Re: [BUGFIX][PATCH] x86: fix set_fixmap to use phys_addr_t

[Masami Hiramatsu <mhiramat@redhat.com>]

Mathieu Desnoyers wrote:
> * Masami Hiramatsu (mhiramat@redhat.com) wrote:
>> Use phys_addr_t for receiving a physical address argument
>> instead of unsigned long. This allows fixmap to handle
>> pages higher than 4GB on x86-32.
>>
> 
> You might also want to update arch/x86/mm/ioremap.c:early_set_fixmap()
> and __early_set_fixmap().

Hmm, it is easy to change unsigned long to phys_addr_t in
early_set_fixmap(), however, ioremap also uses unsigned long for
physical addresses. Do I need to update ioremap functions too?

I mean, is there any chance that over 4GB physical address will
be passed to ioremap? If not, I just change early_set_fixmap()
and __early_set_fixmap().

Thanks,

> 
> Otherwise it looks good.
> 
> Thanks,
> 
> Mathieu
> 
>> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
>> Cc: Ingo Molnar <mingo@elte.hu>
>> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
>> ---
>>
>>  arch/x86/include/asm/fixmap.h   |    4 ++--
>>  arch/x86/include/asm/paravirt.h |    4 ++--
>>  arch/x86/mm/pgtable.c           |    3 ++-
>>  arch/x86/xen/mmu.c              |    2 +-
>>  4 files changed, 7 insertions(+), 6 deletions(-)
>>
>>
>> diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
>> index 81937a5..2d81af3 100644
>> --- a/arch/x86/include/asm/fixmap.h
>> +++ b/arch/x86/include/asm/fixmap.h
>> @@ -151,11 +151,11 @@ extern pte_t *pkmap_page_table;
>>
>>  void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
>>  void native_set_fixmap(enum fixed_addresses idx,
>> -		       unsigned long phys, pgprot_t flags);
>> +		       phys_addr_t phys, pgprot_t flags);
>>
>>  #ifndef CONFIG_PARAVIRT
>>  static inline void __set_fixmap(enum fixed_addresses idx,
>> -				unsigned long phys, pgprot_t flags)
>> +				phys_addr_t phys, pgprot_t flags)
>>  {
>>  	native_set_fixmap(idx, phys, flags);
>>  }
>> diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
>> index 7727aa8..378e369 100644
>> --- a/arch/x86/include/asm/paravirt.h
>> +++ b/arch/x86/include/asm/paravirt.h
>> @@ -347,7 +347,7 @@ struct pv_mmu_ops {
>>  	/* Sometimes the physical address is a pfn, and sometimes its
>>  	   an mfn.  We can tell which is which from the index. */
>>  	void (*set_fixmap)(unsigned /* enum fixed_addresses */ idx,
>> -			   unsigned long phys, pgprot_t flags);
>> +			   phys_addr_t phys, pgprot_t flags);
>>  };
>>
>>  struct raw_spinlock;
>> @@ -1432,7 +1432,7 @@ static inline void arch_leave_lazy_mmu_mode(void)
>>  void arch_flush_lazy_mmu_mode(void);
>>
>>  static inline void __set_fixmap(unsigned /* enum fixed_addresses */ idx,
>> -				unsigned long phys, pgprot_t flags)
>> +				phys_addr_t phys, pgprot_t flags)
>>  {
>>  	pv_mmu_ops.set_fixmap(idx, phys, flags);
>>  }
>> diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
>> index 7a4d6ee..8e43bdd 100644
>> --- a/arch/x86/mm/pgtable.c
>> +++ b/arch/x86/mm/pgtable.c
>> @@ -347,7 +347,8 @@ void __native_set_fixmap(enum fixed_addresses idx, pte_t pte)
>>  	fixmaps_set++;
>>  }
>>
>> -void native_set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
>> +void native_set_fixmap(enum fixed_addresses idx, phys_addr_t phys,
>> +		       pgprot_t flags)
>>  {
>>  	__native_set_fixmap(idx, pfn_pte(phys >> PAGE_SHIFT, flags));
>>  }
>> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
>> index db3802f..2a81838 100644
>> --- a/arch/x86/xen/mmu.c
>> +++ b/arch/x86/xen/mmu.c
>> @@ -1750,7 +1750,7 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
>>  }
>>  #endif	/* CONFIG_X86_64 */
>>
>> -static void xen_set_fixmap(unsigned idx, unsigned long phys, pgprot_t prot)
>> +static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
>>  {
>>  	pte_t pte;
>>
> 

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com