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 <abrodkin at 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
