Merge tag 'arc-fixes-for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC Fixes from Vineet Gupta:
 - Handle unaligned access in zero delay loops
 - spinlock livelock fix for SMP systemC model
 - fix 32bit overflow in access_ok
 - better setup of clockevents

* tag 'arc-fixes-for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: Use clockevents_config_and_register over clockevents_register_device
  ARC: Workaround spinlock livelock in SMP SystemC simulation
  ARC: Fix 32-bit wrap around in access_ok()
  ARC: Handle zero-overhead-loop in unaligned access handler

4 files changed, 18 insertions, 8 deletions

diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h
index f158197ac5b0..b6a8c2dfbe6e 100644
--- a/arch/arc/include/asm/spinlock.h
+++ b/arch/arc/include/asm/spinlock.h
@@ -45,7 +45,14 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock)
 
 static inline void arch_spin_unlock(arch_spinlock_t *lock)
 {
-        lock->slock = __ARCH_SPIN_LOCK_UNLOCKED__;
+        unsigned int tmp = __ARCH_SPIN_LOCK_UNLOCKED__;
+
+        __asm__ __volatile__(
+        "       ex  %0, [%1]            \n"
+        : "+r" (tmp)
+        : "r"(&(lock->slock))
+        : "memory");
+
         smp_mb();
 }
 
diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h
index 32420824375b..30c9baffa96f 100644
--- a/arch/arc/include/asm/uaccess.h
+++ b/arch/arc/include/asm/uaccess.h
@@ -43,7 +43,7 @@
  * Because it essentially checks if buffer end is within limit and @len is
  * non-ngeative, which implies that buffer start will be within limit too.
  *
- * The reason for rewriting being, for majorit yof cases, @len is generally
+ * The reason for rewriting being, for majority of cases, @len is generally
  * compile time constant, causing first sub-expression to be compile time
  * subsumed.
  *
@@ -53,7 +53,7 @@
  *
  */
 #define __user_ok(addr, sz)     (((sz) <= TASK_SIZE) && \
-                                 (((addr)+(sz)) <= get_fs()))
+                                 ((addr) <= (get_fs() - (sz))))
 #define __access_ok(addr, sz)   (unlikely(__kernel_ok) || \
                                  likely(__user_ok((addr), (sz))))
 
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index 0e51e69cf30d..3fde7de3ea67 100644
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -227,12 +227,9 @@ void __attribute__((weak)) arc_local_timer_setup(unsigned int cpu)
 {
         struct clock_event_device *clk = &per_cpu(arc_clockevent_device, cpu);
 
-        clockevents_calc_mult_shift(clk, arc_get_core_freq(), 5);
-
-        clk->max_delta_ns = clockevent_delta2ns(ARC_TIMER_MAX, clk);
         clk->cpumask = cpumask_of(cpu);
-
-        clockevents_register_device(clk);
+        clockevents_config_and_register(clk, arc_get_core_freq(),
+                                        0, ARC_TIMER_MAX);
 
         /*
          * setup the per-cpu timer IRQ handler - for all cpus
diff --git a/arch/arc/kernel/unaligned.c b/arch/arc/kernel/unaligned.c
index 28d170060747..7ff5b5c183bb 100644
--- a/arch/arc/kernel/unaligned.c
+++ b/arch/arc/kernel/unaligned.c
@@ -245,6 +245,12 @@ int misaligned_fixup(unsigned long address, struct pt_regs *regs,
                 regs->status32 &= ~STATUS_DE_MASK;
         } else {
                 regs->ret += state.instr_len;
+
+                /* handle zero-overhead-loop */
+                if ((regs->ret == regs->lp_end) && (regs->lp_count)) {
+                        regs->ret = regs->lp_start;
+                        regs->lp_count--;
+                }
         }
 
         return 0;