v4.19.13 snapshot.
diff --git a/arch/mips/kernel/rtlx-mt.c b/arch/mips/kernel/rtlx-mt.c
new file mode 100644
index 0000000..cb95470
--- /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;
+}