[PATCH 0/1] mcb-pci: fix memory overlapping on MCB devices

From: Rodríguez Barbarin, José Javier
Date: Thu Mar 23 2023 - 08:49:41 EST


mcb-pci driver is allocating the memory region for the "chameleon table"
with a fixed size of 0x200. This region is only use to do a initial
parsing to discover the devices implemented as IP Cores.

If the "chameleon table" is actually smalled than 0x200 and the first
device offset happen to be within 0x200, a memory overlapping can ocurr.

Here an extract of the memory overlapping when registering a 16z125 IP Core:

[ 31.016972] 8250_men_mcb mcb0-16z125-0:0:0: can't request region for resource [mem 0xa8200100-0xa820010f]
[ 31.016994] 8250_men_mcb: probe of mcb0-16z125-0:0:0 failed with error -16
[ 31.017010] 8250_men_mcb mcb0-16z125-1:0:0: can't request region for resource [mem 0xa8200110-0xa820011f]

And here, the memory allocated for the chameleon table parsing:

user@host:$ sudo /proc/iomem
...
a8200000-a82001ff : mcb_pci
...

This patch solves this problem by not allocating the memory region of the
"chamelon table" that is only needed for parsing. Just do an ioremap instead.

This patch is based on linux-next (next-20230323)

Javier Rodriguez (1):
mcb: Remove requesting memory region to avoid memory overlapping

drivers/mcb/mcb-pci.c | 10 ----------
1 file changed, 10 deletions(-)

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2.34.1