Le 12/03/2021 à 02:20, Nicholas Piggin a écrit :
There is no need for this to be in asm, use the new intrrupt entry wrapper.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
Hopefully this works on a real G5 now, but I couldn't reproduce the
problem with QEMU.
Thanks,
Nick
arch/powerpc/include/asm/interrupt.h | 19 +++++++++++
arch/powerpc/include/asm/processor.h | 1 +
arch/powerpc/include/asm/thread_info.h | 6 ++++
arch/powerpc/kernel/exceptions-64s.S | 45 --------------------------
arch/powerpc/kernel/idle_book3s.S | 4 +++
5 files changed, 30 insertions(+), 45 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h
b/arch/powerpc/include/asm/interrupt.h
index aedfba29e43a..ef015d3b5e39 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -9,6 +9,17 @@
#include <asm/kprobes.h>
#include <asm/runlatch.h>
+static inline void nap_adjust_return(struct pt_regs *regs)
+{
+#ifdef CONFIG_PPC_970_NAP
+ if (unlikely(test_thread_local_flags(_TLF_NAPPING))) {
+ /* Can avoid a test-and-clear because NMIs do not call this */
+ clear_thread_local_flags(_TLF_NAPPING);
+ regs->nip = (unsigned long)power4_idle_nap_return;
Why don't you do regs->nip = regs->link like PPC32 instead of going via an intermediate symbol that
does nothing else than branching to LR ?
+ }
+#endif
+}
+
struct interrupt_state {
#ifdef CONFIG_PPC_BOOK3E_64
enum ctx_state ctx_state;
@@ -111,6 +122,9 @@ static inline void interrupt_async_exit_prepare(struct
pt_regs *regs, struct int
{
irq_exit();
interrupt_exit_prepare(regs, state);
+
+ /* Adjust at exit so the main handler sees the true NIA */
+ nap_adjust_return(regs);
}
struct interrupt_nmi_state {
@@ -164,6 +178,11 @@ static inline void interrupt_nmi_exit_prepare(struct
pt_regs *regs, struct inter
radix_enabled() || (mfmsr() & MSR_DR))
nmi_exit();
+ /*
+ * nmi does not call nap_adjust_return because nmi should not create
+ * new work to do (must use irq_work for that).
+ */
+
#ifdef CONFIG_PPC64
if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260)
this_cpu_set_ftrace_enabled(state->ftrace_enabled);
...
diff --git a/arch/powerpc/kernel/idle_book3s.S
b/arch/powerpc/kernel/idle_book3s.S
index f9e6d83e6720..abb719b21cae 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -209,4 +209,8 @@ _GLOBAL(power4_idle_nap)
mtmsrd r7
isync
b 1b
+
+ .globl power4_idle_nap_return
+power4_idle_nap_return:
+ blr
#endif
