diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index d22e73e4618b..e514de57a125 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -439,6 +439,8 @@ ret_from_fork:
 ret_from_kernel_thread:
 	REST_NVGPRS(r1)
 	bl	schedule_tail
+	li	r3,0
+	stw	r3,0(r1)
 	mtlr	r14
 	mr	r3,r15
 	PPC440EP_ERR42
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index b310a0573625..3d990d3bd8ba 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -664,6 +664,19 @@ resume_kernel:
 	ld	r4,TI_FLAGS(r9)
 	andi.	r0,r4,_TIF_NEED_RESCHED
 	bne	1b
+
+	/*
+	 * arch_local_irq_restore() from preempt_schedule_irq above may
+	 * enable hard interrupt but we really should disable interrupts
+	 * when we return from the interrupt, and so that we don't get
+	 * interrupted after loading SRR0/1.
+	 */
+#ifdef CONFIG_PPC_BOOK3E
+	wrteei	0
+#else
+	ld	r10,PACAKMSR(r13) /* Get kernel MSR without EE */
+	mtmsrd	r10,1		  /* Update machine state */
+#endif /* CONFIG_PPC_BOOK3E */
 #endif /* CONFIG_PREEMPT */
 
 	.globl	fast_exc_return_irq
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index c470a40b29f5..a7bc7521c064 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -154,12 +154,12 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs)
 static int kgdb_singlestep(struct pt_regs *regs)
 {
 	struct thread_info *thread_info, *exception_thread_info;
-	struct thread_info *backup_current_thread_info = \
-		(struct thread_info *)kmalloc(sizeof(struct thread_info), GFP_KERNEL);
+	struct thread_info *backup_current_thread_info;
 
 	if (user_mode(regs))
 		return 0;
 
+	backup_current_thread_info = (struct thread_info *)kmalloc(sizeof(struct thread_info), GFP_KERNEL);
 	/*
 	 * On Book E and perhaps other processors, singlestep is handled on
 	 * the critical exception stack.  This causes current_thread_info()
@@ -185,6 +185,7 @@ static int kgdb_singlestep(struct pt_regs *regs)
 		/* Restore current_thread_info lastly. */
 		memcpy(exception_thread_info, backup_current_thread_info, sizeof *thread_info);
 
+	kfree(backup_current_thread_info);
 	return 1;
 }
 
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 6f6b1cccc916..127361e093f4 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -494,10 +494,15 @@ void timer_interrupt(struct pt_regs * regs)
 	set_dec(DECREMENTER_MAX);
 
 	/* Some implementations of hotplug will get timer interrupts while
-	 * offline, just ignore these
+	 * offline, just ignore these and we also need to set
+	 * decrementers_next_tb as MAX to make sure __check_irq_replay
+	 * don't replay timer interrupt when return, otherwise we'll trap
+	 * here infinitely :(
 	 */
-	if (!cpu_online(smp_processor_id()))
+	if (!cpu_online(smp_processor_id())) {
+		*next_tb = ~(u64)0;
 		return;
+	}
 
 	/* Conditionally hard-enable interrupts now that the DEC has been
 	 * bumped to its maximum value
diff --git a/arch/powerpc/oprofile/op_model_power4.c b/arch/powerpc/oprofile/op_model_power4.c
index 315f9495e9b2..f444b94935f5 100644
--- a/arch/powerpc/oprofile/op_model_power4.c
+++ b/arch/powerpc/oprofile/op_model_power4.c
@@ -52,7 +52,7 @@ static int power7_marked_instr_event(u64 mmcr1)
 	for (pmc = 0; pmc < 4; pmc++) {
 		psel = mmcr1 & (OPROFILE_PM_PMCSEL_MSK
 				<< (OPROFILE_MAX_PMC_NUM - pmc)
-				* OPROFILE_MAX_PMC_NUM);
+				* OPROFILE_PMSEL_FIELD_WIDTH);
 		psel = (psel >> ((OPROFILE_MAX_PMC_NUM - pmc)
 				 * OPROFILE_PMSEL_FIELD_WIDTH)) & ~1ULL;
 		unit = mmcr1 & (OPROFILE_PM_UNIT_MSK
diff --git a/arch/powerpc/platforms/pasemi/cpufreq.c b/arch/powerpc/platforms/pasemi/cpufreq.c
index 95d00173029f..890f30e70f98 100644
--- a/arch/powerpc/platforms/pasemi/cpufreq.c
+++ b/arch/powerpc/platforms/pasemi/cpufreq.c
@@ -236,6 +236,13 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
 
 static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 {
+	/*
+	 * We don't support CPU hotplug. Don't unmap after the system
+	 * has already made it to a running state.
+	 */
+	if (system_state != SYSTEM_BOOTING)
+		return 0;
+
 	if (sdcasr_mapbase)
 		iounmap(sdcasr_mapbase);
 	if (sdcpwr_mapbase)