- Clean up and comment writing of MSRs for cache control (Backport from v3)

- Invalidate Cache Tags (by means of in-place rewrite of cache data) which allows CAR data to be flushed to RAM
- Re-enable cache after flush of CAR to RAM


Signed-off-by: Edwin Beasant <edwin_beasant@virtensys.com>
Acked-by: Patrick Georgi <patrick.georgi@coresystems.de>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5055 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

2 files changed, 48 insertions, 52 deletions

diff --git a/src/cpu/amd/model_lx/cache_as_ram.inc b/src/cpu/amd/model_lx/cache_as_ram.inc
index ee4902a..1abfd81 100644
--- a/src/cpu/amd/model_lx/cache_as_ram.inc
+++ b/src/cpu/amd/model_lx/cache_as_ram.inc
@@ -178,31 +178,28 @@ DCacheSetupGood:
 	call	cache_as_ram_main
 done_cache_as_ram_main:
 
-	/* If you wanted to maintain the stack in memory you would need to set the tags as dirty
-	  so the wbinvd would push out the old stack contents to memory */
-	/* Clear the cache, the following code from crt0.S.lb will setup a new stack*/
+        /* We now run over the stack-in-cache, copying it back to itself to invalidate the cache */
+
+        push   %edi
+        mov    $(CONFIG_DCACHE_RAM_SIZE/4),%ecx
+        push   %esi
+        mov    $(CONFIG_DCACHE_RAM_BASE),%edi
+        mov    %edi,%esi
+        cld
+        rep movsl %ds:(%esi),%es:(%edi)
+        pop    %esi
+        pop    %edi
+
+	/* Clear the cache out to ram */
 	wbinvd
-
-/* the following code is from crt0.S.lb */
-/* This takes the place of the post-CAR funtions that the K8 uses to setup the stack and copy LB low.*/
-
-#ifndef CONSOLE_DEBUG_TX_STRING
-	/* uses:	 esp, ebx, ax, dx */
-# define __CRT_CONSOLE_TX_STRING(string) \
-	mov	string, %ebx	; \
-	CALLSP(crt_console_tx_string)
-
-# if defined(CONFIG_TTYS0_BASE) && (ASM_CONSOLE_LOGLEVEL > BIOS_DEBUG)
-#  define CONSOLE_DEBUG_TX_STRING(string)        __CRT_CONSOLE_TX_STRING(string)
-# else
-#  define CONSOLE_DEBUG_TX_STRING(string)
-# endif
-#endif
+        /* re-enable the cache */
+        movl    %cr0, %eax
+        xorl             $(CR0_CD + CR0_NW), %eax        /* clear  the CD and NW bits */
+        movl    %eax, %cr0
 
 	/* clear boot_complete flag */
 	xorl	%ebp, %ebp
 __main:
-	CONSOLE_DEBUG_TX_STRING($str_copying_to_ram)
 
 	/*
 	 *	Copy data into RAM and clear the BSS. Since these segments
@@ -218,9 +215,6 @@ __main:
 	 * Normally this is copying from FLASH ROM to RAM.
 	 */
 	movl	%ebp, %esi
-	/* FIXME: look for a proper place for the stack */
-	movl	$0x4000000, %esp
-	movl	%esp, %ebp
 	pushl	%esi
 	pushl $str_coreboot_ram_name
 	call cbfs_and_run_core
diff --git a/src/mainboard/amd/db800/cache_as_ram_auto.c b/src/mainboard/amd/db800/cache_as_ram_auto.c
index 5ee6dbb..c18b0bb 100644
--- a/src/mainboard/amd/db800/cache_as_ram_auto.c
+++ b/src/mainboard/amd/db800/cache_as_ram_auto.c
@@ -35,6 +35,7 @@
 #include <cpu/amd/geode_post_code.h>
 #include "southbridge/amd/cs5536/cs5536.h"
 
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 #define POST_CODE(x) outb(x, 0x80)
 #define SERIAL_DEV PNP_DEV(0x2e, W83627HF_SP1)
 
