Re: [PATCH v2 1/1] arm64: dts: marvell: armada-ap806: reserve PSCI area

[Emmanuel Vadot]

 Hello all,

 Sorry I forgot to answer this email.

On Wed, 26 Dec 2018 18:09:04 +0100
Heinrich Schuchardt <xypron.glpk@xxxxxx> wrote:

> On 12/26/18 5:16 PM, Gregory CLEMENT wrote:
> > Hi Heinrich,
> >  
> >  On ven., déc. 21 2018, Heinrich Schuchardt <xypron.glpk@xxxxxx> wrote:
> > 
> >> The memory area [0x4000000-0x4200000[ is occupied by the PSCI firmware. Any
> >> attempt to access it from Linux leads to an immediate crash.
> >>
> >> So let's make the same memory reservation as the vendor kernel.
> >>
> >> Signed-off-by: Heinrich Schuchardt <xypron.glpk@xxxxxx>
> > 
> > We got a similar patch one month ago and Russell King pointed that it
> > didn't match waht he saw on his MACCHIATObin:
> > http://lists.infradead.org/pipermail/linux-arm-kernel/2018-November/612360.html
> > 
> > on mine under U-Boot I got:
> > 
> > Marvell>> md 0x4000000
> > 04000000: 00000000 00000007 00000005 00000040    ............@...
> > 04000010: 00000001 00001000 00000007 00000001    ................
> > 04000020: 00000008 00000000 00000009 00000000    ................
> > 04000030: 0000000a 00000000 ffffffff ffffffff    ................
> > 04000040: ffffffff ffffffff ffffffff ffffffff    ................
> > 04000050: ffffffff ffffffff ffffffff ffffffff    ................
> > 04000060: ffffffff ffffffff ffffffff ffffffff    ................
> > 04000070: ffffffff ffffffff ffffffff ffffffff    ................
> > 04000080: ffffffff ffffffff ffffffff ffffffff    ................
> > 04000090: ffffffff ffffffff ffffffff ffffffff    ................
> > 040000a0: ffffffff ffffffff ffffffff ffffffff    ................
> > 040000b0: ffffffff ffffffff ffffffff ffffffff    ................
> > 040000c0: ffffffff ffffffff ffffffff ffffffff    ................
> > 040000d0: ffffffff ffffffff ffffffff ffffffff    ................
> > 040000e0: ffffffff ffffffff ffffffff ffffffff    ................
> > 040000f0: ffffffff ffffffff ffffffff ffffffff    ................
> > 
> > In my case I have an old ATF, however this kind of setting should be
> > done by the bootloader.
> > 
> > I am interested by your claim about causing an immediate crash when
> > accessing this region. How did you trigger it?
> > 
> > Gregory
> 
> Hello Gregory,
> 
> judging from you U-Boot prompt you are not using mainline U-Boot. With
> the legacy Marvell U-Boot I get the same output as you provide above.
> But you are looking in the wrong place to confirm that this is ATF:
> 
> Marvell>> md 04017200
> 04017200: 616d6920 74206567 5043206f 474d2031     image to CP1 MG
> 04017210: 746f6e20 70757320 74726f70 000a6465     not supported..
> 04017220: 4f525245 20203a52 50435320 324c425f    ERROR:   SCP_BL2
> 04017230: 6f727720 6920676e 6620676d 616d726f     wrong img forma
> 04017240: 63282074 745f336d 3d657079 0a296425    t (cm3_type=%d).
> 04017250: 544f4e00 3a454349 43532020 6d492050    .NOTICE:  SCP Im
> 04017260: 20656761 73656f64 2074276e 746e6f63    age doesn't cont
> 04017270: 206e6961 66204d50 776d7269 0a657261    ain PM firmware.
> 04017280: 00000000 00000000 040144d0 00000000    .........D......
> 04017290: 00000001 00000019 4f525245 20203a52    ........ERROR:
> 040172a0: 6e695720 20776f64 203a6425 65736162     Window %d: base
> 040172b0: 64646120 73736572 616e7520 6e67696c     address unalign
> 040172c0: 74206465 7830206f 000a7825 67696c41    ed to 0x%x..Alig
> 040172d0: 7075206e 65687420 73616220 64612065    n up the base ad
> 040172e0: 73657264 6f742073 25783020 000a786c    dress to 0x%lx..
> 040172f0: 4f525245 20203a52 6e695720 20776f64    ERROR:   Window

 I do confirm what Heinrich is saying, this is needed (and made for)
mainline U-Boot.

> Possibly the legacy Marvell U-Boot is running at exception level 3
> (EL3). This would explain why you cannot reproduce the crash with that
> U-Boot.
> 
> The legacy Marvell U-Boot is in bad shape: their booti command cannot
> load the initrd.img created by Debian. This is why I use mainline
> U-Boot. Here you can find my recipe:

 I personnaly uses mainline U-Boot because the efi part is too old and
buggy on Marvell fork.

> https://github.com/xypron/u-boot-build/blob/macchiatobin/Makefile (for
> U-Boot v2018.11)
> 
> When I issue the md command for the region in mainline U-Boot  I get a
> crash:
> 
> => md 0x4000000
> 
> 
> 04000000:"Synchronous Abort" handler, esr 0x96000210
> 
> 
> elr: 000000000006b878 lr : 000000000006b7f4 (reloc)
> 
> 
> elr: 000000007ff8b878 lr : 000000007ff8b7f4
> 
> 
> x0 : 0000000000000009 x1 : 0000000000000000
> 
> 
> x2 : 000000000000003a x3 : 0000000004000000
> 
> 
> x4 : 0000000000000000 x5 : 000000007ffae306
> 
> 
> x6 : 0000000000000004 x7 : 000000007fb0a1e0
> 
> 
> x8 : 000000007fb0a0a0 x9 : 0000000000000008
> 
> 
> x10: 00000000ffffffd0 x11: 0000000000000006
> 
> 
> x12: 000000000001869f x13: 000000000000440c
> 
> 
> x14: 000000007fb0a43c x15: 0000000000000008
> 
> 
> x16: 000000007ffb49ea x17: 000000007ffb49ea
> 
> 
> x18: 000000007fb0fdd8 x19: 0000000000000040
> 
> 
> x20: 0000000004000000 x21: 0000000004000000
> 
> 
> x22: 000000007ffacff1 x23: 0000000000000008
> 
> 
> x24: 0000000000000004 x25: 0000000000000004
> 
> 
> x26: 0000000000000004 x27: 000000007fb0a268
> 
> 
> x28: 0000000000000000 x29: 000000007fb0a1e0
> 
> 
> 
> Resetting CPU ...
> 
> In Linux 4.20 without my patch I regularly experience crashes like the
> one below. With the patch I never experience such a crash.

 For me this is 100% reproducible with the FreeBSD kernel, not the same
kind of crash but a hang as soon as we try to call PSCI/SMCCC functions.

 I don't care personnaly which patch is taken as long as it's applied.

 Cheers,

-- 
Emmanuel Vadot <manu@xxxxxxxxxxxxxxxx> <manu@xxxxxxxxxxx>