From: Will Deacon <will.deacon@arm.com>
Date: Fri, 29 May 2015 17:28:44 +0000 (+0100)
Subject: arm64: force CONFIG_SMP=y and remove redundant #ifdefs
X-Git-Tag: omap-for-v4.3/fixes-rc1~98^2~81
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4b3dc9679cf7;p=pandora-kernel.git

arm64: force CONFIG_SMP=y and remove redundant #ifdefs

Nobody seems to be producing !SMP systems anymore, so this is just
becoming a source of kernel bugs, particularly if people want to use
coherent DMA with non-shared pages.

This patch forces CONFIG_SMP=y for arm64, removing a modest amount of
code in the process.

Signed-off-by: Will Deacon <will.deacon@arm.com>
---

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 40f717f8820a..de8dee60fd82 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -28,7 +28,7 @@ config ARM64
 	select EDAC_SUPPORT
 	select GENERIC_ALLOCATOR
 	select GENERIC_CLOCKEVENTS
-	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
+	select GENERIC_CLOCKEVENTS_BROADCAST
 	select GENERIC_CPU_AUTOPROBE
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_IRQ_PROBE
@@ -137,6 +137,9 @@ config NEED_DMA_MAP_STATE
 config NEED_SG_DMA_LENGTH
 	def_bool y
 
+config SMP
+	def_bool y
+
 config SWIOTLB
 	def_bool y
 
@@ -491,22 +494,8 @@ config CPU_BIG_ENDIAN
        help
          Say Y if you plan on running a kernel in big-endian mode.
 
-config SMP
-	bool "Symmetric Multi-Processing"
-	help
-	  This enables support for systems with more than one CPU.  If
-	  you say N here, the kernel will run on single and
-	  multiprocessor machines, but will use only one CPU of a
-	  multiprocessor machine. If you say Y here, the kernel will run
-	  on many, but not all, single processor machines. On a single
-	  processor machine, the kernel will run faster if you say N
-	  here.
-
-	  If you don't know what to do here, say N.
-
 config SCHED_MC
 	bool "Multi-core scheduler support"
-	depends on SMP
 	help
 	  Multi-core scheduler support improves the CPU scheduler's decision
 	  making when dealing with multi-core CPU chips at a cost of slightly
@@ -514,7 +503,6 @@ config SCHED_MC
 
 config SCHED_SMT
 	bool "SMT scheduler support"
-	depends on SMP
 	help
 	  Improves the CPU scheduler's decision making when dealing with
 	  MultiThreading at a cost of slightly increased overhead in some
@@ -523,23 +511,17 @@ config SCHED_SMT
 config NR_CPUS
 	int "Maximum number of CPUs (2-4096)"
 	range 2 4096
-	depends on SMP
 	# These have to remain sorted largest to smallest
 	default "64"
 
 config HOTPLUG_CPU
 	bool "Support for hot-pluggable CPUs"
-	depends on SMP
 	help
 	  Say Y here to experiment with turning CPUs off and on.  CPUs
 	  can be controlled through /sys/devices/system/cpu.
 
 source kernel/Kconfig.preempt
 
-config UP_LATE_INIT
-       def_bool y
-       depends on !SMP
-
 config HZ
 	int
 	default 100
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index e10516bbe833..b51f2cc22ca9 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -91,9 +91,7 @@
  * SMP data memory barrier
  */
 	.macro	smp_dmb, opt
-#ifdef CONFIG_SMP
 	dmb	\opt
-#endif
 	.endm
 
 #define USER(l, x...)				\
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index 0fa47c4275cb..624f9679f4b0 100644
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -35,28 +35,6 @@
 #define dma_rmb()	dmb(oshld)
 #define dma_wmb()	dmb(oshst)
 
-#ifndef CONFIG_SMP
-#define smp_mb()	barrier()
-#define smp_rmb()	barrier()
-#define smp_wmb()	barrier()
-
-#define smp_store_release(p, v)						\
-do {									\
-	compiletime_assert_atomic_type(*p);				\
-	barrier();							\
-	ACCESS_ONCE(*p) = (v);						\
-} while (0)
-
-#define smp_load_acquire(p)						\
-({									\
-	typeof(*p) ___p1 = ACCESS_ONCE(*p);				\
-	compiletime_assert_atomic_type(*p);				\
-	barrier();							\
-	___p1;								\
-})
-
-#else
-
 #define smp_mb()	dmb(ish)
 #define smp_rmb()	dmb(ishld)
 #define smp_wmb()	dmb(ishst)
@@ -109,8 +87,6 @@ do {									\
 	___p1;								\
 })
 
-#endif
-
 #define read_barrier_depends()		do { } while(0)
 #define smp_read_barrier_depends()	do { } while(0)
 
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