On 07/24/2018 01:46 PM, Randy Dunlap wrote:
> From: Randy Dunlap <rdun...@infradead.org>
>
> ../arch/arc/mm/cache.c: In function 'flush_anon_page':
> ../arch/arc/mm/cache.c:1062:55: warning: passing argument 2 of 
> '__flush_dcache_page' makes integer from pointer without a cast 
> [-Wint-conversion]
>   __flush_dcache_page((phys_addr_t)page_address(page), page_address(page));
>                                                        ^~~~~~~~~~~~~~~~~~
> ../arch/arc/mm/cache.c:1013:59: note: expected 'long unsigned int' but 
> argument is of type 'void *'
>  void __flush_dcache_page(phys_addr_t paddr, unsigned long vaddr)
>                                              ~~~~~~~~~~~~~~^~~~~
>
> Signed-off-by: Randy Dunlap <rdun...@infradead.org>
> Cc: Vineet Gupta <vgu...@synopsys.com>
> Cc: Ofer Levi <ofe...@mellanox.com>
> Cc: linux-snps-arc@lists.infradead.org
> ---
>  arch/arc/mm/cache.c |   11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> --- linux-next-20180723.orig/arch/arc/mm/cache.c
> +++ linux-next-20180723/arch/arc/mm/cache.c
> @@ -1038,7 +1038,7 @@ void flush_cache_mm(struct mm_struct *mm
>  void flush_cache_page(struct vm_area_struct *vma, unsigned long u_vaddr,
>                     unsigned long pfn)
>  {
> -     unsigned int paddr = pfn << PAGE_SHIFT;
> +     phys_addr_t paddr = pfn << PAGE_SHIFT;
>  
>       u_vaddr &= PAGE_MASK;
>  
> @@ -1058,8 +1058,9 @@ void flush_anon_page(struct vm_area_stru
>                    unsigned long u_vaddr)
>  {
>       /* TBD: do we really need to clear the kernel mapping */
> -     __flush_dcache_page(page_address(page), u_vaddr);
> -     __flush_dcache_page(page_address(page), page_address(page));
> +     __flush_dcache_page((phys_addr_t)page_address(page), u_vaddr);
> +     __flush_dcache_page((phys_addr_t)page_address(page),
> +                         (phys_addr_t)page_address(page));

CONFIG_ARC_CACHE_VIPT_ALIASING is a total bitrot and I'm considering removing it
as no sane systems should use it. There's none which I know are using it.
But for now this will do.


>  
>  }
>  
> @@ -1084,7 +1085,7 @@ void copy_user_highpage(struct page *to,
>        * addr_not_cache_congruent() is 0
>        */
>       if (page_mapcount(from) && addr_not_cache_congruent(kfrom, u_vaddr)) {
> -             __flush_dcache_page((unsigned long)kfrom, u_vaddr);
> +             __flush_dcache_page((phys_addr_t)kfrom, u_vaddr);

Was this needed really ? I can't seem to trigger any warnings here.
All of this (original code before your change) is technically incorrect due to 
the
combination of CONFIG_ARC_CACHE_VIPT_ALIASING and CONFIG_HIGHMEM. @kfrom is
returned by kmap_atomic() and in highmem regime it could be a kernel virtual
address, so calling the low level cache flush interface with a kvaddr, 
pretending
it is paddr (whethe runsigned long or phys_addr_t) is just not right. This
combinations needs to be disallowed from Kconfig !

>               clean_src_k_mappings = 1;
>       }
>  
> @@ -1105,7 +1106,7 @@ void copy_user_highpage(struct page *to,
>        * sync the kernel mapping back to physical page
>        */
>       if (clean_src_k_mappings) {
> -             __flush_dcache_page((unsigned long)kfrom, (unsigned long)kfrom);
> +             __flush_dcache_page((phys_addr_t)kfrom, (unsigned long)kfrom);
>               set_bit(PG_dc_clean, &from->flags);
>       } else {
>               clear_bit(PG_dc_clean, &from->flags);
>

Ditto !

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