From 195a6bb9e6786b51f359b427af10f9b7132ebeb2 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Wed, 21 Sep 2016 10:05:51 +0000
Subject: [PATCH] Export the pmap_cache_bits() and pmap_pinit_pml4() functions
 from the amd64 pmap.

The new pmap_pinit_pml4() function initializes the level 4 page table
with entries for the kernel mappings.  Both functions are needed for
upcoming EFI Runtime Services support.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
---
 sys/amd64/amd64/pmap.c   | 40 +++++++++++++++++++++++++---------------
 sys/amd64/include/pmap.h |  2 ++
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index f80b8947d9e4..63042e41dd14 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -1324,7 +1324,7 @@ pmap_swap_pat(pmap_t pmap, pt_entry_t entry)
  * Determine the appropriate bits to set in a PTE or PDE for a specified
  * caching mode.
  */
-static int
+int
 pmap_cache_bits(pmap_t pmap, int mode, boolean_t is_pde)
 {
 	int cache_bits, pat_flag, pat_idx;
@@ -2345,6 +2345,29 @@ pmap_pinit0(pmap_t pmap)
 	CPU_FILL(&kernel_pmap->pm_active);
 }
 
+void
+pmap_pinit_pml4(vm_page_t pml4pg)
+{
+	pml4_entry_t *pm_pml4;
+	int i;
+
+	pm_pml4 = (pml4_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(pml4pg));
+
+	/* Wire in kernel global address entries. */
+	for (i = 0; i < NKPML4E; i++) {
+		pm_pml4[KPML4BASE + i] = (KPDPphys + ptoa(i)) | X86_PG_RW |
+		    X86_PG_V | PG_U;
+	}
+	for (i = 0; i < ndmpdpphys; i++) {
+		pm_pml4[DMPML4I + i] = (DMPDPphys + ptoa(i)) | X86_PG_RW |
+		    X86_PG_V | PG_U;
+	}
+
+	/* install self-referential address mapping entry(s) */
+	pm_pml4[PML4PML4I] = VM_PAGE_TO_PHYS(pml4pg) | X86_PG_V | X86_PG_RW |
+	    X86_PG_A | X86_PG_M;
+}
+
 /*
  * Initialize a preallocated and zeroed pmap structure,
  * such as one in a vmspace structure.
@@ -2381,20 +2404,7 @@ pmap_pinit_type(pmap_t pmap, enum pmap_type pm_type, int flags)
 	 */
 	if ((pmap->pm_type = pm_type) == PT_X86) {
 		pmap->pm_cr3 = pml4phys;
-
-		/* Wire in kernel global address entries. */
-		for (i = 0; i < NKPML4E; i++) {
-			pmap->pm_pml4[KPML4BASE + i] = (KPDPphys + ptoa(i)) |
-			    X86_PG_RW | X86_PG_V | PG_U;
-		}
-		for (i = 0; i < ndmpdpphys; i++) {
-			pmap->pm_pml4[DMPML4I + i] = (DMPDPphys + ptoa(i)) |
-			    X86_PG_RW | X86_PG_V | PG_U;
-		}
-
-		/* install self-referential address mapping entry(s) */
-		pmap->pm_pml4[PML4PML4I] = VM_PAGE_TO_PHYS(pml4pg) |
-		    X86_PG_V | X86_PG_RW | X86_PG_A | X86_PG_M;
+		pmap_pinit_pml4(pml4pg);
 	}
 
 	pmap->pm_root.rt_root = 0;
diff --git a/sys/amd64/include/pmap.h b/sys/amd64/include/pmap.h
index 3300c47c516e..4d924bdbf31e 100644
--- a/sys/amd64/include/pmap.h
+++ b/sys/amd64/include/pmap.h
@@ -391,6 +391,7 @@ struct thread;
 
 void	pmap_activate_sw(struct thread *);
 void	pmap_bootstrap(vm_paddr_t *);
+int	pmap_cache_bits(pmap_t pmap, int mode, boolean_t is_pde);
 int	pmap_change_attr(vm_offset_t, vm_size_t, int);
 void	pmap_demote_DMAP(vm_paddr_t base, vm_size_t len, boolean_t invalidate);
 void	pmap_init_pat(void);
@@ -403,6 +404,7 @@ void	*pmap_mapdev(vm_paddr_t, vm_size_t);
 void	*pmap_mapdev_attr(vm_paddr_t, vm_size_t, int);
 boolean_t pmap_page_is_mapped(vm_page_t m);
 void	pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma);
+void	pmap_pinit_pml4(vm_page_t);
 void	pmap_unmapdev(vm_offset_t, vm_size_t);
 void	pmap_invalidate_page(pmap_t, vm_offset_t);
 void	pmap_invalidate_range(pmap_t, vm_offset_t, vm_offset_t);