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From: =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn@kernel.org>
To: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>, David Hildenbrand <david@redhat.com>,
 Palmer Dabbelt <palmer@dabbelt.com>, Paul Walmsley
 <paul.walmsley@sifive.com>, linux-riscv@lists.infradead.org,
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 <bjorn@rivosinc.com>, Andrew Bresticker <abrestic@rivosinc.com>, Chethan
 Seshadri <Chethan.Seshadri@catalinasystems.io>, Lorenzo Stoakes
 <lstoakes@gmail.com>, Oscar Salvador <osalvador@suse.de>, Santosh Mamila
 <santosh.mamila@catalinasystems.io>, Sivakumar Munnangi
 <siva.munnangi@catalinasystems.io>, Sunil V L <sunilvl@ventanamicro.com>,
 linux-kernel@vger.kernel.org, linux-mm@kvack.org,
 virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v2 4/8] riscv: mm: Add memory hotplugging support
In-Reply-To: <CAHVXubh8VpOmFqXrAN+G_Om-+6VjfeEyTRAFp8EWae3mFgjB=Q@mail.gmail.com>
References: <20240514140446.538622-1-bjorn@kernel.org>
 <20240514140446.538622-5-bjorn@kernel.org>
 <CAHVXubh8VpOmFqXrAN+G_Om-+6VjfeEyTRAFp8EWae3mFgjB=Q@mail.gmail.com>
Date: Tue, 14 May 2024 21:31:38 +0200
Message-ID: <87eda442cl.fsf@all.your.base.are.belong.to.us>
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Alexandre Ghiti <alexghiti@rivosinc.com> writes:

> On Tue, May 14, 2024 at 4:05=E2=80=AFPM Bj=C3=B6rn T=C3=B6pel <bjorn@kern=
el.org> wrote:

>> +int __ref arch_add_memory(int nid, u64 start, u64 size, struct mhp_para=
ms *params)
>> +{
>> +       int ret;
>> +
>> +       create_linear_mapping_range(start, start + size, 0, &params->pgp=
rot);
>> +       flush_tlb_all();
>> +       ret =3D __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT=
, params);
>> +       if (ret) {
>> +               remove_linear_mapping(start, size);
>> +               return ret;
>> +       }
>> +
>
> You need to flush the TLB here too since __add_pages() populates the
> page table with the new vmemmap mapping (only because riscv allows to
> cache invalid entries, I'll adapt this in my next version of Svvptc
> support).
>
>> +       max_pfn =3D PFN_UP(start + size);
>> +       max_low_pfn =3D max_pfn;
>> +       return 0;
>> +}
>> +
>> +void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *=
altmap)
>> +{
>> +       __remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, altmap);
>> +       remove_linear_mapping(start, size);
>
> You need to flush the TLB here too.

I'll address all of the above in the next version. Thanks for reviewing
the series!


Bj=C3=B6rn