When CONFIG_VMAP_STACK is enabled, we set THREAD_SIZE to be at least the
size of a page.
There's a few bits of assembly in the book3s64 code that use THREAD_SIZE in
immediate mode instructions, which can only take an operand of up to 16
bits signed, which isn't quite large enough.
Fix these spots to use a scratch register or use two immediate mode
instructions instead, so we can later enable VMAP_STACK.
Signed-off-by: Andrew Donnellan <a...@linux.ibm.com>
---
arch/powerpc/include/asm/asm-compat.h | 2 ++
arch/powerpc/kernel/entry_64.S | 4 +++-
arch/powerpc/kernel/irq.c | 8 ++++++--
arch/powerpc/kernel/misc_64.S | 4 +++-
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 3 ++-
5 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/asm-compat.h
b/arch/powerpc/include/asm/asm-compat.h
index 2bc53c646ccd..30dd7813bf3b 100644
--- a/arch/powerpc/include/asm/asm-compat.h
+++ b/arch/powerpc/include/asm/asm-compat.h
@@ -11,6 +11,7 @@
#define PPC_LL stringify_in_c(ld)
#define PPC_STL stringify_in_c(std)
#define PPC_STLU stringify_in_c(stdu)
+#define PPC_STLUX stringify_in_c(stdux)
#define PPC_LCMPI stringify_in_c(cmpdi)
#define PPC_LCMPLI stringify_in_c(cmpldi)
#define PPC_LCMP stringify_in_c(cmpd)
@@ -45,6 +46,7 @@
#define PPC_LL stringify_in_c(lwz)
#define PPC_STL stringify_in_c(stw)
#define PPC_STLU stringify_in_c(stwu)
+#define PPC_STLUX stringify_in_c(stwux)
#define PPC_LCMPI stringify_in_c(cmpwi)
#define PPC_LCMPLI stringify_in_c(cmplwi)
#define PPC_LCMP stringify_in_c(cmpw)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 3e2e37e6ecab..af25db6e0205 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -238,7 +238,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
/* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE
because we don't need to leave the 288-byte ABI gap at the
top of the kernel stack. */
- addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE
+ li r9,0
+ ori r9,r9,THREAD_SIZE-SWITCH_FRAME_SIZE
+ add r7,r7,r9
/*
* PMU interrupts in radix may come in here. They will use r1, not
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 9ede61a5a469..098cf6adceec 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -204,7 +204,9 @@ static __always_inline void call_do_softirq(const void *sp)
{
/* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */
asm volatile (
- PPC_STLU " %%r1, %[offset](%[sp]) ;"
+ "li %%r0, 0 ;"
+ "ori %%r0, %%r0, %[offset] ;"
+ PPC_STLUX " %%r1, %[sp], %%r0 ;"
"mr %%r1, %[sp] ;"
"bl %[callee] ;"
PPC_LL " %%r1, 0(%%r1) ;"
@@ -256,7 +258,9 @@ static __always_inline void call_do_irq(struct pt_regs
*regs, void *sp)
/* Temporarily switch r1 to sp, call __do_irq() then restore r1. */
asm volatile (
- PPC_STLU " %%r1, %[offset](%[sp]) ;"
+ "li %%r0, 0 ;"
+ "ori %%r0, %%r0, %[offset] ;"
+ PPC_STLUX " %%r1, %[sp], %%r0 ;"
"mr %%r4, %%r1 ;"
"mr %%r1, %[sp] ;"
"bl %[callee] ;"
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 36184cada00b..ff71b98500a3 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -384,7 +384,9 @@ _GLOBAL(kexec_sequence)
std r0,16(r1)
/* switch stacks to newstack -- &kexec_stack.stack */
- stdu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
+ li r0,0
+ ori r0,r0,THREAD_SIZE-STACK_FRAME_OVERHEAD
+ stdux r1,r3,r0
mr r1,r3
li r0,0
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 37f50861dd98..d05e3d324f4d 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -2686,7 +2686,8 @@ kvmppc_bad_host_intr:
mr r9, r1
std r1, PACAR1(r13)
ld r1, PACAEMERGSP(r13)
- subi r1, r1, THREAD_SIZE/2 + INT_FRAME_SIZE
+ subi r1, r1, THREAD_SIZE/2
+ subi r1, r1, INT_FRAME_SIZE
std r9, 0(r1)
std r0, GPR0(r1)
std r9, GPR1(r1)
--
2.38.1
