Buffers mapped with pgprot_writecombined() are not correctly
flushed. This triggers issues on VPU access using random
memory content such as MMU translation faults, invalid context
descriptors being fetched and can lead to VPU FW crashes.

Fixes: 647371a6 ("accel/ivpu: Add GEM buffer object management")
Cc: stable@vger.kernel.org # 6.3+
Signed-off-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230802063735.3005291-1-stanislaw.gruszka@linux.intel.com