* [RFC PATCH for 4.18 11/23] mm: Provide is_vma_noncached
[not found] <20180412192800.15708-1-mathieu.desnoyers@efficios.com>
@ 2018-04-12 19:27 ` Mathieu Desnoyers
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From: Mathieu Desnoyers @ 2018-04-12 19:27 UTC (permalink / raw)
To: Peter Zijlstra, Paul E . McKenney, Boqun Feng, Andy Lutomirski,
Dave Watson
Cc: linux-kernel, linux-api, Paul Turner, Andrew Morton,
Russell King, Thomas Gleixner, Ingo Molnar, H . Peter Anvin,
Andrew Hunter, Andi Kleen, Chris Lameter, Ben Maurer,
Steven Rostedt, Josh Triplett, Linus Torvalds, Catalin Marinas,
Will Deacon, Michael Kerrisk, Mathieu Desnoyers, linux-mm
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: Andrew Hunter <ahh@google.com>
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 ad06d42adb1a..1f93a061a43b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2425,6 +2425,30 @@ 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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