| Message ID | 149703986971.20620.10303247412197996310.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | Mike Snitzer |
| Headers | show |
On Fri 09-06-17 13:24:29, Dan Williams wrote: > With all calls to this routine re-directed through the pmem driver, we can kill > the pmem api indirection. arch_wb_cache_pmem() is now optionally supplied by > the arch specific asm/pmem.h. Same as before, pmem flushing is only defined > for x86_64, but it is straightforward to add other archs in the future. > > Cc: <x86@kernel.org> > Cc: Jan Kara <jack@suse.cz> > Cc: Jeff Moyer <jmoyer@redhat.com> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Oliver O'Halloran <oohall@gmail.com> > Cc: Matthew Wilcox <mawilcox@microsoft.com> > Cc: Ross Zwisler <ross.zwisler@linux.intel.com> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> Looks good to me. Just one question below... > -/** > - * arch_wb_cache_pmem - write back a cache range with CLWB > - * @vaddr: virtual start address > - * @size: number of bytes to write back > - * > - * Write back a cache range using the CLWB (cache line write back) > - * instruction. Note that @size is internally rounded up to be cache > - * line size aligned. > - */ > static inline void arch_wb_cache_pmem(void *addr, size_t size) > { > - u16 x86_clflush_size = boot_cpu_data.x86_clflush_size; > - unsigned long clflush_mask = x86_clflush_size - 1; > - void *vend = addr + size; > - void *p; > - > - for (p = (void *)((unsigned long)addr & ~clflush_mask); > - p < vend; p += x86_clflush_size) > - clwb(p); > + clean_cache_range(addr,size); > } So this will make compilation break on 32-bit x86 as it does not define clean_cache_range(). Do we somewhere force we are on x86_64 when pmem is enabled? Honza
On Wed, Jun 14, 2017 at 3:54 AM, Jan Kara <jack@suse.cz> wrote: > On Fri 09-06-17 13:24:29, Dan Williams wrote: >> With all calls to this routine re-directed through the pmem driver, we can kill >> the pmem api indirection. arch_wb_cache_pmem() is now optionally supplied by >> the arch specific asm/pmem.h. Same as before, pmem flushing is only defined >> for x86_64, but it is straightforward to add other archs in the future. >> >> Cc: <x86@kernel.org> >> Cc: Jan Kara <jack@suse.cz> >> Cc: Jeff Moyer <jmoyer@redhat.com> >> Cc: Ingo Molnar <mingo@redhat.com> >> Cc: Christoph Hellwig <hch@lst.de> >> Cc: "H. Peter Anvin" <hpa@zytor.com> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Oliver O'Halloran <oohall@gmail.com> >> Cc: Matthew Wilcox <mawilcox@microsoft.com> >> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> >> Signed-off-by: Dan Williams <dan.j.williams@intel.com> > > Looks good to me. Just one question below... > >> -/** >> - * arch_wb_cache_pmem - write back a cache range with CLWB >> - * @vaddr: virtual start address >> - * @size: number of bytes to write back >> - * >> - * Write back a cache range using the CLWB (cache line write back) >> - * instruction. Note that @size is internally rounded up to be cache >> - * line size aligned. >> - */ >> static inline void arch_wb_cache_pmem(void *addr, size_t size) >> { >> - u16 x86_clflush_size = boot_cpu_data.x86_clflush_size; >> - unsigned long clflush_mask = x86_clflush_size - 1; >> - void *vend = addr + size; >> - void *p; >> - >> - for (p = (void *)((unsigned long)addr & ~clflush_mask); >> - p < vend; p += x86_clflush_size) >> - clwb(p); >> + clean_cache_range(addr,size); >> } > > So this will make compilation break on 32-bit x86 as it does not define > clean_cache_range(). Do we somewhere force we are on x86_64 when pmem is > enabled? Yes, this is enforced by: select ARCH_HAS_PMEM_API if X86_64 ...in arch/x86/Kconfig. We fallback to a dummy arch_wb_cache_pmem() implementation and emit this warning for !ARCH_HAS_PMEM_API archs: "nd_pmem namespace0.0: unable to guarantee persistence of writes" -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On Wed 14-06-17 09:49:29, Dan Williams wrote: > On Wed, Jun 14, 2017 at 3:54 AM, Jan Kara <jack@suse.cz> wrote: > >> -/** > >> - * arch_wb_cache_pmem - write back a cache range with CLWB > >> - * @vaddr: virtual start address > >> - * @size: number of bytes to write back > >> - * > >> - * Write back a cache range using the CLWB (cache line write back) > >> - * instruction. Note