Re: [PATCH] mm/ioremap: Pass pgprot_t to ioremap_prot() instead of unsigned long

Catalin Marinas <[email protected]>
Newsgroups gmane.linux.ports.sh.devel,gmane.linux.kernel.mm,gmane.linux.ports.arm.kernel,gmane.linux.kernel.arc,gmane.linux.ports.riscv,gmane.linux.ports.ppc64.devel,gmane.linux.ports.parisc,gmane.linux.ports.mips,gmane.linux.kernel.cross-arch,gmane.linux.kernel
Message-ID <[email protected]>
On Tue, Feb 18, 2025 at 03:49:54PM +0530, Anshuman Khandual wrote:
> From: Ryan Roberts <[email protected]>
> 
> ioremap_prot() currently accepts pgprot_val parameter as an unsigned long,
> thus implicitly assuming that pgprot_val and pgprot_t could never be bigger
> than unsigned long. But this assumption soon will not be true on arm64 when
> using D128 pgtables. In 128 bit page table configuration, unsigned long is
> 64 bit, but pgprot_t is 128 bit.
> 
> Passing platform abstracted pgprot_t argument is better as compared to size
> based data types. Let's change the parameter to directly pass pgprot_t like
> another similar helper generic_ioremap_prot().
> 
> Without this change in place, D128 configuration does not work on arm64 as
> the top 64 bits gets silently stripped when passing the protection value to
> this function.
> 
> Cc: Andrew Morton <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Ryan Roberts <[email protected]>
> Co-developed-by: Anshuman Khandual <[email protected]>
> Signed-off-by: Anshuman Khandual <[email protected]>

For arm64:

Acked-by: Catalin Marinas <[email protected]>
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