1 files changed, 341 insertions, 0 deletions

diff --git a/arch/mips/kernel/rtlx.c b/arch/mips/kernel/rtlx.c
new file mode 100644
index 000000000000..8c81f3cb4e2d
--- /dev/null
+++ b/arch/mips/kernel/rtlx.c
@@ -0,0 +1,341 @@
+/*
+ * Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  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/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <linux/slab.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/cacheflush.h>
+#include <asm/atomic.h>
+#include <asm/cpu.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/rtlx.h>
+
+#define RTLX_MAJOR 64
+#define RTLX_TARG_VPE 1
+
+struct rtlx_info *rtlx;
+static int major;
+static char module_name[] = "rtlx";
+static inline int spacefree(int read, int write, int size);
+
+static struct chan_waitqueues {
+        wait_queue_head_t rt_queue;
+        wait_queue_head_t lx_queue;
+} channel_wqs[RTLX_CHANNELS];
+
+static struct irqaction irq;
+static int irq_num;
+
+extern void *vpe_get_shared(int index);
+
+static void rtlx_dispatch(struct pt_regs *regs)
+{
+        do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_RTLX_IRQ, regs);
+}
+
+irqreturn_t rtlx_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+        irqreturn_t r = IRQ_HANDLED;
+        int i;
+
+        for (i = 0; i < RTLX_CHANNELS; i++) {
+                struct rtlx_channel *chan = &rtlx->channel[i];
+
+                if (chan->lx_read != chan->lx_write)
+                        wake_up_interruptible(&channel_wqs[i].lx_queue);
+        }
+
+        return r;
+}
+
+void 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)
+{
+        int i;
+
+        if (rtlxi->id != RTLX_ID) {
+                printk(KERN_WARNING "no valid RTLX id at 0x%p\n", rtlxi);
+                return (-ENOEXEC);
+        }
+
+        /* 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);
+        }
+
+        /* set up for interrupt handling */
+        memset(&irq, 0, sizeof(struct irqaction));
+
+        if (cpu_has_vint) {
+                set_vi_handler(MIPS_CPU_RTLX_IRQ, rtlx_dispatch);
+        }
+
+        irq_num = MIPSCPU_INT_BASE + MIPS_CPU_RTLX_IRQ;
+        irq.handler = rtlx_interrupt;
+        irq.flags = SA_INTERRUPT;
+        irq.name = "RTLX";
+        irq.dev_id = rtlx;
+        setup_irq(irq_num, &irq);
+
+        rtlx = rtlxi;
+        return (0);
+}
+
+/* only allow one open process at a time to open each channel */
+static int rtlx_open(struct inode *inode, struct file *filp)
+{
+        int minor, ret;
+        struct rtlx_channel *chan;
+
+        /* assume only 1 device at the mo. */
+        minor = MINOR(inode->i_rdev);
+
+        if (rtlx == NULL) {
+                struct rtlx_info **p;
+                if( (p = vpe_get_shared(RTLX_TARG_VPE)) == NULL) {
+                        printk(" vpe_get_shared is NULL. Has an SP program been loaded?\n");
+                        return (-EFAULT);
+                }
+
+                if (*p == NULL) {
+                        printk(" vpe_shared %p %p\n", p, *p);
+                        return (-EFAULT);
+                }
+
+                if ((ret = rtlx_init(*p)) < 0)
+                        return (ret);
+        }
+
+        chan = &rtlx->channel[minor];
+
+        /* already open? */
+        if (chan->lx_state == RTLX_STATE_OPENED)
+                return (-EBUSY);
+
+        chan->lx_state = RTLX_STATE_OPENED;
+        return (0);
+}
+
+static int rtlx_release(struct inode *inode, struct file *filp)
+{
+        int minor;
+
+        minor = MINOR(inode->i_rdev);
+        rtlx->channel[minor].lx_state = RTLX_STATE_UNUSED;
+        return (0);
+}
+
+static unsigned int rtlx_poll(struct file *file, poll_table * wait)
+{
+        int minor;
+        unsigned int mask = 0;
+        struct rtlx_channel *chan;
+
+        minor = MINOR(file->f_dentry->d_inode->i_rdev);
+        chan = &rtlx->channel[minor];
+
+        poll_wait(file, &channel_wqs[minor].rt_queue, wait);
+        poll_wait(file, &channel_wqs[minor].lx_queue, wait);
+
+        /* data available to read? */
+        if (chan->lx_read != chan->lx_write)
