[U-Boot] [PATCH] ppc4xx: Cleanup Boot/FLASH TLB reassignment for PPC440/460

[Stefan Roese]

Background Info:
Some PPC440/460 boards have caches enabled in the Boot/FLASH TLB (via
init.S) to speed up the boot process. In relocate_code (start.S) the
cache inhibit attribute for this TLB is set to disable cache. This is
needed for the CFI FLASH driver.

This patch now cleans this code up:
- CONFIG_SYS_TLB_FOR_BOOT_FLASH is defined to 0 (default TLB) if not
  defined in the top of this file. This way, we can remove an ugly
  #ifdef in this code.
- Replace complex "#if defined(CONFIG_440EP) || defined(CONFIG_GR)..."
  statement with "#if defined(CONFIG_440)".
- Remove unnecessary cache invalidate calls resulting in faster bootup.

Signed-off-by: Stefan Roese <sr at denx.de>
---
 arch/powerpc/cpu/ppc4xx/start.S |   21 ++++++---------------
 1 files changed, 6 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/cpu/ppc4xx/start.S b/arch/powerpc/cpu/ppc4xx/start.S
index c739deb..5296dad 100644
--- a/arch/powerpc/cpu/ppc4xx/start.S
+++ b/arch/powerpc/cpu/ppc4xx/start.S
@@ -207,6 +207,10 @@
 		(0x00000000)
 #endif /* !defined(CONFIG_SYS_DCACHE_SACR_VALUE) */
 
+#if !defined(CONFIG_SYS_TLB_FOR_BOOT_FLASH)
+#define CONFIG_SYS_TLB_FOR_BOOT_FLASH	0	/* use TLB 0 as default */
+#endif
+
 #define function_prolog(func_name)	.text; \
 					.align 2; \
 					.globl func_name; \
@@ -1457,34 +1461,21 @@ relocate_code:
 	isync
 #endif /* CONFIG_SYS_INIT_RAM_DCACHE */
 
-#if defined(CONFIG_440EP) || defined(CONFIG_440GR) || \
-    defined(CONFIG_440EPX) || defined(CONFIG_440GRX) || \
-    defined(CONFIG_440SP) || defined(CONFIG_440SPE) || \
-    defined(CONFIG_460EX) || defined(CONFIG_460GT) || \
-    defined(CONFIG_460SX)
 	/*
 	 * On some 440er platforms the cache is enabled in the first TLB (Boot-CS)
 	 * to speed up the boot process. Now this cache needs to be disabled.
 	 */
-	iccci	0,0			/* Invalidate inst cache */
-	dccci	0,0			/* Invalidate data cache, now no longer our stack */
-	sync
-	isync
-
+#if defined(CONFIG_440)
 	/* Clear all potential pending exceptions */
 	mfspr	r1,SPRN_MCSR
 	mtspr	SPRN_MCSR,r1
-#ifdef CONFIG_SYS_TLB_FOR_BOOT_FLASH
 	addi	r1,r0,CONFIG_SYS_TLB_FOR_BOOT_FLASH	/* Use defined TLB */
-#else
-	addi	r1,r0,0x0000		/* Default TLB entry is #0 */
-#endif /* CONFIG_SYS_TLB_FOR_BOOT_FLASH */
 	tlbre	r0,r1,0x0002		/* Read contents */
 	ori	r0,r0,0x0c00		/* Or in the inhibit, write through bit */
 	tlbwe	r0,r1,0x0002		/* Save it out */
 	sync
 	isync
-#endif /* defined(CONFIG_440EP) || ... || defined(CONFIG_460GT) */
+#endif /* defined(CONFIG_440) */
 	mr	r1,  r3		/* Set new stack pointer		*/
 	mr	r9,  r4		/* Save copy of Init Data pointer	*/
 	mr	r10, r5		/* Save copy of Destination Address	*/
-- 
1.7.1