@@ -60,37 +61,38 @@ static inline int spd_read_byte(unsigned int device, unsigned int address)
 #include "cpu/amd/model_lx/cpureginit.c"
 #include "cpu/amd/model_lx/syspreinit.c"
 
+struct msrinit {
+            u32 msrnum;
+            msr_t msr;
+      };
+
+static const struct msrinit msr_table[] = 
+{
+       {CPU_RCONF_DEFAULT, {.hi = 0x24fffc02,.lo = 0x1000A000}}, /* Setup access to cache under 1MB.
+                                                                  * Rom Properties: Write Serialize, WriteProtect.
+                                                                  * RomBase: 0xFFFC0
+                                                                  * SysTop to RomBase Properties: Write Serialize, Cache Disable.
+                                                                  * SysTop: 0x000A0 
+                                                                  * System Memory Properties:  (Write Back) */
+       {CPU_RCONF_A0_BF,   {.hi = 0x00000000,.lo = 0x00000000}}, /* 0xA0000-0xBFFFF : (Write Back) */
+       {CPU_RCONF_C0_DF,   {.hi = 0x00000000,.lo = 0x00000000}}, /* 0xC0000-0xDFFFF : (Write Back) */
+       {CPU_RCONF_E0_FF,   {.hi = 0x00000000,.lo = 0x00000000}}, /* 0xE0000-0xFFFFF : (Write Back) */
+       
+       /* Setup access to memory under 1MB. Note: VGA hole at 0xA0000-0xBFFFF */
+       {MSR_GLIU0_BASE1,   {.hi = 0x20000000,.lo = 0x000fff80}}, // 0x00000-0x7FFFF
+       {MSR_GLIU0_BASE2,   {.hi = 0x20000000,.lo = 0x080fffe0}}, // 0x80000-0x9FFFF
+       {MSR_GLIU0_SHADOW,  {.hi = 0x2000FFFF,.lo = 0xFFFF0003}}, // 0xC0000-0xFFFFF
+       {MSR_GLIU1_BASE1,   {.hi = 0x20000000,.lo = 0x000fff80}}, // 0x00000-0x7FFFF
+       {MSR_GLIU1_BASE2,   {.hi = 0x20000000,.lo = 0x080fffe0}}, // 0x80000-0x9FFFF
+       {MSR_GLIU1_SHADOW,  {.hi = 0x2000FFFF,.lo = 0xFFFF0003}}, // 0xC0000-0xFFFFF
+};
+
+
 static void msr_init(void)
 {
-	msr_t msr;
-
-	/* Setup access to the cache for under 1MB. */
-	msr.hi = 0x24fffc02;
-	msr.lo = 0x1000A000;	/* 0-A0000 write back */
-	wrmsr(CPU_RCONF_DEFAULT, msr);
-
-	msr.hi = 0x0;		/* Write back */
-	msr.lo = 0x0;
-	wrmsr(CPU_RCONF_A0_BF, msr);
-	wrmsr(CPU_RCONF_C0_DF, msr);
-	wrmsr(CPU_RCONF_E0_FF, msr);
-
-	/* Setup access to the cache for under 640K. Note MC not setup yet. */
-	msr.hi = 0x20000000;
-	msr.lo = 0xfff80;
-	wrmsr(MSR_GLIU0 + 0x20, msr);
-
-	msr.hi = 0x20000000;
-	msr.lo = 0x80fffe0;
-	wrmsr(MSR_GLIU0 + 0x21, msr);
-
-	msr.hi = 0x20000000;
-	msr.lo = 0xfff80;
-	wrmsr(MSR_GLIU1 + 0x20, msr);
-
-	msr.hi = 0x20000000;
-	msr.lo = 0x80fffe0;
-	wrmsr(MSR_GLIU1 + 0x21, msr);
+  int i;
+       for (i = 0; i < ARRAY_SIZE(msr_table); i++)
+                           wrmsr(msr_table[i].msrnum, msr_table[i].msr);
 }
 
 static void mb_gpio_init(void)