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Subject[PATCH 1/1] drivers/char/tpm: remove tasklet and cleanup
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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>
---
James,

This patch is based on your "next" branch.
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git

Thanks,
Ashley Lai
---
drivers/char/tpm/tpm_ibmvtpm.c | 81 +++++++++++++++---------------------------
drivers/char/tpm/tpm_ibmvtpm.h | 5 ++-
2 files changed, 30 insertions(+), 56 deletions(-)

diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index efc4ab3..88a95ea 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 4296eb4..bd82a79 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;
};

--
1.7.11.2



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