| Message ID | 20210407172607.8812-3-rppt@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: drop pfn_valid_within() and simplify pfn_valid() | expand |
On 4/7/21 10:56 PM, Mike Rapoport wrote: > From: Mike Rapoport <rppt@linux.ibm.com> > > The intended semantics of pfn_valid() is to verify whether there is a > struct page for the pfn in question and nothing else. Should there be a comment affirming this semantics interpretation, above the generic pfn_valid() in include/linux/mmzone.h ? > > 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_memory() to perform such check and use it > where appropriate. > > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> > --- > 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 | 6 ++++++ > arch/arm64/mm/ioremap.c | 4 ++-- > arch/arm64/mm/mmu.c | 2 +- > 6 files changed, 12 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > index 0aabc3be9a75..7e77fdf71b9d 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_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..32b485bcc6ff 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_memory(unsigned long); > > #include <asm/memory.h> > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index 8711894db8c2..ad2ea65a3937 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_memory(pfn); > } > > /* > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index 3685e12aba9b..258b1905ed4a 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -258,6 +258,12 @@ int pfn_valid(unsigned long pfn) > } > EXPORT_SYMBOL(pfn_valid); > > +int pfn_is_memory(unsigned long pfn) > +{ > + return memblock_is_map_memory(PFN_PHYS(pfn)); > +} > +EXPORT_SYMBOL(pfn_is_memory);> + Should not this be generic though ? There is nothing platform or arm64 specific in here. Wondering as pfn_is_memory() just indicates that the pfn is linear mapped, should not it be renamed as pfn_is_linear_memory() instead ? Regardless, it's fine either way. > static phys_addr_t memory_limit = PHYS_ADDR_MAX; > > /* > diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c > index b5e83c46b23e..82a369b22ef5 100644 > --- a/arch/arm64/mm/ioremap.c > +++ b/arch/arm64/mm/ioremap.c > @@ -43,7 +43,7 @@ static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, > /* > * Don't allow RAM to be mapped. > */ > - if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr)))) > + if (WARN_ON(pfn_is_memory(__phys_to_pfn(phys_addr)))) > return NULL; > > area = get_vm_area_caller(size, VM_IOREMAP, caller); > @@ -84,7 +84,7 @@ EXPORT_SYMBOL(iounmap); > void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) > { > /* For normal memory we already have a cacheable mapping. */ > - if (pfn_valid(__phys_to_pfn(phys_addr))) > + if (pfn_is_memory(__phys_to_pfn(phys_addr))) > return (void __iomem *)__phys_to_virt(phys_addr); > > return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 5d9550fdb9cf..038d20fe163f 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -81,7 +81,7 @@ void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd) > pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, > unsigned long size, pgprot_t vma_prot) > { > - if (!pfn_valid(pfn)) > + if (!pfn_is_memory(pfn)) > return pgprot_noncached(vma_prot); > else if (file->f_flags & O_SYNC) > return pgprot_writecombine(vma_prot); >
On Thu, Apr 08, 2021 at 10:44:58AM +0530, Anshuman Khandual wrote: > > On 4/7/21 10:56 PM, Mike Rapoport wrote: > > From: Mike Rapoport <rppt@linux.ibm.com> > > > > The intended semantics of pfn_valid() is to verify whether there is a > > struct page for the pfn in question and nothing else. > > Should there be a comment affirming this semantics interpretation, above the > generic pfn_valid() in include/linux/mmzone.h ? Yeah, that would have been helpful :) > > > > 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_memory() to perform such check and use it > > where appropriate. > > > > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> > > --- > > 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 | 6 ++++++ > > arch/arm64/mm/ioremap.c | 4 ++-- > > arch/arm64/mm/mmu.c | 2 +- > > 6 files changed, 12 insertions(+), 5 deletions(-) > > > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > > index 0aabc3be9a75..7e77fdf71b9d 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_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..32b485bcc6ff 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_memory(unsigned long); > > > > #include <asm/memory.h> > > > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > > index 8711894db8c2..ad2ea65a3937 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_memory(pfn); > > } > > > > /* > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > > index 3685e12aba9b..258b1905ed4a 