Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 20 Jul 2021 12:16:17 +0100 | From | Quentin Perret <> | Subject | Re: [PATCH 15/16] arm64: Add a helper to retrieve the PTE of a fixmap |
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On Thursday 15 Jul 2021 at 17:31:58 (+0100), Marc Zyngier wrote: > In order to transfer the early mapping state into KVM's MMIO > guard infrastucture, provide a small helper that will retrieve > the associated PTE. > > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > arch/arm64/include/asm/fixmap.h | 2 ++ > arch/arm64/mm/mmu.c | 15 +++++++++++++++ > 2 files changed, 17 insertions(+) > > diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h > index 4335800201c9..1aae625b944f 100644 > --- a/arch/arm64/include/asm/fixmap.h > +++ b/arch/arm64/include/asm/fixmap.h > @@ -105,6 +105,8 @@ void __init early_fixmap_init(void); > > extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); > > +extern pte_t *__get_fixmap_pte(enum fixed_addresses idx); > + > #include <asm-generic/fixmap.h> > > #endif /* !__ASSEMBLY__ */ > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index d74586508448..f1b7abd04025 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1286,6 +1286,21 @@ void __set_fixmap(enum fixed_addresses idx, > } > } > > +pte_t *__get_fixmap_pte(enum fixed_addresses idx) > +{ > + unsigned long addr = __fix_to_virt(idx);
Nit: odd spacing here.
> + pte_t *ptep; > + > + BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); > + > + ptep = fixmap_pte(addr); > + > + if (!pte_valid(*ptep)) > + return NULL; > + > + return ptep; > +} > + > void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot) > { > const u64 dt_virt_base = __fix_to_virt(FIX_FDT); > -- > 2.30.2 >
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