rtlx-mt.c
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/*
* 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;
/* Ought not to be strictly necessary for SMTC builds */
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)) {
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;
}