forked from Minki/linux
Turn rtlx upside down.
o Coding style
o Race condition on open
o Switch to dynamic major
o Header file cleanup
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle
parent
0b154bb7d0
commit
afc4841d8a
@ -20,42 +20,42 @@
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <asm/uaccess.h>
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <linux/vmalloc.h>
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#include <linux/elf.h>
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#include <linux/seq_file.h>
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#include <linux/syscalls.h>
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#include <linux/moduleloader.h>
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#include <linux/interrupt.h>
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#include <linux/poll.h>
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include <asm/mipsmtregs.h>
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#include <asm/cacheflush.h>
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#include <asm/atomic.h>
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#include <asm/bitops.h>
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#include <asm/cpu.h>
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#include <asm/processor.h>
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#include <asm/system.h>
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#include <asm/rtlx.h>
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#include <asm/uaccess.h>
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#define RTLX_MAJOR 64
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#define RTLX_TARG_VPE 1
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struct rtlx_info *rtlx;
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static struct rtlx_info *rtlx;
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static int major;
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static char module_name[] = "rtlx";
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static inline int spacefree(int read, int write, int size);
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static struct irqaction irq;
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static int irq_num;
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static inline int spacefree(int read, int write, int size)
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{
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if (read == write) {
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/*
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* never fill the buffer completely, so indexes are always
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* equal if empty and only empty, or !equal if data available
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*/
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return size - 1;
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}
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return ((read + size - write) % size) - 1;
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}
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static struct chan_waitqueues {
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wait_queue_head_t rt_queue;
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wait_queue_head_t lx_queue;
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} channel_wqs[RTLX_CHANNELS];
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static struct irqaction irq;
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static int irq_num;
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extern void *vpe_get_shared(int index);
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static void rtlx_dispatch(struct pt_regs *regs)
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@ -63,9 +63,8 @@ static void rtlx_dispatch(struct pt_regs *regs)
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do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_RTLX_IRQ, regs);
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}
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irqreturn_t rtlx_interrupt(int irq, void *dev_id, struct pt_regs *regs)
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static irqreturn_t rtlx_interrupt(int irq, void *dev_id, struct pt_regs *regs)
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{
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irqreturn_t r = IRQ_HANDLED;
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int i;
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for (i = 0; i < RTLX_CHANNELS; i++) {
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@ -75,30 +74,7 @@ irqreturn_t rtlx_interrupt(int irq, void *dev_id, struct pt_regs *regs)
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wake_up_interruptible(&channel_wqs[i].lx_queue);
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}
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return r;
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}
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void dump_rtlx(void)
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{
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int i;
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printk("id 0x%lx state %d\n", rtlx->id, rtlx->state);
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for (i = 0; i < RTLX_CHANNELS; i++) {
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struct rtlx_channel *chan = &rtlx->channel[i];
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printk(" rt_state %d lx_state %d buffer_size %d\n",
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chan->rt_state, chan->lx_state, chan->buffer_size);
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printk(" rt_read %d rt_write %d\n",
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chan->rt_read, chan->rt_write);
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printk(" lx_read %d lx_write %d\n",
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chan->lx_read, chan->lx_write);
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printk(" rt_buffer <%s>\n", chan->rt_buffer);
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printk(" lx_buffer <%s>\n", chan->lx_buffer);
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}
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return IRQ_HANDLED;
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}
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/* call when we have the address of the shared structure from the SP side. */
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@ -108,7 +84,7 @@ static int rtlx_init(struct rtlx_info *rtlxi)
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if (rtlxi->id != RTLX_ID) {
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printk(KERN_WARNING "no valid RTLX id at 0x%p\n", rtlxi);
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return (-ENOEXEC);
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return -ENOEXEC;
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}
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/* initialise the wait queues */
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@ -120,9 +96,8 @@ static int rtlx_init(struct rtlx_info *rtlxi)
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/* set up for interrupt handling */
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memset(&irq, 0, sizeof(struct irqaction));
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if (cpu_has_vint) {
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if (cpu_has_vint)
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set_vi_handler(MIPS_CPU_RTLX_IRQ, rtlx_dispatch);
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}
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irq_num = MIPSCPU_INT_BASE + MIPS_CPU_RTLX_IRQ;
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irq.handler = rtlx_interrupt;
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@ -132,7 +107,8 @@ static int rtlx_init(struct rtlx_info *rtlxi)
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setup_irq(irq_num, &irq);
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rtlx = rtlxi;
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return (0);
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return 0;
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}
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/* only allow one open process at a time to open each channel */
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@ -147,36 +123,36 @@ static int rtlx_open(struct inode *inode, struct file *filp)
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if (rtlx == NULL) {
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struct rtlx_info **p;
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if( (p = vpe_get_shared(RTLX_TARG_VPE)) == NULL) {
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printk(" vpe_get_shared is NULL. Has an SP program been loaded?\n");
