Messages in this thread Patch in this message | | | From | Scott Wood <> | Date | Sat, 14 Sep 2019 09:34:44 -0500 | Subject | Re: [PATCH 2/2] powerpc/83xx: map IMMR with a BAT. |
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On Fri, 2019-08-23 at 12:50 +0000, Christophe Leroy wrote: > On mpc83xx with a QE, IMMR is 2Mbytes. > On mpc83xx without a QE, IMMR is 1Mbytes. > Each driver will map a part of it to access the registers it needs. > Some driver will map the same part of IMMR as other drivers. > > In order to reduce TLB misses, map the full IMMR with a BAT. > > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> > --- > arch/powerpc/platforms/83xx/misc.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/arch/powerpc/platforms/83xx/misc.c > b/arch/powerpc/platforms/83xx/misc.c > index f46d7bf3b140..1e395b01c535 100644 > --- a/arch/powerpc/platforms/83xx/misc.c > +++ b/arch/powerpc/platforms/83xx/misc.c > @@ -18,6 +18,8 @@ > #include <sysdev/fsl_soc.h> > #include <sysdev/fsl_pci.h> > > +#include <mm/mmu_decl.h> > + > #include "mpc83xx.h" > > static __be32 __iomem *restart_reg_base; > @@ -145,6 +147,14 @@ void __init mpc83xx_setup_arch(void) > if (ppc_md.progress) > ppc_md.progress("mpc83xx_setup_arch()", 0); > > + if (!__map_without_bats) { > + int immrsize = IS_ENABLED(CONFIG_QUICC_ENGINE) ? SZ_2M : > SZ_1M;
Any reason not to unconditionally make it 2M? After all, the kernel being built with CONFIG_QUICC_ENGINE doesn't mean that the hardware you're running on has it...
-Scott
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