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
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -28,7 +28,7 @@
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_SG_DMA_LENGTH
def_bool y
+config SMP
+ def_bool y
+
config SWIOTLB
def_bool y
@@ -491,22 +494,8 @@
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_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 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
--- 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
--- 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 @@
___p1; \
})
-#endif
-
#define read_barrier_depends() do { } while(0)
#define smp_read_barrier_depends() do { } while(0)
diff --git a/arch/arm64/include/asm/hardirq.h b/arch/arm64/include/asm/hardirq.h
index 6aae421..2bb7009 100644
--- a/arch/arm64/include/asm/hardirq.h
+++ b/arch/arm64/include/asm/hardirq.h
@@ -24,9 +24,7 @@
typedef struct {
unsigned int __softirq_pending;
-#ifdef CONFIG_SMP
unsigned int ipi_irqs[NR_IPI];
-#endif
} ____cacheline_aligned irq_cpustat_t;
#include <linux/irq_cpustat.h> /* Standard mappings for irq_cpustat_t above */
@@ -34,10 +32,8 @@
#define __inc_irq_stat(cpu, member) __IRQ_STAT(cpu, member)++
#define __get_irq_stat(cpu, member) __IRQ_STAT(cpu, member)
-#ifdef CONFIG_SMP
u64 smp_irq_stat_cpu(unsigned int cpu);
#define arch_irq_stat_cpu smp_irq_stat_cpu
-#endif
#define __ARCH_IRQ_EXIT_IRQS_DISABLED 1
diff --git a/arch/arm64/include/asm/irq_work.h b/arch/arm64/include/asm/irq_work.h
index b4f6b19..8e24ef3 100644
--- a/arch/arm64/include/asm/irq_work.h
+++ b/arch/arm64/include/asm/irq_work.h
@@ -1,8 +1,6 @@
#ifndef __ASM_IRQ_WORK_H
#define __ASM_IRQ_WORK_H
-#ifdef CONFIG_SMP
-
#include <asm/smp.h>
static inline bool arch_irq_work_has_interrupt(void)
@@ -10,13 +8,4 @@
return !!__smp_cross_call;
}
-#else
-
-static inline bool arch_irq_work_has_interrupt(void)
-{
- return false;
-}
-
-#endif
-
#endif /* __ASM_IRQ_WORK_H */
diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h
index 4fde8c1..0a456be 100644
--- a/arch/arm64/include/asm/percpu.h
+++ b/arch/arm64/include/asm/percpu.h
@@ -16,8 +16,6 @@
#ifndef __ASM_PERCPU_H
#define __ASM_PERCPU_H
-#ifdef CONFIG_SMP
-
static inline void set_my_cpu_offset(unsigned long off)
{
asm volatile("msr tpidr_el1, %0" :: "r" (off) : "memory");
@@ -38,12 +36,6 @@
}
#define __my_cpu_offset __my_cpu_offset()
-#else /* !CONFIG_SMP */
-
-#define set_my_cpu_offset(x) do { } while (0)
-
-#endif /* CONFIG_SMP */
-
#define PERCPU_OP(op, asm_op) \
static inline unsigned long __percpu_##op(void *ptr, \
unsigned long val, int size) \
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 8212e6aa..d001846 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -61,13 +61,8 @@
extern void __pud_error(const char *file, int line, unsigned long val);
extern void __pgd_error(const char *file, int line, unsigned long val);
-#ifdef CONFIG_SMP
#define PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
#define PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
-#else
-#define PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF)
-#define PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF)
-#endif
#define PROT_DEVICE_nGnRE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
#define PROT_NORMAL_NC (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_NC))
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index d6dd9fd..536274e 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -183,11 +183,7 @@
#define instruction_pointer(regs) ((unsigned long)(regs)->pc)
-#ifdef CONFIG_SMP
extern unsigned long profile_pc(struct pt_regs *regs);
-#else
-#define profile_pc(regs) instruction_pointer(regs)
-#endif
#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index db02be8..d9c3d6a 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -20,10 +20,6 @@
#include <linux/cpumask.h>
#include <linux/thread_info.h>
-#ifndef CONFIG_SMP
-# error "<asm/smp.h> included in non-SMP build"
-#endif
-
#define raw_smp_processor_id() (current_thread_info()->cpu)
struct seq_file;
diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h
index 225ec35..a3e9d6f 100644
--- a/arch/arm64/include/asm/topology.h
+++ b/arch/arm64/include/asm/topology.h
@@ -1,8 +1,6 @@
#ifndef __ASM_TOPOLOGY_H
#define __ASM_TOPOLOGY_H
-#ifdef CONFIG_SMP
-
#include <linux/cpumask.h>
struct cpu_topology {
@@ -24,13 +22,6 @@
void store_cpu_topology(unsigned int cpuid);
