1 files changed, 112 insertions, 45 deletions

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 8371855042dc..45393919fe61 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -21,12 +21,14 @@
 #include <linux/init.h>
 #include <linux/cpu.h>
 #include <linux/irq.h>
+#include <linux/entry-common.h>
 #include <asm/irq_regs.h>
 #include <asm/cputime.h>
 #include <asm/lowcore.h>
 #include <asm/irq.h>
 #include <asm/hw_irq.h>
 #include <asm/stacktrace.h>
+#include <asm/softirq_stack.h>
 #include "entry.h"
 
 DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
@@ -95,27 +97,106 @@ static const struct irq_class irqclass_sub_desc[] = {
 	{.irq = CPU_RST,    .name = "RST", .desc = "[CPU] CPU Restart"},
 };
 
-void __init init_IRQ(void)
+static void do_IRQ(struct pt_regs *regs, int irq)
 {
-	BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS);
-	init_cio_interrupts();
-	init_airq_interrupts();
-	init_ext_interrupts();
-}
-
-void do_IRQ(struct pt_regs *regs, int irq)
-{
-	struct pt_regs *old_regs;
-
-	old_regs = set_irq_regs(regs);
-	irq_enter();
 	if (tod_after_eq(S390_lowcore.int_clock,
 			 S390_lowcore.clock_comparator))
 		/* Serve timer interrupts first. */
 		clock_comparator_work();
 	generic_handle_irq(irq);
-	irq_exit();
+}
+
+static int on_async_stack(void)
+{
+	unsigned long frame = current_frame_address();
+
+	return ((S390_lowcore.async_stack ^ frame) & ~(THREAD_SIZE - 1)) == 0;
+}
+
+static void do_irq_async(struct pt_regs *regs, int irq)
+{
+	if (on_async_stack()) {
+		do_IRQ(regs, irq);
+	} else {
+		call_on_stack(2, S390_lowcore.async_stack, void, do_IRQ,
+			      struct pt_regs *, regs, int, irq);
+	}
+}
+
+static int irq_pending(struct pt_regs *regs)
+{
+	int cc;
+
+	asm volatile("tpi 0\n"
+		     "ipm %0" : "=d" (cc) : : "cc");
+	return cc >> 28;
+}
+
+void noinstr do_io_irq(struct pt_regs *regs)
+{
+	irqentry_state_t state = irqentry_enter(regs);
+	struct pt_regs *old_regs = set_irq_regs(regs);
+	int from_idle;
+
+	irq_enter_rcu();
+
+	if (user_mode(regs)) {
+		update_timer_sys();
+		if (static_branch_likely(&cpu_has_bear))
+			current->thread.last_break = regs->last_break;
+	}
+
+	from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;
+	if (from_idle)
+		account_idle_time_irq();
+
+	do {
+		regs->tpi_info = S390_lowcore.tpi_info;
+		if (S390_lowcore.tpi_info.adapter_IO)
+			do_irq_async(regs, THIN_INTERRUPT);
+		else
+			do_irq_async(regs, IO_INTERRUPT);
+	} while (MACHINE_IS_LPAR && irq_pending(regs));
+
+	irq_exit_rcu();
+
 	set_irq_regs(old_regs);
+	irqentry_exit(regs, state);
+
+	if (from_idle)
+		regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
+}
+
+void noinstr do_ext_irq(struct pt_regs *regs)
+{
+	irqentry_state_t state = irqentry_enter(regs);
+	struct pt_regs *old_regs = set_irq_regs(regs);
+	int from_idle;
+
+	irq_enter_rcu();
+
+	if (user_mode(regs)) {
+		update_timer_sys();
+		if (static_branch_likely(&cpu_has_bear))
+			current->thread.last_break = regs->last_break;
+	}
+
+	regs->int_code = S390_lowcore.ext_int_code_addr;
+	regs->int_parm = S390_lowcore.ext_params;
+	regs->int_parm_long = S390_lowcore.ext_params2;
+
+	from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;
+	if (from_idle)
+		account_idle_time_irq();
+
+	do_irq_async(regs, EXT_INTERRUPT);
+
+	irq_exit_rcu();
+	set_irq_regs(old_regs);
+	irqentry_exit(regs, state);
+
+	if (from_idle)
+		regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
 }
 
 static void show_msi_interrupt(struct seq_file *p, int irq)
@@ -124,7 +205,7 @@ static void show_msi_interrupt(struct seq_file *p, int irq)
 	unsigned long flags;
 	int cpu;
 
