Re: [PATCH v2 1/3] tpm_crb: map locality registers

[Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Mon, Dec 05, 2016 at 12:07:51PM +0000, Winkler, Tomas wrote:
> > > ---
> > >  drivers/char/tpm/tpm_crb.c | 96
> > > ++++++++++++++++++++++++++++++----------------
> > >  1 file changed, 64 insertions(+), 32 deletions(-)
> > >
> > > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> > > index 717b6b4..8d81b66 100644
> > > --- a/drivers/char/tpm/tpm_crb.c
> > > +++ b/drivers/char/tpm/tpm_crb.c
> > > @@ -52,18 +52,28 @@ enum crb_cancel {
> > >  	CRB_CANCEL_INVOKE	= BIT(0),
> > >  };
> > >
> > > -struct crb_control_area {
> > > -	u32 req;
> > > -	u32 sts;
> > > -	u32 cancel;
> > > -	u32 start;
> > > -	u32 int_enable;
> > > -	u32 int_sts;
> > > -	u32 cmd_size;
> > > -	u32 cmd_pa_low;
> > > -	u32 cmd_pa_high;
> > > -	u32 rsp_size;
> > > -	u64 rsp_pa;
> > > +struct crb_regs_head {
> > > +	u32 loc_state;
> > > +	u32 reserved1;
> > > +	u32 loc_ctrl;
> > > +	u32 loc_sts;
> > > +	u8 reserved2[32];
> > > +	u64 intf_id;
> > > +	u64 ctrl_ext;
> > > +} __packed;
> > > +
> > > +struct crb_regs_tail {
> > > +	u32 ctrl_req;
> > > +	u32 ctrl_sts;
> > > +	u32 ctrl_cancel;
> > > +	u32 ctrl_start;
> > > +	u32 ctrl_int_enable;
> > > +	u32 ctrl_int_sts;
> > > +	u32 ctrl_cmd_size;
> > > +	u32 ctrl_cmd_pa_low;
> > > +	u32 ctrl_cmd_pa_high;
> > > +	u32 ctrl_rsp_size;
> > > +	u64 ctrl_rsp_pa;
> > >  } __packed;
> 
> 
> Now I wonder if using  traditional offsets wouldn't be cleaner solution.

I'm not sure what you are trying to say.

