Commit 4e0bacd6 authored by Zhang Jianhua's avatar Zhang Jianhua Committed by Will Deacon
Browse files

arm64: fix build warning for ARM64_MEMSTART_SHIFT 



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
      |     ^~~~~~~~~~~~~~~~~~~~

The generic PUD_SHIFT was defined in include/asm-generic/pgtable-nopud.h,
however the #ifndef __ASSEMBLY__ guard in this header file makes it unavailable
for assembly files. While someone .S file include the <asm/kernel-pgtable.h>,
the build warning would occur. Now move the macro ARM64_MEMSTART_SHIFT and
ARM64_MEMSTART_ALIGN to arch/arm64/mm/init.c where it is used only, to avoid
this issue.

Signed-off-by: default avatarZhang Jianhua <chris.zjh@huawei.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20230804075615.3334756-1-chris.zjh@huawei.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 42501f6d

arch/arm64/include/asm/kernel-pgtable.h

+0 −27
Original line number Diff line number Diff line
@@ -118,31 +118,4 @@ 
#define SWAPPER_RX_MMUFLAGS	(SWAPPER_RW_MMUFLAGS | PTE_RDONLY)

#endif



/*

 * 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

 * be mapped efficiently, i.e., either PUD_SIZE (4k granule) or PMD_SIZE

 * (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)

#define ARM64_MEMSTART_SHIFT		PUD_SHIFT

#elif defined(CONFIG_ARM64_16K_PAGES)

#define ARM64_MEMSTART_SHIFT		CONT_PMD_SHIFT

#else

#define ARM64_MEMSTART_SHIFT		PMD_SHIFT

#endif



/*

 * sparsemem vmemmap imposes an additional requirement on the alignment of

 * memstart_addr, due to the fact that the base of the vmemmap region

 * has a direct correspondence, and needs to appear sufficiently aligned

 * in the virtual address space.

 */

#if ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS

#define ARM64_MEMSTART_ALIGN	(1UL << SECTION_SIZE_BITS)

#else

#define ARM64_MEMSTART_ALIGN	(1UL << ARM64_MEMSTART_SHIFT)

#endif



#endif	/* __ASM_KERNEL_PGTABLE_H */

arch/arm64/mm/init.c

+27 −0
Original line number Diff line number Diff line
@@ -73,6 +73,33 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit; 


#define DEFAULT_CRASH_KERNEL_LOW_SIZE	(128UL << 20)



/*

 * 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

 * be mapped efficiently, i.e., either PUD_SIZE (4k granule) or PMD_SIZE

 * (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)

#define ARM64_MEMSTART_SHIFT		PUD_SHIFT

#elif defined(CONFIG_ARM64_16K_PAGES)

#define ARM64_MEMSTART_SHIFT		CONT_PMD_SHIFT

#else

#define ARM64_MEMSTART_SHIFT		PMD_SHIFT

#endif



/*

 * sparsemem vmemmap imposes an additional requirement on the alignment of

 * memstart_addr, due to the fact that the base of the vmemmap region

 * has a direct correspondence, and needs to appear sufficiently aligned

 * in the virtual address space.

 */

#if ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS

#define ARM64_MEMSTART_ALIGN	(1UL << SECTION_SIZE_BITS)

#else

#define ARM64_MEMSTART_ALIGN	(1UL << ARM64_MEMSTART_SHIFT)

#endif



static int __init reserve_crashkernel_low(unsigned long long low_size)

{

	unsigned long long low_base;