Add support to uvm to establish write-combining mappings. Use this in the

inteldrm driver to add support for the I915_MMAP_WC flag.

ok deraadt@, jsg@

8 files changed, 37 insertions, 28 deletions

diff --git a/sys/dev/pci/drm/drm_linux.h b/sys/dev/pci/drm/drm_linux.h
index ba24e5faa83..a1a35d1f66a 100644
--- a/sys/dev/pci/drm/drm_linux.h
+++ b/sys/dev/pci/drm/drm_linux.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: drm_linux.h,v 1.91 2018/08/20 19:33:31 kettenis Exp $	*/
+/*	$OpenBSD: drm_linux.h,v 1.92 2018/10/31 08:50:25 kettenis Exp $	*/
 /*
  * Copyright (c) 2013, 2014, 2015 Mark Kettenis
  * Copyright (c) 2017 Martin Pieuchot
@@ -2123,7 +2123,7 @@ typedef int pgprot_t;
 static inline pgprot_t
 pgprot_writecombine(pgprot_t prot)
 {
-#ifdef PMAP_WC
+#if PMAP_WC != 0
 	return prot | PMAP_WC;
 #else
 	return prot | PMAP_NOCACHE;
@@ -2133,7 +2133,7 @@ pgprot_writecombine(pgprot_t prot)
 static inline pgprot_t
 pgprot_noncached(pgprot_t prot)
 {
-#ifdef PMAP_DEVICE
+#if PMAP_DEVICE != 0
 	return prot | PMAP_DEVICE;
 #else
 	return prot | PMAP_NOCACHE;
diff --git a/sys/dev/pci/drm/i915/i915_dma.c b/sys/dev/pci/drm/i915/i915_dma.c
index 51e673480b8..54225532eea 100644
--- a/sys/dev/pci/drm/i915/i915_dma.c
+++ b/sys/dev/pci/drm/i915/i915_dma.c
@@ -156,11 +156,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
 	case I915_PARAM_HAS_COHERENT_PHYS_GTT:
 		value = 1;
 		break;
-#ifdef notyet
 	case I915_PARAM_MMAP_VERSION:
 		value = 1;
 		break;
-#endif
 	case I915_PARAM_SUBSLICE_TOTAL:
 		value = INTEL_INFO(dev)->subslice_total;
 		if (!value)
diff --git a/sys/dev/pci/drm/i915/i915_gem.c b/sys/dev/pci/drm/i915/i915_gem.c
index 017d4ea943c..f018a6adadc 100644
--- a/sys/dev/pci/drm/i915/i915_gem.c
+++ b/sys/dev/pci/drm/i915/i915_gem.c
@@ -1987,7 +1987,8 @@ i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
 	addr = 0;
 	ret = -uvm_map(&curproc->p_vmspace->vm_map, &addr, size,
 	    obj->uao, args->offset, 0, UVM_MAPFLAG(PROT_READ | PROT_WRITE,
-	    PROT_READ | PROT_WRITE, MAP_INHERIT_SHARE, MADV_RANDOM, 0));
+	    PROT_READ | PROT_WRITE, MAP_INHERIT_SHARE, MADV_RANDOM,
+	    (args->flags & I915_MMAP_WC) ? UVM_FLAG_WC : 0));
 	if (ret == 0)
 		uao_reference(obj->uao);
 	drm_gem_object_unreference_unlocked(obj);
diff --git a/sys/uvm/uvm.h b/sys/uvm/uvm.h
index 3e765a66226..7a93862dd97 100644
--- a/sys/uvm/uvm.h
+++ b/sys/uvm/uvm.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm.h,v 1.62 2018/04/12 17:13:44 deraadt Exp $	*/
+/*	$OpenBSD: uvm.h,v 1.63 2018/10/31 08:50:25 kettenis Exp $	*/
 /*	$NetBSD: uvm.h,v 1.24 2000/11/27 08:40:02 chs Exp $	*/
 
