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Diffstat (limited to 'arch/mips/kernel/rtlx.c')
-rw-r--r--arch/mips/kernel/rtlx.c562
1 files changed, 562 insertions, 0 deletions
diff --git a/arch/mips/kernel/rtlx.c b/arch/mips/kernel/rtlx.c
new file mode 100644
index 00000000..b8c18dcd
--- /dev/null
+++ b/arch/mips/kernel/rtlx.c
@@ -0,0 +1,562 @@
+/*
+ * 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, &notify);
+
+ 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");
generated by cgit (git 2.34.1) at 2025-01-15 12:42:37 +0000