Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D1D8C433EF for ; Tue, 11 Jan 2022 16:15:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349870AbiAKQPB (ORCPT ); Tue, 11 Jan 2022 11:15:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349828AbiAKQPA (ORCPT ); Tue, 11 Jan 2022 11:15:00 -0500 X-Greylist: delayed 115851 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 11 Jan 2022 08:15:00 PST Received: from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11D97C06173F for ; Tue, 11 Jan 2022 08:14:59 -0800 (PST) Received: (Authenticated sender: alex@ghiti.fr) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 849BB20003; Tue, 11 Jan 2022 16:14:52 +0000 (UTC) Message-ID: Date: Tue, 11 Jan 2022 17:14:52 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.1 Subject: Re: [PATCH 02/12] RISC-V: MAXPHYSMEM_2GB doesn't depend on CMODEL_MEDLOW Content-Language: en-US To: Geert Uytterhoeven , Palmer Dabbelt Cc: linux-riscv , Paul Walmsley , Palmer Dabbelt , Albert Ou , Anup Patel , heinrich.schuchardt@canonical.com, Atish Patra , Bin Meng , Sagar Kadam , Damien Le Moal , Jens Axboe , Linux Kernel Mailing List , stable References: <20211119164413.29052-1-palmer@rivosinc.com> <20211119164413.29052-3-palmer@rivosinc.com> From: Alexandre ghiti In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Geert, On 1/11/22 17:04, Geert Uytterhoeven wrote: > Hi Palmer, > > On Fri, Nov 19, 2021 at 5:47 PM Palmer Dabbelt wrote: >> From: Palmer Dabbelt >> >> For non-relocatable kernels we need to be able to link the kernel at >> approximately PAGE_OFFSET, thus requiring medany (as medlow requires the >> code to be linked within 2GiB of 0). The inverse doesn't apply, though: >> since medany code can be linked anywhere it's fine to link it close to >> 0, so we can support the smaller memory config. >> >> Fixes: de5f4b8f634b ("RISC-V: Define MAXPHYSMEM_1GB only for RV32") >> Cc: stable@vger.kernel.org >> Signed-off-by: Palmer Dabbelt > Thanks for your patch, which is now commit 9f36b96bc70f9707 ("RISC-V: > MAXPHYSMEM_2GB doesn't depend on CMODEL_MEDLOW"). > >> I found this when going through the savedefconfig diffs for the K210 >> defconfigs. I'm not entirely sure they're doing the right thing here >> (they should probably be setting CMODEL_LOW to take advantage of the >> better code generation), but I don't have any way to test those >> platforms so I don't want to change too much. > I can confirm MAXPHYSMEM_2GB works on K210 with CMODEL_MEDANY. > > As the Icicle has 1760 MiB of RAM, I gave it a try with MAXPHYSMEM_2GB > (and CMODEL_MEDANY), too. Unfortunately it crashes very early > (needs earlycon to see): > > OF: fdt: Ignoring memory range 0x80000000 - 0x80200000 > Machine model: Microchip PolarFire-SoC Icicle Kit > printk: debug: ignoring loglevel setting. > earlycon: ns16550a0 at MMIO32 0x0000000020100000 (options '115200n8') > printk: bootconsole [ns16550a0] enabled > printk: debug: skip boot console de-registration. > efi: UEFI not found. > Unable to handle kernel paging request at virtual address ffffffff87e00001 > Oops [#1] > Modules linked in: > CPU: 0 PID: 0 Comm: swapper Not tainted 5.16.0-08771-g85515233477d #56 > Hardware name: Microchip PolarFire-SoC Icicle Kit (DT) > epc : fdt_check_header+0x14/0x208 > ra : early_init_dt_verify+0x16/0x94 > epc : ffffffff802ddacc ra : ffffffff8082415a sp : ffffffff81203ee0 > gp : ffffffff812ec3a8 tp : ffffffff8120cd80 t0 : 0000000000000005 > t1 : 0000001040000000 t2 : ffffffff80000000 s0 : ffffffff81203f00 > s1 : ffffffff87e00000 a0 : ffffffff87e00000 a1 : 000000040ffffce7 > a2 : 00000000000000e7 a3 : ffffffff8080394c a4 : 0000000000000000 > a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000 > s2 : ffffffff81203f98 s3 : 8000000a00006800 s4 : fffffffffffffff3 > s5 : 0000000000000000 s6 : 0000000000000001 s7 : 0000000000000000 > s8 : 0000000020236c20 s9 : 0000000000000000 s10: 0000000000000000 > s11: 0000000000000000 t3 : 0000000000000018 t4 : 00ff000000000000 > t5 : 0000000000000000 t6 : 0000000000000010 > status: 0000000200000100 badaddr: ffffffff87e00001 cause: 000000000000000d > [] fdt_check_header+0x14/0x208 > [] early_init_dt_verify+0x16/0x94 > [] setup_arch+0xec/0x4ec > [] start_kernel+0x88/0x6d6 > random: get_random_bytes called from > print_oops_end_marker+0x22/0x44 with crng_init=0 > ---[ end trace 903df1a0ade0b876 ]--- > Kernel panic - not syncing: Attempted to kill the idle task! > ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]--- > > So the FDT is at 0xffffffff87e00000, i.e. at 0x7e00000 from the start > of virtual memory (CONFIG_PAGE_OFFSET=0xffffffff80000000), and thus > within the 2 GiB range. I think you have just encountered what I suspected and mentioned in [1]: we recently moved the kernel to the PAGE_OFFSET address used with MAXPHYSMEM_2GB. I would try to cherry-pick [1] and see if that works better :) Alex [1] https://patchwork.kernel.org/project/linux-riscv/patch/20211206104657.433304-6-alexandre.ghiti@canonical.com/ > >> --- a/arch/riscv/Kconfig >> +++ b/arch/riscv/Kconfig >> @@ -280,7 +280,7 @@ choice >> depends on 32BIT >> bool "1GiB" >> config MAXPHYSMEM_2GB >> - depends on 64BIT && CMODEL_MEDLOW >> + depends on 64BIT >> bool "2GiB" >> config MAXPHYSMEM_128GB >> depends on 64BIT && CMODEL_MEDANY > 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 > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv