From 6ae58d871319dc22ef780baaacd393f8543a1e74 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 7 Jan 2021 09:44:51 -0700 Subject: [PATCH 1/2] 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 --- arch/x86/include/asm/special_insns.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index cc177b4431ae..4e234645f0c6 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. From 5c99720b28381bb400d4f546734c34ddaf608761 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 7 Jan 2021 09:45:21 -0700 Subject: [PATCH 2/2] x86/asm: Add a missing __iomem annotation in enqcmds() 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. Also, from the comment in movdir64b(), which also applies to enqcmds(), @__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: drivers/dma/idxd/submit.c: note: in included file (through arch/x86/include/asm/processor.h, \ arch/x86/include/asm/timex.h, include/linux/timex.h, include/linux/time32.h, \ include/linux/time.h, include/linux/stat.h, ...): ./arch/x86/include/asm/special_insns.h:289:41: warning: incorrect type in initializer (different address spaces) ./arch/x86/include/asm/special_insns.h:289:41: expected struct *__dst ./arch/x86/include/asm/special_insns.h:289:41: got void [noderef] __iomem *dst [ bp: Massage commit message. ] Fixes: 7f5933f81bd8 ("x86/asm: Add an enqcmds() wrapper for the ENQCMDS instruction") 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/161003789741.4062451.14362269365703761223.stgit@djiang5-desk3.ch.intel.com --- arch/x86/include/asm/special_insns.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index 4e234645f0c6..1d3cbaef4bb7 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -286,7 +286,7 @@ static inline void movdir64b(void __iomem *dst, const void *src) static inline int enqcmds(void __iomem *dst, const void *src) { const struct { char _[64]; } *__src = src; - struct { char _[64]; } *__dst = dst; + struct { char _[64]; } __iomem *__dst = dst; int zf; /*