[POWERPC] Celleb: support interrupts

This patch creates Celleb platform dependent files to support interrupts.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 307 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/celleb/interrupt.c b/arch/powerpc/platforms/celleb/interrupt.c
new file mode 100644
index 0000000..98e6665
--- /dev/null
+++ b/arch/powerpc/platforms/celleb/interrupt.c
@@ -0,0 +1,274 @@
+/*
+ * Celleb/Beat Interrupt controller
+ *
+ * (C) Copyright 2006-2007 TOSHIBA CORPORATION
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/percpu.h>
+#include <linux/types.h>
+
+#include <asm/machdep.h>
+
+#include "interrupt.h"
+#include "beat_wrapper.h"
+
+#define	MAX_IRQS	NR_IRQS
+static DEFINE_SPINLOCK(beatic_irq_mask_lock);
+static uint64_t	beatic_irq_mask_enable[(MAX_IRQS+255)/64];
+static uint64_t	beatic_irq_mask_ack[(MAX_IRQS+255)/64];
+
+static struct irq_host *beatic_host = NULL;
+
+/*
+ * In this implementation, "virq" == "IRQ plug number",
+ * "(irq_hw_number_t)hwirq" == "IRQ outlet number".
+ */
+
+/* assumption: locked */
+static inline void beatic_update_irq_mask(unsigned int irq_plug)
+{
+	int off;
+	unsigned long masks[4];
+
+	off = (irq_plug / 256) * 4;
+	masks[0] = beatic_irq_mask_enable[off + 0]
+	           & beatic_irq_mask_ack[off + 0];
+	masks[1] = beatic_irq_mask_enable[off + 1]
+	           & beatic_irq_mask_ack[off + 1];
+	masks[2] = beatic_irq_mask_enable[off + 2]
+	           & beatic_irq_mask_ack[off + 2];
+	masks[3] = beatic_irq_mask_enable[off + 3]
+	           & beatic_irq_mask_ack[off + 3];
+	if (beat_set_interrupt_mask(irq_plug&~255UL,
+		masks[0], masks[1], masks[2], masks[3]) != 0)
+		panic("Failed to set mask IRQ!");
+}
+
+static void beatic_mask_irq(unsigned int irq_plug)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&beatic_irq_mask_lock, flags);
+	beatic_irq_mask_enable[irq_plug/64] &= ~(1UL << (63 - (irq_plug%64)));
+	beatic_update_irq_mask(irq_plug);
+	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
+}
+
+static void beatic_unmask_irq(unsigned int irq_plug)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&beatic_irq_mask_lock, flags);
+	beatic_irq_mask_enable[irq_plug/64] |= 1UL << (63 - (irq_plug%64));
+	beatic_update_irq_mask(irq_plug);
+	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
+}
+
+static void beatic_ack_irq(unsigned int irq_plug)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&beatic_irq_mask_lock, flags);
+	beatic_irq_mask_ack[irq_plug/64] &= ~(1UL << (63 - (irq_plug%64)));
+	beatic_update_irq_mask(irq_plug);
+	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
+}
+
+static void beatic_end_irq(unsigned int irq_plug)
+{
+	s64 err;
+	unsigned long flags;
+
+	if ((err = beat_downcount_of_interrupt(irq_plug)) != 0) {
+		if ((err & 0xFFFFFFFF) != 0xFFFFFFF5) /* -11: wrong state */
+			panic("Failed to downcount IRQ! Error = %16lx", err);
+
+		printk(KERN_ERR "IRQ over-downcounted, plug %d\n", irq_plug);
+	}
+	spin_lock_irqsave(&beatic_irq_mask_lock, flags);
+	beatic_irq_mask_ack[irq_plug/64] |= 1UL << (63 - (irq_plug%64));
+	beatic_update_irq_mask(irq_plug);
+	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
+}
+
+static struct irq_chip beatic_pic = {
+	.typename = " CELL-BEAT ",
+	.unmask = beatic_unmask_irq,
+	.mask = beatic_mask_irq,
+	.eoi = beatic_end_irq,
+};
+
+/*
+ * Dispose binding hardware IRQ number (hw) and Virtuql IRQ number (virq),
+ * update flags.
+ *
+ * Note that the number (virq) is already assigned at upper layer.
+ */
+static void beatic_pic_host_unmap(struct irq_host *h, unsigned int virq)
+{
+	beat_destruct_irq_plug(virq);
+}
+
+/*
+ * Create or update binding hardware IRQ number (hw) and Virtuql
+ * IRQ number (virq). This is called only once for a given mapping.
+ *
+ * Note that the number (virq) is already assigned at upper layer.
+ */
+static int beatic_pic_host_map(struct irq_host *h, unsigned int virq,
+			       irq_hw_number_t hw)
+{
+	struct irq_desc *desc = get_irq_desc(virq);
+	int64_t	err;
+
+	if ((err = beat_construct_and_connect_irq_plug(virq, hw)) < 0)
+		return -EIO;
+
+	desc->status |= IRQ_LEVEL;
+	set_irq_chip_and_handler(virq, &beatic_pic, handle_fasteoi_irq);
+	return 0;
+}
+
+/*
+ * Update binding hardware IRQ number (hw) and Virtuql
+ * IRQ number (virq). This is called only once for a given mapping.
