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SubjectRe: [PATCH RFC] tpm, tpm_tis: detect TPM2 devices


On 29-08-15 07:36, Jarkko Sakkinen wrote:
> It turned out that the root cause in b371616b8 was not entirely correct
> for https://bugzilla.kernel.org/show_bug.cgi?id=98181.
>
> All TPM 2.0 FIFO and CRB devices have the same HID. For FIFO devices
> the start method is 6 as it is defined in
>
> http://www.trustedcomputinggroup.org/resources/tcg_acpi_specification
>
> This patch changes FIFO and CRB drivers so that they check start method
> value and initialize only if the start method has a proper value for
> that particular interface.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
> drivers/char/tpm/tpm.h | 7 +++++++
> drivers/char/tpm/tpm_crb.c | 20 +++++---------------
> drivers/char/tpm/tpm_tis.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
> 3 files changed, 55 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index f8319a0..39be5ac 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -115,6 +115,13 @@ enum tpm2_startup_types {
> TPM2_SU_STATE = 0x0001,
> };
>
> +enum tpm2_start_method {
> + TPM2_START_ACPI = 2,
> + TPM2_START_FIFO = 6,
> + TPM2_START_CRB = 7,
> + TPM2_START_CRB_WITH_ACPI = 8,
> +};
> +
> struct tpm_chip;
>
> struct tpm_vendor_specific {
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index 1267322..b4564b6 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -34,12 +34,6 @@ enum crb_defaults {
> CRB_ACPI_START_INDEX = 1,
> };
>
> -enum crb_start_method {
> - CRB_SM_ACPI_START = 2,
> - CRB_SM_CRB = 7,
> - CRB_SM_CRB_WITH_ACPI_START = 8,
> -};
> -
> struct acpi_tpm2 {
> struct acpi_table_header hdr;
> u16 platform_class;
> @@ -233,13 +227,9 @@ static int crb_acpi_add(struct acpi_device *device)
> return -ENODEV;
> }
>
> - /* At least some versions of AMI BIOS have a bug that TPM2 table has
> - * zero address for the control area and therefore we must fail.
> - */
> - if (!buf->control_area_pa) {
> - dev_err(dev, "TPM2 ACPI table has a zero address for the control area\n");
> - return -EINVAL;
> - }
> + /* Should the FIFO driver handle this? */
> + if (buf->start_method == TPM2_START_FIFO)
> + return -ENODEV;
>
> if (buf->hdr.length < sizeof(struct acpi_tpm2)) {
> dev_err(dev, "TPM2 ACPI table has wrong size");
> @@ -259,11 +249,11 @@ static int crb_acpi_add(struct acpi_device *device)
> * report only ACPI start but in practice seems to require both
> * ACPI start and CRB start.
> */
> - if (sm == CRB_SM_CRB || sm == CRB_SM_CRB_WITH_ACPI_START ||
> + if (sm == TPM2_START_CRB || sm == TPM2_START_FIFO ||
> !strcmp(acpi_device_hid(device), "MSFT0101"))
> priv->flags |= CRB_FL_CRB_START;
>
> - if (sm == CRB_SM_ACPI_START || sm == CRB_SM_CRB_WITH_ACPI_START)
> + if (sm == TPM2_START_ACPI || sm == TPM2_START_CRB_WITH_ACPI)
> priv->flags |= CRB_FL_ACPI_START;
>
> priv->cca = (struct crb_control_area __iomem *)
> diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
> index f2dffa7..4760804 100644
> --- a/drivers/char/tpm/tpm_tis.c
> +++ b/drivers/char/tpm/tpm_tis.c
> @@ -28,6 +28,7 @@
> #include <linux/wait.h>
> #include <linux/acpi.h>
> #include <linux/freezer.h>
> +#include <acpi/actbl2.h>
> #include "tpm.h"
>
> enum tis_access {
> @@ -91,7 +92,7 @@ struct priv_data {
> };
>
> #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
> -static int is_itpm(struct pnp_dev *dev)
> +static int has_hid(struct pnp_dev *dev, const char *hid)
> {
> struct acpi_device *acpi = pnp_acpi_device(dev);
> struct acpi_hardware_id *id;
> @@ -100,17 +101,49 @@ static int is_itpm(struct pnp_dev *dev)
> return 0;
>
> list_for_each_entry(id, &acpi->pnp.ids, list) {
> - if (!strcmp("INTC0102", id->id))
> + if (!strcmp(hid, id->id))
> return 1;
> }
>
> return 0;
> }
> +
> +static inline int is_itpm(struct pnp_dev *dev)
> +{
> + return has_hid(dev, "INTC0102");
> +}
> +
> +static inline int validate_pnp_dev(struct pnp_dev *dev)
> +{
> + struct acpi_table_tpm2 *tbl;
> + acpi_status st;
> +
> + if (!has_hid(dev, "MSFT0101"))
> + return 0;
> +
> + st = acpi_get_table(ACPI_SIG_TPM2, 1,
> + (struct acpi_table_header **) &tbl);
> + if (ACPI_FAILURE(st)) {
> + dev_err(&dev->dev, "failed to get TPM2 ACPI table\n");
> + return -ENODEV;
> + }
> +
> + /* Should the CRB driver handle this? */
> + if (le32_to_cpu(tbl->start_method) != TPM2_START_FIFO)
> + return -ENODEV:

This should end in a semicolon.

> +
> + retuurn 0;

This should spell 'return'.

> +}
> #else
> static inline int is_itpm(struct pnp_dev *dev)
> {
> return 0;
> }
> +
> +static inline int validate_pnp_dev(struct pnp_dev *dev)
> +{
> + return 0;
> +}
> #endif
>
> /* Before we attempt to access the TPM we must see that the valid bit is set.
> @@ -893,6 +926,11 @@ static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
> resource_size_t start, len;
> unsigned int irq = 0;
> acpi_handle acpi_dev_handle = NULL;
> + int ret;
> +
> + ret = validate_pnp_dev(pnp_dev);
> + if (ret)
> + return ret;
>
> start = pnp_mem_start(pnp_dev, 0);
> len = pnp_mem_len(pnp_dev, 0);
> @@ -921,6 +959,9 @@ static struct pnp_device_id tpm_pnp_tbl[] = {
> {"BCM0102", 0}, /* Broadcom */
> {"NSC1200", 0}, /* National */
> {"ICO0102", 0}, /* Intel */
> +#ifdef CONFIG_ACPI
> + {"MSFT0101", 0}, /* TPM 2.0 */
> +#endif
> /* Add new here */
> {"", 0}, /* User Specified */
> {"", 0} /* Terminator */
>


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