Messages in this thread Patch in this message | | | From | Mathieu Desnoyers <> | Subject | [RFC PATCH for 4.21 05/16] mm: Provide is_vma_noncached | Date | Thu, 1 Nov 2018 10:58:33 +0100 |
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Provide is_vma_noncached() static inline to allow generic code to check whether the given vma consists of noncached memory.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Peter Zijlstra <peterz@infradead.org> CC: Paul Turner <pjt@google.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Andy Lutomirski <luto@amacapital.net> CC: Andi Kleen <andi@firstfloor.org> CC: Dave Watson <davejwatson@fb.com> CC: Chris Lameter <cl@linux.com> CC: Ingo Molnar <mingo@redhat.com> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Ben Maurer <bmaurer@fb.com> CC: Steven Rostedt <rostedt@goodmis.org> CC: Josh Triplett <josh@joshtriplett.org> CC: Linus Torvalds <torvalds@linux-foundation.org> CC: Andrew Morton <akpm@linux-foundation.org> CC: Russell King <linux@arm.linux.org.uk> CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> CC: Michael Kerrisk <mtk.manpages@gmail.com> CC: Boqun Feng <boqun.feng@gmail.com> CC: linux-mm@kvack.org --- include/linux/mm.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h index 0416a7204be3..18acf4f339f8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2551,6 +2551,30 @@ static inline struct page *follow_page(struct vm_area_struct *vma, return follow_page_mask(vma, address, foll_flags, &unused_page_mask); } +static inline bool pgprot_same(pgprot_t a, pgprot_t b) +{ + return pgprot_val(a) == pgprot_val(b); +} + +#ifdef pgprot_noncached +static inline bool is_vma_noncached(struct vm_area_struct *vma) +{ + pgprot_t pgprot = vma->vm_page_prot; + + /* Check whether architecture implements noncached pages. */ + if (pgprot_same(pgprot_noncached(PAGE_KERNEL), PAGE_KERNEL)) + return false; + if (!pgprot_same(pgprot, pgprot_noncached(pgprot))) + return false; + return true; +} +#else +static inline bool is_vma_noncached(struct vm_area_struct *vma) +{ + return false; +} +#endif + #define FOLL_WRITE 0x01 /* check pte is writable */ #define FOLL_TOUCH 0x02 /* mark page accessed */ #define FOLL_GET 0x04 /* do get_page on page */ -- 2.11.0
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