+++ /dev/null
-/*
- * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
- * Copyright (C) 2005, 06 Ralf Baechle (ralf@linux-mips.org)
- *
- * This program is free software; you can distribute it and/or modify it
- * under the terms of the GNU General Public License (Version 2) as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
- *
- */
-
-#include <linux/device.h>
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/init.h>
-#include <asm/uaccess.h>
-#include <linux/list.h>
-#include <linux/vmalloc.h>
-#include <linux/elf.h>
-#include <linux/seq_file.h>
-#include <linux/syscalls.h>
-#include <linux/moduleloader.h>
-#include <linux/interrupt.h>
-#include <linux/poll.h>
-#include <linux/sched.h>
-#include <linux/wait.h>
-#include <asm/mipsmtregs.h>
-#include <asm/mips_mt.h>
-#include <asm/cacheflush.h>
-#include <linux/atomic.h>
-#include <asm/cpu.h>
-#include <asm/processor.h>
-#include <asm/vpe.h>
-#include <asm/rtlx.h>
-
-static struct rtlx_info *rtlx;
-static int major;
-static char module_name[] = "rtlx";
-
-static struct chan_waitqueues {
- wait_queue_head_t rt_queue;
- wait_queue_head_t lx_queue;
- atomic_t in_open;
- struct mutex mutex;
-} channel_wqs[RTLX_CHANNELS];
-
-static struct vpe_notifications notify;
-static int sp_stopping;
-
-extern void *vpe_get_shared(int index);
-
-static void rtlx_dispatch(void)
-{
- 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 void __used dump_rtlx(void)
-{
- int i;
-
- printk("id 0x%lx state %d\n", rtlx->id, rtlx->state);
-
- for (i = 0; i < RTLX_CHANNELS; i++) {
- struct rtlx_channel *chan = &rtlx->channel[i];
-
- printk(" rt_state %d lx_state %d buffer_size %d\n",
- chan->rt_state, chan->lx_state, chan->buffer_size);
-
- printk(" rt_read %d rt_write %d\n",
- chan->rt_read, chan->rt_write);
-
- printk(" lx_read %d lx_write %d\n",
- chan->lx_read, chan->lx_write);
-
- printk(" rt_buffer <%s>\n", chan->rt_buffer);
- printk(" lx_buffer <%s>\n", chan->lx_buffer);
- }
-}
-
-/* call when we have the address of the shared structure from the SP side. */
-static int rtlx_init(struct rtlx_info *rtlxi)
-{
- if (rtlxi->id != RTLX_ID) {
- printk(KERN_ERR "no valid RTLX id at 0x%p 0x%lx\n",
- rtlxi, rtlxi->id);
- return -ENOEXEC;
- }
-
- rtlx = rtlxi;
-
- return 0;
-}
-
-/* notifications */
-static void starting(int vpe)
-{
- int i;
- sp_stopping = 0;
-
- /* force a reload of rtlx */
- rtlx=NULL;
-
- /* wake up any sleeping rtlx_open's */
- for (i = 0; i < RTLX_CHANNELS; i++)
- wake_up_interruptible(&channel_wqs[i].lx_queue);
-}
-
-static void stopping(int vpe)
-{
- int i;
-
- sp_stopping = 1;
- for (i = 0; i < RTLX_CHANNELS; i++)
- wake_up_interruptible(&channel_wqs[i].lx_queue);
-}
-
-
-int rtlx_open(int index, int can_sleep)
-{
- struct rtlx_info **p;
- struct rtlx_channel *chan;
- enum rtlx_state state;
- int ret = 0;
-
- if (index >= RTLX_CHANNELS) {
- printk(KERN_DEBUG "rtlx_open index out of range\n");
- return -ENOSYS;
- }
-
- if (atomic_inc_return(&channel_wqs[index].in_open) > 1) {
- printk(KERN_DEBUG "rtlx_open channel %d already opened\n",
- index);
- ret = -EBUSY;
- goto out_fail;
- }
-
- if (rtlx == NULL) {
- if( (p = vpe_get_shared(tclimit)) == NULL) {
- if (can_sleep) {
- __wait_event_interruptible(channel_wqs[index].lx_queue,
- (p = vpe_get_shared(tclimit)), ret);
- if (ret)
- goto out_fail;
- } else {
- printk(KERN_DEBUG "No SP program loaded, and device "
- "opened with O_NONBLOCK\n");
- ret = -ENOSYS;
- goto out_fail;
- }
- }
-
- smp_rmb();
- if (*p == NULL) {
- if (can_sleep) {
- DEFINE_WAIT(wait);
-
- for (;;) {
- prepare_to_wait(
- &channel_wqs[index].lx_queue,
- &wait, TASK_INTERRUPTIBLE);
- smp_rmb();
- if (*p != NULL)
- break;
- if (!signal_pending(current)) {
- schedule();
- continue;
- }