100644 > > --- a/arch/arm64/mm/init.c > > +++ b/arch/arm64/mm/init.c > > @@ -258,6 +258,12 @@ int pfn_valid(unsigned long pfn) > > } > > EXPORT_SYMBOL(pfn_valid); > > > > +int pfn_is_memory(unsigned long pfn) > > +{ > > + return memblock_is_map_memory(PFN_PHYS(pfn)); > > +} > > +EXPORT_SYMBOL(pfn_is_memory);> + > > Should not this be generic though ? There is nothing platform or arm64 > specific in here. As NOMAP itself is quite ARM specific, this check is currently only relevant for arm64 and maybe arm32. But probably having an EXPORT_SYMBOL wrapper for memblock_is_map_memory(), say in memblock does make sense for all architectures that have KEEP_MEMBLOCK. > Wondering as pfn_is_memory() just indicates that the > pfn is linear mapped, should not it be renamed as pfn_is_linear_memory() > instead ? Regardless, it's fine either way. Yeah, I agree that naming could be better here. I think that for a generic name we'd need pfn_is_directly_mapped() so that it can be used on x86 ;-) > > static phys_addr_t memory_limit = PHYS_ADDR_MAX; > > > > /* > > diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c > > index b5e83c46b23e..82a369b22ef5 100644 > > --- a/arch/arm64/mm/ioremap.c > > +++ b/arch/arm64/mm/ioremap.c > > @@ -43,7 +43,7 @@ static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, > > /* > > * Don't allow RAM to be mapped. > > */ > > - if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr)))) > > + if (WARN_ON(pfn_is_memory(__phys_to_pfn(phys_addr)))) > > return NULL; > > > > area = get_vm_area_caller(size, VM_IOREMAP, caller); > > @@ -84,7 +84,7 @@ EXPORT_SYMBOL(iounmap); > > void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) > > { > > /* For normal memory we already have a cacheable mapping. */ > > - if (pfn_valid(__phys_to_pfn(phys_addr))) > > + if (pfn_is_memory(__phys_to_pfn(phys_addr))) > > return (void __iomem *)__phys_to_virt(phys_addr); > > > > return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > > index 5d9550fdb9cf..038d20fe163f 100644 > > --- a/arch/arm64/mm/mmu.c > > +++ b/arch/arm64/mm/mmu.c > > @@ -81,7 +81,7 @@ void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd) > > pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, > > unsigned long size, pgprot_t vma_prot) > > { > > - if (!pfn_valid(pfn)) > > + if (!pfn_is_memory(pfn)) > > return pgprot_noncached(vma_prot); > > else if (file->f_flags & O_SYNC) > > return pgprot_writecombine(vma_prot); > >
On 08.04.21 07:14, Anshuman Khandual wrote: > > On 4/7/21 10:56 PM, Mike Rapoport wrote: >> From: Mike Rapoport <rppt@linux.ibm.com> >> >> The intended semantics of pfn_valid() is to verify whether there is a >> struct page for the pfn in question and nothing else. > > Should there be a comment affirming this semantics interpretation, above the > generic pfn_valid() in include/linux/mmzone.h ? > >> >> 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_memory() to perform such check and use it >> where appropriate. >> >> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> >> --- >> 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 | 6 ++++++ >> arch/arm64/mm/ioremap.c | 4 ++-- >> arch/arm64/mm/mmu.c | 2 +- >> 6 files changed, 12 insertions(+), 5 deletions(-) >> >> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h >> index 0aabc3be9a75..7e77fdf71b9d 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_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..32b485bcc6ff 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_memory(unsigned long); >> >> #include <asm/memory.h> >> >> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c >> index 8711894db8c2..ad2ea65a3937 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_memory(pfn); >> } >> >> /* >> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >> index 3685e12aba9b..258b1905ed4a 100644 >> --- a/arch/arm64/mm/init.c >> +++ b/arch/arm64/mm/init.c >> @@ -258,6 +258,12 @@ int pfn_valid(unsigned long pfn) >> } >> EXPORT_SYMBOL(pfn_valid); >> >> +int pfn_is_memory(unsigned long pfn) >> +{ >> + return memblock_is_map_memory(PFN_PHYS(pfn)); >> +} >> +EXPORT_SYMBOL(pfn_is_memory);> + > > Should not this be generic though ? There is nothing platform or arm64 > specific in here. Wondering as pfn_is_memory() just indicates that the > pfn is linear mapped, should not it be renamed as pfn_is_linear_memory() > instead ? Regardless, it's fine either way. TBH, I dislike (generic) pfn_is_memory(). It feels like we're mixing concepts. NOMAP memory vs !NOMAP memory; even NOMAP is some kind of memory after all. pfn_is_map_memory() would be more expressive, although still sub-optimal. We'd actually want some kind of arm64-specific pfn_is_system_memory() or the inverse pfn_is_device_memory() -- to be improved.
