| Message ID | 1409336145-619-4-git-send-email-ulrich.hecht+renesas@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
Hi Ulrich, On Sat, Aug 30, 2014 at 3:15 AM, Ulrich Hecht <ulrich.hecht+renesas@gmail.com> wrote: > From: Hisashi Nakamura <hisashi.nakamura.ak@renesas.com> > > In case of CA7, arch timer CNTVOFF register is uninitialized. > CNTVOFF must be initialized. This patch is for secondary CPUs. > > Signed-off-by: Hisashi Nakamura <hisashi.nakamura.ak@renesas.com> > --- > arch/arm/mach-shmobile/headsmp.S | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) Thanks for the patch. It looks like the CPU core variant is being run-time detected, if so it would be nice with a comment in the code about that. If not then we should do some kind of detection. In my opinion this kind of detection is mainly needed on r8a7790 since it has both CA15 and CA7. On r8a7794 with only CA7 I assume we can provide a boot reset vector for this case that is shared with r8a7790 and performs run-time detection and applies the arch timer setup when needed. The other SMP platforms can simply use a different boot reset vector to not having to deal with this detection. This makes me wonder how the boot CPU is supposed to be handled? I believe it is somehow related to CPU Hotplug as well. Because of that this is all dependent on SMP. Did you try this code on r8a7790 Lager in little boot mode? It would be great to see how it works there. Let's discuss more offline. Cheers, / magnus -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/mach-shmobile/headsmp.S b/arch/arm/mach-shmobile/headsmp.S index 50c4915..9dc660d 100644 --- a/arch/arm/mach-shmobile/headsmp.S +++ b/arch/arm/mach-shmobile/headsmp.S @@ -1,6 +1,7 @@ /* * SMP support for R-Mobile / SH-Mobile * + * Copyright (C) 2014 Renesas Electronics Corporation * Copyright (C) 2010 Magnus Damm * Copyright (C) 2010 Takashi Yoshii * @@ -19,6 +20,31 @@ #ifdef CONFIG_SMP ENTRY(shmobile_invalidate_start) bl v7_invalidate_l1 + + mrc p15, 0, r0, c0, c0, 0 + lsr r0, #4 + tst r0, #0x7 + beq 1f + lsr r0, #4 + tst r0, #0xC0 + beq 1f + /* CA7 setup */ + /* CNTVOFF has to be initialized either from non-secure Hypervisor + * mode or secure Monitor mode with SCR.NS==1. If TrustZone is enabled + * then it should be handled by the secure code */ + cps 0x16 + mrc p15, 0, r1, c1, c1, 0 + orr r0, r1, #1 + mcr p15, 0, r0, c1, c1, 0 + isb + mov r0, #0 + mcrr p15, 4, r0, r0, c14 + isb + mcr p15, 0, r1, c1, c1, 0 + isb + cps 0x13 +1: + b secondary_startup ENDPROC(shmobile_invalidate_start) #endif