[PATCH 14/20] hpilo: add poll f_op

Greg Kroah-Hartman
2009-09-15T19:16:59Z

From: David Altobelli <david.altobelli@hp.com>

Add poll handler to hpilo, to allow applications a low overhead method
of waiting for data.

Signed-off-by: David Altobelli <david.altobelli@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/misc/hpilo.c | 42 +++++++++++++++++++++++++++++++++++++++++-
1 files changed, 41 insertions(+), 1 deletions(-)

diff --git a/drivers/misc/hpilo.c b/drivers/misc/hpilo.c
index 9a370d5..1ad27c6 100644
--- a/drivers/misc/hpilo.c
+++ b/drivers/misc/hpilo.c
@@ -23,6 +23,7 @@
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/wait.h>
+#include <linux/poll.h>
#include "hpilo.h"

static struct class *ilo_class;
@@ -102,6 +103,22 @@ static int fifo_dequeue(struct ilo_hwinfo *hw, char *fifobar, int *entry)
return ret;
}

+static int fifo_check_recv(struct ilo_hwinfo *hw, char *fifobar)
+{
+ struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
+ unsigned long flags;
+ int ret = 0;
+ u64 c;
+
+ spin_lock_irqsave(&hw->fifo_lock, flags);
+ c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
+ if (c & ENTRY_MASK_C)
+ ret = 1;
+ spin_unlock_irqrestore(&hw->fifo_lock, flags);
+
+ return ret;
+}
+
static int ilo_pkt_enqueue(struct ilo_hwinfo *hw, struct ccb *ccb,
int dir, int id, int len)
{
@@ -146,6 +163,13 @@ static int ilo_pkt_dequeue(struct ilo_hwinfo *hw, struct ccb *ccb,
return ret;
}

+static int ilo_pkt_recv(struct ilo_hwinfo *hw, struct ccb *ccb)
+{
+ char *fifobar = ccb->ccb_u3.recv_fifobar;
+
+ return fifo_check_recv(hw, fifobar);
+}
+
static inline void doorbell_set(struct ccb *ccb)
{
iowrite8(1, ccb->ccb_u5.db_base);
@@ -486,6 +510,21 @@ static ssize_t ilo_write(struct file *fp, const char __user *buf,
return err ? -EFAULT : len;
}

+static unsigned int ilo_poll(struct file *fp, poll_table *wait)
+{
+ struct ccb_data *data = fp->private_data;
+ struct ccb *driver_ccb = &data->driver_ccb;
+
+ poll_wait(fp, &data->ccb_waitq, wait);
+
+ if (is_channel_reset(driver_ccb))
+ return POLLERR;
+ else if (ilo_pkt_recv(data->ilo_hw, driver_ccb))
+ return POLLIN | POLLRDNORM;
+
+ return 0;
+}
+
static int ilo_close(struct inode *ip, struct file *fp)
{
int slot;
@@ -595,6 +634,7 @@ static const struct file_operations ilo_fops = {
.owner = THIS_MODULE,
.read = ilo_read,
.write = ilo_write,
+ .poll = ilo_poll,
.open = ilo_open,
.release = ilo_close,
};
@@ -835,7 +875,7 @@ static void __exit ilo_exit(void)
class_destroy(ilo_class);
}

-MODULE_VERSION("1.1");
+MODULE_VERSION("1.2");
MODULE_ALIAS(ILO_NAME);
MODULE_DESCRIPTION(ILO_NAME);
MODULE_AUTHOR("David Altobelli <david.altobelli@hp.com>");
--
1.6.4.2