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Message-ID: <bb8f1d75e26a2c8e427f86ecd5a67703e836ec88.camel@linux.intel.com>
Subject: Re: [PATCH v4 01/21] tpm2: add new tpm2 commands according to TCG
 1.36
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Tomas Winkler <tomas.winkler@intel.com>,
        Jason Gunthorpe <jgg@ziepe.ca>
Cc:     Alexander Usyskin <alexander.usyskin@intel.com>,
        Tadeusz Struk <tadeusz.struk@intel.com>,
        linux-integrity@vger.kernel.org,
        linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Tue, 25 Sep 2018 17:13:25 +0300
In-Reply-To: <20180921135820.20549-2-tomas.winkler@intel.com>
References: <20180921135820.20549-1-tomas.winkler@intel.com>
         <20180921135820.20549-2-tomas.winkler@intel.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
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On Fri, 2018-09-21 at 16:58 +0300, Tomas Winkler wrote:
> 1. TPM2_CC_LAST has moved from 182 to 193
> 2. Convert tpm2_ordinal_duration from an array into a switch statement,
>    as there are not so many commands that require special duration
>    relative to a number of commands, the switch statement function
>    is called tpm2_ordinal_duration_index().
> 3. Fix kdoc comments for tpm2_calc_ordinal_duration().
> 
> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
> V2-V3: Rebase.
> V4: 1. Fix kdoc
>     2. Rename tpm2_ordinal_duration() to tpm2_ordinal_duration_index()
>     3. Move the two functions close to each other in the file.
> 
>  drivers/char/tpm/tpm.h      |  41 +++++---
>  drivers/char/tpm/tpm2-cmd.c | 236 +++++++++++++++++------------------------
> ---
>  2 files changed, 113 insertions(+), 164 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index f20dc8ece348..0f08518b525d 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -134,22 +134,31 @@ enum tpm2_algorithms {
>  };
>  
>  enum tpm2_command_codes {
> -	TPM2_CC_FIRST		= 0x011F,
> -	TPM2_CC_CREATE_PRIMARY  = 0x0131,
> -	TPM2_CC_SELF_TEST	= 0x0143,
> -	TPM2_CC_STARTUP		= 0x0144,
> -	TPM2_CC_SHUTDOWN	= 0x0145,
> -	TPM2_CC_CREATE		= 0x0153,
> -	TPM2_CC_LOAD		= 0x0157,
> -	TPM2_CC_UNSEAL		= 0x015E,
> -	TPM2_CC_CONTEXT_LOAD	= 0x0161,
> -	TPM2_CC_CONTEXT_SAVE	= 0x0162,
> -	TPM2_CC_FLUSH_CONTEXT	= 0x0165,
> -	TPM2_CC_GET_CAPABILITY	= 0x017A,
> -	TPM2_CC_GET_RANDOM	= 0x017B,
> -	TPM2_CC_PCR_READ	= 0x017E,
> -	TPM2_CC_PCR_EXTEND	= 0x0182,
> -	TPM2_CC_LAST		= 0x018F,
> +	TPM2_CC_FIRST		        = 0x011F,
> +	TPM2_CC_HIERARCHY_CONTROL       = 0x0121,
> +	TPM2_CC_HIERARCHY_CHANGE_AUTH   = 0x0129,
> +	TPM2_CC_CREATE_PRIMARY          = 0x0131,
> +	TPM2_CC_SEQUENCE_COMPLETE       = 0x013E,
> +	TPM2_CC_SELF_TEST	        = 0x0143,
> +	TPM2_CC_STARTUP		        = 0x0144,
> +	TPM2_CC_SHUTDOWN	        = 0x0145,
> +	TPM2_CC_NV_READ                 = 0x014E,
> +	TPM2_CC_CREATE		        = 0x0153,
> +	TPM2_CC_LOAD		        = 0x0157,
> +	TPM2_CC_SEQUENCE_UPDATE         = 0x015C,
> +	TPM2_CC_UNSEAL		        = 0x015E,
> +	TPM2_CC_CONTEXT_LOAD	        = 0x0161,
> +	TPM2_CC_CONTEXT_SAVE	        = 0x0162,
> +	TPM2_CC_FLUSH_CONTEXT	        = 0x0165,
> +	TPM2_CC_VERIFY_SIGNATURE        = 0x0177,
> +	TPM2_CC_GET_CAPABILITY	        = 0x017A,
> +	TPM2_CC_GET_RANDOM	        = 0x017B,
> +	TPM2_CC_PCR_READ	        = 0x017E,
> +	TPM2_CC_PCR_EXTEND	        = 0x0182,
> +	TPM2_CC_EVENT_SEQUENCE_COMPLETE = 0x0185,
> +	TPM2_CC_HASH_SEQUENCE_START     = 0x0186,
> +	TPM2_CC_CREATE_LOADED           = 0x0191,
> +	TPM2_CC_LAST		        = 0x0193, /* Spec 1.36 */

Not a bad idea to have that comment.

