[PATCH v4] iommu/arm-smmu-qcom: Limit the SMR groups to 128

[Johan Hovold]

On Tue, Mar 21, 2023 at 02:43:32PM +0530, Manivannan Sadhasivam wrote:
> On some Qualcomm platforms, the hypervisor emulates more than 128 SMR
> (Stream Matching Register) groups. This doesn't conform to the ARM SMMU
> architecture specification which defines the range of 0-127. Moreover, the
> emulated groups don't exhibit the same behavior as the architecture
> supported ones.
> 
> For instance, emulated groups will not detect the quirky behavior of some
> firmware versions intercepting writes to S2CR register, thus skipping the
> quirk implemented in the driver and causing boot crash.
> 
> So let's limit the groups to 128 and issue a notice to users in that case.
> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>

Reviewed-by: Johan Hovold <johan+linaro at kernel.org>
Tested-by: Johan Hovold <johan+linaro at kernel.org>

Johan