[GIT PULL] RISC-V Patches for the 5.19 Merge Window, Part 1

[Ron Economos]

On 6/7/22 4:36 PM, Heiko Stübner wrote:
> Hi Ron,
>
> Am Dienstag, 7. Juni 2022, 22:46:52 CEST schrieb Ron Economos:
>> On 5/31/22 10:13 AM, Palmer Dabbelt wrote:
>>> The following changes since commit 9282d0996936c5fbf877c0d096a3feb456c878ad:
>>>
>>>     csky: Move to generic ticket-spinlock (2022-05-11 11:50:15 -0700)
>>>
>>> are available in the Git repository at:
>>>
>>>     git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git tags/riscv-for-linus-5.19-mw0
>>>
>>> for you to fetch changes up to 7699f7aacf3ebfee51c670b6f796b2797f0f7487:
>>>
>>>     RISC-V: Prepare dropping week attribute from arch_kexec_apply_relocations[_add] (2022-05-30 16:04:37 -0700)
>>>
>>> ----------------------------------------------------------------
>>> RISC-V Patches for the 5.19 Merge Window, Part 1
>>>
>>> * Support for the Svpbmt extension, which allows memory attributes to be
>>>     encoded in pages.
>>>
>>>
>>> Heiko Stuebner (12):
>>>         riscv: integrate alternatives better into the main architecture
>>>         riscv: allow different stages with alternatives
>>>         riscv: implement module alternatives
>>>         riscv: implement ALTERNATIVE_2 macro
>>>         riscv: extend concatenated alternatives-lines to the same length
>>>         riscv: prevent compressed instructions in alternatives
>>>         riscv: move boot alternatives to after fill_hwcap
>>>         riscv: Fix accessing pfn bits in PTEs for non-32bit variants
>>>         riscv: add RISC-V Svpbmt extension support
>>>         riscv: remove FIXMAP_PAGE_IO and fall back to its default value
>>>         riscv: don't use global static vars to store alternative data
>>>         riscv: add memory-type errata for T-Head
>>>
>> An issue was found on the HiFive Unmatched with the 5.19-rc1 kernel. The
>> following warning occurs during boot:
>>
>> riscv64 kernel:
>> ----------------------------------------------------------------
>> riscv64 kernel: WARNING: Missing the following errata may cause
>> potential issues
>> riscv64 kernel:         SiFive Errata[0]:cip-453
>> riscv64 kernel:         SiFive Errata[1]:cip-1200
>> riscv64 kernel: Please enable the corresponding Kconfig to apply them
>> riscv64 kernel:
>> ----------------------------------------------------------------
>>
>> I've manually bisected the problem to this commit:
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ff689fd21cb13098305bae3f8d0c0065df2e2fc1
> hmm, on first glance I can't really see how that specific commit would
> affect Sifive erratas. Patches directly before this one did change
> alternative / errata things though.
>
> (1) From looking at your output, it seems at least CONFIG_ERRATA_SIFIVE
> is enabled as the general sifive errata code is running, but are the
> individual erratas also still enabled in your config?
> They're default=y forever and weren't touched by the svpbmt series,
> but it'd be nice to know how the config looks, to see if the Kconfig
> settings are strange somewhere
>
>
> (2) Going from the list on
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?h=ff689fd21cb13098305bae3f8d0c0065df2e2fc1
>
> could you maybe check if it's really working with the parent of the
> commit you found. (i.e. patches before the svpbmt addition).
>
> Also just to be sure, it still works correctly with 5.18, right?
>
>
> Thanks
> Heiko
>
>
Yes, that commit was surprising. I also thought it would have been one 
of the previous "alternatives" commits. But I tested them all, and the 
warning only appears with the "add RISC-V Svpbmt extension support" 
commit. In other words, "git checkout 100631b" works fine, but "git 
checkout ff689fd" does not.

I have these settings in my .config:

CONFIG_ERRATA_SIFIVE=y
CONFIG_ERRATA_SIFIVE_CIP_453=y
CONFIG_ERRATA_SIFIVE_CIP_1200=y

CONFIG_RISCV_ALTERNATIVE=y

I've uploaded the complete .config file here:

https://www.w6rz.net/config-5.19-rc1

It's based on a modified version of the Ubuntu 22.04 config file.

Linux 5.18 (including 5.18.2) is fine (with the same .config).

You can also find me on irc.libera.chat #riscv with nick drmpeg.

Ron