MIPS: Move GIC to drivers/irqchip/

Move GIC irqchip support to drivers/irqchip/ and rename the Kconfig
option from IRQ_GIC to MIPS_GIC to avoid confusion with the ARM GIC.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Reviewed-by: Qais Yousef <qais.yousef@imgtec.com>
Tested-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeffrey Deans <jeffrey.deans@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: John Crispin <blogic@openwrt.org>
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7812/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 407 insertions, 0 deletions

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index b21f12f..f2dde14 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -125,3 +125,7 @@ config KEYSTONE_IRQ
 	help
 		Support for Texas Instruments Keystone 2 IRQ controller IP which
 		is part of the Keystone 2 IPC mechanism
+
+config MIPS_GIC
+	bool
+	select MIPS_CM
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 173bb5f..0218330 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -38,3 +38,4 @@ obj-$(CONFIG_IRQ_CROSSBAR)		+= irq-crossbar.o
 obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o \
 					   irq-bcm7120-l2.o
 obj-$(CONFIG_KEYSTONE_IRQ)		+= irq-keystone.o
+obj-$(CONFIG_MIPS_GIC)			+= irq-mips-gic.o
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
new file mode 100644
index 0000000..5828830
--- /dev/null
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -0,0 +1,402 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2008 Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
+ */
+#include <linux/bitmap.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/irq.h>
+#include <linux/clocksource.h>
+
+#include <asm/io.h>
+#include <asm/gic.h>
+#include <asm/setup.h>
+#include <asm/traps.h>
+#include <linux/hardirq.h>
+#include <asm-generic/bitops/find.h>
+
+unsigned int gic_frequency;
+unsigned int gic_present;
+unsigned long _gic_base;
+unsigned int gic_irq_base;
+unsigned int gic_irq_flags[GIC_NUM_INTRS];
+
+/* The index into this array is the vector # of the interrupt. */
+struct gic_shared_intr_map gic_shared_intr_map[GIC_NUM_INTRS];
+
+struct gic_pcpu_mask {
+	DECLARE_BITMAP(pcpu_mask, GIC_NUM_INTRS);
+};
+
+struct gic_pending_regs {
+	DECLARE_BITMAP(pending, GIC_NUM_INTRS);
+};
+
+struct gic_intrmask_regs {
+	DECLARE_BITMAP(intrmask, GIC_NUM_INTRS);
+};
+
+static struct gic_pcpu_mask pcpu_masks[NR_CPUS];
+static struct gic_pending_regs pending_regs[NR_CPUS];
+static struct gic_intrmask_regs intrmask_regs[NR_CPUS];
+
+#if defined(CONFIG_CSRC_GIC) || defined(CONFIG_CEVT_GIC)
+cycle_t gic_read_count(void)
+{
+	unsigned int hi, hi2, lo;
+
+	do {
+		GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_63_32), hi);
+		GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_31_00), lo);
+		GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_63_32), hi2);
+	} while (hi2 != hi);
+
+	return (((cycle_t) hi) << 32) + lo;
+}
+
+void gic_write_compare(cycle_t cnt)
+{
+	GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_HI),
+				(int)(cnt >> 32));
