[PATCH 06/10] soc/qbman: Add ARM equivalent for flush_dcache_range()

Russell King - ARM Linux
2017-01-18T23:12:06Z

On Wed, Jan 18, 2017 at 05:39:36PM -0500, Roy Pledge wrote:
> From: Claudiu Manoil <claudiu.manoil@nxp.com>
>
> Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
> Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
> Signed-off-by: Roy Pledge <roy.pledge@nxp.com>
> ---
> drivers/soc/fsl/qbman/qman_ccsr.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/soc/fsl/qbman/qman_ccsr.c b/drivers/soc/fsl/qbman/qman_ccsr.c
> index 43feaa9..67ae073 100644
> --- a/drivers/soc/fsl/qbman/qman_ccsr.c
> +++ b/drivers/soc/fsl/qbman/qman_ccsr.c
> @@ -446,8 +446,14 @@ static int zero_priv_mem(struct device *dev, struct device_node *node,
> return -ENOMEM;
>
> memset(tmpp, 0, sz);
> +#ifdef CONFIG_PPC
> flush_dcache_range((unsigned long)tmpp,
> (unsigned long)tmpp + sz);
> +#elif defined(CONFIG_ARM)
> + __cpuc_flush_dcache_area(tmpp, sz);

Please do not fiddle about under the covers, there be dragons there.

It looks to me like you're trying to use __cpuc_flush_dcache_area()
on an area that's been ioremap()'d, which is a waste of CPU cycles.
ioremap()'d areas are mapped as "device" memory type, which means
the region isn't even cached. So I don't think this is necessary.

--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.