Change amd64 bus_space_{map,unmap} to be the same as i386. While

theoretically the current solution of using the direct (and direct
uncached) maps is better for tlb pressure, two direct maps is dangerous,
especially when we support Page Attribute Tables (soon), since that will
cause illegal cache aliases. When that work is done a clever solution
may be worked out.

"reluctant ok, the uncached direct map is evil" art@

1 files changed, 90 insertions, 34 deletions

diff --git a/sys/arch/amd64/amd64/bus_space.c b/sys/arch/amd64/amd64/bus_space.c
index 6a8f17a611e..6cff8bffc57 100644
--- a/sys/arch/amd64/amd64/bus_space.c
+++ b/sys/arch/amd64/amd64/bus_space.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bus_space.c,v 1.12 2009/03/10 15:03:16 oga Exp $	*/
+/*	$OpenBSD: bus_space.c,v 1.13 2009/03/26 19:04:56 oga Exp $	*/
 /*	$NetBSD: bus_space.c,v 1.2 2003/03/14 18:47:53 christos Exp $	*/
 
 /*-
@@ -138,7 +138,7 @@ bus_space_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size, int flags,
 	 * For memory space, map the bus physical address to
 	 * a kernel virtual address.
 	 */
-	error = x86_mem_add_mapping(bpa, size, 0, bshp);
+	error = x86_mem_add_mapping(bpa, size, flags, bshp);
 	if (error) {
 		if (extent_free(ex, bpa, size, EX_NOWAIT |
 		    (ioport_malloc_safe ? EX_MALLOCOK : 0))) {
@@ -168,7 +168,7 @@ _bus_space_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size, int flags,
 	 * For memory space, map the bus physical address to
 	 * a kernel virtual address.
 	 */
-	return (x86_mem_add_mapping(bpa, size, 0, bshp));
+	return (x86_mem_add_mapping(bpa, size, flags, bshp));
 }
 
 int
@@ -219,7 +219,7 @@ bus_space_alloc(bus_space_tag_t t, bus_addr_t rstart, bus_addr_t rend,
 	 * For memory space, map the bus physical address to
 	 * a kernel virtual address.
 	 */
-	error = x86_mem_add_mapping(bpa, size, 0, bshp);
+	error = x86_mem_add_mapping(bpa, size, flags, bshp);
 	if (error) {
 		if (extent_free(iomem_ex, bpa, size, EX_NOWAIT |
 		    (ioport_malloc_safe ? EX_MALLOCOK : 0))) {
@@ -235,13 +235,45 @@ bus_space_alloc(bus_space_tag_t t, bus_addr_t rstart, bus_addr_t rend,
 }
 
 int
-x86_mem_add_mapping(bus_addr_t bpa, bus_size_t size, int cacheable,
+x86_mem_add_mapping(bus_addr_t bpa, bus_size_t size, int flags,
     bus_space_handle_t *bshp)
 {
-	if (cacheable)
-		*bshp = PMAP_DIRECT_MAP(bpa);
-	else
-		*bshp = PMAP_DIRECT_NC_MAP(bpa);
+	u_long pa, endpa;
+	vaddr_t va, sva;
+	pt_entry_t *pte;
+	bus_size_t map_size;
+
+	pa = trunc_page(bpa);
+	endpa = round_page(bpa + size);
+
+#ifdef DIAGNOSTIC
+	if (endpa <= pa && endpa != 0)
+		panic("bus_mem_add_mapping: overflow");
+#endif
+
+	map_size = endpa - pa;
+
+	va = uvm_km_valloc(kernel_map, map_size);
+	if (va == 0)
+		return (ENOMEM);
+
+	*bshp = (bus_space_handle_t)(va + (bpa & PGOFSET));
+
+	sva = va;
+	for (; map_size > 0;
+	    pa += PAGE_SIZE, va += PAGE_SIZE, map_size -= PAGE_SIZE) {
+		pmap_kenter_pa(va, pa, VM_PROT_READ | VM_PROT_WRITE);
+
+		pte = kvtopte(va);
+		if (flags & BUS_SPACE_MAP_CACHEABLE)
+			*pte &= ~PG_N;
+		else
+			*pte |= PG_N;
+	}
+	pmap_tlb_shootrange(pmap_kernel(), sva, va);
+	pmap_tlb_shootwait();
+	pmap_update(pmap_kernel());
+
 	return 0;
 }
 
