v4.19.13 snapshot.
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
new file mode 100644
index 0000000..f327236
--- /dev/null
+++ b/arch/x86/include/asm/kexec.h
@@ -0,0 +1,228 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_KEXEC_H
+#define _ASM_X86_KEXEC_H
+
+#ifdef CONFIG_X86_32
+# define PA_CONTROL_PAGE 0
+# define VA_CONTROL_PAGE 1
+# define PA_PGD 2
+# define PA_SWAP_PAGE 3
+# define PAGES_NR 4
+#else
+# define PA_CONTROL_PAGE 0
+# define VA_CONTROL_PAGE 1
+# define PA_TABLE_PAGE 2
+# define PA_SWAP_PAGE 3
+# define PAGES_NR 4
+#endif
+
+# define KEXEC_CONTROL_CODE_MAX_SIZE 2048
+
+#ifndef __ASSEMBLY__
+
+#include <linux/string.h>
+
+#include <asm/page.h>
+#include <asm/ptrace.h>
+#include <asm/bootparam.h>
+
+struct kimage;
+
+/*
+ * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
+ * I.e. Maximum page that is mapped directly into kernel memory,
+ * and kmap is not required.
+ *
+ * So far x86_64 is limited to 40 physical address bits.
+ */
+#ifdef CONFIG_X86_32
+/* Maximum physical address we can use pages from */
+# define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
+/* Maximum address we can reach in physical address mode */
+# define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
+/* Maximum address we can use for the control code buffer */
+# define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
+
+# define KEXEC_CONTROL_PAGE_SIZE 4096
+
+/* The native architecture */
+# define KEXEC_ARCH KEXEC_ARCH_386
+
+/* We can also handle crash dumps from 64 bit kernel. */
+# define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
+#else
+/* Maximum physical address we can use pages from */
+# define KEXEC_SOURCE_MEMORY_LIMIT (MAXMEM-1)
+/* Maximum address we can reach in physical address mode */
+# define KEXEC_DESTINATION_MEMORY_LIMIT (MAXMEM-1)
+/* Maximum address we can use for the control pages */
+# define KEXEC_CONTROL_MEMORY_LIMIT (MAXMEM-1)
+
+/* Allocate one page for the pdp and the second for the code */
+# define KEXEC_CONTROL_PAGE_SIZE (4096UL + 4096UL)
+
+/* The native architecture */
+# define KEXEC_ARCH KEXEC_ARCH_X86_64
+#endif
+
+/* Memory to backup during crash kdump */
+#define KEXEC_BACKUP_SRC_START (0UL)
+#define KEXEC_BACKUP_SRC_END (640 * 1024UL) /* 640K */
+
+/*
+ * CPU does not save ss and sp on stack if execution is already
+ * running in kernel mode at the time of NMI occurrence. This code
+ * fixes it.
+ */
+static inline void crash_fixup_ss_esp(struct pt_regs *newregs,
+ struct pt_regs *oldregs)
+{
+#ifdef CONFIG_X86_32
+ newregs->sp = (unsigned long)&(oldregs->sp);
+ asm volatile("xorl %%eax, %%eax\n\t"
+ "movw %%ss, %%ax\n\t"
+ :"=a"(newregs->ss));
+#endif
+}
+
+/*
+ * This function is responsible for capturing register states if coming
+ * via panic otherwise just fix up the ss and sp if coming via kernel
+ * mode exception.
+ */
+static inline void crash_setup_regs(struct pt_regs *newregs,
+ struct pt_regs *oldregs)
+{
+ if (oldregs) {
+ memcpy(newregs, oldregs, sizeof(*newregs));
+ crash_fixup_ss_esp(newregs, oldregs);
+ } else {
+#ifdef CONFIG_X86_32
+ asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
+ asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
+ asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
+ asm volatile("movl %%esi,%0" : "=m"(newregs->si));
+ asm volatile("movl %%edi,%0" : "=m"(newregs->di));
+ asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
+ asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
+ asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
+ asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
+ asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
+ asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
+ asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
+ asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
+#else
+ asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
+ asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
+ asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
+ asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
+ asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
+ asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
+ asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
+ asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
+ asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
+ asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
+ asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
+ asm volatile("movq %%r11,%0" : "=m"(newregs->r11));
+ asm volatile("movq %%r12,%0" : "=m"(newregs->r12));
+ asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
+ asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
+ asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
+ asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
+ asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
+ asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
+#endif
+ newregs->ip = (unsigned long)current_text_addr();
+ }
+}
+
+#ifdef CONFIG_X86_32
+asmlinkage unsigned long
+relocate_kernel(unsigned long indirection_page,
+ unsigned long control_page,
+ unsigned long start_address,
+ unsigned int has_pae,
+ unsigned int preserve_context);
+#else
+unsigned long
+relocate_kernel(unsigned long indirection_page,
+ unsigned long page_list,
+ unsigned long start_address,
+ unsigned int preserve_context,
+ unsigned int sme_active);
+#endif
+
+#define ARCH_HAS_KIMAGE_ARCH
+
+#ifdef CONFIG_X86_32
+struct kimage_arch {
+ pgd_t *pgd;
+#ifdef CONFIG_X86_PAE
+ pmd_t *pmd0;
+ pmd_t *pmd1;
+#endif
+ pte_t *pte0;
+ pte_t *pte1;
+};
+#else
+struct kimage_arch {
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+ /* Details of backup region */
+ unsigned long backup_src_start;
+ unsigned long backup_src_sz;
+
+ /* Physical address of backup segment */
+ unsigned long backup_load_addr;
+
+ /* Core ELF header buffer */
+ void *elf_headers;
+ unsigned long elf_headers_sz;
+ unsigned long elf_load_addr;
+};
+#endif /* CONFIG_X86_32 */
+
+#ifdef CONFIG_X86_64
+/*
+ * Number of elements and order of elements in this structure should match
+ * with the ones in arch/x86/purgatory/entry64.S. If you make a change here
+ * make an appropriate change in purgatory too.
+ */
+struct kexec_entry64_regs {
+ uint64_t rax;
+ uint64_t rcx;
+ uint64_t rdx;
+ uint64_t rbx;
+ uint64_t rsp;
+ uint64_t rbp;
+ uint64_t rsi;
+ uint64_t rdi;
+ uint64_t r8;
+ uint64_t r9;
+ uint64_t r10;
+ uint64_t r11;
+ uint64_t r12;
+ uint64_t r13;
+ uint64_t r14;
+ uint64_t r15;
+ uint64_t rip;
+};
+
+extern int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages,
+ gfp_t gfp);
+#define arch_kexec_post_alloc_pages arch_kexec_post_alloc_pages
+
+extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages);
+#define arch_kexec_pre_free_pages arch_kexec_pre_free_pages
+
+#endif
+
+typedef void crash_vmclear_fn(void);
+extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss;
+extern void kdump_nmi_shootdown_cpus(void);
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_X86_KEXEC_H */