On Wed, Apr 14, 2021 at 05:58:26PM +0200, David Hildenbrand wrote: > On 08.04.21 07:14, Anshuman Khandual wrote: > > > > On 4/7/21 10:56 PM, Mike Rapoport wrote: > > > From: Mike Rapoport <rppt@linux.ibm.com> > > > > > > The intended semantics of pfn_valid() is to verify whether there is a > > > struct page for the pfn in question and nothing else. > > > > Should there be a comment affirming this semantics interpretation, above the > > generic pfn_valid() in include/linux/mmzone.h ? > > > > > > > > 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_memory() to perform such check and use it > > > where appropriate. > > > > > > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> > > > --- > > > 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 | 6 ++++++ > > > arch/arm64/mm/ioremap.c | 4 ++-- > > > arch/arm64/mm/mmu.c | 2 +- > > > 6 files changed, 12 insertions(+), 5 deletions(-) > > > > > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > > > index 0aabc3be9a75..7e77fdf71b9d 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_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..32b485bcc6ff 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_memory(unsigned long); > > > #include <asm/memory.h> > > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > > > index 8711894db8c2..ad2ea65a3937 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_memory(pfn); > > > } > > > /* > > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > > > index 3685e12aba9b..258b1905ed4a 100644 > > > --- a/arch/arm64/mm/init.c > > > +++ b/arch/arm64/mm/init.c > > > @@ -258,6 +258,12 @@ int pfn_valid(unsigned long pfn) > > > } > > > EXPORT_SYMBOL(pfn_valid); > > > +int pfn_is_memory(unsigned long pfn) > > > +{ > > > + return memblock_is_map_memory(PFN_PHYS(pfn)); > > > +} > > > +EXPORT_SYMBOL(pfn_is_memory);> + > > > > Should not this be generic though ? There is nothing platform or arm64 > > specific in here. Wondering as pfn_is_memory() just indicates that the > > pfn is linear mapped, should not it be renamed as pfn_is_linear_memory() > > instead ? Regardless, it's fine either way. > > TBH, I dislike (generic) pfn_is_memory(). It feels like we're mixing > concepts. Yeah, at the moment NOMAP is very much arm specific so I'd keep it this way for now. > NOMAP memory vs !NOMAP memory; even NOMAP is some kind of memory > after all. pfn_is_map_memory() would be more expressive, although still > sub-optimal. > > We'd actually want some kind of arm64-specific pfn_is_system_memory() or the > inverse pfn_is_device_memory() -- to be improved. In my current version (to be posted soon) I've started with pfn_lineary_mapped() but then ended up with pfn_mapped() to make it "upward" compatible with architectures that use direct rather than linear map :)
On 14.04.21 22:29, Mike Rapoport wrote: > On Wed, Apr 14, 2021 at 05:58:26PM +0200, David Hildenbrand wrote: >> On 08.04.21 07:14, Anshuman Khandual wrote: >>> >>> On 4/7/21 10:56 PM, Mike Rapoport wrote: >>>> From: Mike Rapoport <rppt@linux.ibm.com> >>>> >>>> The intended semantics of pfn_valid() is to verify whether there is a >>>> struct page for the pfn in question and nothing else. >>> >>> Should there be a comment affirming this semantics interpretation, above the >>> generic pfn_valid() in include/linux/mmzone.h ? >>> >>>> >>>> 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_memory() to perform such check and use it >>>> where appropriate. >>>> >>>> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> >>>> --- >>>> 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 | 6 ++++++ >>>> arch/arm64/mm/ioremap.c | 4 ++-- >>>> arch/arm64/mm/mmu.c | 2 +- >>>> 6 files changed, 12 insertions(+), 5 deletions(-) >>>> >>>> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h >>>> index 0aabc3be9a75..7e77fdf71b9d 