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/* Size of each exception handler referenced by the IDT */
 13# define KEXEC_DEBUG_EXC_HANDLER_SIZE	6 /* PUSHI, PUSHI, 2-byte JMP */
 14#endif
 15
 16#ifdef CONFIG_X86_64
 17
 18#include <linux/bits.h>
 19
 20#define RELOC_KERNEL_PRESERVE_CONTEXT	BIT(0)
 21#define RELOC_KERNEL_CACHE_INCOHERENT	BIT(1)
 22
 23#endif
 24
 25# define KEXEC_CONTROL_PAGE_SIZE	4096
 26# define KEXEC_CONTROL_CODE_MAX_SIZE	2048
 27
 28#ifndef __ASSEMBLER__
 29
 30#include <linux/string.h>
 31#include <linux/kernel.h>
 32
 33#include <asm/asm.h>
 34#include <asm/page.h>
 35#include <asm/ptrace.h>
 36
 37struct kimage;
 38
 39/*
 40 * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
 41 * I.e. Maximum page that is mapped directly into kernel memory,
 42 * and kmap is not required.
 43 *
 44 * So far x86_64 is limited to 40 physical address bits.
 45 */
 46#ifdef CONFIG_X86_32
 47/* Maximum physical address we can use pages from */
 48# define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
 49/* Maximum address we can reach in physical address mode */
 50# define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
 51/* Maximum address we can use for the control code buffer */
 52# define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
 53
 54
 55/* The native architecture */
 56# define KEXEC_ARCH KEXEC_ARCH_386
 57
 58/* We can also handle crash dumps from 64 bit kernel. */
 59# define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
 60#else
 61/* Maximum physical address we can use pages from */
 62# define KEXEC_SOURCE_MEMORY_LIMIT      (MAXMEM-1)
 63/* Maximum address we can reach in physical address mode */
 64# define KEXEC_DESTINATION_MEMORY_LIMIT (MAXMEM-1)
 65/* Maximum address we can use for the control pages */
 66# define KEXEC_CONTROL_MEMORY_LIMIT     (MAXMEM-1)
 67
 68/* The native architecture */
 69# define KEXEC_ARCH KEXEC_ARCH_X86_64
 70
 71extern unsigned long kexec_va_control_page;
 72extern unsigned long kexec_pa_table_page;
 73extern unsigned long kexec_pa_swap_page;
 74extern gate_desc kexec_debug_idt[];
 75extern unsigned char kexec_debug_exc_vectors[];
 76extern uint16_t kexec_debug_8250_port;
 77extern unsigned long kexec_debug_8250_mmio32;
 78#endif
 79
 80/*
 81 * This function is responsible for capturing register states if coming
 82 * via panic otherwise just fix up the ss and sp if coming via kernel
 83 * mode exception.
 84 */
 85static inline void crash_setup_regs(struct pt_regs *newregs,
 86				    struct pt_regs *oldregs)
 87{
 88	if (oldregs) {
 89		memcpy(newregs, oldregs, sizeof(*newregs));
 90	} else {
 91		asm volatile("mov %%" _ASM_BX ",%0" : "=m"(newregs->bx));
 92		asm volatile("mov %%" _ASM_CX ",%0" : "=m"(newregs->cx));
 93		asm volatile("mov %%" _ASM_DX ",%0" : "=m"(newregs->dx));
 94		asm volatile("mov %%" _ASM_SI ",%0" : "=m"(newregs->si));
 95		asm volatile("mov %%" _ASM_DI ",%0" : "=m"(newregs->di));
 96		asm volatile("mov %%" _ASM_BP ",%0" : "=m"(newregs->bp));
 97		asm volatile("mov %%" _ASM_AX ",%0" : "=m"(newregs->ax));
 98		asm volatile("mov %%" _ASM_SP ",%0" : "=m"(newregs->sp));
 99#ifdef CONFIG_X86_64
100		asm volatile("mov %%r8,%0" : "=m"(newregs->r8));
101		asm volatile("mov %%r9,%0" : "=m"(newregs->r9));
102		asm volatile("mov %%r10,%0" : "=m"(newregs->r10));
103		asm volatile("mov %%r11,%0" : "=m"(newregs->r11));
104		asm volatile("mov %%r12,%0" : "=m"(newregs->r12));
105		asm volatile("mov %%r13,%0" : "=m"(newregs->r13));
106		asm volatile("mov %%r14,%0" : "=m"(newregs->r14));
107		asm volatile("mov %%r15,%0" : "=m"(newregs->r15));
108#endif
109		asm volatile("mov %%ss,%k0" : "=a"(newregs->ss));
110		asm volatile("mov %%cs,%k0" : "=a"(newregs->cs));
111#ifdef CONFIG_X86_32
