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Subject[PATCH] arc: Flush and invalidate caches on start
Date
This is useful to make sure no stale data exists in caches after bootloaders.
The worst thing could be some lines of cache were locked in a bootloader
for example during DDR recalibration and never unlocked. This may lead
to really unpredictable issues later down the line.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
---
arch/arc/kernel/head.S | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 8b90d25a15cc..04e28b664183 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -34,6 +34,10 @@
#endif
sr r5, [ARC_REG_IC_CTRL]

+ ; Invalidate entire I$
+ mov r5, 1
+ sr r5, [ARC_REG_IC_IVIC]
+
1:
lr r5, [ARC_REG_DC_BCR]
breq r5, 0, 1f ; D$ doesn't exist
@@ -46,6 +50,18 @@
#endif
sr r5, [ARC_REG_DC_CTRL]

+ ; Flush entire D$
+ mov r5, 1
+ sr r5, [ARC_REG_DC_FLSH]
+ ; Wait for flush operation to complete
+1:
+ lr r5, [ARC_REG_DC_CTRL]
+ bbit1 r5, DC_CTRL_FLUSH_STATUS, 1b
+
+ ; Invalidate entire D$
+ mov r5, 1
+ sr r5, [ARC_REG_DC_IVDC]
+
1:
.endm

--
2.11.0
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