From 5875509d2f30eb8963163f255ded98095989142f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 11 Jul 2019 20:57:07 -0700 Subject: [PATCH] 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 Reviewed-by: Khalid Aziz Cc: David Miller Cc: Andrey Konovalov Cc: Benjamin Herrenschmidt Cc: James Hogan Cc: Jason Gunthorpe Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Paul Burton Cc: Paul Mackerras Cc: Ralf Baechle Cc: Rich Felker Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/sparc/include/asm/pgtable_64.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h index 439129af9266..8358ba00aa5d 100644 --- a/arch/sparc/include/asm/pgtable_64.h +++ b/arch/sparc/include/asm/pgtable_64.h @@ -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 #include -- 2.30.2