1 files changed, 85 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/irq/imask.c b/arch/sh/kernel/cpu/irq/imask.c
new file mode 100644
index 0000000000..572585c3f2
--- /dev/null
+++ b/arch/sh/kernel/cpu/irq/imask.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/sh/kernel/cpu/irq/imask.c
+ *
+ * Copyright (C) 1999, 2000  Niibe Yutaka
+ *
+ * Simple interrupt handling using IMASK of SR register.
+ *
+ */
+/* NOTE: Will not work on level 15 */
+#include <linux/ptrace.h>
+#include <linux/errno.h>
+#include <linux/kernel_stat.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/spinlock.h>
+#include <linux/cache.h>
+#include <linux/irq.h>
+#include <linux/bitmap.h>
+#include <asm/irq.h>
+
+/* Bitmap of IRQ masked */
+#define IMASK_PRIORITY	15
+
+static DECLARE_BITMAP(imask_mask, IMASK_PRIORITY);
+static int interrupt_priority;
+
+static inline void set_interrupt_registers(int ip)
+{
+	unsigned long __dummy;
+
+	asm volatile(
+#ifdef CONFIG_CPU_HAS_SR_RB
+		     "ldc	%2, r6_bank\n\t"
+#endif
+		     "stc	sr, %0\n\t"
+		     "and	#0xf0, %0\n\t"
+		     "shlr2	%0\n\t"
+		     "cmp/eq	#0x3c, %0\n\t"
+		     "bt/s	1f	! CLI-ed\n\t"
+		     " stc	sr, %0\n\t"
+		     "and	%1, %0\n\t"
+		     "or	%2, %0\n\t"
+		     "ldc	%0, sr\n"
+		     "1:"
+		     : "=&z" (__dummy)
+		     : "r" (~0xf0), "r" (ip << 4)
+		     : "t");
+}
+
+static void mask_imask_irq(struct irq_data *data)
+{
+	unsigned int irq = data->irq;
+
+	clear_bit(irq, imask_mask);
+	if (interrupt_priority < IMASK_PRIORITY - irq)
+		interrupt_priority = IMASK_PRIORITY - irq;
+	set_interrupt_registers(interrupt_priority);
+}
+
+static void unmask_imask_irq(struct irq_data *data)
+{
+	unsigned int irq = data->irq;
+
+	set_bit(irq, imask_mask);
+	interrupt_priority = IMASK_PRIORITY -
+		find_first_zero_bit(imask_mask, IMASK_PRIORITY);
+	set_interrupt_registers(interrupt_priority);
+}
+
+static struct irq_chip imask_irq_chip = {
+	.name		= "SR.IMASK",
+	.irq_mask	= mask_imask_irq,
+	.irq_unmask	= unmask_imask_irq,
+	.irq_mask_ack	= mask_imask_irq,
+};
+
+void make_imask_irq(unsigned int irq)
+{
+	irq_set_chip_and_handler_name(irq, &imask_irq_chip, handle_level_irq,
+				      "level");
+}