From e2b0046ba118954f99c12d150eb0fca9f57a813d Mon Sep 17 00:00:00 2001
From: gallatin <gallatin@FreeBSD.org>
Date: Tue, 5 Jun 2007 15:02:14 +0000
Subject: Use pmap_change_attr() to setup a write combine attribute for our
 device memory, rather than relying on the less reliable MTRR method used by
 mem_range_attr_set().

Glanced at by: jhb
---
 sys/dev/mxge/if_mxge.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

(limited to 'sys/dev/mxge')

diff --git a/sys/dev/mxge/if_mxge.c b/sys/dev/mxge/if_mxge.c
index 93c55a1..2feaaf6 100644
--- a/sys/dev/mxge/if_mxge.c
+++ b/sys/dev/mxge/if_mxge.c
@@ -80,6 +80,10 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm.h>		/* for pmap_mapdev() */
 #include <vm/pmap.h>
 
+#if defined(__i386) || defined(__amd64)
+#include <machine/specialreg.h>
+#endif
+
 #include <dev/mxge/mxge_mcp.h>
 #include <dev/mxge/mcp_gen_header.h>
 #include <dev/mxge/if_mxge_var.h>
@@ -146,8 +150,17 @@ mxge_enable_wc(mxge_softc_t *sc)
 	vm_offset_t len;
 	int err, action;
 
-	pa = rman_get_start(sc->mem_res);
 	len = rman_get_size(sc->mem_res);
+#if defined(__i386) || defined(__amd64)
+	err = pmap_change_attr((vm_offset_t) sc->sram,
+			       len, PAT_WRITE_COMBINING);
+	if (err == 0)
+		return;
+	else
+		device_printf(sc->dev, "pmap_change_attr failed, %d\n",
+			      err);
+#endif		
+	pa = rman_get_start(sc->mem_res);
 	mrdesc.mr_base = pa;
 	mrdesc.mr_len = len;
 	mrdesc.mr_flags = MDF_WRITECOMBINE;
-- 
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