Messages in this thread | | | Date | Mon, 11 May 2015 23:29:55 +0100 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH 1/3] ARM: cache-l2c: Add flag to skip cache unlocking |
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On Tue, May 12, 2015 at 12:17:29AM +0200, Sjoerd Simons wrote: > The L2C cache should only be unlocked when the cache is setup to allow > that. In the common case the l2x0 driver sets up the cache for that to > be the case (e.g. setting L310_AUX_CTRL_NS_LOCKDOWN on L2C-310), making > unlock safe. However when a secure firmware is in use, it may not be > possible for the L2c to be configured that way making unlocking unsafe. > > To handle that case add a flag to skip unlocking the cache for machine > where this can't be done safely. > > Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk> > --- > arch/arm/include/asm/outercache.h | 1 + > arch/arm/mm/cache-l2x0.c | 4 +++- > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/include/asm/outercache.h b/arch/arm/include/asm/outercache.h > index 563b92f..d07ca82 100644 > --- a/arch/arm/include/asm/outercache.h > +++ b/arch/arm/include/asm/outercache.h > @@ -39,6 +39,7 @@ struct outer_cache_fns { > /* This is an ARM L2C thing */ > void (*write_sec)(unsigned long, unsigned); > void (*configure)(const struct l2x0_regs *); > + bool skip_unlock; > }; > > extern struct outer_cache_fns outer_cache; > diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c > index e309c8f..fff7888 100644 > --- a/arch/arm/mm/cache-l2x0.c > +++ b/arch/arm/mm/cache-l2x0.c > @@ -136,7 +136,8 @@ static void l2c_enable(void __iomem *base, u32 aux, unsigned num_lock) > l2x0_saved_regs.aux_ctrl = aux; > l2c_configure(base); > > - l2c_unlock(base, num_lock); > + if (!outer_cache.skip_unlock) > + l2c_unlock(base, num_lock);
I think we can do better here. If the non-secure lockdown access bit has been set, then proceed with the unlock:
if (readl_relaxed(base + L2X0_AUX_CTRL) & L310_AUX_CTRL_NS_LOCKDOWN) l2c_unlock(base, num_lock);
I don't see any need to add a flag for this. This also eliminates your second patch.
-- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net.
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