Messages in this thread | | | From | Alexandre Ghiti <> | Date | Tue, 31 Jan 2023 09:19:08 +0100 | Subject | Re: [PATCH v3 3/4] RISC-V: mm: Enable huge page support to kernel_page_present() function |
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Hi,
On Mon, Jan 30, 2023 at 10:57 PM Conor Dooley <conor@kernel.org> wrote: > > +CC Alex > > On Fri, Jan 27, 2023 at 05:10:50PM +0800, Sia Jee Heng wrote: > > Currently kernel_page_present() function doesn't support huge page > > detection causes the function to mistakenly return false to the > > hibernation core. > > This sounds like a bug & should have a fixes tag, no? I assume for > whatever commit enabled huge page support... > We don't support set_memory, which by the looks of things is the other > usecase for this function, so probably doesn't need backporting.
Maybe add this patch in the Fixes tag: commit 9e953cda5cdf ("riscv: Introduce huge page support for 32/64bit kernel").
> > Alex, does this change look good to you?
Yes, just one thing though: what about a pgd_leaf() test? Even if very unlikely (I see x86 does not even test it), the privileged spec states it is possible to have a 256TB page.
Thanks,
Alex
> > > Add huge page detection to the function to solve the problem. > > > > Signed-off-by: Sia Jee Heng <jeeheng.sia@starfivetech.com> > > Reviewed-by: Ley Foon Tan <leyfoon.tan@starfivetech.com> > > Reviewed-by: Mason Huo <mason.huo@starfivetech.com> > > --- > > arch/riscv/mm/pageattr.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c > > index 86c56616e5de..792b8d10cdfc 100644 > > --- a/arch/riscv/mm/pageattr.c > > +++ b/arch/riscv/mm/pageattr.c > > @@ -221,14 +221,20 @@ bool kernel_page_present(struct page *page) > > p4d = p4d_offset(pgd, addr); > > if (!p4d_present(*p4d)) > > return false; > > + if (p4d_leaf(*p4d)) > > + return true; > > > > pud = pud_offset(p4d, addr); > > if (!pud_present(*pud)) > > return false; > > + if (pud_leaf(*pud)) > > + return true; > > > > pmd = pmd_offset(pud, addr); > > if (!pmd_present(*pmd)) > > return false; > > + if (pmd_leaf(*pmd)) > > + return true; > > > > pte = pte_offset_kernel(pmd, addr); > > return pte_present(*pte); > > -- > > 2.34.1 > >
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