1// SPDX-License-Identifier: GPL-2.0-only
 2#include <asm/trap_pf.h>
 3#include <asm/segment.h>
 4#include <asm/trapnr.h>
 5#include "misc.h"
 6
 7static void set_idt_entry(int vector, void (*handler)(void))
 8{
 9	unsigned long address = (unsigned long)handler;
10	gate_desc entry;
11
12	memset(&entry, 0, sizeof(entry));
13
14	entry.offset_low    = (u16)(address & 0xffff);
15	entry.segment       = __KERNEL_CS;
16	entry.bits.type     = GATE_TRAP;
17	entry.bits.p        = 1;
18	entry.offset_middle = (u16)((address >> 16) & 0xffff);
19	entry.offset_high   = (u32)(address >> 32);
20
21	memcpy(&boot_idt[vector], &entry, sizeof(entry));
22}
23
24/* Have this here so we don't need to include <asm/desc.h> */
25static void load_boot_idt(const struct desc_ptr *dtr)
26{
27	asm volatile("lidt %0"::"m" (*dtr));
28}
29
30/* Setup IDT before kernel jumping to  .Lrelocated */
31void load_stage1_idt(void)
32{
33	boot_idt_desc.address = (unsigned long)boot_idt;
34
35
36	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT))
37		set_idt_entry(X86_TRAP_VC, boot_stage1_vc);
38
39	load_boot_idt(&boot_idt_desc);
40}
41
42/* Setup IDT after kernel jumping to  .Lrelocated */
43void load_stage2_idt(void)
44{
45	boot_idt_desc.address = (unsigned long)boot_idt;
46
47	set_idt_entry(X86_TRAP_PF, boot_page_fault);
48
49#ifdef CONFIG_AMD_MEM_ENCRYPT
50	set_idt_entry(X86_TRAP_VC, boot_stage2_vc);
51#endif
52
53	load_boot_idt(&boot_idt_desc);
54}
55
56void cleanup_exception_handling(void)
57{
58	/*
59	 * Flush GHCB from cache and map it encrypted again when running as
60	 * SEV-ES guest.
61	 */
62	sev_es_shutdown_ghcb();
63
64	/* Set a null-idt, disabling #PF and #VC handling */
65	boot_idt_desc.size    = 0;
66	boot_idt_desc.address = 0;
67	load_boot_idt(&boot_idt_desc);
68}