From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH 03/13] powerpc: Rework runlatch code
Date: Mon, 5 Mar 2012 13:51:21 +1100 [thread overview]
Message-ID: <1330915891-19523-4-git-send-email-benh@kernel.crashing.org> (raw)
In-Reply-To: <1330915891-19523-1-git-send-email-benh@kernel.crashing.org>
This moves the inlines into system.h and changes the runlatch
code to use the thread local flags (non-atomic) rather than
the TIF flags (atomic) to keep track of the latch state.
The code to turn it back on in an asynchronous interrupt is
now simplified and partially inlined.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
arch/powerpc/include/asm/exception-64s.h | 50 ++++++++++++++++--------------
arch/powerpc/include/asm/reg.h | 22 +------------
arch/powerpc/include/asm/system.h | 38 ++++++++++++++++++++++
arch/powerpc/include/asm/thread_info.h | 9 +++++-
arch/powerpc/kernel/exceptions-64s.S | 3 ++
arch/powerpc/kernel/process.c | 24 ++++++--------
6 files changed, 89 insertions(+), 57 deletions(-)
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 041b222..bdc9eeb 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -284,35 +284,39 @@ label##_hv: \
rlwimi r11,r12,0,MSR_EE; \
mtmsrd r11,1
-#define STD_EXCEPTION_COMMON(trap, label, hdlr) \
- .align 7; \
- .globl label##_common; \
-label##_common: \
- EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
- DISABLE_INTS; \
- bl .save_nvgprs; \
- addi r3,r1,STACK_FRAME_OVERHEAD; \
- bl hdlr; \
- b .ret_from_except
+#define ADD_NVGPRS \
+ bl .save_nvgprs
+
+#define RUNLATCH_ON \
+BEGIN_FTR_SECTION \
+ clrrdi r3,r1,THREAD_SHIFT; \
+ ld r4,TI_LOCAL_FLAGS(r3); \
+ andi. r0,r4,_TLF_RUNLATCH; \
+ beql ppc64_runlatch_on_trampoline; \
+END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
+
+#define EXCEPTION_COMMON(trap, label, hdlr, ret, additions) \
+ .align 7; \
+ .globl label##_common; \
+label##_common: \
+ EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
+ additions; \
+ addi r3,r1,STACK_FRAME_OVERHEAD; \
+ bl hdlr; \
+ b ret
+
+#define STD_EXCEPTION_COMMON(trap, label, hdlr) \
+ EXCEPTION_COMMON(trap, label, hdlr, ret_from_except, \
+ ADD_NVGPRS;DISABLE_INTS)
/*
* Like STD_EXCEPTION_COMMON, but for exceptions that can occur
* in the idle task and therefore need the special idle handling
* (finish nap and runlatch)
*/
-#define STD_EXCEPTION_COMMON_ASYNC(trap, label, hdlr) \
- .align 7; \
- .globl label##_common; \
-label##_common: \
- EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
- FINISH_NAP; \
- DISABLE_INTS; \
-BEGIN_FTR_SECTION \
- bl .ppc64_runlatch_on; \
-END_FTR_SECTION_IFSET(CPU_FTR_CTRL) \
- addi r3,r1,STACK_FRAME_OVERHEAD; \
- bl hdlr; \
- b .ret_from_except_lite
+#define STD_EXCEPTION_COMMON_ASYNC(trap, label, hdlr) \
+ EXCEPTION_COMMON(trap, label, hdlr, ret_from_except_lite, \
+ FINISH_NAP;RUNLATCH_ON;DISABLE_INTS)
/*
* When the idle code in power4_idle puts the CPU into NAP mode,
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 7fdc2c0..b1a215e 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1079,30 +1079,12 @@
#define proc_trap() asm volatile("trap")
-#ifdef CONFIG_PPC64
-
-extern void ppc64_runlatch_on(void);
-extern void __ppc64_runlatch_off(void);
-
-#define ppc64_runlatch_off() \
- do { \
- if (cpu_has_feature(CPU_FTR_CTRL) && \
- test_thread_flag(TIF_RUNLATCH)) \
- __ppc64_runlatch_off(); \
- } while (0)
+#define __get_SP() ({unsigned long sp; \
+ asm volatile("mr %0,1": "=r" (sp)); sp;})
extern unsigned long scom970_read(unsigned int address);
extern void scom970_write(unsigned int address, unsigned long value);
-#else
-#define ppc64_runlatch_on()
-#define ppc64_runlatch_off()
-
-#endif /* CONFIG_PPC64 */
-
-#define __get_SP() ({unsigned long sp; \
- asm volatile("mr %0,1": "=r" (sp)); sp;})
-
struct pt_regs;
extern void ppc_save_regs(struct pt_regs *regs);
diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/system.h
index c377457..a02883d 100644
--- a/arch/powerpc/include/asm/system.h
+++ b/arch/powerpc/include/asm/system.h
@@ -550,5 +550,43 @@ extern void reloc_got2(unsigned long);
extern struct dentry *powerpc_debugfs_root;
+#ifdef CONFIG_PPC64
+
+extern void __ppc64_runlatch_on(void);
+extern void __ppc64_runlatch_off(void);
+
+/*
+ * We manually hard enable-disable, this is called
+ * in the idle loop and we don't want to mess up
+ * with soft-disable/enable & interrupt replay.
