Module Name: src
Committed By: cegger
Date: Sat Apr 18 08:51:46 UTC 2009
Modified Files:
src/sys/arch/x86/include: pmap.h
src/sys/arch/x86/x86: bus_dma.c pmap.c
Log Message:
Introduce PMAP_NOCACHE as first PMAP MD bit in x86. Make use of it in
pmap_enter().
This safes one extra TLB flush when mapping dma-safe memory.
Presented on tech-kern@, port-i386@ and port-amd64@
ok ad@
To generate a diff of this commit:
cvs rdiff -u -r1.22 -r1.23 src/sys/arch/x86/include/pmap.h
cvs rdiff -u -r1.49 -r1.50 src/sys/arch/x86/x86/bus_dma.c
cvs rdiff -u -r1.82 -r1.83 src/sys/arch/x86/x86/pmap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/x86/include/pmap.h
diff -u src/sys/arch/x86/include/pmap.h:1.22 src/sys/arch/x86/include/pmap.h:1.23
--- src/sys/arch/x86/include/pmap.h:1.22 Sat Mar 21 14:41:30 2009
+++ src/sys/arch/x86/include/pmap.h Sat Apr 18 08:51:45 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.h,v 1.22 2009/03/21 14:41:30 ad Exp $ */
+/* $NetBSD: pmap.h,v 1.23 2009/04/18 08:51:45 cegger Exp $ */
/*
*
@@ -176,6 +176,11 @@
#endif
/*
+ * MD flags that we use for pmap_enter:
+ */
+#define PMAP_NOCACHE 0x00000100 /* set the non-cacheable bit */
+
+/*
* global kernel variables
*/
Index: src/sys/arch/x86/x86/bus_dma.c
diff -u src/sys/arch/x86/x86/bus_dma.c:1.49 src/sys/arch/x86/x86/bus_dma.c:1.50
--- src/sys/arch/x86/x86/bus_dma.c:1.49 Sat Mar 14 14:46:08 2009
+++ src/sys/arch/x86/x86/bus_dma.c Sat Apr 18 08:51:45 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: bus_dma.c,v 1.49 2009/03/14 14:46:08 dsl Exp $ */
+/* $NetBSD: bus_dma.c,v 1.50 2009/04/18 08:51:45 cegger Exp $ */
/*-
* Copyright (c) 1996, 1997, 1998, 2007 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.49 2009/03/14 14:46:08 dsl Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.50 2009/04/18 08:51:45 cegger Exp $");
/*
* The following is included because _bus_dma_uiomove is derived from
@@ -1017,26 +1017,23 @@
_bus_dmamem_map(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs,
size_t size, void **kvap, int flags)
{
- vaddr_t sva, va, eva;
+ vaddr_t va;
bus_addr_t addr;
int curseg;
- int nocache;
- pt_entry_t *pte, opte, xpte;
const uvm_flag_t kmflags =
(flags & BUS_DMA_NOWAIT) != 0 ? UVM_KMF_NOWAIT : 0;
+ int pmapflags = PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE;
size = round_page(size);
- nocache = (flags & BUS_DMA_NOCACHE) != 0;
+ if (flags & BUS_DMA_NOCACHE)
+ pmapflags |= PMAP_NOCACHE;
va = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_VAONLY | kmflags);
if (va == 0)
- return (ENOMEM);
+ return ENOMEM;
*kvap = (void *)va;
- sva = va;
- eva = sva + size;
- xpte = 0;
for (curseg = 0; curseg < nsegs; curseg++) {
for (addr = segs[curseg].ds_addr;
@@ -1046,30 +1043,12 @@
panic("_bus_dmamem_map: size botch");
_BUS_PMAP_ENTER(pmap_kernel(), va, addr,
VM_PROT_READ | VM_PROT_WRITE,
- PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE);
- /*
- * mark page as non-cacheable
- */
- if (nocache) {
- pte = kvtopte(va);
- opte = *pte;
- if ((opte & PG_N) == 0) {
- pmap_pte_setbits(pte, PG_N);
- xpte |= opte;
- }
- }
+ pmapflags);
}
}
-#ifndef XEN /* XXX */
- if ((xpte & (PG_V | PG_U)) == (PG_V | PG_U)) {
- kpreempt_disable();
- pmap_tlb_shootdown(pmap_kernel(), sva, eva, xpte);
- kpreempt_enable();
- }
pmap_update(pmap_kernel());
-#endif
- return (0);
+ return 0;
}
/*
Index: src/sys/arch/x86/x86/pmap.c
diff -u src/sys/arch/x86/x86/pmap.c:1.82 src/sys/arch/x86/x86/pmap.c:1.83
--- src/sys/arch/x86/x86/pmap.c:1.82 Sat Mar 21 22:55:08 2009
+++ src/sys/arch/x86/x86/pmap.c Sat Apr 18 08:51:45 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.82 2009/03/21 22:55:08 ad Exp $ */
+/* $NetBSD: pmap.c,v 1.83 2009/04/18 08:51:45 cegger Exp $ */
/*
* Copyright (c) 2007 Manuel Bouyer.
@@ -154,7 +154,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.82 2009/03/21 22:55:08 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.83 2009/04/18 08:51:45 cegger Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
@@ -4044,6 +4044,8 @@
npte = ma | protection_codes[prot] | PG_V;
if (wired)
npte |= PG_W;
+ if (flags & PMAP_NOCACHE)
+ npte |= PG_N;
if (va < VM_MAXUSER_ADDRESS)
npte |= PG_u;
else if (va < VM_MAX_ADDRESS)