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_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..32b485bcc6ff 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_memory(unsigned long); >>>> #include <asm/memory.h> >>>> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c >>>> index 8711894db8c2..ad2ea65a3937 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_memory(pfn); >>>> } >>>> /* >>>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >>>> index 3685e12aba9b..258b1905ed4a 100644 >>>> --- a/arch/arm64/mm/init.c >>>> +++ b/arch/arm64/mm/init.c >>>> @@ -258,6 +258,12 @@ int pfn_valid(unsigned long pfn) >>>> } >>>> EXPORT_SYMBOL(pfn_valid); >>>> +int pfn_is_memory(unsigned long pfn) >>>> +{ >>>> + return memblock_is_map_memory(PFN_PHYS(pfn)); >>>> +} >>>> +EXPORT_SYMBOL(pfn_is_memory);> + >>> >>> Should not this be generic though ? There is nothing platform or arm64 >>> specific in here. Wondering as pfn_is_memory() just indicates that the >>> pfn is linear mapped, should not it be renamed as pfn_is_linear_memory() >>> instead ? Regardless, it's fine either way. >> >> TBH, I dislike (generic) pfn_is_memory(). It feels like we're mixing >> concepts. > > Yeah, at the moment NOMAP is very much arm specific so I'd keep it this way > for now. > >> NOMAP memory vs !NOMAP memory; even NOMAP is some kind of memory >> after all. pfn_is_map_memory() would be more expressive, although still >> sub-optimal. >> >> We'd actually want some kind of arm64-specific pfn_is_system_memory() or the >> inverse pfn_is_device_memory() -- to be improved. > > In my current version (to be posted soon) I've started with > pfn_lineary_mapped() but then ended up with pfn_mapped() to make it > "upward" compatible with architectures that use direct rather than linear > map :) And even that is moot. It doesn't tell you if a PFN is *actually* mapped (hello secretmem). I'd suggest to just use memblock_is_map_memory() in arch specific code. Then it's clear what we are querying exactly and what the semantics might be.
On Thu, Apr 15, 2021 at 11:31:26AM +0200, David Hildenbrand wrote: > On 14.04.21 22:29, Mike Rapoport wrote: > > On Wed, Apr 14, 2021 at 05:58:26PM +0200, David Hildenbrand wrote: > > > On 08.04.21 07:14, Anshuman Khandual wrote: > > > > > > > > On 4/7/21 10:56 PM, Mike Rapoport wrote: > > > > > From: Mike Rapoport <rppt@linux.ibm.com> > > > > > > > > > > The intended semantics of pfn_valid() is to verify whether there is a > > > > > struct page for the pfn in question and nothing else. > > > > > > > > Should there be a comment affirming this semantics interpretation, above the > > > > generic pfn_valid() in include/linux/mmzone.h ? > > > > > > > > > > > > > > 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_memory() to perform such check and use it > > > > > where appropriate. > > > > > > > > > > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> > > > > > --- > > > > > 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 | 6 ++++++ > > > > > arch/arm64/mm/ioremap.c | 4 ++-- > > > > > arch/arm64/mm/mmu.c | 2 +- > > > > > 6 files changed, 12 insertions(+), 5 deletions(-) > > > > > > > > > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > > > > > index 0aabc3be9a75..7e77fdf71b9d 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_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..32b485bcc6ff 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_memory(unsigned long); > > > > > #include <asm/memory.h> > > > > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > > > > > index 8711894db8c2..ad2ea65a3937 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_memory(pfn); > > > > > } > > > > > /* > > > > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > > > > > index 3685e12aba9b..258b1905ed4a 100644 > > > > > --- a/arch/arm64/mm/init.c > > > > > +++ b/arch/arm64/mm/init.c > > > > > @@ -258,6 +258,12 @@ int pfn_valid(unsigned long pfn) > > > > > } > > > > > EXPORT_SYMBOL(pfn_valid); > > > > > +int pfn_is_memory(unsigned long pfn) > > > > > +{ > > > > > + return memblock_is_map_memory(PFN_PHYS(pfn)); > > > > > +} > > > > > +EXPORT_SYMBOL(pfn_is_memory);> + > > > > > > > > Should not this be generic though ? There is nothing platform or arm64 > > > > specific in here. Wondering as pfn_is_memory() just indicates that the > > > > pfn is linear mapped, should not it be renamed as pfn_is_linear_memory() > > > > instead ? Regardless, it's fine either way. > > > > > > TBH, I dislike (generic) pfn_is_memory(). It feels like we're mixing > > > concepts. > > > > Yeah, at the moment NOMAP is very much arm specific so I'd keep it this way > > for now. > > > > > NOMAP memory vs !NOMAP memory; even NOMAP is some kind of memory > > > after all. pfn_is_map_memory() would be more expressive, although still > > > sub-optimal. > > > > > > We'd actually want some kind of arm64-specific pfn_is_system_memory() or the > > > inverse pfn_is_device_memory() -- to be improved. > > > > In my current version (to be posted soon) I've started with > > pfn_lineary_mapped() but then ended up with pfn_mapped() to make it > > "upward" compatible with architectures that use direct rather than linear > > map :) > > And even that is moot. It doesn't tell you if a PFN is *actually* mapped > (hello secretmem). > > I'd suggest to just use memblock_is_map_memory() in arch specific code. Then > it's clear what we are querying exactly and what the semantics might be. Ok, let's export memblock_is_map_memory() for the KEEP_MEMBLOCK case.
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 0aabc3be9a75..7e77fdf71b9d 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_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..32b485bcc6ff 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_memory(unsigned long); #include <asm/memory.h> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 8711894db8c2..ad2ea65a3937 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_memory(pfn); } /* diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 3685e12aba9b..258b1905ed4a 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -258,6 +258,12 @@ int pfn_valid(unsigned long pfn) } EXPORT_SYMBOL(pfn_valid); +int pfn_is_memory(unsigned long pfn) +{ + return memblock_is_map_memory(PFN_PHYS(pfn)); +} +EXPORT_SYMBOL(pfn_is_memory); + static phys_addr_t memory_limit = PHYS_ADDR_MAX; /* diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c index b5e83c46b23e..82a369b22ef5 100644 --- a/arch/arm64/mm/ioremap.c +++ b/arch/arm64/mm/ioremap.c @@ -43,7 +43,7 @@ static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, /* * Don't allow RAM to be mapped. */ - if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr)))) + if (WARN_ON(pfn_is_memory(__phys_to_pfn(phys_addr)))) return NULL; area = get_vm_area_caller(size, VM_IOREMAP, caller); @@ -84,7 +84,7 @@ EXPORT_SYMBOL(iounmap); void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) { /* For normal memory we already have a cacheable mapping. */ - if (pfn_valid(__phys_to_pfn(phys_addr))) + if (pfn_is_memory(__phys_to_pfn(phys_addr))) return (void __iomem *)__phys_to_virt(phys_addr); return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 5d9550fdb9cf..038d20fe163f 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -81,7 +81,7 @@ void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd) pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, unsigned long size, pgprot_t vma_prot) { - if (!pfn_valid(pfn)) + if (!pfn_is_memory(pfn)) return pgprot_noncached(vma_prot); else if (file->f_flags & O_SYNC) return pgprot_writecombine(vma_prot);