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v6.2
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Hibernation support for x86-64
  4 *
  5 * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
  6 * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz>
  7 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
  8 */
  9
 10#include <linux/gfp.h>
 11#include <linux/smp.h>
 12#include <linux/suspend.h>
 13#include <linux/scatterlist.h>
 14#include <linux/kdebug.h>
 15#include <linux/pgtable.h>
 16
 17#include <crypto/hash.h>
 18
 19#include <asm/e820/api.h>
 20#include <asm/init.h>
 21#include <asm/proto.h>
 22#include <asm/page.h>
 
 23#include <asm/mtrr.h>
 24#include <asm/sections.h>
 25#include <asm/suspend.h>
 26#include <asm/tlbflush.h>
 27
 28static int set_up_temporary_text_mapping(pgd_t *pgd)
 29{
 30	pmd_t *pmd;
 31	pud_t *pud;
 32	p4d_t *p4d = NULL;
 33	pgprot_t pgtable_prot = __pgprot(_KERNPG_TABLE);
 34	pgprot_t pmd_text_prot = __pgprot(__PAGE_KERNEL_LARGE_EXEC);
 35
 36	/* Filter out unsupported __PAGE_KERNEL* bits: */
 37	pgprot_val(pmd_text_prot) &= __default_kernel_pte_mask;
 38	pgprot_val(pgtable_prot)  &= __default_kernel_pte_mask;
 39
 40	/*
 41	 * The new mapping only has to cover the page containing the image
 42	 * kernel's entry point (jump_address_phys), because the switch over to
 43	 * it is carried out by relocated code running from a page allocated
 44	 * specifically for this purpose and covered by the identity mapping, so
 45	 * the temporary kernel text mapping is only needed for the final jump.
 46	 * Moreover, in that mapping the virtual address of the image kernel's
 47	 * entry point must be the same as its virtual address in the image
 48	 * kernel (restore_jump_address), so the image kernel's
 49	 * restore_registers() code doesn't find itself in a different area of
 50	 * the virtual address space after switching over to the original page
 51	 * tables used by the image kernel.
 52	 */
 53
 54	if (pgtable_l5_enabled()) {
 55		p4d = (p4d_t *)get_safe_page(GFP_ATOMIC);
 56		if (!p4d)
 57			return -ENOMEM;
 58	}
 59
 60	pud = (pud_t *)get_safe_page(GFP_ATOMIC);
 61	if (!pud)
 62		return -ENOMEM;
 63
 64	pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
 65	if (!pmd)
 66		return -ENOMEM;
 67
 68	set_pmd(pmd + pmd_index(restore_jump_address),
 69		__pmd((jump_address_phys & PMD_MASK) | pgprot_val(pmd_text_prot)));
 70	set_pud(pud + pud_index(restore_jump_address),
 71		__pud(__pa(pmd) | pgprot_val(pgtable_prot)));
 72	if (p4d) {
 73		p4d_t new_p4d = __p4d(__pa(pud) | pgprot_val(pgtable_prot));
 74		pgd_t new_pgd = __pgd(__pa(p4d) | pgprot_val(pgtable_prot));
 75
 76		set_p4d(p4d + p4d_index(restore_jump_address), new_p4d);
 77		set_pgd(pgd + pgd_index(restore_jump_address), new_pgd);
 78	} else {
 79		/* No p4d for 4-level paging: point the pgd to the pud page table */
 80		pgd_t new_pgd = __pgd(__pa(pud) | pgprot_val(pgtable_prot));
 81		set_pgd(pgd + pgd_index(restore_jump_address), new_pgd);
 82	}
 83
 84	return 0;
 85}
 86
 87static void *alloc_pgt_page(void *context)
 88{
 89	return (void *)get_safe_page(GFP_ATOMIC);
 90}
 91
 92static int set_up_temporary_mappings(void)
 93{
 94	struct x86_mapping_info info = {
 95		.alloc_pgt_page	= alloc_pgt_page,
 96		.page_flag	= __PAGE_KERNEL_LARGE_EXEC,
 97		.offset		= __PAGE_OFFSET,
 98	};
 99	unsigned long mstart, mend;
100	pgd_t *pgd;
101	int result;
102	int i;
103
104	pgd = (pgd_t *)get_safe_page(GFP_ATOMIC);
105	if (!pgd)
106		return -ENOMEM;
107
108	/* Prepare a temporary mapping for the kernel text */
109	result = set_up_temporary_text_mapping(pgd);
110	if (result)
111		return result;
112
113	/* Set up the direct mapping from scratch */
114	for (i = 0; i < nr_pfn_mapped; i++) {
115		mstart = pfn_mapped[i].start << PAGE_SHIFT;
116		mend   = pfn_mapped[i].end << PAGE_SHIFT;
117
118		result = kernel_ident_mapping_init(&info, pgd, mstart, mend);
119		if (result)
120			return result;
121	}
122
123	temp_pgt = __pa(pgd);
124	return 0;
125}
126
127asmlinkage int swsusp_arch_resume(void)
128{
129	int error;
130
131	/* We have got enough memory and from now on we cannot recover */
132	error = set_up_temporary_mappings();
133	if (error)
134		return error;
135
136	error = relocate_restore_code();
137	if (error)
138		return error;
139
140	restore_image();