const struct cpumask *cpu_coregroup_mask(int cpu);
-#else
-
-static inline void init_cpu_topology(void) { }
-static inline void store_cpu_topology(unsigned int cpuid) { }
-
-#endif
-
#include <asm-generic/topology.h>
#endif /* _ASM_ARM_TOPOLOGY_H */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index e89063ef..f126cfe 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -17,7 +17,8 @@
sys.o stacktrace.o time.o traps.o io.o vdso.o \
hyp-stub.o psci.o psci-call.o cpu_ops.o insn.o \
return_address.o cpuinfo.o cpu_errata.o \
- cpufeature.o alternative.o cacheinfo.o
+ cpufeature.o alternative.o cacheinfo.o \
+ smp.o smp_spin_table.o topology.o
arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \
sys_compat.o entry32.o \
@@ -25,8 +26,8 @@
arm64-obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o
arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o
arm64-obj-$(CONFIG_SMP) += smp.o smp_spin_table.o topology.o
-arm64-obj-$(CONFIG_PERF_EVENTS) += perf_regs.o perf_callchain.o
-arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o
+arm64-obj-$(CONFIG_PERF_EVENTS) += perf_regs.o
+arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o perf_callchain.o
arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
arm64-obj-$(CONFIG_CPU_PM) += sleep.o suspend.o
arm64-obj-$(CONFIG_CPU_IDLE) += cpuidle.o
diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
index 5ea337d..b6bd7d4 100644
--- a/arch/arm64/kernel/cpu_ops.c
+++ b/arch/arm64/kernel/cpu_ops.c
@@ -30,9 +30,7 @@
const struct cpu_operations *cpu_ops[NR_CPUS];
static const struct cpu_operations *supported_cpu_ops[] __initconst = {
-#ifdef CONFIG_SMP
&smp_spin_table_ops,
-#endif
&cpu_psci_ops,
NULL,
};
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index c0ff3ce..3a06541 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -62,13 +62,8 @@
/*
* Initial memory map attributes.
*/
-#ifndef CONFIG_SMP
-#define PTE_FLAGS PTE_TYPE_PAGE | PTE_AF
-#define PMD_FLAGS PMD_TYPE_SECT | PMD_SECT_AF
-#else
#define PTE_FLAGS PTE_TYPE_PAGE | PTE_AF | PTE_SHARED
#define PMD_FLAGS PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S
-#endif
#ifdef CONFIG_ARM64_64K_PAGES
#define MM_MMUFLAGS PTE_ATTRINDX(MT_NORMAL) | PTE_FLAGS
@@ -574,7 +569,6 @@
.long BOOT_CPU_MODE_EL1
.popsection
-#ifdef CONFIG_SMP
/*
* This provides a "holding pen" for platforms to hold all secondary
* cores are held until we're ready for them to initialise.
@@ -622,7 +616,6 @@
mov x29, #0
b secondary_start_kernel
ENDPROC(__secondary_switched)
-#endif /* CONFIG_SMP */
/*
* Enable the MMU.
diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index 463fa2e..11dc3fd 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -33,9 +33,7 @@
int arch_show_interrupts(struct seq_file *p, int prec)
{
-#ifdef CONFIG_SMP
show_ipi_list(p, prec);
-#endif
seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
return 0;
}
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 869f202..ec30152 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -462,8 +462,6 @@
}
#endif
-#ifdef CONFIG_SMP
-
static int __init cpu_psci_cpu_init(unsigned int cpu)
{
return 0;
@@ -550,7 +548,6 @@
return -ETIMEDOUT;
}
#endif
-#endif
static int psci_suspend_finisher(unsigned long index)
{
@@ -585,7 +582,6 @@
.cpu_init_idle = cpu_psci_cpu_init_idle,
.cpu_suspend = cpu_psci_cpu_suspend,
#endif
-#ifdef CONFIG_SMP
.cpu_init = cpu_psci_cpu_init,
.cpu_prepare = cpu_psci_cpu_prepare,
.cpu_boot = cpu_psci_cpu_boot,
@@ -594,6 +590,5 @@
.cpu_die = cpu_psci_cpu_die,
.cpu_kill = cpu_psci_cpu_kill,
#endif
-#endif
};
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index f3067d4..cf609cf 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -131,7 +131,6 @@
}
struct mpidr_hash mpidr_hash;
-#ifdef CONFIG_SMP
/**
* smp_build_mpidr_hash - Pre-compute shifts required at each affinity
* level in order to build a linear index from an
@@ -197,7 +196,6 @@
pr_warn("Large number of MPIDR hash buckets detected\n");
__flush_dcache_area(&mpidr_hash, sizeof(struct mpidr_hash));
}
-#endif
static void __init hyp_mode_check(void)
{
@@ -405,10 +403,8 @@
xen_early_init();
cpu_read_bootcpu_ops();
-#ifdef CONFIG_SMP
smp_init_cpus();
smp_build_mpidr_hash();
-#endif
#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
@@ -508,9 +504,7 @@
* online processors, looking for lines beginning with
* "processor". Give glibc what it expects.
