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From: Max Filippov <jcmvbkbc@gmail.com>
To: Chris Zankel <chris@zankel.net>
Cc: Marc Gauthier <marc@tensilica.com>,
	linux-xtensa@linux-xtensa.org, linux-arch@vger.kernel.org,
	Max Filippov <jcmvbkbc@gmail.com>
Subject: [PATCH v2 05/11] xtensa: check thread flags atomically on return from user exception
Date: Fri, 30 Aug 2013 19:34:57 +0400	[thread overview]
Message-ID: <1377876903-27860-6-git-send-email-jcmvbkbc@gmail.com> (raw)
In-Reply-To: <1377876903-27860-1-git-send-email-jcmvbkbc@gmail.com>

Check pending signals and rescheduling thread flags with interrupts
disabled, and don't enable them if no flags are set. Call
trace_hardirqs_on after thread flags handling, so that rescheduling is
done and hardirqs tracking flag is updated in the correct task context.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
Changes v1->v2:
- remove unneeded call to trace_hardirqs_off from the loop after
  rsil a2, LOCKLEVEL

 arch/xtensa/kernel/entry.S |   39 +++++++++++++++++++++------------------
 1 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 9298742..03709ef 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -423,29 +423,14 @@ common_exception:
 	.global common_exception_return
 common_exception_return:
 
-#ifdef CONFIG_TRACE_IRQFLAGS
-	l32i	a4, a1, PT_DEPC
-	/* Double exception means we came here with an exception
-	 * while PS.EXCM was set, i.e. interrupts disabled.
-	 */
-	bgeui	a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f
-	l32i	a4, a1, PT_EXCCAUSE
-	bnei	a4, EXCCAUSE_LEVEL1_INTERRUPT, 1f
-	/* We came here with an interrupt means interrupts were enabled
-	 * and we'll reenable them on return.
-	 */
-	movi	a4, trace_hardirqs_on
-	callx4	a4
 1:
-#endif
+	rsil	a2, LOCKLEVEL
 
 	/* Jump if we are returning from kernel exceptions. */
 
-1:	l32i	a3, a1, PT_PS
+	l32i	a3, a1, PT_PS
 	_bbci.l	a3, PS_UM_BIT, 4f
 
-	rsil	a2, 0
-
 	/* Specific to a user exception exit:
 	 * We need to check some flags for signal handling and rescheduling,
 	 * and have to restore WB and WS, extra states, and all registers
@@ -465,6 +450,7 @@ common_exception_return:
 
 	/* Call do_signal() */
 
+	rsil	a2, 0
 	movi	a4, do_notify_resume	# int do_notify_resume(struct pt_regs*)
 	mov	a6, a1
 	callx4	a4
@@ -472,6 +458,7 @@ common_exception_return:
 
 3:	/* Reschedule */
 
+	rsil	a2, 0
 	movi	a4, schedule	# void schedule (void)
 	callx4	a4
 	j	1b
@@ -483,7 +470,23 @@ common_exception_return:
 	movi	a4, check_tlb_sanity
 	callx4	a4
 #endif
-4:	/* Restore optional registers. */
+4:
+#ifdef CONFIG_TRACE_IRQFLAGS
+	l32i	a4, a1, PT_DEPC
+	/* Double exception means we came here with an exception
+	 * while PS.EXCM was set, i.e. interrupts disabled.
+	 */
+	bgeui	a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f
+	l32i	a4, a1, PT_EXCCAUSE
+	bnei	a4, EXCCAUSE_LEVEL1_INTERRUPT, 1f
+	/* We came here with an interrupt means interrupts were enabled
+	 * and we'll reenable them on return.
+	 */
+	movi	a4, trace_hardirqs_on
+	callx4	a4
+1:
+#endif
+	/* Restore optional registers. */
 
 	load_xtregs_opt a1 a2 a4 a5 a6 a7 PT_XTREGS_OPT
 
-- 
1.7.7.6

  parent reply	other threads:[~2013-08-30 15:35 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-30 15:34 [PATCH v2 00/11] xtensa queue 2013/08/30 Max Filippov
2013-08-30 15:34 ` [PATCH v2 01/11] xtensa: kernel: add "asm/ftrace.h" for pass compiling Max Filippov
2013-08-30 15:34 ` [PATCH v2 02/11] xtensa: fix arch spinlock function names Max Filippov
2013-08-30 15:34 ` [PATCH v2 03/11] xtensa: fix __delay for small loop count Max Filippov
2013-08-30 15:34 ` [PATCH v2 04/11] xtensa: fix build warning Max Filippov
2013-08-30 15:34 ` Max Filippov [this message]
2013-08-30 15:34 ` [PATCH v2 06/11] xtensa: enable kernel preemption Max Filippov
2013-08-30 15:34 ` [PATCH v2 07/11] xtensa: keep a3 and excsave1 on entry to exception handlers Max Filippov
2013-08-30 15:35 ` [PATCH v2 08/11] xtensa: new fast_alloca handler Max Filippov
2013-08-30 15:35 ` [PATCH v2 09/11] xtensa: don't use echo -e needlessly Max Filippov
2013-08-30 15:35 ` [PATCH v2 10/11] xtensa: fix !CONFIG_XTENSA_CALIBRATE_CCOUNT build failure Max Filippov
2013-08-30 15:35 ` [PATCH v2 11/11] xtensa: remove CCOUNT_PER_JIFFY Max Filippov

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