 /*
@@ -82,14 +82,15 @@ struct uvm {
  * vm_map_entry etype bits:
  */
 
-#define UVM_ET_OBJ		0x01	/* it is a uvm_object */
-#define UVM_ET_SUBMAP		0x02	/* it is a vm_map submap */
-#define UVM_ET_COPYONWRITE 	0x04	/* copy_on_write */
-#define UVM_ET_NEEDSCOPY	0x08	/* needs_copy */
-#define UVM_ET_HOLE		0x10	/* no backend */
-#define UVM_ET_NOFAULT		0x20	/* don't fault */
-#define UVM_ET_STACK		0x40	/* this is a stack */
-#define UVM_ET_FREEMAPPED	0x80	/* map entry is on free list (DEBUG) */
+#define UVM_ET_OBJ		0x0001	/* it is a uvm_object */
+#define UVM_ET_SUBMAP		0x0002	/* it is a vm_map submap */
+#define UVM_ET_COPYONWRITE 	0x0004	/* copy_on_write */
+#define UVM_ET_NEEDSCOPY	0x0008	/* needs_copy */
+#define UVM_ET_HOLE		0x0010	/* no backend */
+#define UVM_ET_NOFAULT		0x0020	/* don't fault */
+#define UVM_ET_STACK		0x0040	/* this is a stack */
+#define UVM_ET_WC		0x0080	/* write combining */
+#define UVM_ET_FREEMAPPED	0x8000	/* map entry is on free list (DEBUG) */
 
 #define UVM_ET_ISOBJ(E)		(((E)->etype & UVM_ET_OBJ) != 0)
 #define UVM_ET_ISSUBMAP(E)	(((E)->etype & UVM_ET_SUBMAP) != 0)
@@ -98,6 +99,7 @@ struct uvm {
 #define UVM_ET_ISHOLE(E)	(((E)->etype & UVM_ET_HOLE) != 0)
 #define UVM_ET_ISNOFAULT(E)	(((E)->etype & UVM_ET_NOFAULT) != 0)
 #define UVM_ET_ISSTACK(E)	(((E)->etype & UVM_ET_STACK) != 0)
+#define UVM_ET_ISWC(E)		(((E)->etype & UVM_ET_WC) != 0)
 
 #ifdef _KERNEL
 
diff --git a/sys/uvm/uvm_extern.h b/sys/uvm/uvm_extern.h
index 3005a61fcd0..a473f251229 100644
--- a/sys/uvm/uvm_extern.h
+++ b/sys/uvm/uvm_extern.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_extern.h,v 1.143 2018/04/12 17:13:44 deraadt Exp $	*/
+/*	$OpenBSD: uvm_extern.h,v 1.144 2018/10/31 08:50:25 kettenis Exp $	*/
 /*	$NetBSD: uvm_extern.h,v 1.57 2001/03/09 01:02:12 chs Exp $	*/
 
 /*
@@ -112,6 +112,7 @@ typedef int		vm_prot_t;
 #define UVM_FLAG_NOFAULT 0x0800000 /* don't fault */
 #define UVM_FLAG_UNMAP   0x1000000 /* unmap to make space */
 #define UVM_FLAG_STACK   0x2000000 /* page may contain a stack */
+#define UVM_FLAG_WC      0x4000000 /* write combining */ 
 
 /* macros to extract info */
 #define UVM_PROTECTION(X)	((X) & PROT_MASK)
diff --git a/sys/uvm/uvm_fault.c b/sys/uvm/uvm_fault.c
index 635283fac7b..e94e28c1987 100644
--- a/sys/uvm/uvm_fault.c
+++ b/sys/uvm/uvm_fault.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_fault.c,v 1.93 2018/04/12 17:13:44 deraadt Exp $	*/
+/*	$OpenBSD: uvm_fault.c,v 1.94 2018/10/31 08:50:25 kettenis Exp $	*/
 /*	$NetBSD: uvm_fault.c,v 1.51 2000/08/06 00:22:53 thorpej Exp $	*/
 
 /*
@@ -497,7 +497,7 @@ uvm_fault(vm_map_t orig_map, vaddr_t vaddr, vm_fault_t fault_type,
 	int npages, nback, nforw, centeridx, result, lcv, gotpages, ret;
 	vaddr_t startva, currva;
 	voff_t uoff;
-	paddr_t pa; 
+	paddr_t pa, pa_flags;
 	struct vm_amap *amap;
 	struct uvm_object *uobj;
 	struct vm_anon *anons_store[UVM_MAXRANGE], **anons, *anon, *oanon;
@@ -545,6 +545,7 @@ ReFault:
 	 */
 
