Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 mm updates from Ingo Molnar:
 "The main x86 MM changes in this cycle were:

   - continued native kernel PCID support preparation patches to the TLB
     flushing code (Andy Lutomirski)

   - various fixes related to 32-bit compat syscall returning address
     over 4Gb in applications, launched from 64-bit binaries - motivated
     by C/R frameworks such as Virtuozzo. (Dmitry Safonov)

   - continued Intel 5-level paging enablement: in particular the
     conversion of x86 GUP to the generic GUP code. (Kirill A. Shutemov)

   - x86/mpx ABI corner case fixes/enhancements (Joerg Roedel)

   - ... plus misc updates, fixes and cleanups"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (62 commits)
  mm, zone_device: Replace {get, put}_zone_device_page() with a single reference to fix pmem crash
  x86/mm: Fix flush_tlb_page() on Xen
  x86/mm: Make flush_tlb_mm_range() more predictable
  x86/mm: Remove flush_tlb() and flush_tlb_current_task()
  x86/vm86/32: Switch to flush_tlb_mm_range() in mark_screen_rdonly()
  x86/mm/64: Fix crash in remove_pagetable()
  Revert "x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation"
  x86/boot/e820: Remove a redundant self assignment
  x86/mm: Fix dump pagetables for 4 levels of page tables
  x86/mpx, selftests: Only check bounds-vs-shadow when we keep shadow
  x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space
  Revert "x86/mm/numa: Remove numa_nodemask_from_meminfo()"
  x86/espfix: Add support for 5-level paging
  x86/kasan: Extend KASAN to support 5-level paging
  x86/mm: Add basic defines/helpers for CONFIG_X86_5LEVEL=y
  x86/paravirt: Add 5-level support to the paravirt code
  x86/mm: Define virtual memory map for 5-level paging
  x86/asm: Remove __VIRTUAL_MASK_SHIFT==47 assert
  x86/boot: Detect 5-level paging support
  x86/mm/numa: Remove numa_nodemask_from_meminfo()
  ...

1 files changed, 44 insertions, 7 deletions

diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c
index 4473cb4f8b90..04210a29dd60 100644
--- a/arch/x86/mm/ident_map.c
+++ b/arch/x86/mm/ident_map.c
@@ -45,6 +45,34 @@ static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,
 	return 0;
 }
 
+static int ident_p4d_init(struct x86_mapping_info *info, p4d_t *p4d_page,
+			  unsigned long addr, unsigned long end)
+{
+	unsigned long next;
+
+	for (; addr < end; addr = next) {
+		p4d_t *p4d = p4d_page + p4d_index(addr);
+		pud_t *pud;
+
+		next = (addr & P4D_MASK) + P4D_SIZE;
+		if (next > end)
+			next = end;
+
+		if (p4d_present(*p4d)) {
+			pud = pud_offset(p4d, 0);
+			ident_pud_init(info, pud, addr, next);
+			continue;
+		}
+		pud = (pud_t *)info->alloc_pgt_page(info->context);
+		if (!pud)
+			return -ENOMEM;
+		ident_pud_init(info, pud, addr, next);
+		set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE));
+	}
+
+	return 0;
+}
+
 int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
 			      unsigned long pstart, unsigned long pend)
 {
@@ -55,27 +83,36 @@ int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
 
 	for (; addr < end; addr = next) {
 		pgd_t *pgd = pgd_page + pgd_index(addr);
-		pud_t *pud;
+		p4d_t *p4d;
 
 		next = (addr & PGDIR_MASK) + PGDIR_SIZE;
 		if (next > end)
 			next = end;
 
 		if (pgd_present(*pgd)) {
-			pud = pud_offset(pgd, 0);
-			result = ident_pud_init(info, pud, addr, next);
+			p4d = p4d_offset(pgd, 0);
+			result = ident_p4d_init(info, p4d, addr, next);
 			if (result)
 				return result;
 			continue;
 		}
 
-		pud = (pud_t *)info->alloc_pgt_page(info->context);
-		if (!pud)
+		p4d = (p4d_t *)info->alloc_pgt_page(info->context);
+		if (!p4d)
 			return -ENOMEM;
-		result = ident_pud_init(info, pud, addr, next);
+		result = ident_p4d_init(info, p4d, addr, next);
 		if (result)
 			return result;
-		set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
+		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+			set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE));
+		} else {
+			/*
+			 * With p4d folded, pgd is equal to p4d.
+			 * The pgd entry has to point to the pud page table in this case.
+			 */
+			pud_t *pud = pud_offset(p4d, 0);
+			set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
+		}
 	}
 
 	return 0;