drivers/char/tpm: remove tasklet and cleanup

This patch removed the tasklet and moved the wait queue into the
private structure.  It also cleaned up the response CRQ path.

Signed-off-by: Ashley Lai <adlai@us.ibm.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>

2 files changed, 30 insertions, 56 deletions

diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index efc4ab36a9d6..88a95ea2ba03 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -38,8 +38,6 @@ static struct vio_device_id tpm_ibmvtpm_device_table[] __devinitdata = {
 };
 MODULE_DEVICE_TABLE(vio, tpm_ibmvtpm_device_table);
 
-DECLARE_WAIT_QUEUE_HEAD(wq);
-
 /**
  * ibmvtpm_send_crq - Send a CRQ request
  * @vdev:       vio device struct
@@ -83,6 +81,7 @@ static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 {
         struct ibmvtpm_dev *ibmvtpm;
         u16 len;
+        int sig;
 
         ibmvtpm = (struct ibmvtpm_dev *)chip->vendor.data;
 
@@ -91,22 +90,23 @@ static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
                 return 0;
         }
 
-        wait_event_interruptible(wq, ibmvtpm->crq_res.len != 0);
+        sig = wait_event_interruptible(ibmvtpm->wq, ibmvtpm->res_len != 0);
+        if (sig)
+                return -EINTR;
+
+        len = ibmvtpm->res_len;
 
-        if (count < ibmvtpm->crq_res.len) {
+        if (count < len) {
                 dev_err(ibmvtpm->dev,
                         "Invalid size in recv: count=%ld, crq_size=%d\n",
-                        count, ibmvtpm->crq_res.len);
+                        count, len);
                 return -EIO;
         }
 
         spin_lock(&ibmvtpm->rtce_lock);
-        memcpy((void *)buf, (void *)ibmvtpm->rtce_buf, ibmvtpm->crq_res.len);
-        memset(ibmvtpm->rtce_buf, 0, ibmvtpm->crq_res.len);
-        ibmvtpm->crq_res.valid = 0;
-        ibmvtpm->crq_res.msg = 0;
-        len = ibmvtpm->crq_res.len;
-        ibmvtpm->crq_res.len = 0;
+        memcpy((void *)buf, (void *)ibmvtpm->rtce_buf, len);
+        memset(ibmvtpm->rtce_buf, 0, len);
+        ibmvtpm->res_len = 0;
         spin_unlock(&ibmvtpm->rtce_lock);
         return len;
 }
@@ -273,7 +273,6 @@ static int __devexit tpm_ibmvtpm_remove(struct vio_dev *vdev)
         int rc = 0;
 
         free_irq(vdev->irq, ibmvtpm);
-        tasklet_kill(&ibmvtpm->tasklet);
 
         do {
                 if (rc)
@@ -372,7 +371,6 @@ static int ibmvtpm_reset_crq(struct ibmvtpm_dev *ibmvtpm)
 static int tpm_ibmvtpm_resume(struct device *dev)
 {
         struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(dev);
-        unsigned long flags;
         int rc = 0;
 
         do {
@@ -387,10 +385,11 @@ static int tpm_ibmvtpm_resume(struct device *dev)
                 return rc;
         }
 
-        spin_lock_irqsave(&ibmvtpm->lock, flags);
-        vio_disable_interrupts(ibmvtpm->vdev);
-        tasklet_schedule(&ibmvtpm->tasklet);
-        spin_unlock_irqrestore(&ibmvtpm->lock, flags);
+        rc = vio_enable_interrupts(ibmvtpm->vdev);
+        if (rc) {
+                dev_err(dev, "Error vio_enable_interrupts rc=%d\n", rc);
+                return rc;
+        }
 