>  };
>  
>  enum tpm2_permanent_handles {
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index 3acf4fd4e5a5..be0a9ebcd7d7 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -40,129 +40,95 @@ static struct tpm2_hash tpm2_hash_map[] = {
>  	{HASH_ALGO_SM3_256, TPM2_ALG_SM3_256},
>  };
>  
> -/*
> - * Array with one entry per ordinal defining the maximum amount
> - * of time the chip could take to return the result. The values
> - * of the SHORT, MEDIUM, and LONG durations are taken from the
> - * PC Client Profile (PTP) specification.
> - * LONG_LONG is for commands that generates keys which empirically
> - * takes longer time on some systems.
> +/**
> + * tpm2_ordinal_duration_index() - returns an index to the chip duration
> + * table (enum tpm_duration), that describes the maximum amount of
> + * time the chip could take to return the result for a  particular ordinal.
> + *
> + * The values of the MEDIUM, and LONG durations are taken
> + * from the PC Client Profile (PTP) specification (750, 2000 msec)
> + *
> + * LONG_LONG is for commands that generates keys which empirically takes
> + * a longer time on some systems.
> + *
> + * @ordinal: TPM command ordinal.
> + *
> + * Return: TPM_MEDIUM, TPM_LONG, TPM_LONG_LONG, and TPM_UNDEFINED.
>   */

You should read Documentation/doc-guide/kernel-doc.rst and fix this
comment.

> -static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
> -	TPM_UNDEFINED,		/* 11F */
> -	TPM_UNDEFINED,		/* 120 */
> -	TPM_LONG,		/* 121 */
> -	TPM_UNDEFINED,		/* 122 */
> -	TPM_UNDEFINED,		/* 123 */
> -	TPM_UNDEFINED,		/* 124 */
> -	TPM_UNDEFINED,		/* 125 */
> -	TPM_UNDEFINED,		/* 126 */
> -	TPM_UNDEFINED,		/* 127 */
> -	TPM_UNDEFINED,		/* 128 */
> -	TPM_LONG,		/* 129 */
> -	TPM_UNDEFINED,		/* 12a */
> -	TPM_UNDEFINED,		/* 12b */
> -	TPM_UNDEFINED,		/* 12c */
> -	TPM_UNDEFINED,		/* 12d */
> -	TPM_UNDEFINED,		/* 12e */
> -	TPM_UNDEFINED,		/* 12f */
> -	TPM_UNDEFINED,		/* 130 */
> -	TPM_LONG_LONG,		/* 131 */
> -	TPM_UNDEFINED,		/* 132 */
> -	TPM_UNDEFINED,		/* 133 */
> -	TPM_UNDEFINED,		/* 134 */
> -	TPM_UNDEFINED,		/* 135 */
> -	TPM_UNDEFINED,		/* 136 */
> -	TPM_UNDEFINED,		/* 137 */
> -	TPM_UNDEFINED,		/* 138 */
> -	TPM_UNDEFINED,		/* 139 */
> -	TPM_UNDEFINED,		/* 13a */
> -	TPM_UNDEFINED,		/* 13b */
> -	TPM_UNDEFINED,		/* 13c */
> -	TPM_UNDEFINED,		/* 13d */
> -	TPM_MEDIUM,		/* 13e */
> -	TPM_UNDEFINED,		/* 13f */
> -	TPM_UNDEFINED,		/* 140 */
> -	TPM_UNDEFINED,		/* 141 */
> -	TPM_UNDEFINED,		/* 142 */
> -	TPM_LONG,		/* 143 */
> -	TPM_MEDIUM,		/* 144 */
> -	TPM_UNDEFINED,		/* 145 */
