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authorBecky Bruce <beckyb@kernel.crashing.org>2011-10-03 19:10:51 -0500
committerKumar Gala <galak@kernel.crashing.org>2011-10-09 17:57:54 -0500
commit1605cc9e1bf193021e86048295148c45a185410d (patch)
treefdb937e62e3ba818f137971320f10daead763d01 /arch/powerpc/cpu/mpc86xx/start.S
parente3fd652087cd9633a0920667a3920ee757f948e7 (diff)
downloadu-boot-linaro-stable-1605cc9e1bf193021e86048295148c45a185410d.tar.gz
powerpc/mpc86xx: Disable translation for BAT setup
We really shouldn't be overwriting bat registers with translation enabled, especially when we're executing code using one of them for translating the current instruction stream. Instead, disable address translation while doing the final BAT setup. In order to do this, setup_bats has to move back to asm code, because we require translation to be enabled to have a stack for C code. The yucky thing about that is that the assembler doesn't like ULL so we have to switch to using HIGH/LOW pairs for physical addresses that are > 32 bits in length. Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org> Acked-by: York Sun <yorksun@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/cpu/mpc86xx/start.S')
-rw-r--r--arch/powerpc/cpu/mpc86xx/start.S69
1 files changed, 68 insertions, 1 deletions
diff --git a/arch/powerpc/cpu/mpc86xx/start.S b/arch/powerpc/cpu/mpc86xx/start.S
index 32896d49e..ef80ecf6e 100644
--- a/arch/powerpc/cpu/mpc86xx/start.S
+++ b/arch/powerpc/cpu/mpc86xx/start.S
@@ -1,5 +1,5 @@
/*
- * Copyright 2004, 2007 Freescale Semiconductor.
+ * Copyright 2004, 2007, 2011 Freescale Semiconductor.
* Srikanth Srinivasan <srikanth.srinivaan@freescale.com>
*
* See file CREDITS for list of people who contributed to this
@@ -322,6 +322,73 @@ invalidate_bats:
sync
blr
+#define CONFIG_BAT_PAIR(n) \
+ lis r4, CONFIG_SYS_IBAT##n##L@h; \
+ ori r4, r4, CONFIG_SYS_IBAT##n##L@l; \
+ lis r3, CONFIG_SYS_IBAT##n##U@h; \
+ ori r3, r3, CONFIG_SYS_IBAT##n##U@l; \
+ mtspr IBAT##n##L, r4; \
+ mtspr IBAT##n##U, r3; \
+ lis r4, CONFIG_SYS_DBAT##n##L@h; \
+ ori r4, r4, CONFIG_SYS_DBAT##n##L@l; \
+ lis r3, CONFIG_SYS_DBAT##n##U@h; \
+ ori r3, r3, CONFIG_SYS_DBAT##n##U@l; \
+ mtspr DBAT##n##L, r4; \
+ mtspr DBAT##n##U, r3;
+
+/*
+ * setup_bats:
+ *
+ * Set up the final BAT registers now that setup is done.
+ *
+ * Assumes that:
+ * 1) Address translation is enabled upon entry
+ * 2) The boot rom is still accessible via 1:1 translation
+ */
+ .globl setup_bats
+setup_bats:
+ mflr r5
+ sync
+
+ /*
+ * When we disable address translation, we will get 1:1 (VA==PA)
+ * translation. The only place we know for sure is safe for that is
+ * the bootrom where we originally started out. Pop back into there.
+ */
+ lis r4, CONFIG_SYS_MONITOR_BASE_EARLY@h
+ ori r4, r4, CONFIG_SYS_MONITOR_BASE_EARLY@l
+ addi r4, r4, trans_disabled - _start + EXC_OFF_SYS_RESET
+
+ /* disable address translation */
+ mfmsr r3
+ rlwinm r3, r3, 0, 28, 25
+ mtspr SRR0, r4
+ mtspr SRR1, r3
+ rfi
+
+trans_disabled:
+#if defined(CONFIG_SYS_DBAT0U) && defined(CONFIG_SYS_DBAT0L) \
+ && defined(CONFIG_SYS_IBAT0U) && defined(CONFIG_SYS_IBAT0L)
+ CONFIG_BAT_PAIR(0)
+#endif
+ CONFIG_BAT_PAIR(1)
+ CONFIG_BAT_PAIR(2)
+ CONFIG_BAT_PAIR(3)
+ CONFIG_BAT_PAIR(4)
+ CONFIG_BAT_PAIR(5)
+ CONFIG_BAT_PAIR(6)
+ CONFIG_BAT_PAIR(7)
+
+ sync
+ isync
+
+ /* Turn translation back on and return */
+ mfmsr r3
+ ori r3, r3, (MSR_IR | MSR_DR)
+ mtspr SPRN_SRR0,r5
+ mtspr SPRN_SRR1,r3
+ rfi
+
/*
* early_bats:
*