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 40f717f..de8dee6 100644 (file)
--- 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 e10516b..b51f2cc 100644 (file)
--- 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 0fa47c4..624f967 100644 (file)
--- 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)
 

diff --cc arch/arm64/include/asm/hardirq.h
Simple merge

diff --cc arch/arm64/include/asm/irq_work.h
Simple merge

diff --cc arch/arm64/include/asm/percpu.h
Simple merge

diff --cc arch/arm64/include/asm/pgtable.h
Simple merge

diff --cc arch/arm64/include/asm/ptrace.h
Simple merge

diff --cc arch/arm64/include/asm/smp.h
Simple merge

diff --cc arch/arm64/include/asm/topology.h
Simple merge

diff --cc arch/arm64/kernel/Makefile
Simple merge

diff --cc arch/arm64/kernel/cpu_ops.c
Simple merge

diff --cc arch/arm64/kernel/head.S
Simple merge

diff --cc arch/arm64/kernel/irq.c
Simple merge

diff --cc arch/arm64/kernel/psci.c
Simple merge

diff --cc arch/arm64/kernel/setup.c
Simple merge

diff --cc arch/arm64/kernel/sleep.S
Simple merge

diff --cc arch/arm64/kernel/time.c
Simple merge

diff --cc arch/arm64/kernel/traps.c
Simple merge

diff --cc arch/arm64/mm/context.c
Simple merge

diff --cc arch/arm64/mm/flush.c
Simple merge

diff --cc arch/arm64/mm/proc.S
Simple merge