On 09/01/2020 01:06 PM, Aneesh Kumar K.V wrote: > On 9/1/20 1:02 PM, Anshuman Khandual wrote: >> >> >> On 09/01/2020 11:51 AM, Aneesh Kumar K.V wrote: >>> On 9/1/20 8:45 AM, Anshuman Khandual wrote: >>>> >>>> >>>> On 08/27/2020 01:34 PM, Aneesh Kumar K.V wrote: >>>>> ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE). Avoid setting that >>>>> bit in >>>>> random value. >>>>> >>>>> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> >>>>> --- >>>>> mm/debug_vm_pgtable.c | 13 ++++++++++--- >>>>> 1 file changed, 10 insertions(+), 3 deletions(-) >>>>> >>>>> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c >>>>> index 086309fb9b6f..bbf9df0e64c6 100644 >>>>> --- a/mm/debug_vm_pgtable.c >>>>> +++ b/mm/debug_vm_pgtable.c >>>>> @@ -44,10 +44,17 @@ >>>>> * entry type. But these bits might affect the ability to clear >>>>> entries with >>>>> * pxx_clear() because of how dynamic page table folding works on >>>>> s390. So >>>>> * while loading up the entries do not change the lower 4 bits. It >>>>> does not >>>>> - * have affect any other platform. >>>>> + * have affect any other platform. Also avoid the 62nd bit on ppc64 that >>>>> is >>>>> + * used to mark a pte entry. >>>>> */ >>>>> -#define S390_MASK_BITS 4 >>>>> -#define RANDOM_ORVALUE GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS) >>>>> +#define S390_SKIP_MASK GENMASK(3, 0) >>>>> +#ifdef CONFIG_PPC_BOOK3S_64 >>>>> +#define PPC64_SKIP_MASK GENMASK(62, 62) >>>>> +#else >>>>> +#define PPC64_SKIP_MASK 0x0 >>>>> +#endif >>>> >>>> Please drop the #ifdef CONFIG_PPC_BOOK3S_64 here. We already accommodate >>>> skip >>>> bits for a s390 platform requirement and can also do so for ppc64 as well. >>>> As >>>> mentioned before, please avoid adding any platform specific constructs in >>>> the >>>> test. >>>> >>> >>> >>> that is needed so that it can be built on 32 bit architectures.I did face >>> build errors with arch-linux >> >> Could not (#if __BITS_PER_LONG == 32) be used instead or something like >> that. But should be a generic conditional check identifying 32 bit arch >> not anything platform specific. >> > > that _PAGE_PTE bit is pretty much specific to PPC BOOK3S_64. Not sure why > other architectures need to bothered about ignoring bit 62.
Thats okay as long it does not adversely affect other architectures, ignoring some more bits is acceptable. Like existing S390_MASK_BITS gets ignored on all other platforms even if it is a s390 specific constraint. Not having platform specific #ifdef here, is essential. _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
