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

From: key
Date: Mon Sep 24 2012 - 10:11:25 EST

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On Mon, Sep 24, 2012 at 12:26:05PM +1000, James Morris wrote:
> 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@xxxxxxxxxx>
>
>
> Kent: any comment on this? You should probably push this to me via your
> tree.

Oh, I thought we were waiting on Ben. This looks good to me, I'll get
this to you today.

Kent

>
>
> > ---
> > 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@xxxxxxxxx>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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>

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Next message: Cyrill Gorcunov: "Re: [RFC] tty: Add get- ioctls to fetch tty status"
Previous message: Stephen Rothwell: "linux-next: build failure after merge of the akpm tree"
Next in thread: key: "Re: [PATCH 1/1] drivers/char/tpm: remove tasklet and cleanup"
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