linux-stable/drivers/firmware/arm_ffa
Sudeep Holla 111a833dc5 firmware: arm_ffa: Set reserved/MBZ fields to zero in the memory descriptors
The transmit buffers allocated by the driver can be used to transmit data
by any messages/commands needing the buffer. However, it is not guaranteed
to have been zero-ed before every new transmission and hence it will just
contain residual value from the previous transmission. There are several
reserved fields in the memory descriptors that must be zero(MBZ). The
receiver can reject the transmission if any such MBZ fields are non-zero.

While we can set the whole page to zero, it is not optimal as most of the
fields get initialised to the value required for the current transmission.

So, just set the reserved/MBZ fields to zero in the memory descriptors
explicitly to honour the requirement and keep the receiver happy.

Fixes: cc2195fe53 ("firmware: arm_ffa: Add support for MEM_* interfaces")
Reported-by: Marc Bonnici <marc.bonnici@arm.com>
Link: https://lore.kernel.org/r/20230503131252.12585-1-sudeep.holla@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-05-08 20:40:46 +01:00
..
Kconfig firmware: arm_ffa: Add support for SMCCC as transport to FFA driver 2021-05-26 22:36:46 +01:00
Makefile firmware: arm_ffa: Add support for SMCCC as transport to FFA driver 2021-05-26 22:36:46 +01:00
bus.c firmware: arm_ffa: Fix FFA device names for logical partitions 2023-05-08 20:40:46 +01:00
common.h firmware: arm_ffa: Setup in-kernel users of FFA partitions 2021-05-26 22:38:43 +01:00
driver.c firmware: arm_ffa: Set reserved/MBZ fields to zero in the memory descriptors 2023-05-08 20:40:46 +01:00
smccc.c firmware: arm_ffa: Add support for SMCCC as transport to FFA driver 2021-05-26 22:36:46 +01:00