Re: [PATCH v5 3/5] riscv: Separate memory init from paging init

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Atish Patra <atish.patra@wdc.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Greentime Hu <greentime.hu@sifive.com>,
	Anup Patel <anup@brainfault.org>,
	Palmer Dabbelt <palmerdabbelt@google.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Anshuman Khandual <anshuman.khandual@arm.com>,
	Ard Biesheuvel <ardb@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	Baoquan He <bhe@redhat.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Linux-Arch <linux-arch@vger.kernel.org>,
	linux-riscv <linux-riscv@lists.infradead.org>,
	Mike Rapoport <rppt@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Steven Price <steven.price@arm.com>,
	Will Deacon <will@kernel.org>,
	Zhengyuan Liu <liuzhengyuan@tj.kylinos.cn>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v5 3/5] riscv: Separate memory init from paging init
Date: Wed, 10 Mar 2021 17:41:07 +0100	[thread overview]
Message-ID: <CAMuHMdUjh9znKTLZ+bST6aDUFdZzvmv2SGVy=sRQ6+D=pYM9cg@mail.gmail.com> (raw)
In-Reply-To: <20201119003829.1282810-4-atish.patra@wdc.com>

Hi Atish,

On Thu, Nov 19, 2020 at 1:40 AM Atish Patra <atish.patra@wdc.com> wrote:
> Currently, we perform some memory init functions in paging init. But,
> that will be an issue for NUMA support where DT needs to be flattened
> before numa initialization and memblock_present can only be called
> after numa initialization.
>
> Move memory initialization related functions to a separate function.
>
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
> Reviewed-by: Anup Patel <anup@brainfault.org>
> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>

This is now commit cbd34f4bb37d62d8 in v5.12-rc1, breaking the boot on
Vexriscv:

[    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
[    0.000000] printk: bootconsole [sbi0] enabled
[    0.000000] printk: debug: ignoring loglevel setting.
[    0.000000] Initial ramdisk at: 0x(ptrval) (8388608 bytes)
[    0.000000] Unable to handle kernel paging request at virtual
address c8000008
[    0.000000] Oops [#1]
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted
5.11.0-orangecrab-00023-g7c4fc8e3e982 #129
[    0.000000] epc: c04d6624 ra : c04d6524 sp : c05ddf70
[    0.000000]  gp : c0678bc0 tp : c05e5b40 t0 : c8000000
[    0.000000]  t1 : 00030000 t2 : ffffffff s0 : c05ddfc0
[    0.000000]  s1 : c8000000 a0 : 00000000 a1 : c7ffffe0
[    0.000000]  a2 : 00000005 a3 : 00000001 a4 : 0000000c
[    0.000000]  a5 : 00000000 a6 : c04fe000 a7 : 0000000c
[    0.000000]  s2 : c04fe098 s3 : 000000a0 s4 : c7ffff60
[    0.000000]  s5 : c04fe0dc s6 : 80000200 s7 : c059f19c
[    0.000000]  s8 : 81000200 s9 : c059f1b8 s10: 80000200
[    0.000000]  s11: c059f19c t3 : 405dba80 t4 : c05e6f08
[    0.000000]  t5 : 81000200 t6 : 40501000
[    0.000000] status: 00000100 badaddr: c8000008 cause: 0000000f
[    0.000000] random: get_random_bytes called from
print_oops_end_marker+0x38/0x7c with crng_init=0
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!

Note that I have "[PATCH v2 3/4] RISC-V: Fix L1_CACHE_BYTES for RV32"[1]
applied, to avoid another crash (7c4fc8e3e982 = v5.11 + [1] +
cherry-picked commits from the riscv-for-linus-5.12-mw0 pull request).

If I revert the L1_CACHE_BYTES change, the boot continues, but I'm back
to the old issue fixed by [1]:

[   22.126687] Freeing initrd memory: 8192K
[   22.321811] workingset: timestamp_bits=30 max_order=15 bucket_order=0
[   29.001509] Block layer SCSI generic (bsg) driver version 0.4
loaded (major 253)
[   29.021555] io scheduler mq-deadline registered
[   29.033692] io scheduler kyber registered
[   29.141294] Unable to handle kernel paging request at virtual
address 69726573
[   29.158523] Oops [#1]
[   29.162232] CPU: 0 PID: 1 Comm: swapper Not tainted
5.11.0-orangecrab-00023-g7c4fc8e3e982-dirty #132
[   29.171970] epc: c000d3b0 ra : c000eb74 sp : c182dca0
[   29.178786]  gp : c067aee0 tp : c1830000 t0 : c18d75e0
[   29.185935]  t1 : 00030000 t2 : 00000000 s0 : c182dcb0
[   29.193028]  s1 : 00000000 a0 : c05eab14 a1 : c18d75c0
[   29.200067]  a2 : c7ffe384 a3 : 69726573 a4 : f000000b
[   29.207095]  a5 : f0000000 a6 : c7fffff8 a7 : 00000000
[   29.214141]  s2 : 01001f00 s3 : c05eb000 s4 : c067c000
[   29.221171]  s5 : c000ec0c s6 : 80000000 s7 : c05eaad4
[   29.228200]  s8 : c05eab58 s9 : c05a1000 s10: c18d75c0
[   29.235238]  s11: c05eab14 t3 : 20b9a6cc t4 : 00000001
[   29.242277]  t5 : 00000000 t6 : c188cd50
[   29.247588] status: 00000120 badaddr: 69726573 cause: 0000000d
[   29.274424] ---[ end trace 69dee1b9ca96f1d6 ]---
[   29.282859] note: swapper[1] exited with preempt_count 1
[   29.293156] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x0000000b

[1] https://lore.kernel.org/linux-riscv/20210111234504.3782179-4-atish.patra@wdc.com/

Will have a deeper look later...

Thanks for any suggestions!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds