Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile

Pull tile arch changes from Chris Metcalf:
 "These are some minor new feature work and other changes that didn't
  merit getting pushed up after the 3.9 merge window closed.

  There should be a lot more activity in the 3.11 merge window"

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile: Fix syscall return value passed to tracepoint
  tile: comment assumption about __insn_mtspr for <asm/irqflags.h>
  tile: ns2cycles should use __raw_get_cpu_var
  arch: remove KCORE_ELF again [tile]
  tile: remove two outdated Kconfig entries
  tile: support atomic64_dec_if_positive()
  tile: support TIF_SYSCALL_TRACEPOINT; select HAVE_SYSCALL_TRACEPOINTS
  tile: Add definition of NR_syscalls
  tile: move declaration of sys_call_table to <asm/syscall.h>
  arch/tile: Enable HAVE_ARCH_TRACEHOOK
  arch/tile: Call tracehook_report_syscall_{entry,exit} in syscall trace

arch/tile/Kconfig

@@ -22,6 +22,9 @@ config TILE
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_CLOCKEVENTS
 	select MODULES_USE_ELF_RELA
+	select HAVE_ARCH_TRACEHOOK
+	select HAVE_SYSCALL_TRACEPOINTS
+	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 
 # FIXME: investigate whether we need/want these options.
 #	select HAVE_IOREMAP_PROT
@@ -40,9 +43,6 @@ config MMU
 config GENERIC_CSUM
 	def_bool y
 
-config SEMAPHORE_SLEEPERS
-	def_bool y
-
 config HAVE_ARCH_ALLOC_REMAP
 	def_bool y
 
@@ -67,12 +67,6 @@ config HUGETLB_SUPER_PAGES
 config RWSEM_GENERIC_SPINLOCK
 	def_bool y
 
-# We have a very flat architecture from a migration point of view,
-# so save boot time by presetting this (particularly useful on tile-sim).
-config DEFAULT_MIGRATION_COST
-	int
-	default "10000000"
-
 # We only support gcc 4.4 and above, so this should work.
 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 	def_bool y
@@ -413,11 +407,6 @@ endmenu
 
 menu "Executable file formats"
 
-# only elf supported
-config KCORE_ELF
-	def_bool y
-	depends on PROC_FS
-
 source "fs/Kconfig.binfmt"
 
 endmenu

arch/tile/include/asm/atomic.h

@@ -131,4 +131,25 @@ static inline int atomic_read(const atomic_t *v)
 #include <asm/atomic_64.h>
 #endif
 
+#ifndef __ASSEMBLY__
+
+static inline long long atomic64_dec_if_positive(atomic64_t *v)
+{
+	long long c, old, dec;
+
+	c = atomic64_read(v);
+	for (;;) {
+		dec = c - 1;
+		if (unlikely(dec < 0))
+			break;
+		old = atomic64_cmpxchg((v), c, dec);
+		if (likely(old == c))
+			break;
+		c = old;
+	}
+	return dec;
+}
+
+#endif /* __ASSEMBLY__ */
+
 #endif /* _ASM_TILE_ATOMIC_H */

arch/tile/include/asm/ptrace.h

@@ -44,7 +44,8 @@ typedef unsigned long pt_reg_t;
 struct pt_regs *get_pt_regs(struct pt_regs *);
 
 /* Trace the current syscall. */
-extern void do_syscall_trace(void);
+extern int do_syscall_trace_enter(struct pt_regs *regs);
+extern void do_syscall_trace_exit(struct pt_regs *regs);
 
 #define arch_has_single_step()	(1)
 

arch/tile/include/asm/syscall.h

@@ -22,6 +22,12 @@
 #include <linux/err.h>
 #include <arch/abi.h>
 
+/* The array of function pointers for syscalls. */
+extern void *sys_call_table[];
+#ifdef CONFIG_COMPAT
+extern void *compat_sys_call_table[];
+#endif
+
 /*
  * Only the low 32 bits of orig_r0 are meaningful, so we return int.
  * This importantly ignores the high bits on 64-bit, so comparisons

arch/tile/include/asm/syscalls.h

@@ -24,12 +24,6 @@
 #include <linux/types.h>
 #include <linux/compat.h>
 
-/* The array of function pointers for syscalls. */
-extern void *sys_call_table[];
-#ifdef CONFIG_COMPAT
-extern void *compat_sys_call_table[];
-#endif
-
 /*
  * Note that by convention, any syscall which requires the current
  * register set takes an additional "struct pt_regs *" pointer; a

arch/tile/include/asm/thread_info.h

@@ -124,6 +124,7 @@ extern void _cpu_idle(void);
 #define TIF_SECCOMP		6	/* secure computing */
 #define TIF_MEMDIE		7	/* OOM killer at work */
 #define TIF_NOTIFY_RESUME	8	/* callback before returning to user */
+#define TIF_SYSCALL_TRACEPOINT	9	/* syscall tracepoint instrumentation */
 
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
@@ -134,12 +135,19 @@ extern void _cpu_idle(void);
 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
 #define _TIF_MEMDIE		(1<<TIF_MEMDIE)
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
+#define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
 
 /* Work to do on any return to user space. */
 #define _TIF_ALLWORK_MASK \
   (_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SINGLESTEP|\
    _TIF_ASYNC_TLB|_TIF_NOTIFY_RESUME)
 
