Messages in this thread Patch in this message | | | Date | Mon, 24 Jul 2023 16:11:56 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH -next v2] arm64: fix build warning for ARM64_MEMSTART_SHIFT |
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On Mon, Jul 24, 2023 at 05:27:51PM +0000, Zhang Jianhua wrote: > When building with W=1, the following warning occurs. > > arch/arm64/include/asm/kernel-pgtable.h:129:41: error: "PUD_SHIFT" is not defined, evaluates to 0 [-Werror=undef] > 129 | #define ARM64_MEMSTART_SHIFT PUD_SHIFT > | ^~~~~~~~~ > arch/arm64/include/asm/kernel-pgtable.h:142:5: note: in expansion of macro ‘ARM64_MEMSTART_SHIFT’ > 142 | #if ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS > | ^~~~~~~~~~~~~~~~~~~~
Another thing that's missing here is that the warning is probably when this file is included from asm-offests.h or some .S file.
> diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h > index 577773870b66..51bdce66885d 100644 > --- a/arch/arm64/include/asm/kernel-pgtable.h > +++ b/arch/arm64/include/asm/kernel-pgtable.h > @@ -125,12 +125,14 @@ > * (64k granule), or a multiple that can be mapped using contiguous bits > * in the page tables: 32 * PMD_SIZE (16k granule) > */ > -#if defined(CONFIG_ARM64_4K_PAGES) > +#if defined(CONFIG_ARM64_4K_PAGES) && defined(PUD_SHIFT) > #define ARM64_MEMSTART_SHIFT PUD_SHIFT
That's not the correct fix since PUD_SHIFT should always be defined. When CONFIG_PGTABLE_LEVELS == 3, pgtable-types.h includes asm-generic/pgtable-nopud.h and this defines PUD_SHIFT. We either got ARM64_MEMSTART_SHIFT defined in the wrong file or kernel-pgtable.h does not pull the relevant headers (either directly or via an included header). Even if kernel-pgtable.h ends up including the nopud/nopmd headers, P*D_SHIFT is guarded by an #indef __ASSEMBLY__ in those files.
Something like below appears to fix this, though I'm not particularly fond of guarding the ARM64_MEMSTART_* definitions by #ifndef __ASSEMBLY__ for no apparent reason (could add a comment though):
-----------------------8<--------------------------- diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h index 577773870b66..fcea7e87a6ca 100644 --- a/arch/arm64/include/asm/kernel-pgtable.h +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -118,6 +118,8 @@ #define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PTE_RDONLY) #endif +#ifndef __ASSEMBLY__ + /* * To make optimal use of block mappings when laying out the linear * mapping, round down the base of physical memory to a size that can @@ -145,4 +147,6 @@ #define ARM64_MEMSTART_ALIGN (1UL << ARM64_MEMSTART_SHIFT) #endif +#endif /* __ASSEMBLY__ */ + #endif /* __ASM_KERNEL_PGTABLE_H */ diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index e4944d517c99..22b36f2d5d93 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -6,6 +6,7 @@ #define __ASM_PGTABLE_HWDEF_H #include <asm/memory.h> +#include <asm/pgtable-types.h> /* * Number of page-table levels required to address 'va_bits' wide diff --git a/arch/arm64/include/asm/pgtable-types.h b/arch/arm64/include/asm/pgtable-types.h index b8f158ae2527..ae86e66fdb11 100644 --- a/arch/arm64/include/asm/pgtable-types.h +++ b/arch/arm64/include/asm/pgtable-types.h @@ -11,6 +11,8 @@ #include <asm/types.h> +#ifndef __ASSEMBLY__ + typedef u64 pteval_t; typedef u64 pmdval_t; typedef u64 pudval_t; @@ -44,6 +46,8 @@ typedef struct { pteval_t pgprot; } pgprot_t; #define pgprot_val(x) ((x).pgprot) #define __pgprot(x) ((pgprot_t) { (x) } ) +#endif /* __ASSEMBLY__ */ + #if CONFIG_PGTABLE_LEVELS == 2 #include <asm-generic/pgtable-nopmd.h> #elif CONFIG_PGTABLE_LEVELS == 3 -----------------------8<--------------------------- To avoid guarding the ARM64_MEMSTART_* definitions, we could instead move the P*D_SHIFT definitions in asm-generic/pgtable-nop*d.h outside the #ifndef __ASSEMBLY__ block.
-- Catalin
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