Re: [tpmdd-devel] [PATCH v7 01/10] tpm: merge duplicate transmit_cmd() functions

[Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Tue, Nov 25, 2014 at 04:18:39PM -0500, Stefan Berger wrote:
> On 11/11/2014 08:45 AM, Jarkko Sakkinen wrote:
> >Merged transmit_cmd() functions in tpm-interface.c and tpm-sysfs.c.
> >Added "tpm_" prefix for consistency sake. Changed cmd parameter as
> >opaque. This enables to use separate command structures for TPM1
> >and TPM2 commands in future. Loose coupling works fine here.
> >
> >Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> >---
> >  drivers/char/tpm/tpm-interface.c | 49 +++++++++++++++++++++-------------------
> >  drivers/char/tpm/tpm-sysfs.c     | 23 ++-----------------
> >  drivers/char/tpm/tpm.h           |  3 ++-
> >  3 files changed, 30 insertions(+), 45 deletions(-)
> >
> >diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> >index 6af1700..0150b7c 100644
> >--- a/drivers/char/tpm/tpm-interface.c
> >+++ b/drivers/char/tpm/tpm-interface.c
> >@@ -398,9 +398,10 @@ out:
> >  #define TPM_DIGEST_SIZE 20
> >  #define TPM_RET_CODE_IDX 6
> >
> >-static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
> >-			    int len, const char *desc)
> >+ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,
> >+			 int len, const char *desc)
> >  {
> >+	struct tpm_output_header *header;
> >  	int err;
> >
> >  	len = tpm_transmit(chip, (u8 *) cmd, len);
> >@@ -409,7 +410,9 @@ static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
> >  	else if (len < TPM_HEADER_SIZE)
> >  		return -EFAULT;
> >
> >-	err = be32_to_cpu(cmd->header.out.return_code);
> >+	header = (struct tpm_output_header *) cmd;
> 
> The cast should not be necessary -- and this change doesn't buy much...
> 
> header = &cmd->header.out;
> 
> Should do the trick without cast.

I changed the cmd parameter opaque to make this function work both with
TPM1 and TPM2 easily so that I do not have to drop everything to 
struct tpm_cmd_t.

I can change this to

header = cmd;

