On 4/21/21 5:49 PM, Mike Rapoport wrote: > On Wed, Apr 21, 2021 at 04:29:48PM +0530, Anshuman Khandual wrote: >> >> 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(). > > I think a reference to the comment in pfn_valid() will suffice. Okay. > > BTW, I wonder how is that other architectures do not need this check? Trying to move that into generic pfn_valid() in mmzone.h, will resend the RFC patch after this series. https://patchwork.kernel.org/project/linux-mm/patch/1615174073-10520-1-git-send-email-anshuman.khandual@xxxxxxx/ > >>> + if (PHYS_PFN(addr) != pfn) >>> + return 0; >>> + >> >> ^^^^^ trailing spaces here. >> >> ERROR: trailing whitespace >> #81: FILE: arch/arm64/mm/init.c:263: >> +^I$ > > Oops :) > >>> + 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() ? > > Yes, this is required for virt_addr_valid() that is used by modules. > There will be two adjacent EXPORT_SYMBOLS(), one for pfn_valid() and one for pfn_is_map_memory(). But its okay I guess, cant help it. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm