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authorRalf Baechle <ralf@linux-mips.org>2005-10-31 00:30:39 +0000
committerRalf Baechle <ralf@linux-mips.org>2005-11-07 18:05:33 +0000
commitafc4841d8a0118fcce9fd520b21ec1da401603a3 (patch)
tree25e16fdb4c00311e025efcd2ef448a3e97ebba12 /arch
parent0b154bb7d0cce80e9c0bcf11d4f9e71b59409d26 (diff)
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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>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kernel/rtlx.c197
1 files changed, 93 insertions, 104 deletions
diff --git a/arch/mips/kernel/rtlx.c b/arch/mips/kernel/rtlx.c
index 8c81f3c..1d85511 100644
--- a/arch/mips/kernel/rtlx.c
+++ b/arch/mips/kernel/rtlx.c
@@ -20,42 +20,42 @@
#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/bitops.h>
#include <asm/cpu.h>
#include <asm/processor.h>
-#include <asm/system.h>
#include <asm/rtlx.h>
+#include <asm/uaccess.h>
-#define RTLX_MAJOR 64
#define RTLX_TARG_VPE 1
-struct rtlx_info *rtlx;
+static struct rtlx_info *rtlx;
static int major;
static char module_name[] = "rtlx";
-static inline int spacefree(int read, int write, int size);
+static struct irqaction irq;
+static int irq_num;
+
+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 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)
@@ -63,9 +63,8 @@ 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)
+static 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++) {
@@ -75,30 +74,7 @@ irqreturn_t rtlx_interrupt(int irq, void *dev_id, struct pt_regs *regs)
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);
- }
+ return IRQ_HANDLED;
}
/* call when we have the address of the shared structure from the SP side. */
@@ -108,7 +84,7 @@ static int rtlx_init(struct rtlx_info *rtlxi)
if (rtlxi->id != RTLX_ID) {
printk(KERN_WARNING "no valid RTLX id at 0x%p\n", rtlxi);
- return (-ENOEXEC);
+ return -ENOEXEC;
}
/* initialise the wait queues */
@@ -120,9 +96,8 @@ static int rtlx_init(struct rtlx_info *rtlxi)
/* set up for interrupt handling */
memset(&irq, 0, sizeof(struct irqaction));
- if (cpu_has_vint) {
+ 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;
@@ -132,7 +107,8 @@ static int rtlx_init(struct rtlx_info *rtlxi)
setup_irq(irq_num, &irq);
rtlx = rtlxi;
- return (0);
+
+ return 0;
}
/* only allow one open process at a time to open each channel */
@@ -147,36 +123,36 @@ static int rtlx_open(struct inode *inode, struct file *filp)
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);
+ printk(KERN_ERR "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);
+ printk(KERN_ERR "vpe_shared %p %p\n", p, *p);
+ return -EFAULT;
}
if ((ret = rtlx_init(*p)) < 0)
- return (ret);
+ return ret;
}
chan = &rtlx->channel[minor];
- /* already open? */
- if (chan->lx_state == RTLX_STATE_OPENED)
- return (-EBUSY);
+ if (test_and_set_bit(RTLX_STATE_OPENED, &chan->lx_state))
+ return -EBUSY;
- chan->lx_state = RTLX_STATE_OPENED;
- return (0);
+ return 0;
}
static int rtlx_release(struct inode *inode, struct file *filp)
{
- int minor;
+ int minor = MINOR(inode->i_rdev);
- minor = MINOR(inode->i_rdev);
- rtlx->channel[minor].lx_state = RTLX_STATE_UNUSED;
- return (0);
+ clear_bit(RTLX_STATE_OPENED, &rtlx->channel[minor].lx_state);
+ smp_mb__after_clear_bit();
+
+ return 0;
}
static unsigned int rtlx_poll(struct file *file, poll_table * wait)
@@ -199,12 +175,13 @@ static unsigned int rtlx_poll(struct file *file, poll_table * wait)
if (spacefree(chan->rt_read, chan->rt_write, chan->buffer_size))
mask |= POLLOUT | POLLWRNORM;
- return (mask);
+ return mask;
}
static ssize_t rtlx_read(struct file *file, char __user * buffer, size_t count,
loff_t * ppos)
{
+ unsigned long failed;
size_t fl = 0L;
int minor;
struct rtlx_channel *lx;
@@ -216,7 +193,7 @@ static ssize_t rtlx_read(struct file *file, char __user * buffer, size_t count,
/* data available? */
if (lx->lx_write == lx->lx_read) {
if (file->f_flags & O_NONBLOCK)
- return (0); // -EAGAIN makes cat whinge
+ return 0; /* -EAGAIN makes cat whinge */
/* go to sleep */
add_wait_queue(&channel_wqs[minor].lx_queue, &wait);
@@ -232,39 +209,39 @@ static ssize_t rtlx_read(struct file *file, char __user * buffer, size_t count,
}
/* find out how much in total */
- count = min( count,
- (size_t)(lx->lx_write + lx->buffer_size - lx->lx_read) % lx->buffer_size);
+ 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);
+ fl = min(count, (size_t)lx->buffer_size - lx->lx_read);
- copy_to_user (buffer, &lx->lx_buffer[lx->lx_read], fl);
+ failed = copy_to_user (buffer, &lx->lx_buffer[lx->lx_read], fl);
+ if (failed) {
+ count = fl - failed;
+ goto out;
+ }
/* 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);
+ if (count - fl) {
+ failed = copy_to_user (buffer + fl, lx->lx_buffer, count - fl);
+ if (failed) {
+ count -= failed;
+ goto out;
+ }
+ }
+out:
/* 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;
+ return count;
}
static ssize_t rtlx_write(struct file *file, const char __user * buffer,
size_t count, loff_t * ppos)
{
+ unsigned long failed;
int minor;
struct rtlx_channel *rt;
size_t fl;
@@ -277,7 +254,7 @@ static ssize_t rtlx_write(struct file *file, const char __user * buffer,
if (!spacefree(rt->rt_read, rt->rt_write, rt->buffer_size)) {
if (file->f_flags & O_NONBLOCK)
- return (-EAGAIN);
+ return -EAGAIN;
add_wait_queue(&channel_wqs[minor].rt_queue, &wait);
set_current_state(TASK_INTERRUPTIBLE);
@@ -290,52 +267,64 @@ static ssize_t rtlx_write(struct file *file, const char __user * buffer,
}
/* total number of bytes to copy */
- count = min( count, (size_t)spacefree(rt->rt_read, rt->rt_write, rt->buffer_size) );
+ 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);
+ failed = copy_from_user(&rt->rt_buffer[rt->rt_write], buffer, fl);
+ if (failed) {
+ count = fl - failed;
+ goto out;
+ }
/* 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);
+ if (count - fl) {
+ failed = copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
+ if (failed) {
+ count -= failed;
+ goto out;
+ }
+ }
+out:
rt->rt_write += count;
rt->rt_write %= rt->buffer_size;
- return(count);
+ 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
+ .owner = THIS_MODULE,
+ .open = rtlx_open,
+ .release = rtlx_release,
+ .write = rtlx_write,
+ .read = rtlx_read,
+ .poll = rtlx_poll
};
-static int rtlx_module_init(void)
+static char register_chrdev_failed[] __initdata =
+ KERN_ERR "rtlx_module_init: unable to register device\n";
+
+static int __init 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);
+ major = register_chrdev(0, module_name, &rtlx_fops);
+ if (major < 0) {
+ printk(register_chrdev_failed);
+ return major;
}
- if (major == 0)
- major = RTLX_MAJOR;
-
- return (0);
+ return 0;
}
-static void rtlx_module_exit(void)
+static void __exit 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_AUTHOR("Elizabeth Clarke, MIPS Technologies, Inc.");
MODULE_LICENSE("GPL");