Re: [PATCH v2 resend 4/5] arm64: mm: Convert to GENERIC_IOREMAP

[Kefeng Wang]

On 2022/5/19 13:34, Anshuman Khandual wrote:
> On 5/2/22 08:57, Kefeng Wang wrote:
> > Add hook for arm64's special operation when ioremap() and iounmap(),
> > then ioremap_wc/np/cache is converted to use ioremap_prot()
> > from GENERIC_IOREMAP, update the Copyright and kill the unused
> > inclusions.
> >
> > Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> > ---
> > v2 resend:
> > - use IOMEM_ERR_PTR to fix sparse warning found by lkp
> >
> >   arch/arm64/Kconfig          |  1 +
> >   arch/arm64/include/asm/io.h | 20 ++++++---
> >   arch/arm64/kernel/acpi.c    |  2 +-
> >   arch/arm64/mm/ioremap.c     | 85 +++++--------------------------------
> >   4 files changed, 27 insertions(+), 81 deletions(-)
> >
> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > index 20ea89d9ac2f..56673209fdb9 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -123,6 +123,7 @@ config ARM64
> >   	select GENERIC_CPU_VULNERABILITIES
> >   	select GENERIC_EARLY_IOREMAP
> >   	select GENERIC_IDLE_POLL_SETUP
> > +	select GENERIC_IOREMAP
> >   	select GENERIC_IRQ_IPI
> >   	select GENERIC_IRQ_PROBE
> >   	select GENERIC_IRQ_SHOW
> > diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
> > index 7fd836bea7eb..042fa01940b8 100644
> > --- a/arch/arm64/include/asm/io.h
> > +++ b/arch/arm64/include/asm/io.h
> > @@ -163,13 +163,21 @@ extern void __memset_io(volatile void __iomem *, int, size_t);
> >   /*
> >    * I/O memory mapping functions.
> >    */
> > -extern void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot);
> > -extern void iounmap(volatile void __iomem *addr);
> > -extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
> >   
> > -#define ioremap(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
> > -#define ioremap_wc(addr, size)		__ioremap((addr), (size), __pgprot(PROT_NORMAL_NC))
> > -#define ioremap_np(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRnE))
> > +void __iomem *arch_ioremap(phys_addr_t phys_addr, size_t size, unsigned long prot);
> > +#define arch_ioremap arch_ioremap
> > +
> > +int arch_iounmap(void __iomem *addr);
> > +#define arch_iounmap arch_iounmap
> > +
> > +#define _PAGE_IOREMAP PROT_DEVICE_nGnRE
> Small nit, should we have a comment here for the above components i.e
> PAGE_IOREMAP and callbacks arch_ioremap()/arch_iounmap() are required
> because of enabling GENERIC_IOREMAP ?

There is a comment in  include/asm-generic/io.h:       /* _PAGE_IOREMAP 
needs to be supplied by the architecture */

so arch's callbacks could not add repeated comments.


> Otherwise LGTM.
>
> Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Thanks.
> .