arm64: entry: move arm64_preempt_schedule_irq to entry-common.c

Subsequent patches will pull more of the IRQ entry handling into C. To
keep this in one place, let's move arm64_preempt_schedule_irq() into
entry-common.c along with the other entry management functions.

We no longer need to include <linux/lockdep.h> in process.c, so the
include directive is removed.

There should be no functional change as a result of this patch.

Reviewed-by Joey Gouly <joey.gouly@arm.com>

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-5-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/kernel/entry-common.c

@@ -6,7 +6,11 @@
  */
 
 #include <linux/context_tracking.h>
+#include <linux/linkage.h>
+#include <linux/lockdep.h>
 #include <linux/ptrace.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
 #include <linux/thread_info.h>
 
 #include <asm/cpufeature.h>
@@ -113,6 +117,22 @@ asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs)
 		exit_to_kernel_mode(regs);
 }
 
+asmlinkage void __sched arm64_preempt_schedule_irq(void)
+{
+	lockdep_assert_irqs_disabled();
+
+	/*
+	 * Preempting a task from an IRQ means we leave copies of PSTATE
+	 * on the stack. cpufeature's enable calls may modify PSTATE, but
+	 * resuming one of these preempted tasks would undo those changes.
+	 *
+	 * Only allow a task to be preempted once cpufeatures have been
+	 * enabled.
+	 */
+	if (system_capabilities_finalized())
+		preempt_schedule_irq();
+}
+
 #ifdef CONFIG_ARM64_ERRATUM_1463225
 static DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
 

arch/arm64/kernel/process.c

@@ -18,7 +18,6 @@
 #include <linux/sched/task.h>
 #include <linux/sched/task_stack.h>
 #include <linux/kernel.h>
-#include <linux/lockdep.h>
 #include <linux/mman.h>
 #include <linux/mm.h>
 #include <linux/nospec.h>
@@ -724,22 +723,6 @@ static int __init tagged_addr_init(void)
 core_initcall(tagged_addr_init);
 #endif	/* CONFIG_ARM64_TAGGED_ADDR_ABI */
 
-asmlinkage void __sched arm64_preempt_schedule_irq(void)
-{
-	lockdep_assert_irqs_disabled();
-
-	/*
-	 * Preempting a task from an IRQ means we leave copies of PSTATE
-	 * on the stack. cpufeature's enable calls may modify PSTATE, but
-	 * resuming one of these preempted tasks would undo those changes.
-	 *
-	 * Only allow a task to be preempted once cpufeatures have been
-	 * enabled.
-	 */
-	if (system_capabilities_finalized())
-		preempt_schedule_irq();
-}
-
 #ifdef CONFIG_BINFMT_ELF
 int arch_elf_adjust_prot(int prot, const struct arch_elf_state *state,
 			 bool has_interp, bool is_interp)