141	return 0;
142}
v5.4
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Hibernation support for x86-64
  4 *
  5 * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
  6 * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz>
  7 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
  8 */
  9
 10#include <linux/gfp.h>
 11#include <linux/smp.h>
 12#include <linux/suspend.h>
 13#include <linux/scatterlist.h>
 14#include <linux/kdebug.h>
 
 15
 16#include <crypto/hash.h>
 17
 18#include <asm/e820/api.h>
 19#include <asm/init.h>
 20#include <asm/proto.h>
 21#include <asm/page.h>
 22#include <asm/pgtable.h>
 23#include <asm/mtrr.h>
 24#include <asm/sections.h>
 25#include <asm/suspend.h>
 26#include <asm/tlbflush.h>
 27
 28static int set_up_temporary_text_mapping(pgd_t *pgd)
 29{
 30	pmd_t *pmd;
 31	pud_t *pud;
 32	p4d_t *p4d = NULL;
 33	pgprot_t pgtable_prot = __pgprot(_KERNPG_TABLE);
 34	pgprot_t pmd_text_prot = __pgprot(__PAGE_KERNEL_LARGE_EXEC);
 35
 36	/* Filter out unsupported __PAGE_KERNEL* bits: */
 37	pgprot_val(pmd_text_prot) &= __default_kernel_pte_mask;
 38	pgprot_val(pgtable_prot)  &= __default_kernel_pte_mask;
 39
 40	/*
 41	 * The new mapping only has to cover the page containing the image
 42	 * kernel's entry point (jump_address_phys), because the switch over to
 43	 * it is carried out by relocated code running from a page allocated
 44	 * specifically for this purpose and covered by the identity mapping, so
 45	 * the temporary kernel text mapping is only needed for the final jump.
 46	 * Moreover, in that mapping the virtual address of the image kernel's
 47	 * entry point must be the same as its virtual address in the image
 48	 * kernel (restore_jump_address), so the image kernel's
 49	 * restore_registers() code doesn't find itself in a different area of
 50	 * the virtual address space after switching over to the original page
 51	 * tables used by the image kernel.
 52	 */
 53
 54	if (pgtable_l5_enabled()) {
 55		p4d = (p4d_t *)get_safe_page(GFP_ATOMIC);
 56		if (!p4d)
 57			return -ENOMEM;
 58	}
 59
 60	pud = (pud_t *)get_safe_page(GFP_ATOMIC);
 61	if (!pud)
 62		return -ENOMEM;
 63
 64	pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
 65	if (!pmd)
 66		return -ENOMEM;
 67
 68	set_pmd(pmd + pmd_index(restore_jump_address),
 69		__pmd((jump_address_phys & PMD_MASK) | pgprot_val(pmd_text_prot)));
 70	set_pud(pud + pud_index(restore_jump_address),
 71		__pud(__pa(pmd) | pgprot_val(pgtable_prot)));
 72	if (p4d) {
 73		p4d_t new_p4d = __p4d(__pa(pud) | pgprot_val(pgtable_prot));
 74		pgd_t new_pgd = __pgd(__pa(p4d) | pgprot_val(pgtable_prot));
 75
 76		set_p4d(p4d + p4d_index(restore_jump_address), new_p4d);
 77		set_pgd(pgd + pgd_index(restore_jump_address), new_pgd);
 78	} else {
 79		/* No p4d for 4-level paging: point the pgd to the pud page table */
 80		pgd_t new_pgd = __pgd(__pa(pud) | pgprot_val(pgtable_prot));
 81		set_pgd(pgd + pgd_index(restore_jump_address), new_pgd);
 82	}
 83
 84	return 0;
 85}
 86
 87static void *alloc_pgt_page(void *context)
 88{
 89	return (void *)get_safe_page(GFP_ATOMIC);
 90}
 91
 92static int set_up_temporary_mappings(void)
 93{
 94	struct x86_mapping_info info = {
 95		.alloc_pgt_page	= alloc_pgt_page,
 96		.page_flag	= __PAGE_KERNEL_LARGE_EXEC,
 97		.offset		= __PAGE_OFFSET,
 98	};
 99	unsigned long mstart, mend;
100	pgd_t *pgd;
101	int result;
102	int i;
103
104	pgd = (pgd_t *)get_safe_page(GFP_ATOMIC);
105	if (!pgd)
106		return -ENOMEM;
107
108	/* Prepare a temporary mapping for the kernel text */
109	result = set_up_temporary_text_mapping(pgd);
110	if (result)
111		return result;
112
113	/* Set up the direct mapping from scratch */
114	for (i = 0; i < nr_pfn_mapped; i++) {
115		mstart = pfn_mapped[i].start << PAGE_SHIFT;
116		mend   = pfn_mapped[i].end << PAGE_SHIFT;
117
118		result = kernel_ident_mapping_init(&info, pgd, mstart, mend);
119		if (result)
120			return result;
121	}
122
123	temp_pgt = __pa(pgd);
124	return 0;
125}
126
127asmlinkage int swsusp_arch_resume(void)
128{
129	int error;
130
131	/* We have got enough memory and from now on we cannot recover */
132	error = set_up_temporary_mappings();
133	if (error)
134		return error;
135
136	error = relocate_restore_code();
137	if (error)
138		return error;
139
140	restore_image();
141	return 0;
142}