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| author | Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> | 2020-06-08 10:09:04 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-09-15 15:13:22 +0300 |
| commit | b32d5d7e920a364287f6206af2d20179978a617d (patch) | |
| tree | 7b59e35679a1beb2c3540f1bb8ea03bdb960a02f /arch/powerpc/include/asm/book3s/64/radix.h | |
| parent | 7746406baa3bc9e23fdd7b7da2f04d86e25ab837 (diff) | |
| download | linux-b32d5d7e920a364287f6206af2d20179978a617d.tar.xz | |
powerpc/mm/book3s: Split radix and hash MAX_PHYSMEM limit
MAX_PHYSMEM #define is used along with sparsemem to determine the SECTION_SHIFT
value. Powerpc also uses the same value to limit the max memory enabled on the
system. With 4K PAGE_SIZE and hash translation mode, we want to limit the max
memory enabled to 64TB due to page table size restrictions. However, with
radix translation, we don't have these restrictions. Hence split the radix
and hash MA_PHYSMEM limit and use different limit for each of them.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200608070904.387440-4-aneesh.kumar@linux.ibm.com
Diffstat (limited to 'arch/powerpc/include/asm/book3s/64/radix.h')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/radix.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h index 0cba794c4fb8..c7813dc628fc 100644 --- a/arch/powerpc/include/asm/book3s/64/radix.h +++ b/arch/powerpc/include/asm/book3s/64/radix.h @@ -91,6 +91,22 @@ * +------------------------------+ Kernel linear (0xc.....) */ + +/* + * If we store section details in page->flags we can't increase the MAX_PHYSMEM_BITS + * if we increase SECTIONS_WIDTH we will not store node details in page->flags and + * page_to_nid does a page->section->node lookup + * Hence only increase for VMEMMAP. Further depending on SPARSEMEM_EXTREME reduce + * memory requirements with large number of sections. + * 51 bits is the max physical real address on POWER9 + */ + +#if defined(CONFIG_SPARSEMEM_VMEMMAP) && defined(CONFIG_SPARSEMEM_EXTREME) +#define R_MAX_PHYSMEM_BITS 51 +#else +#define R_MAX_PHYSMEM_BITS 46 +#endif + #define RADIX_KERN_VIRT_START ASM_CONST(0xc008000000000000) /* * 49 = MAX_EA_BITS_PER_CONTEXT (hash specific). To make sure we pick |