that @size is internally rounded up to be cache > >> - * line size aligned. > >> - */ > >> static inline void arch_wb_cache_pmem(void *addr, size_t size) > >> { > >> - u16 x86_clflush_size = boot_cpu_data.x86_clflush_size; > >> - unsigned long clflush_mask = x86_clflush_size - 1; > >> - void *vend = addr + size; > >> - void *p; > >> - > >> - for (p = (void *)((unsigned long)addr & ~clflush_mask); > >> - p < vend; p += x86_clflush_size) > >> - clwb(p); > >> + clean_cache_range(addr,size); > >> } > > > > So this will make compilation break on 32-bit x86 as it does not define > > clean_cache_range(). Do we somewhere force we are on x86_64 when pmem is > > enabled? > > Yes, this is enforced by: > > select ARCH_HAS_PMEM_API if X86_64 > > ...in arch/x86/Kconfig. We fallback to a dummy arch_wb_cache_pmem() > implementation and emit this warning for !ARCH_HAS_PMEM_API archs: > > "nd_pmem namespace0.0: unable to guarantee persistence of writes" Aha, right. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza
> +void clean_cache_range(void *addr, size_t size); > > static inline int > __copy_from_user_inatomic_nocache(void *dst, const void __user *src, > diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c > index f42d2fd86ca3..baa80ff29da8 100644 > --- a/arch/x86/lib/usercopy_64.c > +++ b/arch/x86/lib/usercopy_64.c > @@ -85,7 +85,7 @@ copy_user_handle_tail(char *to, char *from, unsigned len) > * instruction. Note that @size is internally rounded up to be cache > * line size aligned. > */ > -static void clean_cache_range(void *addr, size_t size) > +void clean_cache_range(void *addr, size_t size) Can you keep clean_cache_range private please? Just add arch_wb_cache_pmem to usercopy_64.c just behind it so that the compiler can tail-call and export that instead. > --- a/drivers/nvdimm/pmem.h > +++ b/drivers/nvdimm/pmem.h > @@ -4,6 +4,13 @@ > #include <linux/types.h> > #include <linux/pfn_t.h> > #include <linux/fs.h> > +#include <asm/pmem.h> > + > +#ifndef CONFIG_ARCH_HAS_PMEM_API > +static inline void arch_wb_cache_pmem(void *addr, size_t size) > +{ > +} > +#endif And our normal Linux style would be to have this linux linux/pmem.h, which should always be included for the asm version. -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On Sun, Jun 18, 2017 at 1:40 AM, Christoph Hellwig <hch@lst.de> wrote: >> +void clean_cache_range(void *addr, size_t size); >> >> static inline int >> __copy_from_user_inatomic_nocache(void *dst, const void __user *src, >> diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c >> index f42d2fd86ca3..baa80ff29da8 100644 >> --- a/arch/x86/lib/usercopy_64.c >> +++ b/arch/x86/lib/usercopy_64.c >> @@ -85,7 +85,7 @@ copy_user_handle_tail(char *to, char *from, unsigned len) >> * instruction. Note that @size is internally rounded up to be cache >> * line size aligned. >> */ >> -static void clean_cache_range(void *addr, size_t size) >> +void clean_cache_range(void *addr, size_t size) > > Can you keep clean_cache_range private please? Just add > arch_wb_cache_pmem to usercopy_64.c just behind it so that the > compiler can tail-call and export that instead. > >> --- a/drivers/nvdimm/pmem.h >> +++ b/drivers/nvdimm/pmem.h >> @@ -4,6 +4,13 @@ >> #include <linux/types.h> >> #include <linux/pfn_t.h> >> #include <linux/fs.h> >> +#include <asm/pmem.h> >> + >> +#ifndef CONFIG_ARCH_HAS_PMEM_API >> +static inline void arch_wb_cache_pmem(void *addr, size_t size) >> +{ >> +} >> +#endif > > And our normal Linux style would be to have this linux linux/pmem.h, > which should always be included for the asm version. Ok, will do. -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h index f4c119d253f3..862be3a9275c 100644 --- a/arch/x86/include/asm/pmem.h +++ b/arch/x86/include/asm/pmem.h @@ -44,25 +44,9 @@ static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n) BUG(); } -/** - * arch_wb_cache_pmem - write back a cache range with CLWB - * @vaddr: virtual start address - * @size: number of bytes to write back - * - * Write back a cache range using the CLWB (cache line write back) - * instruction. Note that @size is internally rounded up to be cache - * line size aligned. - */ static inline void arch_wb_cache_pmem(void *addr, size_t size) { - u16 x86_clflush_size = boot_cpu_data.x86_clflush_size; - unsigned long clflush_mask = x86_clflush_size - 1; - void *vend = addr + size; - void *p; - - for (p = (void *)((unsigned long)addr & ~clflush_mask); - p < vend; p += x86_clflush_size) - clwb(p); + clean_cache_range(addr,size); } static inline void arch_invalidate_pmem(void *addr, size_t size) diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index b16f6a1d8b26..bdc4a2761525 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -174,6 +174,7 @@ extern long __copy_user_nocache(void *dst, const void __user *src, extern long __copy_user_flushcache(void *dst, const void __user *src, unsigned size); extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset, size_t len); +void clean_cache_range(void *addr, size_t size); static inline int __copy_from_user_inatomic_nocache(void *dst, const void __user *src, diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index f42d2fd86ca3..baa80ff29da8 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -85,7 +85,7 @@ copy_user_handle_tail(char *to, char *from, unsigned len) * instruction. Note that @size is internally rounded up to be cache * line size aligned. */ -static void clean_cache_range(void *addr, size_t size) +void clean_cache_range(void *addr, size_t size) { u16 x86_clflush_size = boot_cpu_data.x86_clflush_size; unsigned long clflush_mask = x86_clflush_size - 1; @@ -96,6 +96,7 @@ static void clean_cache_range(void *addr, size_t size) p < vend; p += x86_clflush_size) clwb(p); } +EXPORT_SYMBOL(clean_cache_range); long __copy_user_flushcache(void *dst, const void __user *src, unsigned size) { diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 823b07774244..3b87702d46bb 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -245,7 +245,7 @@ static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, static void pmem_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t size) { - wb_cache_pmem(addr, size); + arch_wb_cache_pmem(addr, size); } static const struct dax_operations pmem_dax_ops = { diff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h index 7f4dbd72a90a..9137ec80b85f 100644 --- a/drivers/nvdimm/pmem.h +++ b/drivers/nvdimm/pmem.h @@ -4,6 +4,13 @@ #include <linux/types.h> #include <linux/pfn_t.h> #include <linux/fs.h> +#include <asm/pmem.h> + +#ifndef CONFIG_ARCH_HAS_PMEM_API +static inline void arch_wb_cache_pmem(void *addr, size_t size) +{ +} +#endif /* this definition is in it's own header for tools/testing/nvdimm to consume */ struct pmem_device { diff --git a/include/linux/pmem.h b/include/linux/pmem.h index 772bd02a5b52..33ae761f010a 100644 --- a/include/linux/pmem.h +++ b/include/linux/pmem.h @@ -31,11 +31,6 @@ static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n) BUG(); } -static inline void arch_wb_cache_pmem(void *addr, size_t size) -{ - BUG(); -} - static inline void arch_invalidate_pmem(void *addr, size_t size) { BUG(); @@ -80,18 +75,4 @@ static inline void invalidate_pmem(void *addr, size_t size) if (arch_has_pmem_api()) arch_invalidate_pmem(addr, size); } - -/** - * wb_cache_pmem - write back processor cache for PMEM memory range - * @addr: virtual start address - * @size: number of bytes to write back - * - * Write back the processor cache range starting at 'addr' for 'size' bytes. - * See blkdev_issue_flush() note for memcpy_to_pmem(). - */ -static inline void wb_cache_pmem(void *addr, size_t size) -{ - if (arch_has_pmem_api()) - arch_wb_cache_pmem(addr, size); -} #endif /* __PMEM_H__ */
With all calls to this routine re-directed through the pmem driver, we can kill the pmem api indirection. arch_wb_cache_pmem() is now optionally supplied by the arch specific asm/pmem.h. Same as before, pmem flushing is only defined for x86_64, but it is straightforward to add other archs in the future. Cc: <x86@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Oliver O'Halloran <oohall@gmail.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- arch/x86/include/asm/pmem.h | 18 +----------------- arch/x86/include/asm/uaccess_64.h | 1 + arch/x86/lib/usercopy_64.c | 3 ++- drivers/nvdimm/pmem.c | 2 +- drivers/nvdimm/pmem.h | 7 +++++++ include/linux/pmem.h | 19 ------------------- 6 files changed, 12 insertions(+), 38 deletions(-) -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel