[PATCH 1/3] powerpc: Define empty_zero_page[] in C
From: Christophe Leroy <hidden>
Date: 2021-06-07 10:56:15
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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 5227cfa71f9e ("arm64: mm: place
empty_zero_page in bss") explains why it is interesting to have
it in BSS.
Signed-off-by: Christophe Leroy <redacted>
---
Applies on top of powerpc next-test with the Fixup for v3 "powerpc/nohash: Refactor update of BDI2000 pointers in switch_mmu_context()".
The last patch of this small series can be applied independently at the cost of a trivial conflict in asm-offsets.c
arch/powerpc/kernel/head_40x.S | 4 ----
arch/powerpc/kernel/head_44x.S | 4 ----
arch/powerpc/kernel/head_64.S | 5 -----
arch/powerpc/kernel/head_8xx.S | 6 ------
arch/powerpc/kernel/head_book3s_32.S | 5 -----
arch/powerpc/kernel/head_fsl_booke.S | 4 ----
arch/powerpc/mm/mem.c | 3 +++
7 files changed, 3 insertions(+), 28 deletions(-)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 2717aa860cae..92b6c7356161 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S@@ -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
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 2c4ffec027a2..e037eb615757 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S@@ -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.
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index ece7f97bafff..730838c7ca39 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S@@ -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)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 817df9fe7fb3..5ce42dfac061 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S@@ -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
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 326262030279..79c744afc6b6 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S@@ -1274,11 +1274,6 @@ 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
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index ab718fd5e2a2..f33bc5a8e73e 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S@@ -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
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 043bbeaf407c..b06e5d969051 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c@@ -27,6 +27,9 @@ 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) {
--
2.25.0