[PATCH v3 1/8] powerpc: Create a helper for getting the kernel toc value

Michael Ellerman
2016-03-03T04:27:07Z

Move the logic to work out the kernel toc pointer into a header. This is
a good cleanup, and also means we can use it elsewhere in future.

Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/include/asm/sections.h | 12 ++++++++++++
arch/powerpc/kernel/paca.c | 11 +----------
2 files changed, 13 insertions(+), 10 deletions(-)

v3: No change.
v2: New.

diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index a5e930aca804..abf5866e08c6 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -22,6 +22,18 @@ static inline int in_kernel_text(unsigned long addr)
return 0;
}

+static inline unsigned long kernel_toc_addr(void)
+{
+ /* Defined by the linker, see vmlinux.lds.S */
+ extern unsigned long __toc_start;
+
+ /*
+ * The TOC register (r2) points 32kB into the TOC, so that 64kB of
+ * the TOC can be addressed using a single machine instruction.
+ */
+ return (unsigned long)(&__toc_start) + 0x8000UL;
+}
+
static inline int overlaps_interrupt_vector_text(unsigned long start,
unsigned long end)
{
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 01ea0edf0579..93dae296b6be 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -17,10 +17,6 @@
#include <asm/pgtable.h>
#include <asm/kexec.h>

-/* This symbol is provided by the linker - let it fill in the paca
- * field correctly */
-extern unsigned long __toc_start;
-
#ifdef CONFIG_PPC_BOOK3S

/*
@@ -149,11 +145,6 @@ EXPORT_SYMBOL(paca);

void __init initialise_paca(struct paca_struct *new_paca, int cpu)
{
- /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
- * of the TOC can be addressed using a single machine instruction.
- */
- unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
-
#ifdef CONFIG_PPC_BOOK3S
new_paca->lppaca_ptr = new_lppaca(cpu);
#else
@@ -161,7 +152,7 @@ void __init initialise_paca(struct paca_struct *new_paca, int cpu)
#endif
new_paca->lock_token = 0x8000;
new_paca->paca_index = cpu;
- new_paca->kernel_toc = kernel_toc;
+ new_paca->kernel_toc = kernel_toc_addr();
new_paca->kernelbase = (unsigned long) _stext;
/* Only set MSR:IR/DR when MMU is initialized */
new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
--
2.5.0