-	irq_lock_sparse();
+	rcu_read_lock();
 	desc = irq_to_desc(irq);
 	if (!desc)
 		goto out;
@@ -132,7 +213,7 @@ static void show_msi_interrupt(struct seq_file *p, int irq)
 	raw_spin_lock_irqsave(&desc->lock, flags);
 	seq_printf(p, "%3d: ", irq);
 	for_each_online_cpu(cpu)
-		seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
+		seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, cpu));
 
 	if (desc->irq_data.chip)
 		seq_printf(p, " %8s", desc->irq_data.chip->name);
@@ -143,7 +224,7 @@ static void show_msi_interrupt(struct seq_file *p, int irq)
 	seq_putc(p, '\n');
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 out:
-	irq_unlock_sparse();
+	rcu_read_unlock();
 }
 
 /*
@@ -154,7 +235,7 @@ int show_interrupts(struct seq_file *p, void *v)
 	int index = *(loff_t *) v;
 	int cpu, irq;
 
-	get_online_cpus();
+	cpus_read_lock();
 	if (index == 0) {
 		seq_puts(p, "           ");
 		for_each_online_cpu(cpu)
@@ -184,7 +265,7 @@ int show_interrupts(struct seq_file *p, void *v)
 		seq_putc(p, '\n');
 	}
 out:
-	put_online_cpus();
+	cpus_read_unlock();
 	return 0;
 }
 
@@ -194,24 +275,6 @@ unsigned int arch_dynirq_lower_bound(unsigned int from)
 }
 
 /*
- * Switch to the asynchronous interrupt stack for softirq execution.
- */
-void do_softirq_own_stack(void)
-{
-	unsigned long old, new;
-
-	old = current_stack_pointer();
-	/* Check against async. stack address range. */
-	new = S390_lowcore.async_stack;
-	if (((new - old) >> (PAGE_SHIFT + THREAD_SIZE_ORDER)) != 0) {
-		CALL_ON_STACK(__do_softirq, new, 0);
-	} else {
-		/* We are already on the async stack. */
-		__do_softirq();
-	}
-}
-
-/*
  * ext_int_hash[index] is the list head for all external interrupts that hash
  * to this index.
  */
@@ -279,7 +342,7 @@ static irqreturn_t do_ext_interrupt(int irq, void *dummy)
 	struct ext_int_info *p;
 	int index;
 
-	ext_code = *(struct ext_code *) &regs->int_code;
+	ext_code.int_code = regs->int_code;
 	if (ext_code.code != EXT_IRQ_CLK_COMP)
 		set_cpu_flag(CIF_NOHZ_DELAY);
 
@@ -294,12 +357,7 @@ static irqreturn_t do_ext_interrupt(int irq, void *dummy)
 	return IRQ_HANDLED;
 }
 
-static struct irqaction external_interrupt = {
-	.name	 = "EXT",
-	.handler = do_ext_interrupt,
-};
-
-void __init init_ext_interrupts(void)
+static void __init init_ext_interrupts(void)
 {
 	int idx;
 
@@ -308,7 +366,16 @@ void __init init_ext_interrupts(void)
 
 	irq_set_chip_and_handler(EXT_INTERRUPT,
 				 &dummy_irq_chip, handle_percpu_irq);
-	setup_irq(EXT_INTERRUPT, &external_interrupt);
+	if (request_irq(EXT_INTERRUPT, do_ext_interrupt, 0, "EXT", NULL))
+		panic("Failed to register EXT interrupt\n");
+}
+
+void __init init_IRQ(void)
+{
+	BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS);
+	init_cio_interrupts();
+	init_airq_interrupts();
+	init_ext_interrupts();
 }
 
 static DEFINE_SPINLOCK(irq_subclass_lock);