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

[Jarkko Sakkinen]

On Tue, Oct 11, 2016 at 12:23:04PM +0300, Jarkko Sakkinen wrote:
> In order to provide access to locality registers, this commits adds
> mapping of the head of the CRB registers, which are located right
> before the control area.
> 
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> ---
>  drivers/char/tpm/tpm_crb.c | 86 +++++++++++++++++++++++++++++-----------------
>  1 file changed, 54 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index 65040d7..c34318b 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;
>  
>  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;
>  	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;
> @@ -128,16 +139,18 @@ 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)) {
>  			dev_dbg(dev, "cmdReady in %lld usecs\n",
>  				ktime_to_us(ktime_sub(ktime_get(), start)));
>  			return 0;
> @@ -145,7 +158,7 @@ static int __maybe_unused crb_cmd_ready(struct device *dev,
>  		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;
>  	}
> @@ -158,7 +171,7 @@ 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;
>  
> @@ -174,7 +187,7 @@ 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);
> @@ -213,7 +226,7 @@ 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",
> @@ -227,7 +240,7 @@ 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);
> @@ -239,7 +252,7 @@ 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");
> @@ -248,7 +261,7 @@ 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;
>  }
> @@ -290,6 +303,8 @@ 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);
>  
> @@ -325,10 +340,17 @@ 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);
> +	if (priv->flags & CRB_FL_CRB_START) {

Oops. Should be check for CRB_FL_ACPI_START.

Because we anyway *always* set CRB_FL_CRB_START for everything
how about ripping of CRB_FL_CRB_START flag completely in order
to not cause mistakes like this in future?

/Jarkko

> +		priv->regs_h = crb_map_res(dev, priv, &io_res, io_res.start,
> +					   sizeof(struct crb_regs_head));
> +		if (IS_ERR(priv->regs_h))
> +			return PTR_ERR(priv->regs_h);
> +	}
> +
> +	priv->regs_t = crb_map_res(dev, priv, &io_res, buf->control_address,
> +				   sizeof(struct crb_regs_tail));
> +	if (IS_ERR(priv->regs_t))
> +		return PTR_ERR(priv->regs_t);