From: Dave Jiang Date: Thu, 7 Jan 2021 16:44:51 +0000 (-0700) Subject: x86/asm: Annotate movdir64b()'s dst argument with __iomem X-Git-Tag: accepted/tizen/unified/20230118.172025~7880^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6ae58d871319dc22ef780baaacd393f8543a1e74;p=platform%2Fkernel%2Flinux-rpi.git x86/asm: Annotate movdir64b()'s dst argument with __iomem Add a missing __iomem annotation to address a sparse warning. The caller is expected to pass an __iomem annotated pointer to this function. The current usages send a 64-bytes command descriptor to an MMIO location (portal) on a device for consumption. When future usages for the MOVDIR64B instruction warrant a separate variant of a memory to memory operation, the argument annotation can be revisited. Also, from the comment in movdir64b() @__dst must be supplied as an lvalue because this tells the compiler what the object is (its size) the instruction accesses. I.e., not the pointers but what they point to, thus the deref'ing '*'." The actual sparse warning is: sparse warnings: (new ones prefixed by >>) drivers/dma/idxd/submit.c: note: in included file (through include/linux/io.h, include/linux/pci.h): >> arch/x86/include/asm/io.h:422:27: sparse: sparse: incorrect type in \ argument 1 (different address spaces) @@ expected void *dst @@ got void [noderef] __iomem *dst @@ arch/x86/include/asm/io.h:422:27: sparse: expected void *dst arch/x86/include/asm/io.h:422:27: sparse: got void [noderef] __iomem *dst [ bp: Massage commit message. ] Fixes: 0888e1030d3e ("x86/asm: Carve out a generic movdir64b() helper for general usage") Reported-by: kernel test robot Signed-off-by: Dave Jiang Signed-off-by: Borislav Petkov Reviewed-by: Ben Widawsky Reviewed-by: Dan Williams Link: https://lkml.kernel.org/r/161003787823.4062451.6564503265464317197.stgit@djiang5-desk3.ch.intel.com --- diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index cc177b4..4e234645 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -243,10 +243,10 @@ static inline void serialize(void) } /* The dst parameter must be 64-bytes aligned */ -static inline void movdir64b(void *dst, const void *src) +static inline void movdir64b(void __iomem *dst, const void *src) { const struct { char _[64]; } *__src = src; - struct { char _[64]; } *__dst = dst; + struct { char _[64]; } __iomem *__dst = dst; /* * MOVDIR64B %(rdx), rax.