 	enter_prot = ufi.entry->protection;
+	pa_flags = UVM_ET_ISWC(ufi.entry) ? PMAP_WC : 0;
 	wired = VM_MAPENT_ISWIRED(ufi.entry) || (fault_type == VM_FAULT_WIRE);
 	if (wired)
 		access_type = enter_prot; /* full access for wired */
@@ -688,7 +689,7 @@ ReFault:
 			 * that we enter these right now.
 			 */
 			(void) pmap_enter(ufi.orig_map->pmap, currva,
-			    VM_PAGE_TO_PHYS(anon->an_page),
+			    VM_PAGE_TO_PHYS(anon->an_page) | pa_flags,
 			    (anon->an_ref > 1) ? (enter_prot & ~PROT_WRITE) :
 			    enter_prot,
 			    PMAP_CANFAIL |
@@ -789,7 +790,7 @@ ReFault:
 				 * enter these right now.
 				 */
 				(void) pmap_enter(ufi.orig_map->pmap, currva,
-				    VM_PAGE_TO_PHYS(pages[lcv]),
+				    VM_PAGE_TO_PHYS(pages[lcv]) | pa_flags,
 				    enter_prot & MASK(ufi.entry),
 				    PMAP_CANFAIL |
 				     (wired ? PMAP_WIRED : 0));
@@ -935,9 +936,9 @@ ReFault:
 	 * suspect since some other thread could blast the page out from
 	 * under us between the unlock and the pmap_enter.
 	 */
-	if (pmap_enter(ufi.orig_map->pmap, ufi.orig_rvaddr, VM_PAGE_TO_PHYS(pg),
-	    enter_prot, access_type | PMAP_CANFAIL | (wired ? PMAP_WIRED : 0))
-	    != 0) {
+	if (pmap_enter(ufi.orig_map->pmap, ufi.orig_rvaddr,
+	    VM_PAGE_TO_PHYS(pg) | pa_flags, enter_prot,
+	    access_type | PMAP_CANFAIL | (wired ? PMAP_WIRED : 0)) != 0) {
 		/*
 		 * No need to undo what we did; we can simply think of
 		 * this as the pmap throwing away the mapping information.
@@ -1211,9 +1212,9 @@ Case2:
 	 * all resources are present.   we can now map it in and free our
 	 * resources.
 	 */
-	if (pmap_enter(ufi.orig_map->pmap, ufi.orig_rvaddr, VM_PAGE_TO_PHYS(pg),
-	    enter_prot, access_type | PMAP_CANFAIL | (wired ? PMAP_WIRED : 0))
-	    != 0) {
+	if (pmap_enter(ufi.orig_map->pmap, ufi.orig_rvaddr,
+	    VM_PAGE_TO_PHYS(pg) | pa_flags, enter_prot,
+	    access_type | PMAP_CANFAIL | (wired ? PMAP_WIRED : 0)) != 0) {
 		/*
 		 * No need to undo what we did; we can simply think of
 		 * this as the pmap throwing away the mapping information.
diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c
index c8a814d8e3c..d97f60fdf09 100644
--- a/sys/uvm/uvm_map.c
+++ b/sys/uvm/uvm_map.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_map.c,v 1.238 2018/07/22 14:33:44 kettenis Exp $	*/
+/*	$OpenBSD: uvm_map.c,v 1.239 2018/10/31 08:50:25 kettenis Exp $	*/
 /*	$NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $	*/
 
 /*
@@ -1343,6 +1343,8 @@ uvm_map(struct vm_map *map, vaddr_t *addr, vsize_t sz,
 		entry->etype |= UVM_ET_HOLE;
 	if (flags & UVM_FLAG_NOFAULT)
 		entry->etype |= UVM_ET_NOFAULT;
+	if (flags & UVM_FLAG_WC)
+		entry->etype |= UVM_ET_WC;
 	if (flags & UVM_FLAG_COPYONW) {
 		entry->etype |= UVM_ET_COPYONWRITE;
 		if ((flags & UVM_FLAG_OVERLAY) == 0)
diff --git a/sys/uvm/uvm_pmap.h b/sys/uvm/uvm_pmap.h
index a8f5eafbc2b..dd071ddbfac 100644
--- a/sys/uvm/uvm_pmap.h
+++ b/sys/uvm/uvm_pmap.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_pmap.h,v 1.27 2016/10/19 08:28:19 guenther Exp $	*/
+/*	$OpenBSD: uvm_pmap.h,v 1.28 2018/10/31 08:50:25 kettenis Exp $	*/
 /*	$NetBSD: uvm_pmap.h,v 1.1 2000/06/27 09:00:14 mrg Exp $	*/
 
 /* 
@@ -97,6 +97,10 @@ typedef struct pmap_statistics	*pmap_statistics_t;
 #define	PMAP_MD2	0x00000100	/* Machine dependant */
 #define	PMAP_MD3	0x00000200	/* Machine dependant */
 
+#ifndef PMAP_WC
+#define PMAP_WC		0
+#endif
+
 #ifndef PMAP_EXCLUDE_DECLS	/* Used in Sparc port to virtualize pmap mod */
 #ifdef _KERNEL
 __BEGIN_DECLS