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| author | Daniel Axtens <dja@axtens.net> | 2021-06-28 19:40:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-29 10:53:53 -0700 |
| commit | c0f8aa4fa815daacb6eca52cae04820d6aecb7c2 (patch) | |
| tree | 2484107da350ea1c6d4e77ec5c2b88d59c692b6f /include | |
| parent | af3751f3c2b6282bebcb56c35bbe4c8b671f80aa (diff) | |
| download | lwn-c0f8aa4fa815daacb6eca52cae04820d6aecb7c2.tar.gz lwn-c0f8aa4fa815daacb6eca52cae04820d6aecb7c2.zip | |
mm: define default MAX_PTRS_PER_* in include/pgtable.h
Commit c65e774fb3f6 ("x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable")
made PTRS_PER_P4D variable on x86 and introduced MAX_PTRS_PER_P4D as a
constant for cases which need a compile-time constant (e.g. fixed-size
arrays).
powerpc likewise has boot-time selectable MMU features which can cause
other mm "constants" to vary. For KASAN, we have some static
PTE/PMD/PUD/P4D arrays so we need compile-time maximums for all these
constants. Extend the MAX_PTRS_PER_ idiom, and place default definitions
in include/pgtable.h. These define MAX_PTRS_PER_x to be PTRS_PER_x unless
an architecture has defined MAX_PTRS_PER_x in its arch headers.
Clean up pgtable-nop4d.h and s390's MAX_PTRS_PER_P4D definitions while
we're at it: both can just pick up the default now.
Link: https://lkml.kernel.org/r/20210624034050.511391-4-dja@axtens.net
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/pgtable-nop4d.h | 1 | ||||
| -rw-r--r-- | include/linux/pgtable.h | 22 |
2 files changed, 22 insertions, 1 deletions
diff --git a/include/asm-generic/pgtable-nop4d.h b/include/asm-generic/pgtable-nop4d.h index ce2cbb3c380f..2f6b1befb129 100644 --- a/include/asm-generic/pgtable-nop4d.h +++ b/include/asm-generic/pgtable-nop4d.h @@ -9,7 +9,6 @@ typedef struct { pgd_t pgd; } p4d_t; #define P4D_SHIFT PGDIR_SHIFT -#define MAX_PTRS_PER_P4D 1 #define PTRS_PER_P4D 1 #define P4D_SIZE (1UL << P4D_SHIFT) #define P4D_MASK (~(P4D_SIZE-1)) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index a43047b1030d..c32600c9e1ad 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1592,4 +1592,26 @@ typedef unsigned int pgtbl_mod_mask; #define pte_leaf_size(x) PAGE_SIZE #endif +/* + * Some architectures have MMUs that are configurable or selectable at boot + * time. These lead to variable PTRS_PER_x. For statically allocated arrays it + * helps to have a static maximum value. + */ + +#ifndef MAX_PTRS_PER_PTE +#define MAX_PTRS_PER_PTE PTRS_PER_PTE +#endif + +#ifndef MAX_PTRS_PER_PMD +#define MAX_PTRS_PER_PMD PTRS_PER_PMD +#endif + +#ifndef MAX_PTRS_PER_PUD +#define MAX_PTRS_PER_PUD PTRS_PER_PUD +#endif + +#ifndef MAX_PTRS_PER_P4D +#define MAX_PTRS_PER_P4D PTRS_PER_P4D +#endif + #endif /* _LINUX_PGTABLE_H */ |