On 08/31/2017 07:22 AM, Alexey Brodkin wrote:
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 <abrod...@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]
+
AFAIK uboot already flushes the caches before handing control over to kernel - so
why do we need it here.
If uboot is locking lines, it needs to fix that and not penalize the general case
with or w/o uboot !
-Vineet
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