[PATCH 1/1] drivers/char/tpm: remove tasklet and cleanup

James Morris jmorris at namei.org
Mon Sep 24 12:26:05 EST 2012


On Wed, 12 Sep 2012, Ashley Lai wrote:

> 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 at us.ibm.com>


Kent: any comment on this?  You should probably push this to me via your 
tree.


> ---
> 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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-- 
James Morris
<jmorris at namei.org>


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