From: kettenis <kettenis@openbsd.org>
Date: Wed, 3 Jul 2024 21:04:04 +0000 (+0000)
Subject: Map BUS_SPACE_MAP_PREFETCHABLE to Normal-NC.  There are other memory
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=1b96b3b977dfac01c78cc8d9e321ae6a5015a49f;p=openbsd

Map BUS_SPACE_MAP_PREFETCHABLE to Normal-NC.  There are other memory
attributes that could map to what we call write-combining on x86, but
this is what Linux uses.  This speeds up framebuffer access significantly.

ok patrick@
---

diff --git a/sys/arch/arm64/arm64/machdep.c b/sys/arch/arm64/arm64/machdep.c
index 98437f72c2f..7b53ee1f446 100644
--- a/sys/arch/arm64/arm64/machdep.c
+++ b/sys/arch/arm64/arm64/machdep.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: machdep.c,v 1.89 2024/04/29 13:01:54 jsg Exp $ */
+/* $OpenBSD: machdep.c,v 1.90 2024/07/03 21:04:04 kettenis Exp $ */
 /*
  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
  * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
@@ -1170,6 +1170,10 @@ pmap_bootstrap_bs_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size,
 {
 	u_long startpa, pa, endpa;
 	vaddr_t va;
+	int cache = PMAP_CACHE_DEV_NGNRNE;
+
+	if (flags & BUS_SPACE_MAP_PREFETCHABLE)
+		cache = PMAP_CACHE_CI;
 
 	va = virtual_avail;	/* steal memory from virtual avail. */
 
@@ -1179,8 +1183,7 @@ pmap_bootstrap_bs_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size,
 	*bshp = (bus_space_handle_t)(va + (bpa - startpa));
 
 	for (pa = startpa; pa < endpa; pa += PAGE_SIZE, va += PAGE_SIZE)
-		pmap_kenter_cache(va, pa, PROT_READ | PROT_WRITE,
-		    PMAP_CACHE_DEV_NGNRNE);
+		pmap_kenter_cache(va, pa, PROT_READ | PROT_WRITE, cache);
 
 	virtual_avail = va;
 
diff --git a/sys/arch/arm64/dev/arm64_bus_space.c b/sys/arch/arm64/dev/arm64_bus_space.c
index e4847cbb004..f78905fb47c 100644
--- a/sys/arch/arm64/dev/arm64_bus_space.c
+++ b/sys/arch/arm64/dev/arm64_bus_space.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: arm64_bus_space.c,v 1.8 2021/02/16 12:33:22 kettenis Exp $ */
+/*	$OpenBSD: arm64_bus_space.c,v 1.9 2024/07/03 21:04:04 kettenis Exp $ */
 
 /*
  * Copyright (c) 2001-2003 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -195,6 +195,8 @@ generic_space_map(bus_space_tag_t t, bus_addr_t offs, bus_size_t size,
 
 	if (flags & BUS_SPACE_MAP_CACHEABLE)
 		cache = PMAP_CACHE_WB;
+	if (flags & BUS_SPACE_MAP_PREFETCHABLE)
+		cache = PMAP_CACHE_CI;
 	if (flags & BUS_SPACE_MAP_POSTED)
 		cache = PMAP_CACHE_DEV_NGNRE;