+/* Work to do at syscall entry. */
+#define _TIF_SYSCALL_ENTRY_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)
+
+/* Work to do at syscall exit. */
+#define _TIF_SYSCALL_EXIT_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)
+
 /*
  * Thread-synchronous status.
  *

arch/tile/include/uapi/asm/unistd.h

@@ -20,6 +20,8 @@
 /* Use the standard ABI for syscalls. */
 #include <asm-generic/unistd.h>
 
+#define NR_syscalls __NR_syscalls
+
 /* Additional Tilera-specific syscalls. */
 #define __NR_cacheflush	(__NR_arch_specific_syscall + 1)
 __SYSCALL(__NR_cacheflush, sys_cacheflush)

arch/tile/kernel/intvec_32.S

@@ -1201,7 +1201,10 @@ handle_syscall:
 	lw	r30, r31
 	andi    r30, r30, _TIF_SYSCALL_TRACE
 	bzt	r30, .Lrestore_syscall_regs
-	jal	do_syscall_trace
+	{
+	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
+	 jal    do_syscall_trace_enter
+	}
 	FEEDBACK_REENTER(handle_syscall)
 
 	/*
@@ -1252,7 +1255,10 @@ handle_syscall:
 	lw	r30, r31
 	andi    r30, r30, _TIF_SYSCALL_TRACE
 	bzt     r30, 1f
-	jal	do_syscall_trace
+	{
+	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
+	 jal    do_syscall_trace_exit
+	}
 	FEEDBACK_REENTER(handle_syscall)
 1:	{
 	 movei  r30, 0               /* not an NMI */

arch/tile/kernel/intvec_64.S

@@ -1000,13 +1000,19 @@ handle_syscall:
 
 	/* Trace syscalls, if requested. */
 	addi	r31, r31, THREAD_INFO_FLAGS_OFFSET
+	{
 	 ld     r30, r31
-	andi    r30, r30, _TIF_SYSCALL_TRACE
+	 moveli r32, _TIF_SYSCALL_ENTRY_WORK
+	}
+	and     r30, r30, r32
 	{
 	 addi   r30, r31, THREAD_INFO_STATUS_OFFSET - THREAD_INFO_FLAGS_OFFSET
 	 beqzt	r30, .Lrestore_syscall_regs
 	}
-	jal	do_syscall_trace
+	{
+	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
+	 jal    do_syscall_trace_enter
+	}
 	FEEDBACK_REENTER(handle_syscall)
 
 	/*
@@ -1071,13 +1077,19 @@ handle_syscall:
 	FEEDBACK_REENTER(handle_syscall)
 
 	/* Do syscall trace again, if requested. */
+	{
 	 ld      r30, r31
-	andi    r0, r30, _TIF_SYSCALL_TRACE
+	 moveli  r32, _TIF_SYSCALL_EXIT_WORK
+	}
+	and      r0, r30, r32
 	{
 	 andi    r0, r30, _TIF_SINGLESTEP
 	 beqzt   r0, 1f
 	}
-	jal	do_syscall_trace
+	{
+	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
+	 jal    do_syscall_trace_exit
+	}
 	FEEDBACK_REENTER(handle_syscall)
 	andi    r0, r30, _TIF_SINGLESTEP
 

arch/tile/kernel/ptrace.c

@@ -21,9 +21,13 @@
 #include <linux/uaccess.h>
 #include <linux/regset.h>
 #include <linux/elf.h>
+#include <linux/tracehook.h>
 #include <asm/traps.h>
 #include <arch/chip.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
 void user_enable_single_step(struct task_struct *child)
 {
 	set_tsk_thread_flag(child, TIF_SINGLESTEP);
@@ -246,29 +250,26 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 }
 #endif
 
-void do_syscall_trace(void)
+int do_syscall_trace_enter(struct pt_regs *regs)
 {
-	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		return;
-
-	if (!(current->ptrace & PT_PTRACED))
-		return;
-
-	/*
-	 * The 0x80 provides a way for the tracing parent to distinguish
-	 * between a syscall stop and SIGTRAP delivery
-	 */
-	ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
-
-	/*
-	 * this isn't the same as continuing with a signal, but it will do
-	 * for normal use.  strace only continues with a signal if the
-	 * stopping signal is not SIGTRAP.  -brl
-	 */
-	if (current->exit_code) {
-		send_sig(current->exit_code, current, 1);
-		current->exit_code = 0;
+	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
+		if (tracehook_report_syscall_entry(regs))
+			regs->regs[TREG_SYSCALL_NR] = -1;
 	}
+
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_enter(regs, regs->regs[TREG_SYSCALL_NR]);
+
+	return regs->regs[TREG_SYSCALL_NR];
+}
+
+void do_syscall_trace_exit(struct pt_regs *regs)
+{
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(regs, 0);
+
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_exit(regs, regs->regs[0]);
 }
 
 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)

arch/tile/kernel/time.c

@@ -230,6 +230,10 @@ int setup_profiling_timer(unsigned int multiplier)
  */
 cycles_t ns2cycles(unsigned long nsecs)
 {
-	struct clock_event_device *dev = &__get_cpu_var(tile_timer);
+	/*
+	 * We do not have to disable preemption here as each core has the same
+	 * clock frequency.
+	 */
+	struct clock_event_device *dev = &__raw_get_cpu_var(tile_timer);
 	return ((u64)nsecs * dev->mult) >> dev->shift;
 }