- ret = -ERESTARTSYS;
- goto out_fail;
- }
- finish_wait(&channel_wqs[index].lx_queue, &wait);
- } else {
- pr_err(" *vpe_get_shared is NULL. "
- "Has an SP program been loaded?\n");
- ret = -ENOSYS;
- goto out_fail;
- }
- }
-
- if ((unsigned int)*p < KSEG0) {
- printk(KERN_WARNING "vpe_get_shared returned an "
- "invalid pointer maybe an error code %d\n",
- (int)*p);
- ret = -ENOSYS;
- goto out_fail;
- }
-
- if ((ret = rtlx_init(*p)) < 0)
- goto out_ret;
- }
-
- chan = &rtlx->channel[index];
-
- state = xchg(&chan->lx_state, RTLX_STATE_OPENED);
- if (state == RTLX_STATE_OPENED) {
- ret = -EBUSY;
- goto out_fail;
- }
-
-out_fail:
- smp_mb();
- atomic_dec(&channel_wqs[index].in_open);
- smp_mb();
-
-out_ret:
- return ret;
-}
-
-int rtlx_release(int index)
-{
- if (rtlx == NULL) {
- pr_err("rtlx_release() with null rtlx\n");
- return 0;
- }
- rtlx->channel[index].lx_state = RTLX_STATE_UNUSED;
- return 0;
-}
-
-unsigned int rtlx_read_poll(int index, int can_sleep)
-{
- struct rtlx_channel *chan;
-
- if (rtlx == NULL)
- return 0;
-
- chan = &rtlx->channel[index];
-
- /* data available to read? */
- if (chan->lx_read == chan->lx_write) {
- if (can_sleep) {
- int ret = 0;
-
- __wait_event_interruptible(channel_wqs[index].lx_queue,
- (chan->lx_read != chan->lx_write) ||
- sp_stopping, ret);
- if (ret)
- return ret;
-
- if (sp_stopping)
- return 0;
- } else
- return 0;
- }
-
- return (chan->lx_write + chan->buffer_size - chan->lx_read)
- % chan->buffer_size;
-}
-
-static inline int write_spacefree(int read, int write, int size)
-{
- if (read == write) {
- /*
- * Never fill the buffer completely, so indexes are always
- * equal if empty and only empty, or !equal if data available
- */
- return size - 1;
- }
-
- return ((read + size - write) % size) - 1;
-}
-
-unsigned int rtlx_write_poll(int index)
-{
- struct rtlx_channel *chan = &rtlx->channel[index];
-
- return write_spacefree(chan->rt_read, chan->rt_write,
- chan->buffer_size);
-}
-
-ssize_t rtlx_read(int index, void __user *buff, size_t count)
-{
- size_t lx_write, fl = 0L;
- struct rtlx_channel *lx;
- unsigned long failed;
-
- if (rtlx == NULL)
- return -ENOSYS;
-
- lx = &rtlx->channel[index];
-
- mutex_lock(&channel_wqs[index].mutex);
- smp_rmb();
- lx_write = lx->lx_write;
-
- /* find out how much in total */
- count = min(count,
- (size_t)(lx_write + lx->buffer_size - lx->lx_read)
- % lx->buffer_size);
-
- /* then how much from the read pointer onwards */
- fl = min(count, (size_t)lx->buffer_size - lx->lx_read);
-
- failed = copy_to_user(buff, lx->lx_buffer + lx->lx_read, fl);
- if (failed)
- goto out;
-
- /* and if there is anything left at the beginning of the buffer */
- if (count - fl)
- failed = copy_to_user(buff + fl, lx->lx_buffer, count - fl);
-
-out:
- count -= failed;
-
- smp_wmb();
- lx->lx_read = (lx->lx_read + count) % lx->buffer_size;
- smp_wmb();
- mutex_unlock(&channel_wqs[index].mutex);
-
- return count;
-}
-
-ssize_t rtlx_write(int index, const void __user *buffer, size_t count)
-{
- struct rtlx_channel *rt;
- unsigned long failed;
- size_t rt_read;
- size_t fl;
-
- if (rtlx == NULL)
- return(-ENOSYS);
-
- rt = &rtlx->channel[index];
-
- mutex_lock(&channel_wqs[index].mutex);
- smp_rmb();
- rt_read = rt->rt_read;
-
- /* total number of bytes to copy */
- count = min(count, (size_t)write_spacefree(rt_read, rt->rt_write,
- rt->buffer_size));
-
- /* first bit from write pointer to the end of the buffer, or count */
- fl = min(count, (size_t) rt->buffer_size - rt->rt_write);
-
- failed = copy_from_user(rt->rt_buffer + rt->rt_write, buffer, fl);
- if (failed)
- goto out;
-
- /* if there's any left copy to the beginning of the buffer */
- if (count - fl) {
- failed = copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
