On 4/21/21 12:21 PM, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
>
> The intended semantics of pfn_valid() is to verify whether there is a
> struct page for the pfn in question and nothing else.
>
> Yet, on arm64 it is used to distinguish memory areas that are mapped in the
> linear map vs those that require ioremap() to access them.
>
> Introduce a dedicated pfn_is_map_memory() wrapper for
> memblock_is_map_memory() to perform such check and use it where
> appropriate.
>
> Using a wrapper allows to avoid cyclic include dependencies.
>
> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> ---
> arch/arm64/include/asm/memory.h | 2 +-
> arch/arm64/include/asm/page.h | 1 +
> arch/arm64/kvm/mmu.c | 2 +-
> arch/arm64/mm/init.c | 11 +++++++++++
> arch/arm64/mm/ioremap.c | 4 ++--
> arch/arm64/mm/mmu.c | 2 +-
> 6 files changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index 0aabc3be9a75..194f9f993d30 100644
> --- a/arch/arm64/include/asm/memory.h
> +++ b/arch/arm64/include/asm/memory.h
> @@ -351,7 +351,7 @@ static inline void *phys_to_virt(phys_addr_t x)
>
> #define virt_addr_valid(addr) ({ \
> __typeof__(addr) __addr = __tag_reset(addr); \
> - __is_lm_address(__addr) && pfn_valid(virt_to_pfn(__addr)); \
> + __is_lm_address(__addr) && pfn_is_map_memory(virt_to_pfn(__addr)); \
> })
>
> void dump_mem_limit(void);
> diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
> index 012cffc574e8..99a6da91f870 100644
> --- a/arch/arm64/include/asm/page.h
> +++ b/arch/arm64/include/asm/page.h
> @@ -38,6 +38,7 @@ void copy_highpage(struct page *to, struct page *from);
> typedef struct page *pgtable_t;
>
> extern int pfn_valid(unsigned long);
> +extern int pfn_is_map_memory(unsigned long);
Check patch is complaining about this.
WARNING: function definition argument 'unsigned long' should also have an identifier name
#50: FILE: arch/arm64/include/asm/page.h:41:
+extern int pfn_is_map_memory(unsigned long);
>
> #include <asm/memory.h>
>
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 8711894db8c2..23dd99e29b23 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -85,7 +85,7 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
>
> static bool kvm_is_device_pfn(unsigned long pfn)
> {
> - return !pfn_valid(pfn);
> + return !pfn_is_map_memory(pfn);
> }
>
> /*
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index 3685e12aba9b..dc03bdc12c0f 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -258,6 +258,17 @@ int pfn_valid(unsigned long pfn)
> }
> EXPORT_SYMBOL(pfn_valid);
>
> +int pfn_is_map_memory(unsigned long pfn)
> +{
> + phys_addr_t addr = PFN_PHYS(pfn);
> +
Should also bring with it, the comment regarding upper bits in
the pfn from arm64 pfn_valid().
> + if (PHYS_PFN(addr) != pfn)
> + return 0;
> +
^^^^^ trailing spaces here.
ERROR: trailing whitespace
#81: FILE: arch/arm64/mm/init.c:263:
+^I$
> + return memblock_is_map_memory(addr);
> +}
> +EXPORT_SYMBOL(pfn_is_map_memory);
> +
Is the EXPORT_SYMBOL() required to build drivers which will use
pfn_is_map_memory() but currently use pfn_valid() ?