+	GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_LO),
+				(int)(cnt & 0xffffffff));
+}
+
+void gic_write_cpu_compare(cycle_t cnt, int cpu)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_OTHER_ADDR), cpu);
+	GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_COMPARE_HI),
+				(int)(cnt >> 32));
+	GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_COMPARE_LO),
+				(int)(cnt & 0xffffffff));
+
+	local_irq_restore(flags);
+}
+
+cycle_t gic_read_compare(void)
+{
+	unsigned int hi, lo;
+
+	GICREAD(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_HI), hi);
+	GICREAD(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_LO), lo);
+
+	return (((cycle_t) hi) << 32) + lo;
+}
+#endif
+
+unsigned int gic_get_timer_pending(void)
+{
+	unsigned int vpe_pending;
+
+	GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_OTHER_ADDR), 0);
+	GICREAD(GIC_REG(VPE_OTHER, GIC_VPE_PEND), vpe_pending);
+	return vpe_pending & GIC_VPE_PEND_TIMER_MSK;
+}
+
+void gic_bind_eic_interrupt(int irq, int set)
+{
+	/* Convert irq vector # to hw int # */
+	irq -= GIC_PIN_TO_VEC_OFFSET;
+
+	/* Set irq to use shadow set */
+	GICWRITE(GIC_REG_ADDR(VPE_LOCAL, GIC_VPE_EIC_SS(irq)), set);
+}
+
+void gic_send_ipi(unsigned int intr)
+{
+	GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), 0x80000000 | intr);
+}
+
+static void gic_eic_irq_dispatch(void)
+{
+	unsigned int cause = read_c0_cause();
+	int irq;
+
+	irq = (cause & ST0_IM) >> STATUSB_IP2;
+	if (irq == 0)
+		irq = -1;
+
+	if (irq >= 0)
+		do_IRQ(gic_irq_base + irq);
+	else
+		spurious_interrupt();
+}
+
+static void __init vpe_local_setup(unsigned int numvpes)
+{
+	unsigned long timer_intr = GIC_INT_TMR;
+	unsigned long perf_intr = GIC_INT_PERFCTR;
+	unsigned int vpe_ctl;
+	int i;
+
+	if (cpu_has_veic) {
+		/*
+		 * GIC timer interrupt -> CPU HW Int X (vector X+2) ->
+		 * map to pin X+2-1 (since GIC adds 1)
+		 */
+		timer_intr += (GIC_CPU_TO_VEC_OFFSET - GIC_PIN_TO_VEC_OFFSET);
+		/*
+		 * GIC perfcnt interrupt -> CPU HW Int X (vector X+2) ->
+		 * map to pin X+2-1 (since GIC adds 1)
+		 */
+		perf_intr += (GIC_CPU_TO_VEC_OFFSET - GIC_PIN_TO_VEC_OFFSET);
+	}
+
+	/*
+	 * Setup the default performance counter timer interrupts
+	 * for all VPEs
+	 */
+	for (i = 0; i < numvpes; i++) {
+		GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_OTHER_ADDR), i);
+
+		/* Are Interrupts locally routable? */
+		GICREAD(GIC_REG(VPE_OTHER, GIC_VPE_CTL), vpe_ctl);
+		if (vpe_ctl & GIC_VPE_CTL_TIMER_RTBL_MSK)
+			GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_TIMER_MAP),
+				 GIC_MAP_TO_PIN_MSK | timer_intr);
+		if (cpu_has_veic) {
+			set_vi_handler(timer_intr + GIC_PIN_TO_VEC_OFFSET,
+				gic_eic_irq_dispatch);
+			gic_shared_intr_map[timer_intr + GIC_PIN_TO_VEC_OFFSET].local_intr_mask |= GIC_VPE_RMASK_TIMER_MSK;
+		}
+
+		if (vpe_ctl & GIC_VPE_CTL_PERFCNT_RTBL_MSK)
+			GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_PERFCTR_MAP),
+				 GIC_MAP_TO_PIN_MSK | perf_intr);
+		if (cpu_has_veic) {
+			set_vi_handler(perf_intr + GIC_PIN_TO_VEC_OFFSET, gic_eic_irq_dispatch);