         rc = ibmvtpm_crq_send_init(ibmvtpm);
         if (rc)
@@ -467,7 +466,7 @@ static struct ibmvtpm_crq *ibmvtpm_crq_get_next(struct ibmvtpm_dev *ibmvtpm)
         if (crq->valid & VTPM_MSG_RES) {
                 if (++crq_q->index == crq_q->num_entry)
                         crq_q->index = 0;
-                rmb();
+                smp_rmb();
         } else
                 crq = NULL;
         return crq;
@@ -535,11 +534,9 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
                         ibmvtpm->vtpm_version = crq->data;
                         return;
                 case VTPM_TPM_COMMAND_RES:
-                        ibmvtpm->crq_res.valid = crq->valid;
-                        ibmvtpm->crq_res.msg = crq->msg;
-                        ibmvtpm->crq_res.len = crq->len;
-                        ibmvtpm->crq_res.data = crq->data;
-                        wake_up_interruptible(&wq);
+                        /* len of the data in rtce buffer */
+                        ibmvtpm->res_len = crq->len;
+                        wake_up_interruptible(&ibmvtpm->wq);
                         return;
                 default:
                         return;
@@ -559,38 +556,19 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
 static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance)
 {
         struct ibmvtpm_dev *ibmvtpm = (struct ibmvtpm_dev *) vtpm_instance;
-        unsigned long flags;
-
-        spin_lock_irqsave(&ibmvtpm->lock, flags);
-        vio_disable_interrupts(ibmvtpm->vdev);
-        tasklet_schedule(&ibmvtpm->tasklet);
-        spin_unlock_irqrestore(&ibmvtpm->lock, flags);
-
-        return IRQ_HANDLED;
-}
-
-/**
- * ibmvtpm_tasklet - Interrupt handler tasklet
- * @data:       ibm vtpm device struct
- *
- * Returns:
- *      Nothing
- **/
-static void ibmvtpm_tasklet(void *data)
-{
-        struct ibmvtpm_dev *ibmvtpm = data;
         struct ibmvtpm_crq *crq;
-        unsigned long flags;
 
-        spin_lock_irqsave(&ibmvtpm->lock, flags);
+        /* while loop is needed for initial setup (get version and
+         * get rtce_size). There should be only one tpm request at any
+         * given time.
+         */
         while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) {
                 ibmvtpm_crq_process(crq, ibmvtpm);
                 crq->valid = 0;
-                wmb();
+                smp_wmb();
         }
 
-        vio_enable_interrupts(ibmvtpm->vdev);
-        spin_unlock_irqrestore(&ibmvtpm->lock, flags);
+        return IRQ_HANDLED;
 }
 
 /**
@@ -650,9 +628,6 @@ static int __devinit tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
                 goto reg_crq_cleanup;
         }
 
-        tasklet_init(&ibmvtpm->tasklet, (void *)ibmvtpm_tasklet,
-                     (unsigned long)ibmvtpm);
-
         rc = request_irq(vio_dev->irq, ibmvtpm_interrupt, 0,
                          tpm_ibmvtpm_driver_name, ibmvtpm);
         if (rc) {
@@ -666,13 +641,14 @@ static int __devinit tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
                 goto init_irq_cleanup;
         }
 
+        init_waitqueue_head(&ibmvtpm->wq);
+
         crq_q->index = 0;
 
         ibmvtpm->dev = dev;
         ibmvtpm->vdev = vio_dev;
         chip->vendor.data = (void *)ibmvtpm;
 
-        spin_lock_init(&ibmvtpm->lock);
         spin_lock_init(&ibmvtpm->rtce_lock);
 
         rc = ibmvtpm_crq_send_init(ibmvtpm);
@@ -689,7 +665,6 @@ static int __devinit tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
 
         return rc;
 init_irq_cleanup:
-        tasklet_kill(&ibmvtpm->tasklet);
         do {
                 rc1 = plpar_hcall_norets(H_FREE_CRQ, vio_dev->unit_address);
         } while (rc1 == H_BUSY || H_IS_LONG_BUSY(rc1));
diff --git a/drivers/char/tpm/tpm_ibmvtpm.h b/drivers/char/tpm/tpm_ibmvtpm.h
index 4296eb4b4d82..bd82a791f995 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.h
+++ b/drivers/char/tpm/tpm_ibmvtpm.h
@@ -38,13 +38,12 @@ struct ibmvtpm_dev {
         struct vio_dev *vdev;
         struct ibmvtpm_crq_queue crq_queue;
         dma_addr_t crq_dma_handle;
-        spinlock_t lock;
-        struct tasklet_struct tasklet;
         u32 rtce_size;
         void __iomem *rtce_buf;
         dma_addr_t rtce_dma_handle;
         spinlock_t rtce_lock;
-        struct ibmvtpm_crq crq_res;
+        wait_queue_head_t wq;
+        u16 res_len;
         u32 vtpm_version;
 };