x86/efi: Replace efi_pgd with efi_mm.pgd

Since the previous patch added support for efi_mm, let's handle efi_pgd
through efi_mm and remove global variable efi_pgd.
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Lee, Chun-Yi <jlee@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-efi@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/mm/debug_pagetables.c

 #include <linux/debugfs.h>
+#include <linux/efi.h>
 #include <linux/module.h>
 #include <linux/seq_file.h>
 #include <asm/pgtable.h>
@@ -73,13 +74,12 @@ static const struct file_operations ptdump_curusr_fops = {
 #endif
 
 #if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
-extern pgd_t *efi_pgd;
 static struct dentry *pe_efi;
 
 static int ptdump_show_efi(struct seq_file *m, void *v)
 {
-	if (efi_pgd)
-		ptdump_walk_pgd_level_debugfs(m, efi_pgd, false);
+	if (efi_mm.pgd)
+		ptdump_walk_pgd_level_debugfs(m, efi_mm.pgd, false);
 	return 0;
 }
 

arch/x86/platform/efi/efi_64.c

@@ -191,8 +191,7 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd)
 	early_code_mapping_set_exec(0);
 }
 
-pgd_t *efi_pgd;
-EXPORT_SYMBOL_GPL(efi_pgd);
+EXPORT_SYMBOL_GPL(efi_mm);
 
 /*
  * We need our own copy of the higher levels of the page tables
@@ -205,7 +204,7 @@ EXPORT_SYMBOL_GPL(efi_pgd);
  */
 int __init efi_alloc_page_tables(void)
 {
-	pgd_t *pgd;
+	pgd_t *pgd, *efi_pgd;
 	p4d_t *p4d;
 	pud_t *pud;
 	gfp_t gfp_mask;
@@ -233,6 +232,7 @@ int __init efi_alloc_page_tables(void)
 		return -ENOMEM;
 	}
 
+	efi_mm.pgd = efi_pgd;
 	mm_init_cpumask(&efi_mm);
 	init_new_context(NULL, &efi_mm);
 
@@ -248,6 +248,7 @@ void efi_sync_low_kernel_mappings(void)
 	pgd_t *pgd_k, *pgd_efi;
 	p4d_t *p4d_k, *p4d_efi;
 	pud_t *pud_k, *pud_efi;
+	pgd_t *efi_pgd = efi_mm.pgd;
 
 	if (efi_enabled(EFI_OLD_MEMMAP))
 		return;
@@ -341,7 +342,7 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 	unsigned long pfn, text, pf;
 	struct page *page;
 	unsigned npages;
-	pgd_t *pgd;
+	pgd_t *pgd = efi_mm.pgd;
 
 	if (efi_enabled(EFI_OLD_MEMMAP))
 		return 0;
@@ -351,8 +352,7 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 	 * this value is loaded into cr3 the PGD will be decrypted during
 	 * the pagetable walk.
 	 */
-	efi_scratch.efi_pgt = (pgd_t *)__sme_pa(efi_pgd);
-	pgd = efi_pgd;
+	efi_scratch.efi_pgt = (pgd_t *)__sme_pa(pgd);
 
 	/*
 	 * It can happen that the physical address of new_memmap lands in memory
@@ -422,7 +422,7 @@ static void __init __map_region(efi_memory_desc_t *md, u64 va)
 {
 	unsigned long flags = _PAGE_RW;
 	unsigned long pfn;
-	pgd_t *pgd = efi_pgd;
+	pgd_t *pgd = efi_mm.pgd;
 
 	if (!(md->attribute & EFI_MEMORY_WB))
 		flags |= _PAGE_PCD;
@@ -526,7 +526,7 @@ void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
 {
 	unsigned long pfn;
-	pgd_t *pgd = efi_pgd;
+	pgd_t *pgd = efi_mm.pgd;
 	int err1, err2;
 
 	/* Update the 1:1 mapping */
@@ -623,7 +623,7 @@ void __init efi_dump_pagetable(void)
 	if (efi_enabled(EFI_OLD_MEMMAP))
 		ptdump_walk_pgd_level(NULL, swapper_pg_dir);
 	else
-		ptdump_walk_pgd_level(NULL, efi_pgd);
+		ptdump_walk_pgd_level(NULL, efi_mm.pgd);
 #endif
 }