From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/mips/kernel/rtlx-mt.c | 153 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100644 arch/mips/kernel/rtlx-mt.c

(limited to 'arch/mips/kernel/rtlx-mt.c')

diff --git a/arch/mips/kernel/rtlx-mt.c b/arch/mips/kernel/rtlx-mt.c
new file mode 100644
index 000000000..cb95470e2
--- /dev/null
+++ b/arch/mips/kernel/rtlx-mt.c
@@ -0,0 +1,153 @@
+/*
+ * 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) 2005 MIPS Technologies, Inc.  All rights reserved.
+ * Copyright (C) 2013 Imagination Technologies Ltd.
+ */
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/err.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+
+#include <asm/mips_mt.h>
+#include <asm/vpe.h>
+#include <asm/rtlx.h>
+
+static int major;
+
+static void rtlx_dispatch(void)
+{
+	if (read_c0_cause() & read_c0_status() & C_SW0)
+		do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ);
+}
+
+/*
+ * Interrupt handler may be called before rtlx_init has otherwise had
+ * a chance to run.
+ */
+static irqreturn_t rtlx_interrupt(int irq, void *dev_id)
+{
+	unsigned int vpeflags;
+	unsigned long flags;
+	int i;
+
+	local_irq_save(flags);
+	vpeflags = dvpe();
+	set_c0_status(0x100 << MIPS_CPU_RTLX_IRQ);
+	irq_enable_hazard();
+	evpe(vpeflags);
+	local_irq_restore(flags);
+
+	for (i = 0; i < RTLX_CHANNELS; i++) {
+		wake_up(&channel_wqs[i].lx_queue);
+		wake_up(&channel_wqs[i].rt_queue);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction rtlx_irq = {
+	.handler	= rtlx_interrupt,
+	.name		= "RTLX",
+};
+
+static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
+
+void _interrupt_sp(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	dvpe();
+	settc(1);
+	write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0);
+	evpe(EVPE_ENABLE);
+	local_irq_restore(flags);
+}
+
+int __init rtlx_module_init(void)
+{
+	struct device *dev;
+	int i, err;
+
+	if (!cpu_has_mipsmt) {
+		pr_warn("VPE loader: not a MIPS MT capable processor\n");
+		return -ENODEV;
+	}
+
+	if (aprp_cpu_index() == 0) {
+		pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
+			"Pass maxtcs=<n> argument as kernel argument\n");
+
+		return -ENODEV;
+	}
+
+	major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
+	if (major < 0) {
+		pr_err("rtlx_module_init: unable to register device\n");
+		return major;
+	}
+
+	/* initialise the wait queues */
+	for (i = 0; i < RTLX_CHANNELS; i++) {
+		init_waitqueue_head(&channel_wqs[i].rt_queue);
+		init_waitqueue_head(&channel_wqs[i].lx_queue);
+		atomic_set(&channel_wqs[i].in_open, 0);
+		mutex_init(&channel_wqs[i].mutex);
+
+		dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
+				    "%s%d", RTLX_MODULE_NAME, i);
+		if (IS_ERR(dev)) {
+			while (i--)
+				device_destroy(mt_class, MKDEV(major, i));
+
+			err = PTR_ERR(dev);
+			goto out_chrdev;
+		}
+	}
+
+	/* set up notifiers */
+	rtlx_notify.start = rtlx_starting;
+	rtlx_notify.stop = rtlx_stopping;
+	vpe_notify(aprp_cpu_index(), &rtlx_notify);
+
+	if (cpu_has_vint) {
+		aprp_hook = rtlx_dispatch;
+	} else {
+		pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
+		err = -ENODEV;
+		goto out_class;
+	}
+
+	rtlx_irq.dev_id = rtlx;
+	err = setup_irq(rtlx_irq_num, &rtlx_irq);
+	if (err)
+		goto out_class;
+
+	return 0;
+
+out_class:
+	for (i = 0; i < RTLX_CHANNELS; i++)
+		device_destroy(mt_class, MKDEV(major, i));
+out_chrdev:
+	unregister_chrdev(major, RTLX_MODULE_NAME);
+
+	return err;
+}
+
+void __exit rtlx_module_exit(void)
+{
+	int i;
+
+	for (i = 0; i < RTLX_CHANNELS; i++)
+		device_destroy(mt_class, MKDEV(major, i));
+
+	unregister_chrdev(major, RTLX_MODULE_NAME);
+
+	aprp_hook = NULL;
+}
-- 
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