This patch is an attempt at introducing 4k CAR size granularity for the

generic x86 CAR code. For the old supported CAR sizes, the newly
generated code is equivalent, so it should be a no-brainer.

Add a copyright header to the code, the header is derived from the one
found in the same piece of code in v3.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net> 
Acked-by: Marc Jones <marc.jones@amd.com> 


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3038 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

src/cpu/x86/car/cache_as_ram.inc

@@ -1,3 +1,28 @@
+/* 
+ * This file is part of the LinuxBIOS project.
+ * 
+ * Copyright (C) 2000,2007 Ronald G. Minnich <rminnich@gmail.com>
+ * Copyright (C) 2005 Eswar Nallusamy, LANL
+ * Copyright (C) 2005 Tyan
+ * (Written by Yinghai Lu <yhlu@tyan.com> for Tyan)
+ * Copyright (C) 2007 coresystems GmbH
+ * (Written by Stefan Reinauer <stepan@coresystems.de> for coresystems GmbH)
+ * Copyright (C) 2007 Carl-Daniel Hailfinger
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
 /* We will use 4K bytes only */
 /* disable HyperThreading is done by eswar*/
 /* other's is the same as AMD except remove amd specific msr */
@@ -106,38 +131,58 @@ clear_fixed_var_mtrr:
         jmp     clear_fixed_var_mtrr
 clear_fixed_var_mtrr_out:
 
-#if CacheSize == 0x10000 
+/* 0x06 is the WB IO type for a given 4k segment.
-        /* enable caching for 64K using fixed mtrr */
+ * segs is the number of 4k segments in the area of the particular
+ *   register we want to use for CAR.
+ * reg is the register where the IO type should be stored.
+ */
+.macro extractmask segs, reg
+.if \segs <= 0
+	/* The xorl here is superfluous because at the point of first execution
+	 * of this macro, %eax and %edx are cleared. Later invocations of this
+	 * macro will have a monotonically increasing segs parameter.
+	 */
+	xorl \reg, \reg
+.elseif \segs == 1
+	movl $0x06000000, \reg
+.elseif \segs == 2
+	movl $0x06060000, \reg
+.elseif \segs == 3
+	movl $0x06060600, \reg
+.elseif \segs >= 4
+	movl $0x06060606, \reg
+.endif
+.endm
+
+/* size is the cache size in bytes we want to use for CAR.
+ * windowoffset is the 32k-aligned window into CAR size
+ */
+.macro simplemask carsize, windowoffset
+	simplemask_helper (((\carsize - \windowoffset) / 0x1000) - 4), %eax
+	simplemask_helper (((\carsize - \windowoffset) / 0x1000)), %edx
+.endm
+
+#if CacheSize > 0x10000
+#error Invalid CAR size, must be at most 64k.
+#endif
+#if CacheSize < 0x1000
+#error Invalid CAR size, must be at least 4k. This is a processor limitation.
+#endif
+#if (CacheSize & (0x1000 - 1))
+#error Invalid CAR size, is not a multiple of 4k. This is a processor limitation.
+#endif
+
+#if CacheSize > 0x8000 
+        /* enable caching for 32K-64K using fixed mtrr */
         movl    $0x268, %ecx  /* fix4k_c0000*/
-        movl    $0x06060606, %eax /* WB IO type */
+	simplemask CacheSize, 0x8000
-	movl    %eax, %edx
-        wrmsr
-	movl	$0x269, %ecx
         wrmsr
 #endif
 
-#if CacheSize == 0x8000
+        /* enable caching for 0-32K using fixed mtrr */
-        /* enable caching for 32K using fixed mtrr */
         movl    $0x269, %ecx  /* fix4k_c8000*/
-        movl    $0x06060606, %eax /* WB IO type */
+	simplemask CacheSize, 0
-	movl    %eax, %edx
 	wrmsr
-#endif
-
-        /* enable caching for 16K/8K/4K using fixed mtrr */
-        movl    $0x269, %ecx  /* fix4k_cc000*/
-#if CacheSize == 0x4000
-        movl    $0x06060606, %edx /* WB IO type */
-#endif
-#if CacheSize == 0x2000
-        movl    $0x06060000, %edx /* WB IO type */
-#endif
-#if CacheSize == 0x1000
-        movl    $0x06000000, %edx /* WB IO type */
-#endif
-	xorl    %eax, %eax
-	wrmsr
-
 
 #else
         /* disable cache */