powerpc: Define empty_zero_page[] in C

At the time being, empty_zero_page[] is defined in each
platform head.S.

Define it in mm/mem.c instead, and put it in BSS section instead
of the DATA section. Commit 5227cfa71f ("arm64: mm: place
empty_zero_page in bss") explains why it is interesting to have
it in BSS.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5838caffa269e0957c5a50cc85477876220298b0.1623063174.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-06-07 10:56:04 +00:00 committed by Michael Ellerman
parent a1ea0ca8a6
commit 45b30fafe5
7 changed files with 3 additions and 28 deletions

View File

@ -709,10 +709,6 @@ _GLOBAL(abort)
.align 12
.globl sdata
sdata:
.globl empty_zero_page
empty_zero_page:
.space 4096
EXPORT_SYMBOL(empty_zero_page)
.globl swapper_pg_dir
swapper_pg_dir:
.space PGD_TABLE_SIZE

View File

@ -1241,10 +1241,6 @@ head_start_common:
.align PAGE_SHIFT
.globl sdata
sdata:
.globl empty_zero_page
empty_zero_page:
.space PAGE_SIZE
EXPORT_SYMBOL(empty_zero_page)
/*
* To support >32-bit physical addresses, we use an 8KB pgdir.

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@ -1012,8 +1012,3 @@ start_here_common:
.globl swapper_pg_dir
swapper_pg_dir:
.space PGD_TABLE_SIZE
.globl empty_zero_page
empty_zero_page:
.space PAGE_SIZE
EXPORT_SYMBOL(empty_zero_page)

View File

@ -795,12 +795,6 @@ _GLOBAL(mmu_pin_tlb)
.data
.globl sdata
sdata:
.globl empty_zero_page
.align PAGE_SHIFT
empty_zero_page:
.space PAGE_SIZE
EXPORT_SYMBOL(empty_zero_page)
.globl swapper_pg_dir
swapper_pg_dir:
.space PGD_TABLE_SIZE

View File

@ -1216,11 +1216,6 @@ setup_usbgecko_bat:
.data
.globl sdata
sdata:
.globl empty_zero_page
empty_zero_page:
.space 4096
EXPORT_SYMBOL(empty_zero_page)
.globl swapper_pg_dir
swapper_pg_dir:
.space PGD_TABLE_SIZE

View File

@ -1221,10 +1221,6 @@ _GLOBAL(restore_to_as0)
.align 12
.globl sdata
sdata:
.globl empty_zero_page
empty_zero_page:
.space 4096
EXPORT_SYMBOL(empty_zero_page)
.globl swapper_pg_dir
swapper_pg_dir:
.space PGD_TABLE_SIZE

View File

@ -28,6 +28,9 @@
unsigned long long memory_limit;
bool init_mem_is_free;
unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
EXPORT_SYMBOL(empty_zero_page);
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{