Re: [PATCH v3 7/7] tpm_crb: Use devm_ioremap_resource

[Jarkko Sakkinen]

On Thu, Dec 17, 2015 at 11:23:20AM -0700, Jason Gunthorpe wrote:
> To support the force mode in tpm_tis we need to use resource locking
> in tpm_crb as well, via devm_ioremap_resource.
> 
> The light restructuring better aligns crb and tis and makes it easier
> to see the that new changes make sense.

This patch mixes two items: restructing and actual change.

It might make the code cleaner but this patch harder to accept because
it contains more code changes are therefore more risks of regressions.
Tested code is better than clean code.

You should propose clean ups on smaller scale (patches) and not and not
hidden into other changes.

/Jarkko

> 
> Signed-off-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> ---
>  drivers/char/tpm/tpm_crb.c | 157 +++++++++++++++++++++++++++++++--------------
>  1 file changed, 108 insertions(+), 49 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index 0237006dc4d8..1f844cc63016 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -77,6 +77,8 @@ enum crb_flags {
>  
>  struct crb_priv {
>  	unsigned int flags;
> +	struct resource res;
> +	void __iomem *iobase;
>  	struct crb_control_area __iomem *cca;
>  	u8 __iomem *cmd;
>  	u8 __iomem *rsp;
> @@ -196,22 +198,121 @@ static const struct tpm_class_ops tpm_crb = {
>  	.req_complete_val = CRB_STS_COMPLETE,
>  };
>  
> -static int crb_acpi_add(struct acpi_device *device)
> +static int crb_init(struct acpi_device *device, struct crb_priv *priv)
>  {
>  	struct tpm_chip *chip;
> +	int rc;
> +
> +	chip = tpmm_chip_alloc(&device->dev, &tpm_crb);
> +	if (IS_ERR(chip))
> +		return PTR_ERR(chip);
> +
> +	chip->vendor.priv = priv;
> +	chip->acpi_dev_handle = device->handle;
> +	chip->flags = TPM_CHIP_FLAG_TPM2;
> +
> +	rc = tpm_get_timeouts(chip);
> +	if (rc)
> +		return rc;
> +
> +	rc = tpm2_do_selftest(chip);
> +	if (rc)
> +		return rc;
> +
> +	return tpm_chip_register(chip);
> +}
> +
> +static int crb_check_resource(struct acpi_resource *ares, void *data)
> +{
> +	struct crb_priv *priv = data;
> +	struct resource res;
> +
> +	if (acpi_dev_resource_memory(ares, &res))
> +		priv->res = res;
> +
> +	return 1;
> +}
> +
> +static void __iomem *crb_access(struct device *dev, struct crb_priv *priv,
> +				u64 start, u32 size)
> +{
> +	struct resource tmp = {};
> +
> +	tmp.start = start;
> +	tmp.end = start + size - 1;
> +	tmp.flags = IORESOURCE_MEM;
> +
> +	/* Detect a 64 bit address on a 32 bit system */
> +	if (start != tmp.start)
> +		return ERR_PTR(-EINVAL);
> +
> +	if (!resource_contains(&priv->res, &tmp)) {
> +		dev_err(dev,
> +			FW_BUG "TPM2 ACPI sub resource %pR is not in the device's region of %pR\n",
> +			&tmp, &priv->res);
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	return priv->iobase + (tmp.start - priv->res.start);
> +}
> +
> +static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
> +		      struct acpi_table_tpm2 *buf)
> +{
> +	struct list_head resources;
> +	struct device *dev = &device->dev;
> +	u64 pa;
> +	int ret;
> +
> +	INIT_LIST_HEAD(&resources);
> +	ret = acpi_dev_get_resources(device, &resources, crb_check_resource,
> +				     priv);
> +	if (ret < 0)
> +		return ret;
> +	acpi_dev_free_resource_list(&resources);
> +
> +	if (resource_type(&priv->res) != IORESOURCE_MEM) {
> +		dev_err(dev,
> +			FW_BUG "TPM2 ACPI table does not define a memory resource\n");
> +		return -EINVAL;
