softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig

To prepare for inlining do_softirq_own_stack() replace
__ARCH_HAS_DO_SOFTIRQ with a Kconfig switch and select it in the affected
architectures.

This allows in the next step to move the function prototype and the inline
stub into a seperate asm-generic header file which is required to avoid
include recursion.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210210002513.181713427@linutronix.de

arch/Kconfig

@@ -759,6 +759,12 @@ config HAVE_IRQ_EXIT_ON_IRQ_STACK
 	  This spares a stack switch and improves cache usage on softirq
 	  processing.
 
+config HAVE_SOFTIRQ_ON_OWN_STACK
+	bool
+	help
+	  Architecture provides a function to run __do_softirq() on a
+	  seperate stack.
+
 config PGTABLE_LEVELS
 	int
 	default 2

arch/parisc/Kconfig

@@ -63,6 +63,7 @@ config PARISC
 	select HAVE_FTRACE_MCOUNT_RECORD if HAVE_DYNAMIC_FTRACE
 	select HAVE_KPROBES_ON_FTRACE
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
+	select HAVE_SOFTIRQ_ON_OWN_STACK if IRQSTACKS
 	select SET_FS
 
 	help

arch/parisc/include/asm/hardirq.h

@@ -12,10 +12,6 @@
 #include <linux/threads.h>
 #include <linux/irq.h>
 
-#ifdef CONFIG_IRQSTACKS
-#define __ARCH_HAS_DO_SOFTIRQ
-#endif
-
 typedef struct {
 	unsigned int __softirq_pending;
 	unsigned int kernel_stack_usage;

arch/powerpc/Kconfig

@@ -237,6 +237,7 @@ config PPC
 	select MMU_GATHER_PAGE_SIZE
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RELIABLE_STACKTRACE		if PPC_BOOK3S_64 && CPU_LITTLE_ENDIAN
+	select HAVE_SOFTIRQ_ON_OWN_STACK
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_VIRT_CPU_ACCOUNTING
 	select HAVE_IRQ_TIME_ACCOUNTING

arch/powerpc/include/asm/irq.h

@@ -37,8 +37,6 @@ extern int distribute_irqs;
 
 struct pt_regs;
 
-#define __ARCH_HAS_DO_SOFTIRQ
-
 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 /*
  * Per-cpu stacks for handling critical, debug and machine check

arch/s390/Kconfig

@@ -182,6 +182,7 @@ config S390
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RELIABLE_STACKTRACE
 	select HAVE_RSEQ
+	select HAVE_SOFTIRQ_ON_OWN_STACK
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_VIRT_CPU_ACCOUNTING
 	select HAVE_VIRT_CPU_ACCOUNTING_IDLE

arch/s390/include/asm/hardirq.h

@@ -18,7 +18,6 @@
 #define or_softirq_pending(x)  (S390_lowcore.softirq_pending |= (x))
 
 #define __ARCH_IRQ_STAT
-#define __ARCH_HAS_DO_SOFTIRQ
 #define __ARCH_IRQ_EXIT_IRQS_DISABLED
 
 static inline void ack_bad_irq(unsigned int irq)

arch/sh/Kconfig

@@ -56,6 +56,7 @@ config SUPERH
 	select HAVE_PERF_EVENTS
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_UID16
+	select HAVE_SOFTIRQ_ON_OWN_STACK if IRQSTACKS
 	select HAVE_STACKPROTECTOR
 	select HAVE_SYSCALL_TRACEPOINTS
 	select IRQ_FORCED_THREADING

arch/sh/include/asm/irq.h

@@ -51,7 +51,6 @@ asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs);
 #ifdef CONFIG_IRQSTACKS
 extern void irq_ctx_init(int cpu);
 extern void irq_ctx_exit(int cpu);
-# define __ARCH_HAS_DO_SOFTIRQ
 #else
 # define irq_ctx_init(cpu) do { } while (0)
 # define irq_ctx_exit(cpu) do { } while (0)

arch/sparc/Kconfig

@@ -97,6 +97,7 @@ config SPARC64
 	select ARCH_HAS_PTE_SPECIAL
 	select PCI_DOMAINS if PCI
 	select ARCH_HAS_GIGANTIC_PAGE
+	select HAVE_SOFTIRQ_ON_OWN_STACK
 
 config ARCH_PROC_KCORE_TEXT
 	def_bool y

arch/sparc/include/asm/irq_64.h

@@ -93,7 +93,6 @@ void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
 
 extern void *hardirq_stack[NR_CPUS];
 extern void *softirq_stack[NR_CPUS];
-#define __ARCH_HAS_DO_SOFTIRQ
 
 #define NO_IRQ		0xffffffff
 

arch/x86/Kconfig

@@ -221,6 +221,7 @@ config X86
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
 	select HAVE_FUNCTION_ARG_ACCESS_API
+	select HAVE_SOFTIRQ_ON_OWN_STACK
 	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
 	select HAVE_STACK_VALIDATION		if X86_64
 	select HAVE_STATIC_CALL

arch/x86/include/asm/irq.h

@@ -25,8 +25,6 @@ static inline int irq_canonicalize(int irq)
 
 extern int irq_init_percpu_irqstack(unsigned int cpu);
 
-#define __ARCH_HAS_DO_SOFTIRQ
-
 struct irq_desc;
 
 extern void fixup_irqs(void);

include/linux/interrupt.h

@@ -569,7 +569,7 @@ struct softirq_action
 asmlinkage void do_softirq(void);
 asmlinkage void __do_softirq(void);
 
-#ifdef __ARCH_HAS_DO_SOFTIRQ
+#ifdef CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK
 void do_softirq_own_stack(void);
 #else
 static inline void do_softirq_own_stack(void)