- }
-
-out:
- count -= failed;
-
- smp_wmb();
- rt->rt_write = (rt->rt_write + count) % rt->buffer_size;
- smp_wmb();
- mutex_unlock(&channel_wqs[index].mutex);
-
- return count;
-}
-
-
-static int file_open(struct inode *inode, struct file *filp)
-{
- return rtlx_open(iminor(inode), (filp->f_flags & O_NONBLOCK) ? 0 : 1);
-}
-
-static int file_release(struct inode *inode, struct file *filp)
-{
- return rtlx_release(iminor(inode));
-}
-
-static unsigned int file_poll(struct file *file, poll_table * wait)
-{
- int minor;
- unsigned int mask = 0;
-
- minor = iminor(file->f_path.dentry->d_inode);
-
- poll_wait(file, &channel_wqs[minor].rt_queue, wait);
- poll_wait(file, &channel_wqs[minor].lx_queue, wait);
-
- if (rtlx == NULL)
- return 0;
-
- /* data available to read? */
- if (rtlx_read_poll(minor, 0))
- mask |= POLLIN | POLLRDNORM;
-
- /* space to write */
- if (rtlx_write_poll(minor))
- mask |= POLLOUT | POLLWRNORM;
-
- return mask;
-}
-
-static ssize_t file_read(struct file *file, char __user * buffer, size_t count,
- loff_t * ppos)
-{
- int minor = iminor(file->f_path.dentry->d_inode);
-
- /* data available? */
- if (!rtlx_read_poll(minor, (file->f_flags & O_NONBLOCK) ? 0 : 1)) {
- return 0; // -EAGAIN makes cat whinge
- }
-
- return rtlx_read(minor, buffer, count);
-}
-
-static ssize_t file_write(struct file *file, const char __user * buffer,
- size_t count, loff_t * ppos)
-{
- int minor;
- struct rtlx_channel *rt;
-
- minor = iminor(file->f_path.dentry->d_inode);
- rt = &rtlx->channel[minor];
-
- /* any space left... */
- if (!rtlx_write_poll(minor)) {
- int ret = 0;
-
- if (file->f_flags & O_NONBLOCK)
- return -EAGAIN;
-
- __wait_event_interruptible(channel_wqs[minor].rt_queue,
- rtlx_write_poll(minor),
- ret);
- if (ret)
- return ret;
- }
-
- return rtlx_write(minor, buffer, count);
-}
-
-static const struct file_operations rtlx_fops = {
- .owner = THIS_MODULE,
- .open = file_open,
- .release = file_release,
- .write = file_write,
- .read = file_read,
- .poll = file_poll,
- .llseek = noop_llseek,
-};
-
-static struct irqaction rtlx_irq = {
- .handler = rtlx_interrupt,
- .name = "RTLX",
-};
-
-static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
-
-static char register_chrdev_failed[] __initdata =
- KERN_ERR "rtlx_module_init: unable to register device\n";
-
-static int __init rtlx_module_init(void)
-{
- struct device *dev;
- int i, err;
-
- if (!cpu_has_mipsmt) {
- printk("VPE loader: not a MIPS MT capable processor\n");
- return -ENODEV;
- }
-
- if (tclimit == 0) {
- printk(KERN_WARNING "No TCs reserved for AP/SP, not "
- "initializing RTLX.\nPass maxtcs=<n> argument as kernel "
- "argument\n");
-
- return -ENODEV;
- }
-
- major = register_chrdev(0, module_name, &rtlx_fops);
- if (major < 0) {
- printk(register_chrdev_failed);
- 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", module_name, i);
- if (IS_ERR(dev)) {
- err = PTR_ERR(dev);
- goto out_chrdev;
- }
- }
-
- /* set up notifiers */
- notify.start = starting;
- notify.stop = stopping;
- vpe_notify(tclimit, ¬ify);
-
- if (cpu_has_vint)
- set_vi_handler(MIPS_CPU_RTLX_IRQ, rtlx_dispatch);
- else {
- pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
- err = -ENODEV;
- goto out_chrdev;
- }
-
- rtlx_irq.dev_id = rtlx;
- setup_irq(rtlx_irq_num, &rtlx_irq);
-
- return 0;
-
-out_chrdev:
- for (i = 0; i < RTLX_CHANNELS; i++)
- device_destroy(mt_class, MKDEV(major, i));
-
- return err;
-}
-
-static 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, module_name);
-}
-
-module_init(rtlx_module_init);
-module_exit(rtlx_module_exit);
-
-MODULE_DESCRIPTION("MIPS RTLX");
-MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
-MODULE_LICENSE("GPL");
projects / karo-tx-linux.git / commitdiff