From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen-Yu Tsai Date: Fri, 23 Jun 2017 21:50:42 +0800 Subject: [U-Boot] [linux-sunxi] [RFC PATCH 8/8] sunxi: enable PSCI for A83T SoC In-Reply-To: <27424350c4a34d9a76c404ee61e5c55e@aosc.io> References: <20170607004721.24194-9-icenowy@aosc.io> <20170607065036.rlv5oif2majhxi7s@flea.lan> <40F87103-B0D5-47C0-BE60-59B84CC261F6@aosc.io> <9c72276f-5523-872d-9f69-22400ac51a11@arm.com> <20170623133552.opmdhtlvcljh53t5@flea.lan> <27424350c4a34d9a76c404ee61e5c55e@aosc.io> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: u-boot@lists.denx.de On Fri, Jun 23, 2017 at 9:39 PM, wrote: > 在 2017-06-23 21:35，Maxime Ripard 写道： >> >> On Fri, Jun 23, 2017 at 09:24:25PM +0800, icenowy at aosc.io wrote: >>> >>> 在 2017-06-07 20:51，Marc Zyngier 写道： >>> > On 07/06/17 13:12, Icenowy Zheng wrote: >>> > > >>> > > >>> > > 于 2017年6月7日 GMT+08:00 下午8:11:12, Marc Zyngier >>> > > 写到: >>> > > > On 07/06/17 08:00, Chen-Yu Tsai wrote: >>> > > > > On Wed, Jun 7, 2017 at 2:50 PM, Maxime Ripard >>> > > > > wrote: >>> > > > > > On Wed, Jun 07, 2017 at 11:47:24AM +0800, Chen-Yu Tsai wrote: >>> > > > > > > On Wed, Jun 7, 2017 at 11:40 AM, Icenowy Zheng >>> > > > > > > >>> > > > wrote: >>> > > > > > > > >>> > > > > > > > >>> > > > > > > > 于 2017年6月7日 GMT+08:00 上午11:36:27, Chen-Yu >>> > > > > > > > Tsai 写到: >>> > > > > > > > > On Wed, Jun 7, 2017 at 8:47 AM, Icenowy Zheng >>> > > > > > > > > >>> > > > wrote: >>> > > > > > > > > > As we have now a basical implementation >>> > > > > > > > > > of PSCI for A83T, enable >>> > > > > > > > > > non-secure boot support and PSCI on A83T now. >>> > > > > > > > > > >>> > > > > > > > > > Signed-off-by: Icenowy Zheng >>> > > > > > > > > > --- >>> > > > > > > > > > arch/arm/mach-sunxi/Kconfig | 4 ++++ >>> > > > > > > > > > 1 file changed, 4 insertions(+) >>> > > > > > > > > > >>> > > > > > > > > > diff --git a/arch/arm/mach-sunxi/Kconfig >>> > > > > > > > > b/arch/arm/mach-sunxi/Kconfig >>> > > > > > > > > > index 7ced838d6a..31d29de428 100644 >>> > > > > > > > > > --- a/arch/arm/mach-sunxi/Kconfig >>> > > > > > > > > > +++ b/arch/arm/mach-sunxi/Kconfig >>> > > > > > > > > > @@ -98,8 +98,12 @@ config MACH_SUN8I_A33 >>> > > > > > > > > > config MACH_SUN8I_A83T >>> > > > > > > > > > bool "sun8i (Allwinner A83T)" >>> > > > > > > > > > select CPU_V7 >>> > > > > > > > > > + select CPU_V7_HAS_NONSEC >>> > > > > > > > > > + select CPU_V7_HAS_VIRT >>> > > > > > > > > > + select ARCH_SUPPORT_PSCI >>> > > > > > > > > > select SUNXI_GEN_SUN6I >>> > > > > > > > > > select SUPPORT_SPL >>> > > > > > > > > > + select ARMV7_BOOT_SEC_DEFAULT if >>> > > > > > > > > > OLD_SUNXI_KERNEL_COMPAT >>> > > > > > > > > >>> > > > > > > > > The kernel does not work yet. Please have it boot to >>> > > > > > > > > secure by >>> > > > default >>> > > > > > > > > regardless of the kernel. We can have it >>> > > > > > > > > boot non-secure once the >>> > > > > > > > > kernel >>> > > > > > > > > has been working for a reasonable amount of time. >>> > > > > > > > > >>> > > > > > > > > I don't want clueless users coming and asking why it >>> > > > > > > > > suddenly >>> > > > stopped >>> > > > > > > > > working. This should be an experimental feature. >>> > > > > > > > >>> > > > > > > > Maybe you should send out the fix, and tag them to also >>> > > > > > > > apply to >>> > > > > > > > stable tree. >>> > > > > > > > >>> > > > > > > > GIC is really broken, UP systems only work by chance. We >>> > > > > > > > shouldn't depend on this behavior. >>> > > > > > > >>> > > > > > > As I previously explained, it is not the GIC that is broken. >>> > > > > > > I >>> > > > believe >>> > > > > > > the GIC is working exactly as it is supposed to with >>> > > > > > > regards to its >>> > > > > > > input signals. >>> > > > > > > >>> > > > > > > Allwinner's security extensions implementation simply does >>> > > > > > > not >>> > > > properly >>> > > > > > > forward the AXI secure bit when the e-fuse's secure bit isn't >>> > > > burned. >>> > > > >>> > > > Arghh. Puke. Now I remember this, and I wish I didn't... >>> > > > >>> > > > > > Is that on all revisions, or just the revB ? >>> > > > > >>> > > > > It's the A80, but I'm guessing the same applies to the A83T. It's >>> > > > more >>> > > > > of a guess really, but I think it's a logical one. If the e-fuse >>> > > > isn't >>> > > > > programmed, the TZPC doesn't work, and access to all secure >>> > > > peripherals >>> > > > > still work, even from non-secure mode. The only one that >>> > > > > does work is >>> > > > > the secure SRAM. >>> > > > > >>> > > > > The GIC still has the banked secure/non-secure registers, just >>> > > > > that >>> > > > all >>> > > > > cores access the secure bank, even when in non-secure mode. The >>> > > > workaround >>> > > > > is to use the alias set of non-secure registers in Linux. >>> > > > >>> > > > That's a pretty dire workaround. Also, I expect that secure writes >>> > > > to >>> > > > GICV/GICH will not do the right thing. At this point, what is the >>> > > > requirement for running non-secure? >>> > > >>> > > Write Secure Boot eFUSE, which will break *all* existing softwares. >>> > >>> > Don't do it, then. >>> > >>> > Any other *real* use case for running non-secure? As in "Stuff that >>> > would benefit to a user"? Because if the answer is "none" as I suspect >>> > it is, you might as well keep the system in secure mode. >>> >>> Maybe we should then use legacy SMP bringup method (code in kernel) >>> rather than PSCI? >> >> >> I guess it all depends on the answer to Marc's question. If >> virtualization doesn't work, then we don't have any incentive anymore >> to use PSCI and that would be a sensible option, yes. > > > I remember non-secure is a dependency for virtualization (HYP mode). > > So if we do not do the workaround on GIC, we won't have stable > non-secure, then we won't have HYP mode, then we can drop PSCI. I think you got it the other way around. If virtualization doesn't work, despite the workaround, then there's no need for it, and we can just do legacy SMP. ChenYu