[PATCH v1 14/30] powerpc/vdso: Simplify __get_datapage()

From: Christophe Leroy
Date: Sun Sep 27 2020 - 05:16:47 EST


The VDSO datapage and the text pages are always located immediately
next to each other, so it can be hardcoded without an indirection
through __kernel_datapage_offset

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/vdso_datapage.h | 8 +++++---
arch/powerpc/kernel/vdso32/vdso32.lds.S | 2 ++
arch/powerpc/kernel/vdso64/vdso64.lds.S | 2 ++
3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
index 3d996db05acd..535ba737397d 100644
--- a/arch/powerpc/include/asm/vdso_datapage.h
+++ b/arch/powerpc/include/asm/vdso_datapage.h
@@ -105,10 +105,12 @@ extern struct vdso_arch_data *vdso_data;

.macro get_datapage ptr, tmp
bcl 20, 31, .+4
+999:
mflr \ptr
- addi \ptr, \ptr, (__kernel_datapage_offset - (.-4))@l
- lwz \tmp, 0(\ptr)
- add \ptr, \tmp, \ptr
+#if CONFIG_PPC_PAGE_SHIFT > 14
+ addis \ptr, \ptr, (_vdso_datapage - 999b)@ha
+#endif
+ addi \ptr, \ptr, (_vdso_datapage - 999b)@l
.endm

#endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/kernel/vdso32/vdso32.lds.S b/arch/powerpc/kernel/vdso32/vdso32.lds.S
index af5812ca5dce..c96b5141738e 100644
--- a/arch/powerpc/kernel/vdso32/vdso32.lds.S
+++ b/arch/powerpc/kernel/vdso32/vdso32.lds.S
@@ -4,6 +4,7 @@
* library
*/
#include <asm/vdso.h>
+#include <asm/page.h>

#ifdef __LITTLE_ENDIAN__
OUTPUT_FORMAT("elf32-powerpcle", "elf32-powerpcle", "elf32-powerpcle")
@@ -15,6 +16,7 @@ ENTRY(_start)

SECTIONS
{
+ PROVIDE(_vdso_datapage = . - PAGE_SIZE);
. = VDSO32_LBASE + SIZEOF_HEADERS;

.hash : { *(.hash) } :text
diff --git a/arch/powerpc/kernel/vdso64/vdso64.lds.S b/arch/powerpc/kernel/vdso64/vdso64.lds.S
index 256fb9720298..aa5b924683c5 100644
--- a/arch/powerpc/kernel/vdso64/vdso64.lds.S
+++ b/arch/powerpc/kernel/vdso64/vdso64.lds.S
@@ -4,6 +4,7 @@
* library
*/
#include <asm/vdso.h>
+#include <asm/page.h>

#ifdef __LITTLE_ENDIAN__
OUTPUT_FORMAT("elf64-powerpcle", "elf64-powerpcle", "elf64-powerpcle")
@@ -15,6 +16,7 @@ ENTRY(_start)

SECTIONS
{
+ PROVIDE(_vdso_datapage = . - PAGE_SIZE);
. = VDSO64_LBASE + SIZEOF_HEADERS;

.hash : { *(.hash) } :text
--
2.25.0