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return (-EFAULT);
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printk(KERN_ERR "vpe_get_shared is NULL. "
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"Has an SP program been loaded?\n");
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return -EFAULT;
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}
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if (*p == NULL) {
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printk(" vpe_shared %p %p\n", p, *p);
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return (-EFAULT);
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printk(KERN_ERR "vpe_shared %p %p\n", p, *p);
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return -EFAULT;
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}
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if ((ret = rtlx_init(*p)) < 0)
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return (ret);
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return ret;
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}
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chan = &rtlx->channel[minor];
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/* already open? */
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if (chan->lx_state == RTLX_STATE_OPENED)
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return (-EBUSY);
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if (test_and_set_bit(RTLX_STATE_OPENED, &chan->lx_state))
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return -EBUSY;
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chan->lx_state = RTLX_STATE_OPENED;
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return (0);
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return 0;
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}
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static int rtlx_release(struct inode *inode, struct file *filp)
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{
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int minor;
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int minor = MINOR(inode->i_rdev);
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minor = MINOR(inode->i_rdev);
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rtlx->channel[minor].lx_state = RTLX_STATE_UNUSED;
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return (0);
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clear_bit(RTLX_STATE_OPENED, &rtlx->channel[minor].lx_state);
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smp_mb__after_clear_bit();
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return 0;
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}
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static unsigned int rtlx_poll(struct file *file, poll_table * wait)
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@ -199,12 +175,13 @@ static unsigned int rtlx_poll(struct file *file, poll_table * wait)
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if (spacefree(chan->rt_read, chan->rt_write, chan->buffer_size))
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mask |= POLLOUT | POLLWRNORM;
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return (mask);
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return mask;
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}
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static ssize_t rtlx_read(struct file *file, char __user * buffer, size_t count,
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loff_t * ppos)
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{
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unsigned long failed;
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size_t fl = 0L;
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int minor;
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struct rtlx_channel *lx;
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@ -216,7 +193,7 @@ static ssize_t rtlx_read(struct file *file, char __user * buffer, size_t count,
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/* data available? */
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if (lx->lx_write == lx->lx_read) {
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if (file->f_flags & O_NONBLOCK)
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return (0); // -EAGAIN makes cat whinge
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return 0; /* -EAGAIN makes cat whinge */
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/* go to sleep */
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add_wait_queue(&channel_wqs[minor].lx_queue, &wait);
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@ -232,39 +209,39 @@ static ssize_t rtlx_read(struct file *file, char __user * buffer, size_t count,
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}
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/* find out how much in total */
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count = min( count,
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(size_t)(lx->lx_write + lx->buffer_size - lx->lx_read) % lx->buffer_size);
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count = min(count,
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(size_t)(lx->lx_write + lx->buffer_size - lx->lx_read) % lx->buffer_size);
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/* then how much from the read pointer onwards */
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fl = min( count, (size_t)lx->buffer_size - lx->lx_read);
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fl = min(count, (size_t)lx->buffer_size - lx->lx_read);
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copy_to_user (buffer, &lx->lx_buffer[lx->lx_read], fl);
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failed = copy_to_user (buffer, &lx->lx_buffer[lx->lx_read], fl);
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if (failed) {
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count = fl - failed;
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goto out;
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}
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/* and if there is anything left at the beginning of the buffer */
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if ( count - fl )
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copy_to_user (buffer + fl, lx->lx_buffer, count - fl);
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if (count - fl) {
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failed = copy_to_user (buffer + fl, lx->lx_buffer, count - fl);
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if (failed) {
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count -= failed;
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goto out;
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}
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}
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out:
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/* update the index */
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lx->lx_read += count;
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lx->lx_read %= lx->buffer_size;
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return (count);
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}
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static inline int spacefree(int read, int write, int size)
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{
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if (read == write) {
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/* never fill the buffer completely, so indexes are always equal if empty
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and only empty, or !equal if data available */
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return (size - 1);
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}
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return ((read + size - write) % size) - 1;
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return count;
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}
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static ssize_t rtlx_write(struct file *file, const char __user * buffer,
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size_t count, loff_t * ppos)
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{
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unsigned long failed;
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int minor;
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struct rtlx_channel *rt;
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size_t fl;
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@ -277,7 +254,7 @@ static ssize_t rtlx_write(struct file *file, const char __user * buffer,
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if (!spacefree(rt->rt_read, rt->rt_write, rt->buffer_size)) {
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if (file->f_flags & O_NONBLOCK)