112		asm volatile("mov %%ds,%k0" : "=a"(newregs->ds));
113		asm volatile("mov %%es,%k0" : "=a"(newregs->es));
114#endif
115		asm volatile("pushf\n\t"
116			     "pop %0" : "=m"(newregs->flags));
117		newregs->ip = _THIS_IP_;
118	}
119}
120
121#ifdef CONFIG_X86_32
122typedef asmlinkage unsigned long
123relocate_kernel_fn(unsigned long indirection_page,
124		   unsigned long control_page,
125		   unsigned long start_address,
126		   unsigned int has_pae,
127		   unsigned int preserve_context);
128#else
129typedef unsigned long
130relocate_kernel_fn(unsigned long indirection_page,
131		   unsigned long pa_control_page,
132		   unsigned long start_address,
133		   unsigned int flags);
134#endif
135extern relocate_kernel_fn relocate_kernel;
136#define ARCH_HAS_KIMAGE_ARCH
137
138#ifdef CONFIG_X86_32
139struct kimage_arch {
140	pgd_t *pgd;
141#ifdef CONFIG_X86_PAE
142	pmd_t *pmd0;
143	pmd_t *pmd1;
144#endif
145	pte_t *pte0;
146	pte_t *pte1;
147};
148#else
149struct kimage_arch {
150	/*
151	 * This is a kimage control page, as it must not overlap with either
152	 * source or destination address ranges.
153	 */
154	pgd_t *pgd;
155	/*
156	 * The virtual mapping of the control code page itself is used only
157	 * during the transition, while the current kernel's pages are all
158	 * in place. Thus the intermediate page table pages used to map it
159	 * are not control pages, but instead just normal pages obtained
160	 * with get_zeroed_page(). And have to be tracked (below) so that
161	 * they can be freed.
162	 */
163	p4d_t *p4d;
164	pud_t *pud;
165	pmd_t *pmd;
166	pte_t *pte;
167};
168#endif /* CONFIG_X86_32 */
169
170#ifdef CONFIG_X86_64
171/*
172 * Number of elements and order of elements in this structure should match
173 * with the ones in arch/x86/purgatory/entry64.S. If you make a change here
174 * make an appropriate change in purgatory too.
175 */
176struct kexec_entry64_regs {
177	uint64_t rax;
178	uint64_t rcx;
179	uint64_t rdx;
180	uint64_t rbx;
181	uint64_t rsp;
182	uint64_t rbp;
183	uint64_t rsi;
184	uint64_t rdi;
185	uint64_t r8;
186	uint64_t r9;
187	uint64_t r10;
188	uint64_t r11;
189	uint64_t r12;
190	uint64_t r13;
191	uint64_t r14;
192	uint64_t r15;
193	uint64_t rip;
194};
195
196extern int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages,
197				       gfp_t gfp);
198#define arch_kexec_post_alloc_pages arch_kexec_post_alloc_pages
199
200extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages);
201#define arch_kexec_pre_free_pages arch_kexec_pre_free_pages
202
203void arch_kexec_protect_crashkres(void);
204#define arch_kexec_protect_crashkres arch_kexec_protect_crashkres
205
206void arch_kexec_unprotect_crashkres(void);
207#define arch_kexec_unprotect_crashkres arch_kexec_unprotect_crashkres
208
209#ifdef CONFIG_KEXEC_FILE
210struct purgatory_info;
211int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
212				     Elf_Shdr *section,
213				     const Elf_Shdr *relsec,
214				     const Elf_Shdr *symtab);
215#define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add
216
217int arch_kimage_file_post_load_cleanup(struct kimage *image);
218#define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup
219#endif
220#endif
221
222extern void kdump_nmi_shootdown_cpus(void);
223
224#ifdef CONFIG_CRASH_HOTPLUG
225void arch_crash_handle_hotplug_event(struct kimage *image, void *arg);
226#define arch_crash_handle_hotplug_event arch_crash_handle_hotplug_event
227
228int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags);
229#define arch_crash_hotplug_support arch_crash_hotplug_support
230
231unsigned int arch_crash_get_elfcorehdr_size(void);
232#define crash_get_elfcorehdr_size arch_crash_get_elfcorehdr_size
233#endif
234
235#endif /* __ASSEMBLER__ */
236
237#endif /* _ASM_X86_KEXEC_H */