+                mask |= POLLIN | POLLRDNORM;
+
+        /* space to write */
+        if (spacefree(chan->rt_read, chan->rt_write, chan->buffer_size))
+                mask |= POLLOUT | POLLWRNORM;
+
+        return (mask);
+}
+
+static ssize_t rtlx_read(struct file *file, char __user * buffer, size_t count,
+                         loff_t * ppos)
+{
+        size_t fl = 0L;
+        int minor;
+        struct rtlx_channel *lx;
+        DECLARE_WAITQUEUE(wait, current);
+
+        minor = MINOR(file->f_dentry->d_inode->i_rdev);
+        lx = &rtlx->channel[minor];
+
+        /* data available? */
+        if (lx->lx_write == lx->lx_read) {
+                if (file->f_flags & O_NONBLOCK)
+                        return (0);     // -EAGAIN makes cat whinge
+
+                /* go to sleep */
+                add_wait_queue(&channel_wqs[minor].lx_queue, &wait);
+                set_current_state(TASK_INTERRUPTIBLE);
+
+                while (lx->lx_write == lx->lx_read)
+                        schedule();
+
+                set_current_state(TASK_RUNNING);
+                remove_wait_queue(&channel_wqs[minor].lx_queue, &wait);
+
+                /* back running */
+        }
+
+        /* find out how much in total */
+        count = min( count,
+                     (size_t)(lx->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);
+
+        copy_to_user (buffer, &lx->lx_buffer[lx->lx_read], fl);
+
+        /* and if there is anything left at the beginning of the buffer */
+        if ( count - fl )
+                copy_to_user (buffer + fl, lx->lx_buffer, count - fl);
+
+        /* update the index */
+        lx->lx_read += count;
+        lx->lx_read %= lx->buffer_size;
+
+        return (count);
+}
+
+static inline int 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;
+}
+
+static ssize_t rtlx_write(struct file *file, const char __user * buffer,
+                          size_t count, loff_t * ppos)
+{
+        int minor;
+        struct rtlx_channel *rt;
+        size_t fl;
+        DECLARE_WAITQUEUE(wait, current);
+
+        minor = MINOR(file->f_dentry->d_inode->i_rdev);
+        rt = &rtlx->channel[minor];
+
+        /* any space left... */
+        if (!spacefree(rt->rt_read, rt->rt_write, rt->buffer_size)) {
+
+                if (file->f_flags & O_NONBLOCK)
+                        return (-EAGAIN);
+
+                add_wait_queue(&channel_wqs[minor].rt_queue, &wait);
+                set_current_state(TASK_INTERRUPTIBLE);
+
+                while (!spacefree(rt->rt_read, rt->rt_write, rt->buffer_size))
+                        schedule();
+
+                set_current_state(TASK_RUNNING);
+                remove_wait_queue(&channel_wqs[minor].rt_queue, &wait);
+        }
+
+        /* total number of bytes to copy */
+        count = min( count, (size_t)spacefree(rt->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);
+
+        copy_from_user(&rt->rt_buffer[rt->rt_write], buffer, fl);
+
+        /* if there's any left copy to the beginning of the buffer */
+        if( count - fl )
+                copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
+
+        rt->rt_write += count;
+        rt->rt_write %= rt->buffer_size;
+
+        return(count);
+}
+
+static struct file_operations rtlx_fops = {
+        .owner = THIS_MODULE,
+        .open = rtlx_open,
+        .release = rtlx_release,
+        .write = rtlx_write,
+        .read = rtlx_read,
+        .poll = rtlx_poll
+};
+
+static int rtlx_module_init(void)
+{
+        if ((major = register_chrdev(RTLX_MAJOR, module_name, &rtlx_fops)) < 0) {
+                printk("rtlx_module_init: unable to register device\n");
+                return (-EBUSY);
+        }
+
+        if (major == 0)
+                major = RTLX_MAJOR;
+
+        return (0);
+}
+
+static void rtlx_module_exit(void)
+{
+        unregister_chrdev(major, module_name);
+}
+
+module_init(rtlx_module_init);
+module_exit(rtlx_module_exit);
+MODULE_DESCRIPTION("MIPS RTLX");
+MODULE_AUTHOR("Elizabeth Clarke, MIPS Technologies, Inc");
+MODULE_LICENSE("GPL");