ppc4xx: Cleanup Boot/FLASH TLB reassignment for PPC440/460

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@denx.de>

diff --git a/arch/powerpc/cpu/ppc4xx/start.S b/arch/powerpc/cpu/ppc4xx/start.S
index c739deb9b4663123358ac8091635efe0e8e3fdac..5296dad569caf9d80353c3d0c488aae311643cb3 100644 (file)
--- 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     */