On Sunday 22 November 2015 13:29:29 Peter Maydell wrote: > On 21 November 2015 at 23:21, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > Regarding PJ4, it's still unclear whether that has the same > > problem and it only reports idivt when it actually supports idiva, > > or whether the lack of idiva support on PJ4 is instead the reason > > why the ARM ARM was updated to have separate flags. > > SDIV/IDIV were originally introduced for R and M profile only > and there the Thumb encodings of SDIV/IDIV are mandatory > whereas the ARM ones are optional (and weren't initially > defined at all). So if you're looking for CPUs with only the > Thumb encodings I would try checking older R profile cores > like the Cortex-R4. The question is really about Marvell Dove, MMP and Armada 370, which are all based on PJ4 or PJ4B (CPU part : 0x581), so ARMv7-A and report idivt support but idiva. There are a couple of explanations here: a) Marvell really implemented only idivt but not idiva and reports it correctly, and the people from https://groups.google.com/a/dartlang.org/forum/#!topic/reviews/9wvsJvq0YYY just misinterpreted the flags b) the dartlag.org folks are correct, and it supports neither idivt nor idiva, and the /proc/cpuinfo flag is just wrong and requires a fixup c) like Krait, it actually implements both idiva and idivt but gets the reporting wrong. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
