Initial import

1 files changed, 407 insertions, 0 deletions

diff --git a/arch/mips/kernel/rtlx.c b/arch/mips/kernel/rtlx.c
new file mode 100644
index 000000000..c5c4fd54d
--- /dev/null
+++ b/arch/mips/kernel/rtlx.c
@@ -0,0 +1,407 @@
+/*
+ * 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) 2005, 06 Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 2013 Imagination Technologies Ltd.
+ */
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/syscalls.h>
+#include <linux/moduleloader.h>
+#include <linux/atomic.h>
+#include <asm/mipsmtregs.h>
+#include <asm/mips_mt.h>
+#include <asm/processor.h>
+#include <asm/rtlx.h>
+#include <asm/setup.h>
+#include <asm/vpe.h>
+
+static int sp_stopping;
+struct rtlx_info *rtlx;
+struct chan_waitqueues channel_wqs[RTLX_CHANNELS];
+struct vpe_notifications rtlx_notify;
+void (*aprp_hook)(void) = NULL;
+EXPORT_SYMBOL(aprp_hook);
+
+static void __used dump_rtlx(void)
+{
+	int i;
+
+	pr_info("id 0x%lx state %d\n", rtlx->id, rtlx->state);
+
+	for (i = 0; i < RTLX_CHANNELS; i++) {
+		struct rtlx_channel *chan = &rtlx->channel[i];
+
+		pr_info(" rt_state %d lx_state %d buffer_size %d\n",
+			chan->rt_state, chan->lx_state, chan->buffer_size);
+
+		pr_info(" rt_read %d rt_write %d\n",
+			chan->rt_read, chan->rt_write);
+
+		pr_info(" lx_read %d lx_write %d\n",
+			chan->lx_read, chan->lx_write);
+
+		pr_info(" rt_buffer <%s>\n", chan->rt_buffer);
+		pr_info(" 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) {
+		pr_err("no valid RTLX id at 0x%p 0x%lx\n", rtlxi, rtlxi->id);
+		return -ENOEXEC;
+	}
+
+	rtlx = rtlxi;
+
+	return 0;
+}
+
+/* notifications */
+void rtlx_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);
+}
+
+void rtlx_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) {
+		pr_debug("rtlx_open index out of range\n");
+		return -ENOSYS;
+	}
+
+	if (atomic_inc_return(&channel_wqs[index].in_open) > 1) {
+		pr_debug("rtlx_open channel %d already opened\n", index);
+		ret = -EBUSY;
+		goto out_fail;
+	}
+
+	if (rtlx == NULL) {
+		p = vpe_get_shared(aprp_cpu_index());
+		if (p == NULL) {
+			if (can_sleep) {
+				ret = __wait_event_interruptible(
+					channel_wqs[index].lx_queue,
+					(p = vpe_get_shared(aprp_cpu_index())));
+				if (ret)
+					goto out_fail;
+			} else {
+				pr_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) {
+			pr_warn("vpe_get_shared returned an invalid pointer maybe an error code %d\n",
+				(int)*p);
+			ret = -ENOSYS;
+			goto out_fail;
+		}
+
+		ret = rtlx_init(*p);
+		if (ret < 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 = __wait_event_interruptible(
+				channel_wqs[index].lx_queue,
+				(chan->lx_read != chan->lx_write) ||
+				sp_stopping);
+			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_t(size_t, count, 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);
+
+	_interrupt_sp();
+
+	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 = iminor(file_inode(file));
+	unsigned int mask = 0;
+
+	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_inode(file));
+
+	/* data available? */
+	if (!rtlx_read_poll(minor, (file->f_flags & O_NONBLOCK) ? 0 : 1))
+		return 0;	/* -EAGAIN makes 'cat' whine */
+
+	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 = iminor(file_inode(file));
+
+	/* any space left... */
+	if (!rtlx_write_poll(minor)) {
+		int ret;
+
+		if (file->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+
+		ret = __wait_event_interruptible(channel_wqs[minor].rt_queue,
+					   rtlx_write_poll(minor));
+		if (ret)
+			return ret;
+	}
+
+	return rtlx_write(minor, buffer, count);
+}
+
+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,
+};
+
+module_init(rtlx_module_init);
+module_exit(rtlx_module_exit);
+
+MODULE_DESCRIPTION("MIPS RTLX");
+MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
+MODULE_LICENSE("GPL");