On Thu, Jul 15, 2021 at 01:34:23PM +0300, Mikko Perttunen wrote: > On Tegra186 and later, a portion of the SYSRAM may be reserved for use > by TZ. Non-TZ memory accesses to this portion, including speculative > accesses, trigger SErrors that bring down the system. This does also > happen in practice occasionally (due to speculative accesses). > > To fix the issue, add a flag to the SRAM driver to only map the > device tree-specified reserved areas depending on a flag set > based on the compatibility string. This would not affect non-Tegra > systems that rely on the entire thing being memory mapped. > > If 64K pages are being used, we cannot exactly map the 4K regions > that are placed in SYSRAM - ioremap code instead aligns to closest > 64K pages. However, since in practice the non-accessible memory area > is 64K aligned, these mappings do not overlap with the non-accessible > memory area and things work out. > > Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx> Reviewed-by: Mian Yousaf Kaukab <ykaukab@xxxxxxx>