> +	}
> +
> +	priv->iobase = devm_ioremap_resource(dev, &priv->res);
> +	if (IS_ERR(priv->iobase))
> +		return PTR_ERR(priv->iobase);
> +
> +	priv->cca = crb_access(dev, priv, buf->control_address, 0x1000);
> +	if (IS_ERR(priv->cca))
> +		return PTR_ERR(priv->cca);
> +
> +	pa = ((u64)ioread32(&priv->cca->cmd_pa_high) << 32) |
> +	     (u64)ioread32(&priv->cca->cmd_pa_low);
> +	priv->cmd = crb_access(dev, priv, pa, ioread32(&priv->cca->cmd_size));
> +	if (IS_ERR(priv->cmd))
> +		return PTR_ERR(priv->cmd);
> +
> +	memcpy_fromio(&pa, &priv->cca->rsp_pa, 8);
> +	pa = le64_to_cpu(pa);
> +	priv->rsp = crb_access(dev, priv, pa, ioread32(&priv->cca->rsp_size));
> +	if (IS_ERR(priv->rsp))
> +		return PTR_ERR(priv->rsp);
> +	return 0;
> +}
> +
> +static int crb_acpi_add(struct acpi_device *device)
> +{
>  	struct acpi_table_tpm2 *buf;
>  	struct crb_priv *priv;
>  	struct device *dev = &device->dev;
>  	acpi_status status;
>  	u32 sm;
> -	u64 pa;
>  	int rc;
>  
>  	status = acpi_get_table(ACPI_SIG_TPM2, 1,
>  				(struct acpi_table_header **) &buf);
>  	if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
>  		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
> -		return -ENODEV;
> +		return -EINVAL;
>  	}
>  
>  	/* Should the FIFO driver handle this? */
> @@ -219,18 +320,9 @@ static int crb_acpi_add(struct acpi_device *device)
>  	if (sm == ACPI_TPM2_MEMORY_MAPPED)
>  		return -ENODEV;
>  
> -	chip = tpmm_chip_alloc(dev, &tpm_crb);
> -	if (IS_ERR(chip))
> -		return PTR_ERR(chip);
> -
> -	chip->flags = TPM_CHIP_FLAG_TPM2;
> -
> -	priv = (struct crb_priv *) devm_kzalloc(dev, sizeof(struct crb_priv),
> -						GFP_KERNEL);
> -	if (!priv) {
> -		dev_err(dev, "failed to devm_kzalloc for private data\n");
> +	priv = devm_kzalloc(dev, sizeof(struct crb_priv), GFP_KERNEL);
> +	if (!priv)
>  		return -ENOMEM;
> -	}
>  
>  	/* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
>  	 * report only ACPI start but in practice seems to require both
> @@ -244,44 +336,11 @@ static int crb_acpi_add(struct acpi_device *device)
>  	    sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
>  		priv->flags |= CRB_FL_ACPI_START;
>  
> -	priv->cca = (struct crb_control_area __iomem *)
> -		devm_ioremap_nocache(dev, buf->control_address, 0x1000);
> -	if (!priv->cca) {
> -		dev_err(dev, "ioremap of the control area failed\n");
> -		return -ENOMEM;
> -	}
> -
> -	pa = ((u64)ioread32(&priv->cca->cmd_pa_high) << 32) |
> -	     (u64)ioread32(&priv->cca->cmd_pa_low);
> -	priv->cmd =
> -	    devm_ioremap_nocache(dev, pa, ioread32(&priv->cca->cmd_size));
> -	if (!priv->cmd) {
> -		dev_err(dev, "ioremap of the command buffer failed\n");
> -		return -ENOMEM;
> -	}
> -
> -	memcpy_fromio(&pa, &priv->cca->rsp_pa, 8);
> -	pa = le64_to_cpu(pa);
> -	priv->rsp =
> -	    devm_ioremap_nocache(dev, pa, ioread32(&priv->cca->rsp_size));
> -	if (!priv->rsp) {
> -		dev_err(dev, "ioremap of the response buffer failed\n");
> -		return -ENOMEM;
> -	}
> -
> -	chip->vendor.priv = priv;
> -
> -	rc = tpm_get_timeouts(chip);
> -	if (rc)
> -		return rc;
> -
> -	chip->acpi_dev_handle = device->handle;
> -
> -	rc = tpm2_do_selftest(chip);
> +	rc = crb_map_io(device, priv, buf);
>  	if (rc)
>  		return rc;
>  
> -	return tpm_chip_register(chip);
> +	return crb_init(device, priv);
>  }
>  
>  static int crb_acpi_remove(struct acpi_device *device)
> -- 
> 2.1.4
> 
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