Staging: poch: Fetch Flush IOCTL interface
Change user space interface to an IOCTL based interface instead of a
memory mapped circular buffer. The circular buffer had some serious
cache(?) issues and never worked.
Signed-off-by: Vijay Kumar B. <vijaykumar@bravegnu.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/poch/poch.c b/drivers/staging/poch/poch.c
index 1308c7b..6b4aa5f1 100644
--- a/drivers/staging/poch/poch.c
+++ b/drivers/staging/poch/poch.c
@@ -201,6 +201,8 @@
struct page *header_pg;
unsigned long header_size;
+ /* Last group consumed by user space. */
+ unsigned int consumed;
/* Last group indicated as 'complete' to user space. */
unsigned int transfer;
@@ -589,6 +591,7 @@
if (ret != 0)
goto out;
+ channel->consumed = 0;
channel->transfer = 0;
/* Allocate memory to hold group information. */
@@ -1033,6 +1036,51 @@
break;
}
break;
+ case POCH_IOC_CONSUME:
+ {
+ int available;
+ int nfetch;
+ unsigned int from;
+ unsigned int count;
+ unsigned int i, j;
+ struct poch_consume consume;
+ struct poch_consume *uconsume;
+
+ uconsume = argp;
+ ret = copy_from_user(&consume, uconsume, sizeof(consume));
+ if (ret)
+ return ret;
+
+ spin_lock_irq(&channel->group_offsets_lock);
+
+ channel->consumed += consume.nflush;
+ channel->consumed %= channel->group_count;
+
+ available = channel->transfer - channel->consumed;
+ if (available < 0)
+ available += channel->group_count;
+
+ from = channel->consumed;
+
+ spin_unlock_irq(&channel->group_offsets_lock);
+
+ nfetch = consume.nfetch;
+ count = min(available, nfetch);
+
+ for (i = 0; i < count; i++) {
+ j = (from + i) % channel->group_count;
+ ret = put_user(channel->groups[j].user_offset,
+ &consume.offsets[i]);
+ if (ret)
+ return -EFAULT;
+ }
+
+ ret = put_user(count, &uconsume->nfetch);
+ if (ret)
+ return -EFAULT;
+
+ break;
+ }
case POCH_IOC_GET_COUNTERS:
if (!access_ok(VERIFY_WRITE, argp, sizeof(struct poch_counters)))
return -EFAULT;
@@ -1108,12 +1156,18 @@
for (i = 0; i < groups_done; i++) {
j = (prev_transfer + i) % channel->group_count;
group_offsets[j] = groups[j].user_offset;
+
+ channel->transfer += 1;
+ channel->transfer %= channel->group_count;
+
+ if (channel->transfer == channel->consumed) {
+ channel->consumed += 1;
+ channel->consumed %= channel->group_count;
+ }
}
spin_unlock(&channel->group_offsets_lock);
- channel->transfer = curr_transfer;
-
wake_up_interruptible(&channel->wq);
}
diff --git a/drivers/staging/poch/poch.h b/drivers/staging/poch/poch.h
index 51a2d14..ba1490b 100644
--- a/drivers/staging/poch/poch.h
+++ b/drivers/staging/poch/poch.h
@@ -19,6 +19,12 @@
__u32 pll_unlock;
};
+struct poch_consume {
+ __u32 __user *offsets;
+ __u32 nfetch;
+ __u32 nflush;
+};
+
#define POCH_IOC_NUM '9'
#define POCH_IOC_TRANSFER_START _IO(POCH_IOC_NUM, 0)
@@ -27,3 +33,6 @@
struct poch_counters)
#define POCH_IOC_SYNC_GROUP_FOR_USER _IO(POCH_IOC_NUM, 3)
#define POCH_IOC_SYNC_GROUP_FOR_DEVICE _IO(POCH_IOC_NUM, 4)
+
+#define POCH_IOC_CONSUME _IOWR(POCH_IOC_NUM, 5, \
+ struct poch_consume)