1 files changed, 142 insertions, 0 deletions
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
new file mode 100644
index 000000000..a595953f1
--- /dev/null
+++ b/arch/x86/power/hibernate_64.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Hibernation support for x86-64
+ *
+ * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
+ * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz>
+ * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
+ */
+
+#include <linux/gfp.h>
+#include <linux/smp.h>
+#include <linux/suspend.h>
+#include <linux/scatterlist.h>
+#include <linux/kdebug.h>
+#include <linux/pgtable.h>
+
+#include <crypto/hash.h>
+
+#include <asm/e820/api.h>
+#include <asm/init.h>
+#include <asm/proto.h>
+#include <asm/page.h>
+#include <asm/mtrr.h>
+#include <asm/sections.h>
+#include <asm/suspend.h>
+#include <asm/tlbflush.h>
+
+static int set_up_temporary_text_mapping(pgd_t *pgd)
+{
+	pmd_t *pmd;
+	pud_t *pud;
+	p4d_t *p4d = NULL;
+	pgprot_t pgtable_prot = __pgprot(_KERNPG_TABLE);
+	pgprot_t pmd_text_prot = __pgprot(__PAGE_KERNEL_LARGE_EXEC);
+
+	/* Filter out unsupported __PAGE_KERNEL* bits: */
+	pgprot_val(pmd_text_prot) &= __default_kernel_pte_mask;
+	pgprot_val(pgtable_prot)  &= __default_kernel_pte_mask;
+
+	/*
+	 * The new mapping only has to cover the page containing the image
+	 * kernel's entry point (jump_address_phys), because the switch over to
+	 * it is carried out by relocated code running from a page allocated
+	 * specifically for this purpose and covered by the identity mapping, so
+	 * the temporary kernel text mapping is only needed for the final jump.
+	 * Moreover, in that mapping the virtual address of the image kernel's
+	 * entry point must be the same as its virtual address in the image
+	 * kernel (restore_jump_address), so the image kernel's
+	 * restore_registers() code doesn't find itself in a different area of
+	 * the virtual address space after switching over to the original page
+	 * tables used by the image kernel.
+	 */
+
+	if (pgtable_l5_enabled()) {
+		p4d = (p4d_t *)get_safe_page(GFP_ATOMIC);
+		if (!p4d)
+			return -ENOMEM;
+	}
+
+	pud = (pud_t *)get_safe_page(GFP_ATOMIC);
+	if (!pud)
+		return -ENOMEM;
+
+	pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
+	if (!pmd)
+		return -ENOMEM;
+
+	set_pmd(pmd + pmd_index(restore_jump_address),
+		__pmd((jump_address_phys & PMD_MASK) | pgprot_val(pmd_text_prot)));
+	set_pud(pud + pud_index(restore_jump_address),
+		__pud(__pa(pmd) | pgprot_val(pgtable_prot)));
+	if (p4d) {
+		p4d_t new_p4d = __p4d(__pa(pud) | pgprot_val(pgtable_prot));
+		pgd_t new_pgd = __pgd(__pa(p4d) | pgprot_val(pgtable_prot));
+
+		set_p4d(p4d + p4d_index(restore_jump_address), new_p4d);
+		set_pgd(pgd + pgd_index(restore_jump_address), new_pgd);
+	} else {
+		/* No p4d for 4-level paging: point the pgd to the pud page table */
+		pgd_t new_pgd = __pgd(__pa(pud) | pgprot_val(pgtable_prot));
+		set_pgd(pgd + pgd_index(restore_jump_address), new_pgd);
+	}
+
+	return 0;
+}
+
+static void *alloc_pgt_page(void *context)
+{
+	return (void *)get_safe_page(GFP_ATOMIC);
+}
+
+static int set_up_temporary_mappings(void)
+{
+	struct x86_mapping_info info = {
+		.alloc_pgt_page	= alloc_pgt_page,
+		.page_flag	= __PAGE_KERNEL_LARGE_EXEC,
+		.offset		= __PAGE_OFFSET,
+	};
+	unsigned long mstart, mend;
+	pgd_t *pgd;
+	int result;
+	int i;
+
+	pgd = (pgd_t *)get_safe_page(GFP_ATOMIC);
+	if (!pgd)
+		return -ENOMEM;
+
+	/* Prepare a temporary mapping for the kernel text */
+	result = set_up_temporary_text_mapping(pgd);
+	if (result)
+		return result;
+
+	/* Set up the direct mapping from scratch */
+	for (i = 0; i < nr_pfn_mapped; i++) {
+		mstart = pfn_mapped[i].start << PAGE_SHIFT;
+		mend   = pfn_mapped[i].end << PAGE_SHIFT;
+
+		result = kernel_ident_mapping_init(&info, pgd, mstart, mend);
+		if (result)
+			return result;
+	}
+
+	temp_pgt = __pa(pgd);
+	return 0;
+}
+
+asmlinkage int swsusp_arch_resume(void)
+{
+	int error;
+
+	/* We have got enough memory and from now on we cannot recover */
+	error = set_up_temporary_mappings();
+	if (error)
+		return error;
+
+	error = relocate_restore_code();
+	if (error)
+		return error;
+
+	restore_image();
+	return 0;
+}