Re: [PATCH v4 1/5] fbdev: Avoid file argument in fb_pgprotect()

Javier Martinez Canillas
2023-09-20T08:02:24Z

Thomas Zimmermann <tzimmermann@suse.de> writes:

Hello Thomas,

> Only PowerPC's fb_pgprotect() needs the file argument, although
> the implementation does not use it. Pass NULL to the internal

Can you please mention the function that's the implementation for
PowerPC ? If I'm looking at the code correctly, that function is
phys_mem_access_prot() defined in the arch/powerpc/mm/mem.c file:

pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
if (ppc_md.phys_mem_access_prot)
return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);

if (!page_is_ram(pfn))
vma_prot = pgprot_noncached(vma_prot);

return vma_prot;
}

and if set, ppc_md.phys_mem_access_prot is pci_phys_mem_access_prot()
that is defined in the arch/powerpc/kernel/pci-common.c source file:

https://elixir.bootlin.com/linux/v6.6-rc2/source/arch/powerpc/kernel/pci-common.c#L524

That function indeed doesn't use the file argument. So your patch looks
correct to me.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

--
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat