openwrtv4/target/linux/bcm53xx/patches-4.3/300-ARM-BCM5301X-Disable-MMU-and-Dcache-for-decompression.patch

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From: Florian Fainelli <f.fainelli@gmail.com>
Subject: [PATCH] ARM: BCM5301x: Disable MMU and Dcache during decompression
Date: Tue, 14 Jul 2015 16:12:08 -0700
Use the existing __armv7_mmu_cache_flush() to perform the cache flush
since this does what we are after.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/boot/compressed/Makefile | 4 +++
arch/arm/boot/compressed/head-bcm_5301x-mpcore.S | 37 ++++++++++++++++++++++++
arch/arm/boot/compressed/head.S | 2 ++
3 files changed, 43 insertions(+)
create mode 100644 arch/arm/boot/compressed/head-bcm_5301x-mpcore.S
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -31,6 +31,10 @@ ifeq ($(CONFIG_ARCH_ACORN),y)
OBJS += ll_char_wr.o font.o
endif
+ifeq ($(CONFIG_ARCH_BCM_5301X),y)
+OBJS += head-bcm_5301x-mpcore.o
+endif
+
ifeq ($(CONFIG_ARCH_SA1100),y)
OBJS += head-sa1100.o
endif
--- /dev/null
+++ b/arch/arm/boot/compressed/head-bcm_5301x-mpcore.S
@@ -0,0 +1,37 @@
+/*
+ *
+ * Platform specific tweaks. This is merged into head.S by the linker.
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/cp15.h>
+
+ .section ".start", "ax"
+
+/*
+ * This code section is spliced into the head code by the linker
+ */
+
+__plat_uncompress_start:
+
+ @ Preserve r8/r7 i.e. kernel entry values
+ mov r12, r8
+
+ @ Clear MMU enable and Dcache enable bits
+ mrc p15, 0, r0, c1, c0, 0 @ Read SCTLR
+ bic r0, #CR_C|CR_M
+ mcr p15, 0, r0, c1, c0, 0 @ Write SCTLR
+ nop
+
+ @ Call the cache invalidation routine
+ bl __armv7_mmu_cache_flush_fn
+ nop
+ mov r0,#0
+ ldr r3, =0x19022000 @ L2 cache controller, control reg
+ str r0, [r3, #0x100] @ Disable L2 cache
+ nop
+
+ @ Restore
+ mov r8, r12
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -1152,6 +1152,7 @@ __armv7_mmu_cache_flush:
hierarchical:
mcr p15, 0, r10, c7, c10, 5 @ DMB
stmfd sp!, {r0-r7, r9-r11}
+ENTRY(__armv7_mmu_cache_flush_fn)
mrc p15, 1, r0, c0, c0, 1 @ read clidr
ands r3, r0, #0x7000000 @ extract loc from clidr
mov r3, r3, lsr #23 @ left align loc bit field
@@ -1201,6 +1202,7 @@ iflush:
mcr p15, 0, r10, c7, c10, 4 @ DSB
mcr p15, 0, r10, c7, c5, 4 @ ISB
mov pc, lr
+ENDPROC(__armv7_mmu_cache_flush_fn)
__armv5tej_mmu_cache_flush:
tst r4, #1