On Fri, 2017-09-15 at 05:25:48 UTC, Michael Neuling wrote: > POWER9 DD2.1 and earlier has an issue where some cache inhibited > vector load will return bad data. The workaround is two part, one > firmware/microcode part triggers HMI interrupts when hitting such > loads, the other part is this patch which then emulates the > instructions in Linux. > > The affected instructions are limited to lxvd2x, lxvw4x, lxvb16x and > lxvh8x. > > When an instruction triggers the HMI, all threads in the core will be > sent to the HMI handler, not just the one running the vector load. > > In general, these spurious HMIs are detected by the emulation code and > we just return back to the running process. Unfortunately, if a > spurious interrupt occurs on a vector load that's to normal memory we > have no way to detect that it's spurious (unless we walk the page > tables, which is very expensive). In this case we emulate the load but > we need do so using a vector load itself to ensure 128bit atomicity is > preserved. > > Some additional debugfs emulated instruction counters are added also. > > Signed-off-by: Michael Neuling <mi...@neuling.org> > Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Patch 1 applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/5080332c2c893118dbc18755f35c8b cheers