@@ -259,36 +291,50 @@ void
 _bus_space_unmap(bus_space_tag_t t, bus_space_handle_t bsh, bus_size_t size,
     bus_addr_t *adrp)
 {
+	u_long va, endva;
 	bus_addr_t bpa;
 
 	/*
-	 * Find the correct extent and bus physical address.
+	 * Find the correct bus physical address.
 	 */
 	if (t == X86_BUS_SPACE_IO) {
 		bpa = bsh;
 	} else if (t == X86_BUS_SPACE_MEM) {
-		if (bsh >= atdevbase && (bsh + size) <= (atdevbase + IOM_SIZE)) {
-			bpa = (bus_addr_t)ISA_PHYSADDR(bsh);
-		} else {
-			if (bsh >= PMAP_DIRECT_BASE_NC &&
-			    bsh < PMAP_DIRECT_END_NC)
-				bpa = PMAP_DIRECT_NC_UNMAP(bsh);
-			else
-				bpa = PMAP_DIRECT_UNMAP(bsh);
-		}
-	} else {
-		panic("_bus_space_unmap: bad bus space tag");
-	}
+		bpa = (bus_addr_t)ISA_PHYSADDR(bsh);
+		if (IOM_BEGIN <= bpa && bpa <= IOM_END)
+			goto ok;
 
-	if (adrp != NULL) {
+		va = trunc_page(bsh);
+		endva = round_page(bsh + size);
+
+#ifdef DIAGNOSTIC
+		if (endva <= va)
+			panic("_bus_space_unmap: overflow");
+#endif
+
+		(void) pmap_extract(pmap_kernel(), va, &bpa);
+		bpa += (bsh & PGOFSET);
+
+		pmap_kremove(va, endva - va);
+		pmap_update(pmap_kernel());
+
+		/*
+		 * Free the kernel virtual mapping.
+		 */
+		uvm_km_free(kernel_map, va, endva - va);
+	} else
+		panic("bus_space_unmap: bad bus space tag");
+
+ok:
+	if (adrp != NULL)
 		*adrp = bpa;
-	}
 }
 
 void
 bus_space_unmap(bus_space_tag_t t, bus_space_handle_t bsh, bus_size_t size)
 {
 	struct extent *ex;
+	u_long va, endva;
 	bus_addr_t bpa;
 
 	/*
@@ -299,18 +345,28 @@ bus_space_unmap(bus_space_tag_t t, bus_space_handle_t bsh, bus_size_t size)
 		bpa = bsh;
 	} else if (t == X86_BUS_SPACE_MEM) {
 		ex = iomem_ex;
-
-		if (bsh >= atdevbase &&
-		    (bsh + size) <= (atdevbase + IOM_SIZE)) {
-			bpa = (bus_addr_t)ISA_PHYSADDR(bsh);
+		bpa = (bus_addr_t)ISA_PHYSADDR(bsh);
+		if (IOM_BEGIN <= bpa && bpa <= IOM_END)
 			goto ok;
-		}
 
-		if (bsh >= PMAP_DIRECT_BASE_NC &&
-		    bsh < PMAP_DIRECT_END_NC)
-			bpa = PMAP_DIRECT_NC_UNMAP(bsh);
-		else
-			bpa = PMAP_DIRECT_UNMAP(bsh);
+		va = trunc_page(bsh);
+		endva = round_page(bsh + size);
+
+#ifdef DIAGNOSTIC
+		if (endva <= va)
+			panic("bus_space_unmap: overflow");
+#endif
+
+		(void)pmap_extract(pmap_kernel(), va, &bpa);
+		bpa += (bsh & PGOFSET);
+
+		pmap_kremove(va, endva - va);
+		pmap_update(pmap_kernel());
+
+		/*
+		 * Free the kernel virtual mapping.
+		 */
+		uvm_km_free(kernel_map, va, endva - va);
 	} else
 		panic("bus_space_unmap: bad bus space tag");