PATCH - panic on resume in pmap_invalidate

[Nate Lawson]

Attached is a patch by Alan Cox (alc@) that changes how we map memory
for acpi wake code.  It should solve a problem that was reported of a
panic after resume in pmap_invalidate().  It should work on 7.x or 6.x.

If you have that problem, please report if it works.

-- 
Nate
-------------- next part --------------
Index: sys/i386/acpica/acpi_wakeup.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/acpica/acpi_wakeup.c,v
retrieving revision 1.45
diff -u -r1.45 acpi_wakeup.c
--- sys/i386/acpica/acpi_wakeup.c	8 Aug 2006 01:30:54 -0000	1.45
+++ sys/i386/acpica/acpi_wakeup.c	27 Feb 2007 05:28:53 -0000
@@ -192,11 +192,9 @@
 {
 	ACPI_STATUS		status;
 	struct pmap		*pm;
-	vm_page_t		page;
 	int			ret;
 	uint32_t		cr3;
 	u_long			ef;
-	struct proc		*p;
 
 	ret = 0;
 	if (sc->acpi_wakeaddr == 0)
@@ -206,10 +204,12 @@
 
 	ef = read_eflags();
 
-	/* Create Identity Mapping */
-	if ((p = curproc) == NULL)
-		p = &proc0;
-	pm = vmspace_pmap(p->p_vmspace);
+	/*
+	 * Temporarily switch to the kernel pmap because it provides an
+	 * identity mapping (setup at boot) for the low physical memory
+	 * region containing the wakeup code.
+	 */
+	pm = kernel_pmap;
 	cr3 = rcr3();
 #ifdef PAE
 	load_cr3(vtophys(pm->pm_pdpt));
@@ -217,10 +217,6 @@
 	load_cr3(vtophys(pm->pm_pdir));
 #endif
 
-	page = PHYS_TO_VM_PAGE(sc->acpi_wakephys);
-	pmap_enter(pm, sc->acpi_wakephys, page,
-		   VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE, 1);
-
 	ret_addr = 0;
 	ACPI_DISABLE_IRQS();
 	if (acpi_savecpu()) {
@@ -283,7 +279,6 @@
 	}
 
 out:
-	pmap_remove(pm, sc->acpi_wakephys, sc->acpi_wakephys + PAGE_SIZE);
 	load_cr3(cr3);
 	write_eflags(ef);
 
Index: sys/i386/i386/pmap.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/i386/pmap.c,v
retrieving revision 1.581
diff -u -r1.581 pmap.c
--- sys/i386/i386/pmap.c	18 Feb 2007 06:33:02 -0000	1.581
+++ sys/i386/i386/pmap.c	27 Feb 2007 05:26:22 -0000
@@ -422,6 +422,13 @@
 
 	/* Turn on PG_G on kernel page(s) */
 	pmap_set_pg();
+
+	/*
+	 * Create an identity mapping (virt == phys) for the low 1 MB
+	 * physical memory region that is used by the ACPI wakeup code.
+	 * This mapping must not have PG_G set. 
+	 */
+	kernel_pmap->pm_pdir[0] = PG_PS | PG_RW | PG_V;
 }
 
 /*