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authorVineet Gupta <vgupta@synopsys.com>2014-03-07 18:08:11 +0530
committerVineet Gupta <vgupta@synopsys.com>2014-06-03 15:14:48 +0530
commitef680cdc24376f394841a3f19b3a7ef6d57a009d (patch)
treed70faaeb25f0109b051d675e3ca02641785cbe34 /arch/arc/kernel
parente87a850b9c92be6a8cf5735c516ec864d65f24dd (diff)
ARC: Disable caches in early boot if so configured
Requested-by: Noam Camus <noamc@ezchip.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel')
-rw-r--r--arch/arc/kernel/head.S38
1 files changed, 35 insertions, 3 deletions
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 4ad04915dc6b..07a58f2d3077 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -12,10 +12,42 @@
* to skip certain things during boot on simulator
*/
+#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/entry.h>
-#include <linux/linkage.h>
#include <asm/arcregs.h>
+#include <asm/cache.h>
+
+.macro CPU_EARLY_SETUP
+
+ ; Setting up Vectror Table (in case exception happens in early boot
+ sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE]
+
+ ; Disable I-cache/D-cache if kernel so configured
+ lr r5, [ARC_REG_IC_BCR]
+ breq r5, 0, 1f ; I$ doesn't exist
+ lr r5, [ARC_REG_IC_CTRL]
+#ifdef CONFIG_ARC_HAS_ICACHE
+ bclr r5, r5, 0 ; 0 - Enable, 1 is Disable
+#else
+ bset r5, r5, 0 ; I$ exists, but is not used
+#endif
+ sr r5, [ARC_REG_IC_CTRL]
+
+1:
+ lr r5, [ARC_REG_DC_BCR]
+ breq r5, 0, 1f ; D$ doesn't exist
+ lr r5, [ARC_REG_DC_CTRL]
+ bclr r5, r5, 6 ; Invalidate (discard w/o wback)
+#ifdef CONFIG_ARC_HAS_DCACHE
+ bclr r5, r5, 0 ; Enable (+Inv)
+#else
+ bset r5, r5, 0 ; Disable (+Inv)
+#endif
+ sr r5, [ARC_REG_DC_CTRL]
+
+1:
+.endm
.cpu A7
@@ -27,7 +59,7 @@ stext:
; Don't clobber r0-r2 yet. It might have bootloader provided info
;-------------------------------------------------------------------
- sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE]
+ CPU_EARLY_SETUP
#ifdef CONFIG_SMP
; Ensure Boot (Master) proceeds. Others wait in platform dependent way
@@ -90,7 +122,7 @@ stext:
first_lines_of_secondary:
- sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE]
+ CPU_EARLY_SETUP
; setup per-cpu idle task as "current" on this CPU
ld r0, [@secondary_idle_tsk]