Re: [PATCH v3] arm64: mm: fix pass user prot to ioremap_prot in generic_access_phys

[Catalin Marinas <catalin.marinas@arm.com>]

On Thu, Feb 05, 2026 at 03:23:27PM +0800, Jinjiang Tu wrote:
> 在 2026/2/3 17:23, Will Deacon 写道:
> > On Tue, Feb 03, 2026 at 11:38:15AM +0800, Jinjiang Tu wrote:
> > > 在 2026/2/2 22:55, Will Deacon 写道:
> > > > On Fri, Jan 30, 2026 at 03:38:07PM +0800, Jinjiang Tu wrote:
> > > > > +#define arch_mk_kernel_prot arch_mk_kernel_prot
> > > > > +static inline pgprot_t arch_mk_kernel_prot(pgprot_t user_prot)
> > > > > +{
> > > > > +	ptdesc_t mem_type = pgprot_val(user_prot) & PTE_ATTRINDX_MASK;
> > > > > +
> > > > > +	return __pgprot_modify(PAGE_KERNEL, PTE_ATTRINDX_MASK, mem_type);
> > > > > +}
> > > > 
> > > > Do we really need another arch helper here?
[...]
> > My point is that we already have the helper: ioremap_prot(). Just fix
> > that for arm64 and cc the other arch maintainers if you're not sure how
> > to fix it for them. What we don't need to do is add an additional helper.
> 
> ioremap_prot() may be called outside of arch/arm64 in the future, and I think
> most of the cases will not pass a user prot to ioremap_prot().
> 
> generic_access_phys() is a special case, so I want to limit the modification to
> generic_access_phys() only.

Or we can just have an ioremap_user_prot() (or some more meaningful
name), defined by default as ioremap_prot(). It's still introducing a
new macro though, unless we go and rename it on all architectures.

-- 
Catalin