> > >  enum crb_status {
> > > @@ -78,7 +88,8 @@ enum crb_flags {
> > >  struct crb_priv {
> > >  	unsigned int flags;
> > >  	void __iomem *iobase;
> > > -	struct crb_control_area __iomem *cca;
> > > +	struct crb_regs_head __iomem *regs_h;
> > > +	struct crb_regs_tail __iomem *regs_t;
> Why just not leaving it cca, it's descriptive enough. 
> > >  	u8 __iomem *cmd;
> > >  	u8 __iomem *rsp;
> > >  	u32 cmd_size;
> > > @@ -104,7 +115,7 @@ static int __maybe_unused crb_go_idle(struct device
> > *dev, struct crb_priv *priv)
> > >  	if (priv->flags & CRB_FL_ACPI_START)
> > >  		return 0;
> > >
> > > -	iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->cca->req);
> > > +	iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
> > >  	/* we don't really care when this settles */
> > >
> > >  	return 0;
> > > @@ -128,21 +139,23 @@ static int __maybe_unused crb_cmd_ready(struct
> > device *dev,
> > >  					struct crb_priv *priv)
> > >  {
> > >  	ktime_t stop, start;
> > > +	u32 req;
> > >
> > >  	if (priv->flags & CRB_FL_ACPI_START)
> > >  		return 0;
> > >
> > > -	iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->cca->req);
> > > +	iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
> > >
> > >  	start = ktime_get();
> > >  	stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C));
> > >  	do {
> > > -		if (!(ioread32(&priv->cca->req) &
> > CRB_CTRL_REQ_CMD_READY))
> > > +		req = ioread32(&priv->regs_t->ctrl_req);
> > > +		if (!(req & CRB_CTRL_REQ_CMD_READY))
> > >  			return 0;
> > >  		usleep_range(50, 100);
> > >  	} while (ktime_before(ktime_get(), stop));
> > >
> > > -	if (ioread32(&priv->cca->req) & CRB_CTRL_REQ_CMD_READY) {
> > > +	if (ioread32(&priv->regs_t->ctrl_req) & CRB_CTRL_REQ_CMD_READY)
> > {
> > >  		dev_warn(dev, "cmdReady timed out\n");
> > >  		return -ETIME;
> > >  	}
> > > @@ -155,7 +168,7 @@ static u8 crb_status(struct tpm_chip *chip)
> > >  	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
> > >  	u8 sts = 0;
> > >
> > > -	if ((ioread32(&priv->cca->start) & CRB_START_INVOKE) !=
> > > +	if ((ioread32(&priv->regs_t->ctrl_start) & CRB_START_INVOKE) !=
> > >  	    CRB_START_INVOKE)
> > >  		sts |= CRB_DRV_STS_COMPLETE;
> > >
> > > @@ -171,7 +184,7 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf,
> > size_t count)
> > >  	if (count < 6)
> > >  		return -EIO;
> > >
> > > -	if (ioread32(&priv->cca->sts) & CRB_CTRL_STS_ERROR)
> > > +	if (ioread32(&priv->regs_t->ctrl_sts) & CRB_CTRL_STS_ERROR)
> > >  		return -EIO;
> > >
> > >  	memcpy_fromio(buf, priv->rsp, 6);
> > > @@ -210,7 +223,7 @@ static int crb_send(struct tpm_chip *chip, u8 *buf,
> > size_t len)
> > >  	/* Zero the cancel register so that the next command will not get
> > >  	 * canceled.
> > >  	 */
> > > -	iowrite32(0, &priv->cca->cancel);
> > > +	iowrite32(0, &priv->regs_t->ctrl_cancel);
> > >
> > >  	if (len > priv->cmd_size) {
> > >  		dev_err(&chip->dev, "invalid command count value %zd %d\n",
> > @@
> > > -224,7 +237,7 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t
> > len)
> > >  	wmb();
> > >
> > >  	if (priv->flags & CRB_FL_CRB_START)
> > > -		iowrite32(CRB_START_INVOKE, &priv->cca->start);
> > > +		iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
> > >
> > >  	if (priv->flags & CRB_FL_ACPI_START)
> > >  		rc = crb_do_acpi_start(chip);
> > > @@ -236,7 +249,7 @@ static void crb_cancel(struct tpm_chip *chip)  {
> > >  	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
> > >
> > > -	iowrite32(CRB_CANCEL_INVOKE, &priv->cca->cancel);
> > > +	iowrite32(CRB_CANCEL_INVOKE, &priv->regs_t->ctrl_cancel);
> > >
> > >  	if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip))
> > >  		dev_err(&chip->dev, "ACPI Start failed\n"); @@ -245,7 +258,7
> > @@
> > > static void crb_cancel(struct tpm_chip *chip)  static bool
> > > crb_req_canceled(struct tpm_chip *chip, u8 status)  {
> > >  	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
> > > -	u32 cancel = ioread32(&priv->cca->cancel);
> > > +	u32 cancel = ioread32(&priv->regs_t->ctrl_cancel);
> > >
> > >  	return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;  }
> > @@
> > > -287,6 +300,8 @@ static void __iomem *crb_map_res(struct device *dev,
> > struct crb_priv *priv,
> > >  	if (start != new_res.start)
> > >  		return (void __iomem *) ERR_PTR(-EINVAL);
> > >
> > > +	dev_dbg(dev, "%pr %pr", io_res, &new_res);
> > > +
> > >  	if (!resource_contains(io_res, &new_res))
> > >  		return devm_ioremap_resource(dev, &new_res);
> > >
> > > @@ -322,10 +337,27 @@ static int crb_map_io(struct acpi_device *device,
> > struct crb_priv *priv,
> > >  	if (IS_ERR(priv->iobase))
> > >  		return PTR_ERR(priv->iobase);
> > >
> > > -	priv->cca = crb_map_res(dev, priv, &io_res, buf->control_address,
> > > -				sizeof(struct crb_control_area));
> > > -	if (IS_ERR(priv->cca))
> > > -		return PTR_ERR(priv->cca);
> > > +	/* The ACPI IO region starts at the head area and continues to include
> > > +	 * the control area, as one nice sane region except for some older
> > > +	 * stuff that puts the control area outside the ACPI IO region.
> > > +	 */
> 
> This is not by the spec, can you be more specific, what platforms has that behavior?

Pre-Skylake (Haswell, Broadwell) does not follow the spec.

> > > +	if (!(priv->flags & CRB_FL_ACPI_START)) {
> > > +		if (buf->control_address == io_res.start +
> > > +		    sizeof(struct crb_regs_head)) {
> > > +			priv->regs_h = crb_map_res(
> Why do you need to map this again it just same as iobase ? 

crb_map_res() works in a way that it does ioremap only when the range
is not included to iomem.


/Jarkko

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