lkml.org 
[lkml]   [2016]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] of/irq: Fix msi-map calculation for nonzero rid-base
From
Date
Hi Robin,

On 09/02/16 11:04, Robin Murphy wrote:
> The existing msi-map code is fine for shifting the entire RID space
> upwards, but attempting finer-grained remapping reveals a bug. It turns
> out that we are mistakenly treating the msi-base part as an offset, not
> as a new base to remap onto, so things get squiffy when rid-base is
> nonzero. Fix this, and at the same time add a sanity check against
> having msi-map-mask clash with a nonzero rid-base, as that's another
> thing one can easily get wrong.
>
> CC: <stable@vger.kernel.org>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>

Looks like Stuart and you both found the same bug at the same time:
https://lkml.org/lkml/2016/2/8/1066

but yours seem more correct to me (the rid_base masking in Stuart's
version seems odd).

> ---
> drivers/of/irq.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
> index 7ee21ae..e7bfc17 100644
> --- a/drivers/of/irq.c
> +++ b/drivers/of/irq.c
> @@ -635,6 +635,13 @@ static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
> msi_base = be32_to_cpup(msi_map + 2);
> rid_len = be32_to_cpup(msi_map + 3);
>
> + if (rid_base & ~map_mask) {
> + dev_err(parent_dev,
> + "Invalid msi-map translation - msi-map-mask (0x%x) ignores rid-base (0x%x)\n",
> + map_mask, rid_base);
> + return rid_out;
> + }
> +
> msi_controller_node = of_find_node_by_phandle(phandle);
>
> matched = (masked_rid >= rid_base &&
> @@ -654,7 +661,7 @@ static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
> if (!matched)
> return rid_out;
>
> - rid_out = masked_rid + msi_base;
> + rid_out = masked_rid - rid_base + msi_base;
> dev_dbg(dev,
> "msi-map at: %s, using mask %08x, rid-base: %08x, msi-base: %08x, length: %08x, rid: %08x -> %08x\n",
> dev_name(parent_dev), map_mask, rid_base, msi_base,
>

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>

M.
--
Jazz is not dead. It just smells funny...

\
 
 \ /
  Last update: 2016-02-09 13:21    [W:0.109 / U:25.520 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site