+ */
+static void beatic_pic_host_remap(struct irq_host *h, unsigned int virq,
+			       irq_hw_number_t hw)
+{
+	beat_construct_and_connect_irq_plug(virq, hw);
+}
+
+/*
+ * Translate device-tree interrupt spec to irq_hw_number_t style (ulong),
+ * to pass away to irq_create_mapping().
+ *
+ * Called from irq_create_of_mapping() only.
+ * Note: We have only 1 entry to translate.
+ */
+static int beatic_pic_host_xlate(struct irq_host *h, struct device_node *ct,
+				 u32 *intspec, unsigned int intsize,
+				 irq_hw_number_t *out_hwirq,
+				 unsigned int *out_flags)
+{
+	u64 *intspec2 = (u64 *)intspec;
+
+	*out_hwirq = *intspec2;
+	*out_flags |= IRQ_TYPE_LEVEL_LOW;
+	return 0;
+}
+
+static struct irq_host_ops beatic_pic_host_ops = {
+	.map = beatic_pic_host_map,
+	.remap = beatic_pic_host_remap,
+	.unmap = beatic_pic_host_unmap,
+	.xlate = beatic_pic_host_xlate,
+};
+
+/*
+ * Get an IRQ number
+ * Note: returns VIRQ
+ */
+static inline unsigned int beatic_get_irq_plug(void)
+{
+	int i;
+	uint64_t	pending[4], ub;
+
+	for (i = 0; i < MAX_IRQS; i += 256) {
+		beat_detect_pending_interrupts(i, pending);
+		__asm__ ("cntlzd %0,%1":"=r"(ub):
+			"r"(pending[0] & beatic_irq_mask_enable[i/64+0]
+			               & beatic_irq_mask_ack[i/64+0]));
+		if (ub != 64)
+			return i + ub + 0;
+		__asm__ ("cntlzd %0,%1":"=r"(ub):
+			"r"(pending[1] & beatic_irq_mask_enable[i/64+1]
+			               & beatic_irq_mask_ack[i/64+1]));
+		if (ub != 64)
+			return i + ub + 64;
+		__asm__ ("cntlzd %0,%1":"=r"(ub):
+			"r"(pending[2] & beatic_irq_mask_enable[i/64+2]
+			               & beatic_irq_mask_ack[i/64+2]));
+		if (ub != 64)
+			return i + ub + 128;
+		__asm__ ("cntlzd %0,%1":"=r"(ub):
+			"r"(pending[3] & beatic_irq_mask_enable[i/64+3]
+			               & beatic_irq_mask_ack[i/64+3]));
+		if (ub != 64)
+			return i + ub + 192;
+	}
+
+	return NO_IRQ;
+}
+unsigned int beatic_get_irq(void)
+{
+	unsigned int ret;
+
+	ret = beatic_get_irq_plug();
+	if (ret != NO_IRQ)
+		beatic_ack_irq(ret);
+	return ret;
+}
+
+/*
+ */
+void __init beatic_init_IRQ(void)
+{
+	int	i;
+
+	memset(beatic_irq_mask_enable, 0, sizeof(beatic_irq_mask_enable));
+	memset(beatic_irq_mask_ack, 255, sizeof(beatic_irq_mask_ack));
+	for (i = 0; i < MAX_IRQS; i += 256)
+		beat_set_interrupt_mask(i, 0L, 0L, 0L, 0L);
+
+	/* Set out get_irq function */
+	ppc_md.get_irq = beatic_get_irq;
+
+	/* Allocate an irq host */
+	beatic_host = irq_alloc_host(IRQ_HOST_MAP_NOMAP, 0,
+					 &beatic_pic_host_ops,
+					 0);
+	BUG_ON(beatic_host == NULL);
+	irq_set_default_host(beatic_host);
+}
+
+#ifdef CONFIG_SMP
+
+/* Nullified to compile with SMP mode */
+void beatic_setup_cpu(int cpu)
+{
+}
+
+void beatic_cause_IPI(int cpu, int mesg)
+{
+}
+
+void beatic_request_IPIs(void)
+{
+}
+#endif /* CONFIG_SMP */
+
+void beatic_deinit_IRQ(void)
+{
+	int	i;
+
+	for (i = 1; i < NR_IRQS; i++)
+		beat_destruct_irq_plug(i);
+}
diff --git a/arch/powerpc/platforms/celleb/interrupt.h b/arch/powerpc/platforms/celleb/interrupt.h
new file mode 100644
index 0000000..b470fd0
--- /dev/null
+++ b/arch/powerpc/platforms/celleb/interrupt.h
@@ -0,0 +1,33 @@
+/*
+ * Celleb/Beat Interrupt controller
+ *
+ * (C) Copyright 2006 TOSHIBA CORPORATION
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef ASM_BEAT_PIC_H
+#define ASM_BEAT_PIC_H
+#ifdef __KERNEL__
+
+extern void beatic_init_IRQ(void);
+extern unsigned int beatic_get_irq(void);
+extern void beatic_cause_IPI(int cpu, int mesg);
+extern void beatic_request_IPIs(void);
+extern void beatic_setup_cpu(int);
+extern void beatic_deinit_IRQ(void);
+
+#endif
+#endif /* ASM_BEAT_PIC_H */