> >+
> >+	err = be32_to_cpu(header->return_code);
> >  	if (err != 0 && desc)
> >  		dev_err(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
> >
> >@@ -448,7 +451,7 @@ ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
> >  		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> >  		tpm_cmd.params.getcap_in.subcap = subcap_id;
> >  	}
> >-	rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
> >+	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
> >  	if (!rc)
> >  		*cap = tpm_cmd.params.getcap_out.cap;
> >  	return rc;
> >@@ -464,8 +467,8 @@ void tpm_gen_interrupt(struct tpm_chip *chip)
> >  	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> >  	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
> >
> >-	rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> >-			"attempting to determine the timeouts");
> >+	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> >+			      "attempting to determine the timeouts");
> >  }
> >  EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
> >
> >@@ -484,8 +487,8 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
> >  	struct tpm_cmd_t start_cmd;
> >  	start_cmd.header.in = tpm_startup_header;
> >  	start_cmd.params.startup_in.startup_type = startup_type;
> >-	return transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
> >-			    "attempting to start the TPM");
> >+	return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
> >+				"attempting to start the TPM");
> >  }
> >
> >  int tpm_get_timeouts(struct tpm_chip *chip)
> >@@ -500,7 +503,7 @@ int tpm_get_timeouts(struct tpm_chip *chip)
> >  	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
> >  	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> >  	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
> >-	rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
> >+	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
> >
> >  	if (rc == TPM_ERR_INVALID_POSTINIT) {
> >  		/* The TPM is not started, we are the first to talk to it.
> >@@ -513,7 +516,7 @@ int tpm_get_timeouts(struct tpm_chip *chip)
> >  		tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
> >  		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> >  		tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
> >-		rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> >+		rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> >  				  NULL);
> >  	}
> >  	if (rc) {
> >@@ -575,8 +578,8 @@ duration:
> >  	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> >  	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
> >
> >-	rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> >-			"attempting to determine the durations");
> >+	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> >+			      "attempting to determine the durations");
> >  	if (rc)
> >  		return rc;
> >
> >@@ -631,8 +634,8 @@ static int tpm_continue_selftest(struct tpm_chip *chip)
> >  	struct tpm_cmd_t cmd;
> >
> >  	cmd.header.in = continue_selftest_header;
> >-	rc = transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
> >-			  "continue selftest");
> >+	rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
> >+			      "continue selftest");
> >  	return rc;
> >  }
> >
> >@@ -672,8 +675,8 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
> >
> >  	cmd.header.in = pcrread_header;
> >  	cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
> >-	rc = transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
> >-			  "attempting to read a pcr value");
> >+	rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
> >+			      "attempting to read a pcr value");
> >
> >  	if (rc == 0)
> >  		memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
> >@@ -737,8 +740,8 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
> >  	cmd.header.in = pcrextend_header;
> >  	cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
> >  	memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
> >-	rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
> >-			  "attempting extend a PCR value");
> >+	rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
> >+			      "attempting extend a PCR value");
> >
> >  	tpm_chip_put(chip);
> >  	return rc;
> >@@ -817,7 +820,7 @@ int tpm_send(u32 chip_num, void *cmd, size_t buflen)
> >  	if (chip == NULL)
> >  		return -ENODEV;
> >
> >-	rc = transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
> >+	rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
> >
> >  	tpm_chip_put(chip);
> >  	return rc;
> >@@ -938,14 +941,14 @@ int tpm_pm_suspend(struct device *dev)
> >  		cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
> >  		memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
> >  		       TPM_DIGEST_SIZE);
> >-		rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
> >-				  "extending dummy pcr before suspend");
> >+		rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
> >+				      "extending dummy pcr before suspend");
> >  	}
> >
> >  	/* now do the actual savestate */
> >  	for (try = 0; try < TPM_RETRY; try++) {
> >  		cmd.header.in = savestate_header;
> >-		rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
> >+		rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
> >
> >  		/*
> >  		 * If the TPM indicates that it is too busy to respond to
> >@@ -1022,7 +1025,7 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
> >  		tpm_cmd.header.in = tpm_getrandom_header;
> >  		tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
> >
> >-		err = transmit_cmd(chip, &tpm_cmd,
> >+		err = tpm_transmit_cmd(chip, &tpm_cmd,
> >  				   TPM_GETRANDOM_RESULT_SIZE + num_bytes,
> >  				   "attempting get random");
> >  		if (err)
> >diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
> >index 01730a2..8ecb052 100644
> >--- a/drivers/char/tpm/tpm-sysfs.c
> >+++ b/drivers/char/tpm/tpm-sysfs.c
> >@@ -20,25 +20,6 @@
> >  #include <linux/device.h>
> >  #include "tpm.h"
> >
> >-/* XXX for now this helper is duplicated in tpm-interface.c */
> >-static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
> >-			    int len, const char *desc)
> >-{
> >-	int err;
> >-
> >-	len = tpm_transmit(chip, (u8 *) cmd, len);
> >-	if (len <  0)
> >-		return len;
> >-	else if (len < TPM_HEADER_SIZE)
> >-		return -EFAULT;
> >-
> >-	err = be32_to_cpu(cmd->header.out.return_code);
> >-	if (err != 0 && desc)
> >-		dev_err(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
> >-
> >-	return err;
> >-}
> >-
> >  #define READ_PUBEK_RESULT_SIZE 314
> >  #define TPM_ORD_READPUBEK cpu_to_be32(124)
> >  static struct tpm_input_header tpm_readpubek_header = {
> >@@ -58,8 +39,8 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
> >  	struct tpm_chip *chip = dev_get_drvdata(dev);
> >
> >  	tpm_cmd.header.in = tpm_readpubek_header;
> >-	err = transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
> >-			   "attempting to read the PUBEK");
> >+	err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
> >+			       "attempting to read the PUBEK");
> >  	if (err)
> >  		goto out;
> >
> >diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> >index e4d0888..e638eb0 100644
> >--- a/drivers/char/tpm/tpm.h
> >+++ b/drivers/char/tpm/tpm.h
> >@@ -314,9 +314,10 @@ struct tpm_cmd_t {
> >  } __packed;
> >
> >  ssize_t	tpm_getcap(struct device *, __be32, cap_t *, const char *);
> >-
> >  ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
> >  		     size_t bufsiz);
> 
> Delete this prototype ?

tpm-dev.c uses tpm_transmit() and tpm_transmit_cmd() does unnecessary
steps for that use.

> >+ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, int len,
> >+			 const char *desc);
> >  extern int tpm_get_timeouts(struct tpm_chip *);
> >  extern void tpm_gen_interrupt(struct tpm_chip *);
> >  extern int tpm_do_selftest(struct tpm_chip *);
> 
> 
>    Stefan

/Jarkko