[LinuxBIOS] [PATCH] rewrite generic x86 CAR code

[Carl-Daniel Hailfinger]

This patch is an attempt at introducing 4k CAR size granularity for the
generic x86 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 at gmx.net>

Index: LinuxBIOSv2-CARx86/src/cpu/x86/car/cache_as_ram.inc
===================================================================
--- LinuxBIOSv2-CARx86/src/cpu/x86/car/cache_as_ram.inc	(Revision 3026)
+++ LinuxBIOSv2-CARx86/src/cpu/x86/car/cache_as_ram.inc	(Arbeitskopie)
@@ -1,3 +1,28 @@
+/* 
+ * This file is part of the LinuxBIOS project.
+ * 
+ * Copyright (C) 2000,2007 Ronald G. Minnich <rminnich at gmail.com>
+ * Copyright (C) 2005 Eswar Nallusamy, LANL
+ * Copyright (C) 2005 Tyan
+ * (Written by Yinghai Lu <yhlu at tyan.com> for Tyan)
+ * Copyright (C) 2007 coresystems GmbH
+ * (Written by Stefan Reinauer <stepan at 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 */
@@ -106,39 +131,61 @@
         jmp     clear_fixed_var_mtrr
 clear_fixed_var_mtrr_out:
 
-#if CacheSize == 0x10000 
-        /* enable caching for 64K using fixed mtrr */
+/* 0x06 is the WB IO type for a given 4k segment.
+ * segs is the number of 4k segments we want to use for CAR.
+ * subpart is the nth 32-bit window into IO type configuration.
+ * reg is the register where the IO type should be stored.
+ */
+.macro extractmask segs, subpart, reg
+.if \segs - (\subpart * 4) <= 0
+	xorl \reg, \reg
+.elseif \segs - (\subpart * 4) == 1
+	movl $0x06000000, \reg
+.elseif \segs - (\subpart * 4) == 2
+	movl $0x06060000, \reg
+.elseif \segs - (\subpart * 4) == 3
+	movl $0x06060600, \reg
+.elseif \segs - (\subpart * 4) >= 4
+	movl $0x06060606, \reg
+.endif
+.endm
+.macro simplemask_helper segs, subpart
+.if \subpart & 0x1
+	extractmask \segs, \subpart, %eax
+.else
+	extractmask \segs, \subpart, %edx
+.endif
+.endm
+/* size is the cache size in bytes we want to use for CAR.
+ * part is the nth 64-bit window into IO type configuration.
+ */
+.macro simplemask size, part
+	simplemask_helper (\size / 0x1000), (\part * 2 + 1)
+	simplemask_helper (\size / 0x1000), (\part * 2)
+.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 */
-	movl    %eax, %edx
+	simplemask CacheSize, 1
         wrmsr
-	movl	$0x269, %ecx
-	wrmsr
 #endif
 
-#if CacheSize == 0x8000
-        /* enable caching for 32K using fixed mtrr */
+        /* enable caching for 0-32K using fixed mtrr */
         movl    $0x269, %ecx  /* fix4k_c8000*/
-        movl    $0x06060606, %eax /* WB IO type */
-	movl    %eax, %edx
+	simplemask CacheSize, 0
 	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 */
         movl    %cr0, %eax