+ */
+#define ppc64_runlatch_off() \
+ do { \
+ if (cpu_has_feature(CPU_FTR_CTRL) && \
+ test_thread_local_flags(_TLF_RUNLATCH)) { \
+ unsigned long msr = mfmsr(); \
+ __hard_irq_disable(); \
+ __ppc64_runlatch_off(); \
+ if (msr & MSR_EE) \
+ __hard_irq_enable(); \
+ } \
+ } while (0)
+
+#define ppc64_runlatch_on() \
+ do { \
+ if (cpu_has_feature(CPU_FTR_CTRL) && \
+ !test_thread_local_flags(_TLF_RUNLATCH)) { \
+ unsigned long msr = mfmsr(); \
+ __hard_irq_disable(); \
+ __ppc64_runlatch_on(); \
+ if (msr & MSR_EE) \
+ __hard_irq_enable(); \
+ } \
+ } while (0)
+#else
+#define ppc64_runlatch_on()
+#define ppc64_runlatch_off()
+#endif /* CONFIG_PPC64 */
+
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_SYSTEM_H */
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 96471494..4a741c7 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -110,7 +110,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_NOERROR 12 /* Force successful syscall return */
#define TIF_NOTIFY_RESUME 13 /* callback before returning to user */
#define TIF_SYSCALL_TRACEPOINT 15 /* syscall tracepoint instrumentation */
-#define TIF_RUNLATCH 16 /* Is the runlatch enabled? */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@@ -141,11 +140,13 @@ static inline struct thread_info *current_thread_info(void)
#define TLF_SLEEPING 1 /* suspend code enabled SLEEP mode */
#define TLF_RESTORE_SIGMASK 2 /* Restore signal mask in do_signal */
#define TLF_LAZY_MMU 3 /* tlb_batch is active */
+#define TLF_RUNLATCH 4 /* Is the runlatch enabled? */
#define _TLF_NAPPING (1 << TLF_NAPPING)
#define _TLF_SLEEPING (1 << TLF_SLEEPING)
#define _TLF_RESTORE_SIGMASK (1 << TLF_RESTORE_SIGMASK)
#define _TLF_LAZY_MMU (1 << TLF_LAZY_MMU)
+#define _TLF_RUNLATCH (1 << TLF_RUNLATCH)
#ifndef __ASSEMBLY__
#define HAVE_SET_RESTORE_SIGMASK 1
@@ -156,6 +157,12 @@ static inline void set_restore_sigmask(void)
set_bit(TIF_SIGPENDING, &ti->flags);
}
+static inline bool test_thread_local_flags(unsigned int flags)
+{
+ struct thread_info *ti = current_thread_info();
+ return (ti->local_flags & flags) != 0;
+}
+
#ifdef CONFIG_PPC64
#define is_32bit_task() (test_thread_flag(TIF_32BIT))
#else
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 2240d4e..3af80e8 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -483,6 +483,9 @@ machine_check_common:
system_call_entry:
b system_call_common
+ppc64_runlatch_on_trampoline:
+ b .__ppc64_runlatch_on
+
/*
* Here we have detected that the kernel stack pointer is bad.
* R9 contains the saved CR, r13 points to the paca,
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index d817ab0..bf80a1d 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1220,34 +1220,32 @@ void dump_stack(void)
EXPORT_SYMBOL(dump_stack);
#ifdef CONFIG_PPC64
-void ppc64_runlatch_on(void)
+/* Called with hard IRQs off */
+void __ppc64_runlatch_on(void)
{
+ struct thread_info *ti = current_thread_info();
unsigned long ctrl;
- if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) {
- HMT_medium();
-
- ctrl = mfspr(SPRN_CTRLF);
- ctrl |= CTRL_RUNLATCH;
- mtspr(SPRN_CTRLT, ctrl);
+ ctrl = mfspr(SPRN_CTRLF);
+ ctrl |= CTRL_RUNLATCH;
+ mtspr(SPRN_CTRLT, ctrl);
- set_thread_flag(TIF_RUNLATCH);
- }
+ ti->local_flags |= TLF_RUNLATCH;
}
+/* Called with hard IRQs off */
void __ppc64_runlatch_off(void)
{
+ struct thread_info *ti = current_thread_info();
unsigned long ctrl;
- HMT_medium();
-
- clear_thread_flag(TIF_RUNLATCH);
+ ti->local_flags &= ~TLF_RUNLATCH;
ctrl = mfspr(SPRN_CTRLF);
ctrl &= ~CTRL_RUNLATCH;
mtspr(SPRN_CTRLT, ctrl);
}
-#endif
+#endif /* CONFIG_PPC64 */
#if THREAD_SHIFT < PAGE_SHIFT
--
1.7.9
next prev parent reply other threads:[~2012-03-05 2:52 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-05 2:51 [PATCH 00/13 v2] powerpc: Low level spring cleaning Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 01/13] powerpc: Remove legacy iSeries bits from assembly files Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 02/13] powerpc: Use the same interrupt prolog for perfmon as other interrupts Benjamin Herrenschmidt
2012-03-05 2:51 ` Benjamin Herrenschmidt [this message]
2012-03-05 2:51 ` [PATCH 04/13] powerpc: Improve 64-bit syscall entry/exit Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 05/13] powerpc: Improve behaviour of irq tracing on 64-bit exception entry Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 06/13] powerpc: Disable interrupts in 64-bit kernel FP and vector faults Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 07/13] powerpc: Call do_page_fault() with interrupts off Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 08/13] powerpc: Add support for page fault retry and fatal signals Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 09/13] powerpc/xmon: Add display of soft & hard irq states Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 10/13] powerpc: Fix register clobbering when accumulating stolen time Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 11/13] powerpc: Fix 64-bit BookE FP unavailable exceptions Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 12/13] powerpc: Replace mfmsr instructions with load from PACA kernel_msr field Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 13/13] powerpc: Rework lazy-interrupt handling Benjamin Herrenschmidt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1330915891-19523-4-git-send-email-benh@kernel.crashing.org \
--to=benh@kernel.crashing.org \
--cc=linuxppc-dev@ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).