Re: [Xen-devel] [PATCH 04/15] xen: mm: add ioremap_cache

[Julien Grall <julien.grall@xxxxxxx>]

Hi,

On 07/09/2017 09:10 AM, Kai Huang wrote:
> Currently Xen only has non-cacheable version of ioremap. Although EPC is
> reported as reserved memory in e820 but it can be mapped as cacheable. This
> patch adds ioremap_cache (cacheable version of ioremap).
>
> Signed-off-by: Kai Huang <kai.huang@xxxxxxxxxxxxxxx>
> ---
>   xen/arch/x86/mm.c      | 15 +++++++++++++--
>   xen/include/xen/vmap.h |  1 +
First of all, this is common code and the "REST" maintainers should have 
been CCed for this include.
But xen/include/xen/vmap.h is common code and going to break ARM. We 
already have an inline implementation of ioremap_nocache. You should 
move the definition in x86 specific headers.
Please make sure to at least build test ARM when touching common code.

Cheers,

>   2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
> index 101ab33193..d0b6b3a247 100644
> --- a/xen/arch/x86/mm.c
> +++ b/xen/arch/x86/mm.c
> @@ -6284,9 +6284,10 @@ void *__init arch_vmap_virt_end(void)
>       return (void *)fix_to_virt(__end_of_fixed_addresses);
>   }
>   
> -void __iomem *ioremap(paddr_t pa, size_t len)
> +static void __iomem *__ioremap(paddr_t pa, size_t len, bool_t cache)
>   {
>       mfn_t mfn = _mfn(PFN_DOWN(pa));
> +    unsigned int flags = cache ? PAGE_HYPERVISOR : PAGE_HYPERVISOR_NOCACHE;
>       void *va;
>   
>       WARN_ON(page_is_ram_type(mfn_x(mfn), RAM_TYPE_CONVENTIONAL));
> @@ -6299,12 +6300,22 @@ void __iomem *ioremap(paddr_t pa, size_t len)
>           unsigned int offs = pa & (PAGE_SIZE - 1);
>           unsigned int nr = PFN_UP(offs + len);
>   
> -        va = __vmap(&mfn, nr, 1, 1, PAGE_HYPERVISOR_NOCACHE, VMAP_DEFAULT) + offs;
> +        va = __vmap(&mfn, nr, 1, 1, flags, VMAP_DEFAULT) + offs;
>       }
>   
>       return (void __force __iomem *)va;
>   }
>   
> +void __iomem *ioremap(paddr_t pa, size_t len)
> +{
> +    return __ioremap(pa, len, false);
> +}
> +
> +void __iomem *ioremap_cache(paddr_t pa, size_t len)
> +{
> +    return __ioremap(pa, len, true);
> +}
> +
>   int create_perdomain_mapping(struct domain *d, unsigned long va,
>                                unsigned int nr, l1_pgentry_t **pl1tab,
>                                struct page_info **ppg)
> diff --git a/xen/include/xen/vmap.h b/xen/include/xen/vmap.h
> index 369560e620..f6037e368c 100644
> --- a/xen/include/xen/vmap.h
> +++ b/xen/include/xen/vmap.h
> @@ -24,6 +24,7 @@ void *vzalloc(size_t size);
>   void vfree(void *va);
>   
>   void __iomem *ioremap(paddr_t, size_t);
> +void __iomem *ioremap_cache(paddr_t, size_t);
>   
>   static inline void iounmap(void __iomem *va)
>   {
--
Julien Grall

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