From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>, Anton Blanchard <anton@samba.org>
Subject: [PATCH 06/14] powerpc/64s: branch to idle handler with virtual mode offset
Date: Fri, 2 Jun 2017 17:39:38 +1000 [thread overview]
Message-ID: <20170602073946.8983-7-npiggin@gmail.com> (raw)
In-Reply-To: <20170602073946.8983-1-npiggin@gmail.com>
Have the system reset idle wakeup handlers branched to in real mode
with the 0xc... kernel address applied. This allows simplifications
of avoiding rfid when switching to virtual mode in the wakeup handler.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/exception-64s.h | 17 ++++++++++++++---
arch/powerpc/kernel/exceptions-64s.S | 6 ++++--
2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 183d73b6ed99..0912e328e1d7 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -236,15 +236,26 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
#define kvmppc_interrupt kvmppc_interrupt_pr
#endif
+/*
+ * Branch to label using its 0xC000 address. This gives the same real address
+ * when relocation is off, but allows mtmsr to set MSR[IR|DR]=1.
+ * This could set the 0xc bits for !RELOCATABLE rather than load KBASE for
+ * a slight optimisation.
+ */
+#define BRANCH_TO_C000(reg, label) \
+ __LOAD_HANDLER(reg, label); \
+ mtctr reg; \
+ bctr
+
#ifdef CONFIG_RELOCATABLE
#define BRANCH_TO_COMMON(reg, label) \
__LOAD_HANDLER(reg, label); \
mtctr reg; \
bctr
-#define BRANCH_LINK_TO_FAR(label) \
- __LOAD_FAR_HANDLER(r12, label); \
- mtctr r12; \
+#define BRANCH_LINK_TO_FAR(reg, label) \
+ __LOAD_FAR_HANDLER(reg, label); \
+ mtctr reg; \
bctrl
/*
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 06f9c573b1a1..0c07a3e3158a 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -99,7 +99,9 @@ EXC_VIRT_NONE(0x4000, 0x100)
#ifdef CONFIG_PPC_P7_NAP
/*
* If running native on arch 2.06 or later, check if we are waking up
- * from nap/sleep/winkle, and branch to idle handler.
+ * from nap/sleep/winkle, and branch to idle handler. The idle wakeup
+ * handler initially runs in real mode, but we branch to the 0xc000...
+ * address so we can turn on relocation with mtmsr.
*/
#define IDLETEST(n) \
BEGIN_FTR_SECTION ; \
@@ -107,7 +109,7 @@ EXC_VIRT_NONE(0x4000, 0x100)
rlwinm. r10,r10,47-31,30,31 ; \
beq- 1f ; \
cmpwi cr3,r10,2 ; \
- BRANCH_TO_COMMON(r10, system_reset_idle_common) ; \
+ BRANCH_TO_C000(r10, system_reset_idle_common) ; \
1: \
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
#else
--
2.11.0
next prev parent reply other threads:[~2017-06-02 7:40 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-02 7:39 [RFC][PATCH 00/14] syscall, context switch, idle performance stuff Nicholas Piggin
2017-06-02 7:39 ` [PATCH 01/14] powerpc/64s: optimize hypercall/syscall Nicholas Piggin
2017-06-02 7:39 ` [PATCH 02/14] powerpc/64: syscall avoid restore_math call if possible Nicholas Piggin
2017-06-02 7:39 ` [PATCH 03/14] powerpc/64s: idle move soft interrupt mask logic into C code Nicholas Piggin
2017-06-02 7:39 ` [PATCH 04/14] powerpc/64s: process interrupts from system reset wakeup Nicholas Piggin
2017-06-02 7:39 ` [PATCH 05/14] powerpc/64s: msgclr when handling doorbell exceptions Nicholas Piggin
2017-06-02 7:39 ` Nicholas Piggin [this message]
2017-06-02 7:39 ` [PATCH 07/14] powerpc/64s: idle avoid SRR usage in idle sleep/wake paths Nicholas Piggin
2017-06-02 13:37 ` kbuild test robot
2017-06-02 7:39 ` [PATCH 08/14] powerpc/64s: idle set polling before enabling irqs Nicholas Piggin
2017-06-02 7:39 ` [PATCH 09/14] powerpc/64s: idle read mostly for common globals Nicholas Piggin
2017-06-02 7:39 ` [PATCH 10/14] powerpc/64: CTRL[RUN] run-latch setting optimisation Nicholas Piggin
2017-06-02 7:39 ` [PATCH 11/14] powerpc/64s: idle no memory barrier after break from idle Nicholas Piggin
2017-06-02 7:39 ` [PATCH 12/14] powerpc/64s: Leave IRQs hard enabled over context switch for radix Nicholas Piggin
2017-06-02 7:39 ` [PATCH 13/14] powerpc/64: context switch can avoid reservation clear Nicholas Piggin
2017-06-02 7:39 ` [PATCH 14/14] powerpc/64: context switch additional hwsync can be avoided Nicholas Piggin
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