MIPS: Implement HAVE_CONTEXT_TRACKING.

This enables support for CONFIG_NO_HZ_FULL. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
git-mirror · Jun 10, 2013 · c3fc5cd · c3fc5cd
1 parent e7f3b48
commit c3fc5cd
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Showing 8 changed files with 108 additions and 19 deletions.
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
@@ -1,6 +1,7 @@
 config MIPS
 	bool
 	default y
+	select HAVE_CONTEXT_TRACKING
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_IDE
 	select HAVE_OPROFILE

diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
@@ -109,6 +109,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
 #define TIF_USEDFPU		16	/* FPU was used by this task this quantum (SMP) */
 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
+#define TIF_NOHZ		19	/* in adaptive nohz mode */
 #define TIF_FIXADE		20	/* Fix address errors in software */
 #define TIF_LOGADE		21	/* Log address errors to syslog */
 #define TIF_32BIT_REGS		22	/* also implies 16/32 fprs */
@@ -124,23 +125,27 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
+#define _TIF_NOHZ		(1<<TIF_NOHZ)
 #define _TIF_FIXADE		(1<<TIF_FIXADE)
 #define _TIF_LOGADE		(1<<TIF_LOGADE)
 #define _TIF_32BIT_REGS		(1<<TIF_32BIT_REGS)
 #define _TIF_32BIT_ADDR		(1<<TIF_32BIT_ADDR)
 #define _TIF_FPUBOUND		(1<<TIF_FPUBOUND)
 #define _TIF_LOAD_WATCH		(1<<TIF_LOAD_WATCH)
 
-#define _TIF_WORK_SYSCALL_ENTRY	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT)
+#define _TIF_WORK_SYSCALL_ENTRY	(_TIF_NOHZ | _TIF_SYSCALL_TRACE |	\
+				 _TIF_SYSCALL_AUDIT)
 
 /* work to do in syscall_trace_leave() */
-#define _TIF_WORK_SYSCALL_EXIT	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT)
+#define _TIF_WORK_SYSCALL_EXIT	(_TIF_NOHZ | _TIF_SYSCALL_TRACE |	\
+				 _TIF_SYSCALL_AUDIT)
 
 /* work to do on interrupt/exception return */
 #define _TIF_WORK_MASK		\
 	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME)
 /* work to do on any return to u-space */
-#define _TIF_ALLWORK_MASK	(_TIF_WORK_MASK | _TIF_WORK_SYSCALL_EXIT)
+#define _TIF_ALLWORK_MASK	(_TIF_NOHZ | _TIF_WORK_MASK |		\
+				 _TIF_WORK_SYSCALL_EXIT)
 
 #endif /* __KERNEL__ */
 

diff --git a/arch/mips/kernel/cpu-bugs64.c b/arch/mips/kernel/cpu-bugs64.c
@@ -6,6 +6,7 @@
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  */
+#include <linux/context_tracking.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/ptrace.h>
@@ -171,8 +172,12 @@ static volatile int daddi_ov __cpuinitdata;
 
 asmlinkage void __init do_daddi_ov(struct pt_regs *regs)
 {
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
 	daddi_ov = 1;
 	regs->cp0_epc += 4;
+	exception_exit(prev_state);
 }
 
 static inline void check_daddi(void)

diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
@@ -15,6 +15,7 @@
  * binaries.
  */
 #include <linux/compiler.h>
+#include <linux/context_tracking.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
@@ -534,6 +535,8 @@ static inline int audit_arch(void)
  */
 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
 {
+	user_exit();
+
 	/* do the secure computing check first */
 	secure_computing_strict(regs->regs[2]);
 
@@ -570,6 +573,13 @@ asmlinkage void syscall_trace_enter(struct pt_regs *regs)
  */
 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
 {
+        /*
+	 * We may come here right after calling schedule_user()
+	 * or do_notify_resume(), in which case we can be in RCU
+	 * user mode.
+	 */
+	user_exit();
+
 	audit_syscall_exit(regs);
 
 	if (!(current->ptrace & PT_PTRACED))
@@ -592,4 +602,6 @@ asmlinkage void syscall_trace_leave(struct pt_regs *regs)
 		send_sig(current->exit_code, current, 1);
 		current->exit_code = 0;
 	}
+
+	user_enter();
 }
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
@@ -8,6 +8,7 @@
  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  */
 #include <linux/cache.h>
+#include <linux/context_tracking.h>
 #include <linux/irqflags.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
@@ -573,6 +574,8 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 {
 	local_irq_enable();
 
+	user_exit();
+
 	/* deal with pending signal delivery */
 	if (thread_info_flags & _TIF_SIGPENDING)
 		do_signal(regs);
@@ -581,6 +584,8 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
 	}
+
+	user_enter();
 }
 
 #ifdef CONFIG_SMP