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return (-EAGAIN);
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return -EAGAIN;
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add_wait_queue(&channel_wqs[minor].rt_queue, &wait);
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set_current_state(TASK_INTERRUPTIBLE);
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@ -290,52 +267,64 @@ static ssize_t rtlx_write(struct file *file, const char __user * buffer,
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}
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/* total number of bytes to copy */
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count = min( count, (size_t)spacefree(rt->rt_read, rt->rt_write, rt->buffer_size) );
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count = min(count, (size_t)spacefree(rt->rt_read, rt->rt_write, rt->buffer_size) );
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/* first bit from write pointer to the end of the buffer, or count */
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fl = min(count, (size_t) rt->buffer_size - rt->rt_write);
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copy_from_user(&rt->rt_buffer[rt->rt_write], buffer, fl);
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failed = copy_from_user(&rt->rt_buffer[rt->rt_write], buffer, fl);
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if (failed) {
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count = fl - failed;
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goto out;
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}
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/* if there's any left copy to the beginning of the buffer */
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if( count - fl )
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copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
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if (count - fl) {
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failed = copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
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if (failed) {
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count -= failed;
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goto out;
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}
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}
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out:
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rt->rt_write += count;
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rt->rt_write %= rt->buffer_size;
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return(count);
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return count;
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}
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static struct file_operations rtlx_fops = {
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.owner = THIS_MODULE,
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.open = rtlx_open,
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.release = rtlx_release,
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.write = rtlx_write,
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.read = rtlx_read,
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.poll = rtlx_poll
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.owner = THIS_MODULE,
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.open = rtlx_open,
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.release = rtlx_release,
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.write = rtlx_write,
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.read = rtlx_read,
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.poll = rtlx_poll
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};
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static int rtlx_module_init(void)
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static char register_chrdev_failed[] __initdata =
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KERN_ERR "rtlx_module_init: unable to register device\n";
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static int __init rtlx_module_init(void)
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{
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if ((major = register_chrdev(RTLX_MAJOR, module_name, &rtlx_fops)) < 0) {
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printk("rtlx_module_init: unable to register device\n");
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return (-EBUSY);
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major = register_chrdev(0, module_name, &rtlx_fops);
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if (major < 0) {
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printk(register_chrdev_failed);
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return major;
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}
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if (major == 0)
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major = RTLX_MAJOR;
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return (0);
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return 0;
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}
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static void rtlx_module_exit(void)
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static void __exit rtlx_module_exit(void)
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{
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unregister_chrdev(major, module_name);
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}
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module_init(rtlx_module_init);
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module_exit(rtlx_module_exit);
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MODULE_DESCRIPTION("MIPS RTLX");
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MODULE_AUTHOR("Elizabeth Clarke, MIPS Technologies, Inc");
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MODULE_AUTHOR("Elizabeth Clarke, MIPS Technologies, Inc.");
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MODULE_LICENSE("GPL");
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@ -16,21 +16,19 @@
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#define RTLX_ID (RTLX_xID | RTLX_VERSION)
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#define RTLX_CHANNELS 8
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enum rtlx_state {
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RTLX_STATE_UNUSED = 0,
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RTLX_STATE_INITIALISED,
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RTLX_STATE_REMOTE_READY,
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RTLX_STATE_OPENED
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};
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#define RTLX_BUFFER_SIZE 1024
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/*
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* lx_state bits
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*/
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#define RTLX_STATE_OPENED 1UL
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/* each channel supports read and write.
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linux (vpe0) reads lx_buffer and writes rt_buffer
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SP (vpe1) reads rt_buffer and writes lx_buffer
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*/
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typedef struct rtlx_channel {
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enum rtlx_state rt_state;
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enum rtlx_state lx_state;
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struct rtlx_channel {
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unsigned long lx_state;
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int buffer_size;
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@ -43,14 +41,12 @@ typedef struct rtlx_channel {
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void *queues;
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} rtlx_channel_t;
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};
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typedef struct rtlx_info {
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struct rtlx_info {
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unsigned long id;
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enum rtlx_state state;
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struct rtlx_channel channel[RTLX_CHANNELS];
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};
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} rtlx_info_t;
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#endif
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#endif /* _RTLX_H_ */
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