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>

9 files changed, 4 insertions, 36 deletions

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 @@ arm64-obj-y		:= debug-monitors.o entry.o irq.o fpsimd.o		\
 			   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_COMPAT)		+= sys32.o kuser32.o signal32.o 	\
 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 @@ extern const struct cpu_operations cpu_psci_ops;
 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 @@ ENTRY(__boot_cpu_mode)
 	.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 @@ ENTRY(__secondary_switched)
 	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 @@ unsigned long irq_err_count;
 
 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 @@ int __init psci_acpi_init(void)
 }
 #endif
 
-#ifdef CONFIG_SMP
-
 static int __init cpu_psci_cpu_init(unsigned int cpu)
 {
 	return 0;
@@ -550,7 +548,6 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
 	return -ETIMEDOUT;
 }
 #endif
-#endif
 
 static int psci_suspend_finisher(unsigned long index)
 {
@@ -585,7 +582,6 @@ const struct cpu_operations cpu_psci_ops = {
 	.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 @@ const struct cpu_operations cpu_psci_ops = {
 	.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 @@ bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
 }
 
 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 @@ static void __init smp_build_mpidr_hash(void)
 		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 @@ void __init setup_arch(char **cmdline_p)
 	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 @@ static int c_show(struct seq_file *m, void *v)
 		 * 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 @@ ENTRY(__cpu_suspend_enter)
 	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 @@ ENTRY(__cpu_suspend_enter)
 	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 @@ ENDPROC(cpu_resume_after_mmu)
 
 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 @@ ENTRY(cpu_resume)
 	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 @@ unsigned long profile_pc(struct pt_regs *regs)
 	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 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
 #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)