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

From: Jarkko Sakkinen
Date: Tue Oct 11 2016 - 07:30:28 EST


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);