+			gic_shared_intr_map[perf_intr + GIC_PIN_TO_VEC_OFFSET].local_intr_mask |= GIC_VPE_RMASK_PERFCNT_MSK;
+		}
+	}
+}
+
+unsigned int gic_compare_int(void)
+{
+	unsigned int pending;
+
+	GICREAD(GIC_REG(VPE_LOCAL, GIC_VPE_PEND), pending);
+	if (pending & GIC_VPE_PEND_CMP_MSK)
+		return 1;
+	else
+		return 0;
+}
+
+void gic_get_int_mask(unsigned long *dst, const unsigned long *src)
+{
+	unsigned int i;
+	unsigned long *pending, *intrmask, *pcpu_mask;
+	unsigned long *pending_abs, *intrmask_abs;
+
+	/* Get per-cpu bitmaps */
+	pending = pending_regs[smp_processor_id()].pending;
+	intrmask = intrmask_regs[smp_processor_id()].intrmask;
+	pcpu_mask = pcpu_masks[smp_processor_id()].pcpu_mask;
+
+	pending_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
+							 GIC_SH_PEND_31_0_OFS);
+	intrmask_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
+							  GIC_SH_MASK_31_0_OFS);
+
+	for (i = 0; i < BITS_TO_LONGS(GIC_NUM_INTRS); i++) {
+		GICREAD(*pending_abs, pending[i]);
+		GICREAD(*intrmask_abs, intrmask[i]);
+		pending_abs++;
+		intrmask_abs++;
+	}
+
+	bitmap_and(pending, pending, intrmask, GIC_NUM_INTRS);
+	bitmap_and(pending, pending, pcpu_mask, GIC_NUM_INTRS);
+	bitmap_and(dst, src, pending, GIC_NUM_INTRS);
+}
+
+unsigned int gic_get_int(void)
+{
+	DECLARE_BITMAP(interrupts, GIC_NUM_INTRS);
+
+	bitmap_fill(interrupts, GIC_NUM_INTRS);
+	gic_get_int_mask(interrupts, interrupts);
+
+	return find_first_bit(interrupts, GIC_NUM_INTRS);
+}
+
+static void gic_mask_irq(struct irq_data *d)
+{
+	GIC_CLR_INTR_MASK(d->irq - gic_irq_base);
+}
+
+static void gic_unmask_irq(struct irq_data *d)
+{
+	GIC_SET_INTR_MASK(d->irq - gic_irq_base);
+}
+
+#ifdef CONFIG_SMP
+static DEFINE_SPINLOCK(gic_lock);
+
+static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
+			    bool force)
+{
+	unsigned int irq = (d->irq - gic_irq_base);
+	cpumask_t	tmp = CPU_MASK_NONE;
+	unsigned long	flags;
+	int		i;
+
+	cpumask_and(&tmp, cpumask, cpu_online_mask);
+	if (cpus_empty(tmp))
+		return -1;
+
+	/* Assumption : cpumask refers to a single CPU */
+	spin_lock_irqsave(&gic_lock, flags);
+
+	/* Re-route this IRQ */
+	GIC_SH_MAP_TO_VPE_SMASK(irq, first_cpu(tmp));
+
+	/* Update the pcpu_masks */
+	for (i = 0; i < NR_CPUS; i++)
+		clear_bit(irq, pcpu_masks[i].pcpu_mask);
+	set_bit(irq, pcpu_masks[first_cpu(tmp)].pcpu_mask);
+
+	cpumask_copy(d->affinity, cpumask);
+	spin_unlock_irqrestore(&gic_lock, flags);
+
+	return IRQ_SET_MASK_OK_NOCOPY;
+}
+#endif
+
+static struct irq_chip gic_irq_controller = {
+	.name			=	"MIPS GIC",
+	.irq_ack		=	gic_irq_ack,
+	.irq_mask		=	gic_mask_irq,
+	.irq_mask_ack		=	gic_mask_irq,
+	.irq_unmask		=	gic_unmask_irq,
+	.irq_eoi		=	gic_finish_irq,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	=	gic_set_affinity,
+#endif
+};
+
+static void __init gic_setup_intr(unsigned int intr, unsigned int cpu,
+	unsigned int pin, unsigned int polarity, unsigned int trigtype,
+	unsigned int flags)
+{
+	struct gic_shared_intr_map *map_ptr;
+
+	/* Setup Intr to Pin mapping */
+	if (pin & GIC_MAP_TO_NMI_MSK) {
+		int i;
+
+		GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)), pin);
+		/* FIXME: hack to route NMI to all cpu's */
+		for (i = 0; i < NR_CPUS; i += 32) {
+			GICWRITE(GIC_REG_ADDR(SHARED,
+					  GIC_SH_MAP_TO_VPE_REG_OFF(intr, i)),
+				 0xffffffff);
+		}
+	} else {
+		GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)),
+			 GIC_MAP_TO_PIN_MSK | pin);
+		/* Setup Intr to CPU mapping */
+		GIC_SH_MAP_TO_VPE_SMASK(intr, cpu);
+		if (cpu_has_veic) {
+			set_vi_handler(pin + GIC_PIN_TO_VEC_OFFSET,
+				gic_eic_irq_dispatch);
+			map_ptr = &gic_shared_intr_map[pin + GIC_PIN_TO_VEC_OFFSET];
+			if (map_ptr->num_shared_intr >= GIC_MAX_SHARED_INTR)
+				BUG();
+			map_ptr->intr_list[map_ptr->num_shared_intr++] = intr;
+		}
+	}
+
+	/* Setup Intr Polarity */
+	GIC_SET_POLARITY(intr, polarity);
+
+	/* Setup Intr Trigger Type */
+	GIC_SET_TRIGGER(intr, trigtype);
+
+	/* Init Intr Masks */
+	GIC_CLR_INTR_MASK(intr);
+
+	/* Initialise per-cpu Interrupt software masks */
+	set_bit(intr, pcpu_masks[cpu].pcpu_mask);
+
+	if ((flags & GIC_FLAG_TRANSPARENT) && (cpu_has_veic == 0))
+		GIC_SET_INTR_MASK(intr);
+	if (trigtype == GIC_TRIG_EDGE)
+		gic_irq_flags[intr] |= GIC_TRIG_EDGE;
+}
+
+static void __init gic_basic_init(int numintrs, int numvpes,
+			struct gic_intr_map *intrmap, int mapsize)
+{
+	unsigned int i, cpu;
+	unsigned int pin_offset = 0;
+
+	board_bind_eic_interrupt = &gic_bind_eic_interrupt;
+
+	/* Setup defaults */
+	for (i = 0; i < numintrs; i++) {
+		GIC_SET_POLARITY(i, GIC_POL_POS);
+		GIC_SET_TRIGGER(i, GIC_TRIG_LEVEL);
+		GIC_CLR_INTR_MASK(i);
+		if (i < GIC_NUM_INTRS) {
+			gic_irq_flags[i] = 0;
+			gic_shared_intr_map[i].num_shared_intr = 0;
+			gic_shared_intr_map[i].local_intr_mask = 0;
+		}
+	}
+
+	/*
+	 * In EIC mode, the HW_INT# is offset by (2-1). Need to subtract
+	 * one because the GIC will add one (since 0=no intr).
+	 */
+	if (cpu_has_veic)
+		pin_offset = (GIC_CPU_TO_VEC_OFFSET - GIC_PIN_TO_VEC_OFFSET);
+
+	/* Setup specifics */
+	for (i = 0; i < mapsize; i++) {
+		cpu = intrmap[i].cpunum;
+		if (cpu == GIC_UNUSED)
+			continue;
+		gic_setup_intr(i,
+			intrmap[i].cpunum,
+			intrmap[i].pin + pin_offset,
+			intrmap[i].polarity,
+			intrmap[i].trigtype,
+			intrmap[i].flags);
+	}
+
+	vpe_local_setup(numvpes);
+}
+
+void __init gic_init(unsigned long gic_base_addr,
+		     unsigned long gic_addrspace_size,
+		     struct gic_intr_map *intr_map, unsigned int intr_map_size,
+		     unsigned int irqbase)
+{
+	unsigned int gicconfig;
+	int numvpes, numintrs;
+
+	_gic_base = (unsigned long) ioremap_nocache(gic_base_addr,
+						    gic_addrspace_size);
+	gic_irq_base = irqbase;
+
+	GICREAD(GIC_REG(SHARED, GIC_SH_CONFIG), gicconfig);
+	numintrs = (gicconfig & GIC_SH_CONFIG_NUMINTRS_MSK) >>
+		   GIC_SH_CONFIG_NUMINTRS_SHF;
+	numintrs = ((numintrs + 1) * 8);
+
+	numvpes = (gicconfig & GIC_SH_CONFIG_NUMVPES_MSK) >>
+		  GIC_SH_CONFIG_NUMVPES_SHF;
+	numvpes = numvpes + 1;
+
+	gic_basic_init(numintrs, numvpes, intr_map, intr_map_size);
+
+	gic_platform_init(numintrs, &gic_irq_controller);
+}