1 files changed, 18 insertions, 58 deletions

diff --git a/arch/arm/mach-vexpress/dcscb.c b/arch/arm/mach-vexpress/dcscb.c
index 3a6384c6c43..30b993399ed 100644
--- a/arch/arm/mach-vexpress/dcscb.c
+++ b/arch/arm/mach-vexpress/dcscb.c
@@ -51,12 +51,14 @@ static int dcscb_allcpus_mask[2];
 static int dcscb_power_up(unsigned int cpu, unsigned int cluster)
 {
 	unsigned int rst_hold, cpumask = (1 << cpu);
-	unsigned int all_mask = dcscb_allcpus_mask[cluster];
+	unsigned int all_mask;
 
 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 	if (cpu >= 4 || cluster >= 2)
 		return -EINVAL;
 
+	all_mask = dcscb_allcpus_mask[cluster];
+
 	/*
 	 * Since this is called with IRQs enabled, and no arch_spin_lock_irq
 	 * variant exists, we need to disable IRQs manually here.
@@ -101,11 +103,12 @@ static void dcscb_power_down(void)
 	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 	cpumask = (1 << cpu);
-	all_mask = dcscb_allcpus_mask[cluster];
 
 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 	BUG_ON(cpu >= 4 || cluster >= 2);
 
+	all_mask = dcscb_allcpus_mask[cluster];
+
 	__mcpm_cpu_going_down(cpu, cluster);
 
 	arch_spin_lock(&dcscb_lock);
@@ -133,45 +136,20 @@ static void dcscb_power_down(void)
 	if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
 		arch_spin_unlock(&dcscb_lock);
 
-		/*
-		 * Flush all cache levels for this cluster.
-		 *
-		 * To do so we do:
-		 * - Clear the SCTLR.C bit to prevent further cache allocations
-		 * - Flush the whole cache
-		 * - Clear the ACTLR "SMP" bit to disable local coherency
-		 *
-		 * Let's do it in the safest possible way i.e. with
-		 * no memory access within the following sequence
-		 * including to the stack.
-		 *
-		 * Note: fp is preserved to the stack explicitly prior doing
-		 * this since adding it to the clobber list is incompatible
-		 * with having CONFIG_FRAME_POINTER=y.
-		 */
-		asm volatile(
-		"str	fp, [sp, #-4]! \n\t"
-		"mrc	p15, 0, r0, c1, c0, 0	@ get CR \n\t"
-		"bic	r0, r0, #"__stringify(CR_C)" \n\t"
-		"mcr	p15, 0, r0, c1, c0, 0	@ set CR \n\t"
-		"isb	\n\t"
-		"bl	v7_flush_dcache_all \n\t"
-		"clrex	\n\t"
-		"mrc	p15, 0, r0, c1, c0, 1	@ get AUXCR \n\t"
-		"bic	r0, r0, #(1 << 6)	@ disable local coherency \n\t"
-		"mcr	p15, 0, r0, c1, c0, 1	@ set AUXCR \n\t"
-		"isb	\n\t"
-		"dsb	\n\t"
-		"ldr	fp, [sp], #4"
-		: : : "r0","r1","r2","r3","r4","r5","r6","r7",
-		      "r9","r10","lr","memory");
+		/* Flush all cache levels for this cluster. */
+		v7_exit_coherency_flush(all);
 
 		/*
-		 * This is a harmless no-op.  On platforms with a real
-		 * outer cache this might either be needed or not,
-		 * depending on where the outer cache sits.
+		 * A full outer cache flush could be needed at this point
+		 * on platforms with such a cache, depending on where the
+		 * outer cache sits. In some cases the notion of a "last
+		 * cluster standing" would need to be implemented if the
+		 * outer cache is shared across clusters. In any case, when
+		 * the outer cache needs flushing, there is no concurrent
+		 * access to the cache controller to worry about and no
+		 * special locking besides what is already provided by the
+		 * MCPM state machinery is needed.
 		 */
-		outer_flush_all();
 
 		/*
 		 * Disable cluster-level coherency by masking
@@ -183,26 +161,8 @@ static void dcscb_power_down(void)
 	} else {
 		arch_spin_unlock(&dcscb_lock);
 
-		/*
-		 * Flush the local CPU cache.
-		 * Let's do it in the safest possible way as above.
-		 */
-		asm volatile(
-		"str	fp, [sp, #-4]! \n\t"
-		"mrc	p15, 0, r0, c1, c0, 0	@ get CR \n\t"
-		"bic	r0, r0, #"__stringify(CR_C)" \n\t"
-		"mcr	p15, 0, r0, c1, c0, 0	@ set CR \n\t"
-		"isb	\n\t"
-		"bl	v7_flush_dcache_louis \n\t"
-		"clrex	\n\t"
-		"mrc	p15, 0, r0, c1, c0, 1	@ get AUXCR \n\t"
-		"bic	r0, r0, #(1 << 6)	@ disable local coherency \n\t"
-		"mcr	p15, 0, r0, c1, c0, 1	@ set AUXCR \n\t"
-		"isb	\n\t"
-		"dsb	\n\t"
-		"ldr	fp, [sp], #4"
-		: : : "r0","r1","r2","r3","r4","r5","r6","r7",
-		      "r9","r10","lr","memory");
+		/* Disable and flush the local CPU cache. */
+		v7_exit_coherency_flush(louis);
 	}
 
 	__mcpm_cpu_down(cpu, cluster);