ARCv2: SMP: Support ARConnect (MCIP) for Inter-Core-Interrupts et al

Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

3 files changed, 119 insertions, 1 deletions

diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile
index 0be7ba087260..e7f3625a19b5 100644
--- a/arch/arc/kernel/Makefile
+++ b/arch/arc/kernel/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_ISA_ARCV2)			+= entry-arcv2.o intc-arcv2.o
 
 obj-$(CONFIG_MODULES)			+= arcksyms.o module.o
 obj-$(CONFIG_SMP) 			+= smp.o
+obj-$(CONFIG_ARC_MCIP)			+= mcip.o
 obj-$(CONFIG_ARC_DW2_UNWIND)		+= unwind.o
 obj-$(CONFIG_KPROBES)      		+= kprobes.o
 obj-$(CONFIG_ARC_EMUL_UNALIGNED) 	+= unaligned.o
diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c
index c5c64dc47655..6208c630abed 100644
--- a/arch/arc/kernel/intc-arcv2.c
+++ b/arch/arc/kernel/intc-arcv2.c
@@ -107,7 +107,7 @@ static struct irq_chip arcv2_irq_chip = {
 static int arcv2_irq_map(struct irq_domain *d, unsigned int irq,
 			 irq_hw_number_t hw)
 {
-	if (irq == TIMER0_IRQ)
+	if (irq == TIMER0_IRQ || irq == IPI_IRQ)
 		irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_percpu_irq);
 	else
 		irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_level_irq);
diff --git a/arch/arc/kernel/mcip.c b/arch/arc/kernel/mcip.c
new file mode 100644
index 000000000000..e6ad6e64440a
--- /dev/null
+++ b/arch/arc/kernel/mcip.c
@@ -0,0 +1,117 @@
+/*
+ * ARC ARConnect (MultiCore IP) support (formerly known as MCIP)
+ *
+ * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/smp.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <asm/mcip.h>
+
+static char smp_cpuinfo_buf[128];
+
+static DEFINE_RAW_SPINLOCK(mcip_lock);
+
+
+/*
+ * Any SMP specific init any CPU does when it comes up.
+ * Here we setup the CPU to enable Inter-Processor-Interrupts
+ * Called for each CPU
+ * -Master      : init_IRQ()
+ * -Other(s)    : start_kernel_secondary()
+ */
+void mcip_init_smp(unsigned int cpu)
+{
+	smp_ipi_irq_setup(cpu, IPI_IRQ);
+}
+
+static void mcip_ipi_send(int cpu)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&mcip_lock, flags);
+	__mcip_cmd(CMD_INTRPT_GENERATE_IRQ, cpu);
+	raw_spin_unlock_irqrestore(&mcip_lock, flags);
+}
+
+static void mcip_ipi_clear(int irq)
+{
+	unsigned int cpu;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&mcip_lock, flags);
+
+	/* Who sent the IPI */
+	__mcip_cmd(CMD_INTRPT_CHECK_SOURCE, 0);
+
+	cpu = read_aux_reg(ARC_REG_MCIP_READBACK);	/* 1,2,4,8... */
+
+	__mcip_cmd(CMD_INTRPT_GENERATE_ACK, __ffs(cpu)); /* 0,1,2,3... */
+
+	raw_spin_unlock_irqrestore(&mcip_lock, flags);
+}
+
+volatile int wake_flag;
+
+static void mcip_wakeup_cpu(int cpu, unsigned long pc)
+{
+	BUG_ON(cpu == 0);
+	wake_flag = cpu;
+}
+
+void arc_platform_smp_wait_to_boot(int cpu)
+{
+	while (wake_flag != cpu)
+		;
+
+	wake_flag = 0;
+	__asm__ __volatile__("j @first_lines_of_secondary	\n");
+}
+
+struct plat_smp_ops plat_smp_ops = {
+	.info		= smp_cpuinfo_buf,
+	.cpu_kick	= mcip_wakeup_cpu,
+	.ipi_send	= mcip_ipi_send,
+	.ipi_clear	= mcip_ipi_clear,
+};
+
+void mcip_init_early_smp(void)
+{
+#define IS_AVAIL1(var, str)    ((var) ? str : "")
+
+	struct mcip_bcr {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		unsigned int pad3:8,
+			     idu:1, llm:1, num_cores:6,
+			     iocoh:1,  grtc:1, dbg:1, pad2:1,
+			     msg:1, sem:1, ipi:1, pad:1,
+			     ver:8;
+#else
+		unsigned int ver:8,
+			     pad:1, ipi:1, sem:1, msg:1,
+			     pad2:1, dbg:1, grtc:1, iocoh:1,
+			     num_cores:6, llm:1, idu:1,
+			     pad3:8;
+#endif
+	} mp;
+
+	READ_BCR(ARC_REG_MCIP_BCR, mp);
+
+	sprintf(smp_cpuinfo_buf,
+		"Extn [SMP]\t: ARConnect (v%d): %d cores with %s%s%s%s\n",
+		mp.ver, mp.num_cores,
+		IS_AVAIL1(mp.ipi, "IPI "),
+		IS_AVAIL1(mp.idu, "IDU "),
+		IS_AVAIL1(mp.dbg, "DEBUG "),
+		IS_AVAIL1(mp.grtc, "GRTC"));
+
+	if (mp.dbg) {
+		__mcip_cmd_data(CMD_DEBUG_SET_SELECT, 0, 0xf);
+		__mcip_cmd_data(CMD_DEBUG_SET_MASK, 0xf, 0xf);
+	}
+}