*/
-#ifdef CONFIG_SMP
seq_printf(m, "processor\t: %d\n", i);
-#endif
/*
* Dump out the common processor features in a single line.
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index 803cfea..5686a3ae 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S
@@ -82,7 +82,6 @@
str x2, [x0, #CPU_CTX_SP]
ldr x1, =sleep_save_sp
ldr x1, [x1, #SLEEP_SAVE_SP_VIRT]
-#ifdef CONFIG_SMP
mrs x7, mpidr_el1
ldr x9, =mpidr_hash
ldr x10, [x9, #MPIDR_HASH_MASK]
@@ -94,7 +93,6 @@
ldp w5, w6, [x9, #(MPIDR_HASH_SHIFTS + 8)]
compute_mpidr_hash x8, x3, x4, x5, x6, x7, x10
add x1, x1, x8, lsl #3
-#endif
bl __cpu_suspend_save
/*
* Grab suspend finisher in x20 and its argument in x19
@@ -151,7 +149,6 @@
ENTRY(cpu_resume)
bl el2_setup // if in EL2 drop to EL1 cleanly
-#ifdef CONFIG_SMP
mrs x1, mpidr_el1
adrp x8, mpidr_hash
add x8, x8, #:lo12:mpidr_hash // x8 = struct mpidr_hash phys address
@@ -161,9 +158,7 @@
ldp w5, w6, [x8, #(MPIDR_HASH_SHIFTS + 8)]
compute_mpidr_hash x7, x3, x4, x5, x6, x1, x2
/* x7 contains hash index, let's use it to grab context pointer */
-#else
mov x7, xzr
-#endif
ldr_l x0, sleep_save_sp + SLEEP_SAVE_SP_PHYS
ldr x0, [x0, x7, lsl #3]
/* load sp from context */
diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
index 42f9195..149151f 100644
--- a/arch/arm64/kernel/time.c
+++ b/arch/arm64/kernel/time.c
@@ -42,7 +42,6 @@
#include <asm/thread_info.h>
#include <asm/stacktrace.h>
-#ifdef CONFIG_SMP
unsigned long profile_pc(struct pt_regs *regs)
{
struct stackframe frame;
@@ -62,7 +61,6 @@
return frame.pc;
}
EXPORT_SYMBOL(profile_pc);
-#endif
void __init time_init(void)
{
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 4db6a25..1ea920c 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -189,11 +189,7 @@
#else
#define S_PREEMPT ""
#endif
-#ifdef CONFIG_SMP
#define S_SMP " SMP"
-#else
-#define S_SMP ""
-#endif
static int __die(const char *str, int err, struct thread_info *thread,
struct pt_regs *regs)
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index 76c1e6c..d70ff14 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -53,8 +53,6 @@
__flush_icache_all();
}
-#ifdef CONFIG_SMP
-
static void set_mm_context(struct mm_struct *mm, unsigned int asid)
{
unsigned long flags;
@@ -110,23 +108,12 @@
cpu_switch_mm(mm->pgd, mm);
}
-#else
-
-static inline void set_mm_context(struct mm_struct *mm, unsigned int asid)
-{
- mm->context.id = asid;
- cpumask_copy(mm_cpumask(mm), cpumask_of(smp_processor_id()));
-}
-
-#endif
-
void __new_context(struct mm_struct *mm)
{
unsigned int asid;
unsigned int bits = asid_bits();
raw_spin_lock(&cpu_asid_lock);
-#ifdef CONFIG_SMP
/*
* Check the ASID again, in case the change was broadcast from another
* CPU before we acquired the lock.
@@ -136,7 +123,6 @@
raw_spin_unlock(&cpu_asid_lock);
return;
}
-#endif
/*
* At this point, it is guaranteed that the current mm (with an old
* ASID) isn't active on any other CPU since the ASIDs are changed
@@ -155,10 +141,8 @@
cpu_last_asid = ASID_FIRST_VERSION;
asid = cpu_last_asid + smp_processor_id();
flush_context();
-#ifdef CONFIG_SMP
smp_wmb();
smp_call_function(reset_context, NULL, 1);
-#endif
cpu_last_asid += NR_CPUS - 1;
}
diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index 4dfa397..c26b804 100644
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -60,14 +60,10 @@
unsigned long uaddr, void *dst, const void *src,
unsigned long len)
{
-#ifdef CONFIG_SMP
preempt_disable();
-#endif
memcpy(dst, src, len);
flush_ptrace_access(vma, page, uaddr, dst, len);
-#ifdef CONFIG_SMP
preempt_enable();
-#endif
}
void __sync_icache_dcache(pte_t pte, unsigned long addr)
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index a8be513..34da270 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -34,11 +34,7 @@
#define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K
#endif
-#ifdef CONFIG_SMP
#define TCR_SMP_FLAGS TCR_SHARED
-#else
-#define TCR_SMP_FLAGS 0
-#endif
/* PTWs cacheable, inner/outer WBWA */
#define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA
