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
 120                 asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
 121                 asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
 122                 asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
 123                 asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
 124                 asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
 125                 asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
 126                 asm volatile("movq %%r11,%0" : "=m"(newregs->r11));
 127                 asm volatile("movq %%r12,%0" : "=m"(newregs->r12));
 128                 asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
 129                 asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
 130                 asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
 131                 asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
 132                 asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
 133                 asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
 134 #endif
 135                 newregs->ip = (unsigned long)current_text_addr();
 136         }
 137 }
 138
 139 #ifdef CONFIG_X86_32
 140 asmlinkage unsigned long
 141 relocate_kernel(unsigned long indirection_page,
 142                 unsigned long control_page,
 143                 unsigned long start_address,
 144                 unsigned int has_pae,
 145                 unsigned int preserve_context);
 146 #else
 147 unsigned long
 148 relocate_kernel(unsigned long indirection_page,
 149                 unsigned long page_list,
 150                 unsigned long start_address,
 151                 unsigned int preserve_context,
 152                 unsigned int sme_active);
 153 #endif
 154
 155 #define ARCH_HAS_KIMAGE_ARCH
 156
 157 #ifdef CONFIG_X86_32
 158 struct kimage_arch {
 159         pgd_t *pgd;
 160 #ifdef CONFIG_X86_PAE
 161         pmd_t *pmd0;
 162         pmd_t *pmd1;
 163 #endif
 164         pte_t *pte0;
 165         pte_t *pte1;
 166 };
 167 #else
 168 struct kimage_arch {
 169         p4d_t *p4d;
 170         pud_t *pud;
 171         pmd_t *pmd;
 172         pte_t *pte;
 173         /* Details of backup region */
 174         unsigned long backup_src_start;
 175         unsigned long backup_src_sz;
 176
 177         /* Physical address of backup segment */
 178         unsigned long backup_load_addr;
 179
 180         /* Core ELF header buffer */
 181         void *elf_headers;
 182         unsigned long elf_headers_sz;
 183         unsigned long elf_load_addr;
 184 };
 185 #endif /* CONFIG_X86_32 */
 186
 187 #ifdef CONFIG_X86_64
 188 /*
 189  * Number of elements and order of elements in this structure should match
 190  * with the ones in arch/x86/purgatory/entry64.S. If you make a change here
 191  * make an appropriate change in purgatory too.
 192  */
 193 struct kexec_entry64_regs {
 194         uint64_t rax;
 195         uint64_t rcx;
 196         uint64_t rdx;
 197         uint64_t rbx;
 198         uint64_t rsp;
 199         uint64_t rbp;
 200         uint64_t rsi;
 201         uint64_t rdi;
 202         uint64_t r8;
 203         uint64_t r9;
 204         uint64_t r10;
 205         uint64_t r11;
 206         uint64_t r12;
 207         uint64_t r13;
 208         uint64_t r14;
 209         uint64_t r15;
 210         uint64_t rip;
 211 };
 212
 213 extern int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages,
 214                                        gfp_t gfp);
 215 #define arch_kexec_post_alloc_pages arch_kexec_post_alloc_pages
 216
 217 extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages);
 218 #define arch_kexec_pre_free_pages arch_kexec_pre_free_pages
 219
 220 #endif
 221
 222 typedef void crash_vmclear_fn(void);
 223 extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss;
 224 extern void kdump_nmi_shootdown_cpus(void);
 225
 226 #endif /* __ASSEMBLY__ */
 227
 228 #endif /* _ASM_X86_KEXEC_H */