Commit 5875509d authored Jul 11, 2019 by Christoph Hellwig Committed by Linus Torvalds Jul 12, 2019

sparc64: define untagged_addr()

Add a helper to untag a user pointer.  This is needed for ADI support
in get_user_pages_fast.

Link: http://lkml.kernel.org/r/20190625143715.1689-9-hch@lst.de


Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent d8550790

arch/sparc/include/asm/pgtable_64.h

+22 −0

Original line number	Diff line number	Diff line
		@@ -1078,6 +1078,28 @@ static inline int io_remap_pfn_range(struct vm_area_struct *vma,
		}
		#define io_remap_pfn_range io_remap_pfn_range

		static inline unsigned long untagged_addr(unsigned long start)
		{
		if (adi_capable()) {
		long addr = start;

		/* If userspace has passed a versioned address, kernel
		* will not find it in the VMAs since it does not store
		* the version tags in the list of VMAs. Storing version
		* tags in list of VMAs is impractical since they can be
		* changed any time from userspace without dropping into
		* kernel. Any address search in VMAs will be done with
		* non-versioned addresses. Ensure the ADI version bits
		* are dropped here by sign extending the last bit before
		* ADI bits. IOMMU does not implement version tags.
		*/
		return (addr << (long)adi_nbits()) >> (long)adi_nbits();
		}

		return start;
		}
		#define untagged_addr untagged_addr

		#include <asm/tlbflush.h>
		#include <asm-generic/pgtable.h>