On 10/09/2016 03:44 PM, Jarkko Sakkinen wrote:
Refactored tpm2_get_tpm_pt to tpm2_getcap_cmd, which means that it also
takes capability ID as input. This is required to access
TPM_CAP_HANDLES, which contains metadata needed for swapping transient
data.

Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
---
  drivers/char/tpm/tpm.h          |  6 +++-
  drivers/char/tpm/tpm2-cmd.c     | 64 ++++++++++++++++++++---------------------
  drivers/char/tpm/tpm_tis_core.c |  3 +-
  3 files changed, 38 insertions(+), 35 deletions(-)

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 0fab6d5..8176f42 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -85,6 +85,10 @@ enum tpm2_capabilities {
        TPM2_CAP_TPM_PROPERTIES = 6,
  };

+enum tpm2_properties {
+       TPM2_PT_FAMILY_INDICATOR        = 0x100,
+};
+
  enum tpm2_startup_types {
        TPM2_SU_CLEAR   = 0x0000,
        TPM2_SU_STATE   = 0x0001,
@@ -485,7 +489,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
  int tpm2_unseal_trusted(struct tpm_chip *chip,
                        struct trusted_key_payload *payload,
                        struct trusted_key_options *options);
-ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,
+ssize_t tpm2_getcap_cmd(struct tpm_chip *chip, u32 cap_id, u32 property_id,
                        u32 *value, const char *desc);

  int tpm2_auto_startup(struct tpm_chip *chip);
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 2900e18..fcf3d86 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -111,13 +111,13 @@ struct tpm2_pcr_extend_in {
        u8                              digest[TPM_DIGEST_SIZE];
  } __packed;

-struct tpm2_get_tpm_pt_in {
+struct tpm2_getcap_in {
        __be32  cap_id;
        __be32  property_id;
        __be32  property_cnt;
  } __packed;

-struct tpm2_get_tpm_pt_out {
+struct tpm2_getcap_out {
        u8      more_data;
        __be32  subcap_id;
        __be32  property_cnt;
@@ -140,8 +140,8 @@ union tpm2_cmd_params {
        struct  tpm2_pcr_read_in        pcrread_in;
        struct  tpm2_pcr_read_out       pcrread_out;
        struct  tpm2_pcr_extend_in      pcrextend_in;
-       struct  tpm2_get_tpm_pt_in      get_tpm_pt_in;
-       struct  tpm2_get_tpm_pt_out     get_tpm_pt_out;
+       struct  tpm2_getcap_in          getcap_in;
+       struct  tpm2_getcap_out         getcap_out;
        struct  tpm2_get_random_in      getrandom_in;
        struct  tpm2_get_random_out     getrandom_out;
  };
@@ -435,16 +435,6 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t 
max)
        return total ? total : -EIO;
  }

-#define TPM2_GET_TPM_PT_IN_SIZE \
-       (sizeof(struct tpm_input_header) + \
-        sizeof(struct tpm2_get_tpm_pt_in))
-
-static const struct tpm_input_header tpm2_get_tpm_pt_header = {
-       .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
-       .length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
-       .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
-};
-
  /**
   * Append TPMS_AUTH_COMMAND to the buffer. The buffer must be allocated with
   * tpm_buf_alloc().
@@ -750,35 +740,43 @@ out:
        return rc;
  }

+#define TPM2_GETCAP_IN_SIZE \
+       (sizeof(struct tpm_input_header) + sizeof(struct tpm2_getcap_in))
+
+static const struct tpm_input_header tpm2_getcap_header = {
+       .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+       .length = cpu_to_be32(TPM2_GETCAP_IN_SIZE),
+       .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
+};
+
  /**
- * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
- * @chip:              TPM chip to use.
- * @property_id:       property ID.
- * @value:             output variable.
+ * tpm2_getcap_cmd() - execute a TPM2_GetCapability command
+ * @chip:              TPM chip to use
+ * @cap_id:            capability ID
+ * @property_id:       property ID
+ * @value:             value of the property
   * @desc:             passed to tpm_transmit_cmd()
   *
- * 0 is returned when the operation is successful. If a negative number is
- * returned it remarks a POSIX error code. If a positive number is returned
- * it remarks a TPM error.
+ * Return: same as with tpm_transmit_cmd
   */
-ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
-                       const char *desc)
+ssize_t tpm2_getcap_cmd(struct tpm_chip *chip, u32 cap_id, u32 property_id,
+                       u32 *value, const char *desc)

This function currently returns single value "u32 *value" as output data.

Some calling function expect list of values from capabilities output.
For eg., get_active_banks() use TPM_CAP_PCRS capability to retrieve list of active banks. And this capability returns array of pcr selections(which is a struct representing each active PCR bank)

I was thinking, can we define output parameter as struct of cap_id and union of expected cap_data ?

struct cap_out {
  u32 cap_id;
  union cap_data {
     struct tpml_pcr_selection assignedPCR;
     struct tpml_tagged_tpm_property tpmProperties;
     struct tpml_handle handles;
  }
}

And then the calling function, map union to the cap_data expected as per id, and parse it.

Thanks & Regards,
  - Nayna


  {
        struct tpm2_cmd cmd;
        int rc;

-       cmd.header.in = tpm2_get_tpm_pt_header;
-       cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
-       cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
-       cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
+       cmd.header.in = tpm2_getcap_header;
+       cmd.params.getcap_in.cap_id = cpu_to_be32(cap_id);
+       cmd.params.getcap_in.property_id = cpu_to_be32(property_id);
+       cmd.params.getcap_in.property_cnt = cpu_to_be32(1);

        rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, desc);
        if (!rc)
-               *value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
+               *value = be32_to_cpu(cmd.params.getcap_out.value);

        return rc;
  }
-EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
+EXPORT_SYMBOL_GPL(tpm2_getcap_cmd);

  #define TPM2_STARTUP_IN_SIZE \
        (sizeof(struct tpm_input_header) + \
@@ -978,10 +976,10 @@ int tpm2_probe(struct tpm_chip *chip)
        struct tpm2_cmd cmd;
        int rc;

-       cmd.header.in = tpm2_get_tpm_pt_header;
-       cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
-       cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
-       cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
+       cmd.header.in = tpm2_getcap_header;
+       cmd.params.getcap_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
+       cmd.params.getcap_in.property_id = 
cpu_to_be32(TPM2_PT_FAMILY_INDICATOR);
+       cmd.params.getcap_in.property_cnt = cpu_to_be32(1);

        rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),  0, NULL);
        if (rc <  0)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index e3bf31b..792ccd1 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -528,7 +528,8 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
        cap_t cap;

        if (chip->flags & TPM_CHIP_FLAG_TPM2)
-               return tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
+               return tpm2_getcap_cmd(chip, TPM2_CAP_TPM_PROPERTIES,
+                                      TPM2_PT_FAMILY_INDICATOR, &cap2, desc);
        else
                return tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc);
  }


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