> -	TPM_UNDEFINED,		/* 146 */
> -	TPM_UNDEFINED,		/* 147 */
> -	TPM_UNDEFINED,		/* 148 */
> -	TPM_UNDEFINED,		/* 149 */
> -	TPM_UNDEFINED,		/* 14a */
> -	TPM_UNDEFINED,		/* 14b */
> -	TPM_UNDEFINED,		/* 14c */
> -	TPM_UNDEFINED,		/* 14d */
> -	TPM_LONG,		/* 14e */
> -	TPM_UNDEFINED,		/* 14f */
> -	TPM_UNDEFINED,		/* 150 */
> -	TPM_UNDEFINED,		/* 151 */
> -	TPM_UNDEFINED,		/* 152 */
> -	TPM_LONG_LONG,		/* 153 */
> -	TPM_UNDEFINED,		/* 154 */
> -	TPM_UNDEFINED,		/* 155 */
> -	TPM_UNDEFINED,		/* 156 */
> -	TPM_UNDEFINED,		/* 157 */
> -	TPM_UNDEFINED,		/* 158 */
> -	TPM_UNDEFINED,		/* 159 */
> -	TPM_UNDEFINED,		/* 15a */
> -	TPM_UNDEFINED,		/* 15b */
> -	TPM_MEDIUM,		/* 15c */
> -	TPM_UNDEFINED,		/* 15d */
> -	TPM_UNDEFINED,		/* 15e */
> -	TPM_UNDEFINED,		/* 15f */
> -	TPM_UNDEFINED,		/* 160 */
> -	TPM_UNDEFINED,		/* 161 */
> -	TPM_UNDEFINED,		/* 162 */
> -	TPM_UNDEFINED,		/* 163 */
> -	TPM_UNDEFINED,		/* 164 */
> -	TPM_UNDEFINED,		/* 165 */
> -	TPM_UNDEFINED,		/* 166 */
> -	TPM_UNDEFINED,		/* 167 */
> -	TPM_UNDEFINED,		/* 168 */
> -	TPM_UNDEFINED,		/* 169 */
> -	TPM_UNDEFINED,		/* 16a */
> -	TPM_UNDEFINED,		/* 16b */
> -	TPM_UNDEFINED,		/* 16c */
> -	TPM_UNDEFINED,		/* 16d */
> -	TPM_UNDEFINED,		/* 16e */
> -	TPM_UNDEFINED,		/* 16f */
> -	TPM_UNDEFINED,		/* 170 */
> -	TPM_UNDEFINED,		/* 171 */
> -	TPM_UNDEFINED,		/* 172 */
> -	TPM_UNDEFINED,		/* 173 */
> -	TPM_UNDEFINED,		/* 174 */
> -	TPM_UNDEFINED,		/* 175 */
> -	TPM_UNDEFINED,		/* 176 */
> -	TPM_LONG,		/* 177 */
> -	TPM_UNDEFINED,		/* 178 */
> -	TPM_UNDEFINED,		/* 179 */
> -	TPM_MEDIUM,		/* 17a */
> -	TPM_LONG,		/* 17b */
> -	TPM_UNDEFINED,		/* 17c */
> -	TPM_UNDEFINED,		/* 17d */
> -	TPM_UNDEFINED,		/* 17e */
> -	TPM_UNDEFINED,		/* 17f */
> -	TPM_UNDEFINED,		/* 180 */
> -	TPM_UNDEFINED,		/* 181 */
> -	TPM_MEDIUM,		/* 182 */
> -	TPM_UNDEFINED,		/* 183 */
> -	TPM_UNDEFINED,		/* 184 */
> -	TPM_MEDIUM,		/* 185 */
> -	TPM_MEDIUM,		/* 186 */
> -	TPM_UNDEFINED,		/* 187 */
> -	TPM_UNDEFINED,		/* 188 */
> -	TPM_UNDEFINED,		/* 189 */
> -	TPM_UNDEFINED,		/* 18a */
> -	TPM_UNDEFINED,		/* 18b */
> -	TPM_UNDEFINED,		/* 18c */
> -	TPM_UNDEFINED,		/* 18d */
> -	TPM_UNDEFINED,		/* 18e */
> -	TPM_UNDEFINED		/* 18f */
> -};
> +static u8 tpm2_ordinal_duration_index(u32 ordinal)
> +{
> +	switch (ordinal) {
> +	/* Startup */
> +	case TPM2_CC_STARTUP:                 /* 144 */
> +		return TPM_MEDIUM;
> +
> +	case TPM2_CC_SELF_TEST:               /* 143 */
> +		return TPM_LONG;
> +
> +	case TPM2_CC_GET_RANDOM:              /* 17B */
> +		return TPM_LONG;
> +
> +	case TPM2_CC_SEQUENCE_UPDATE:         /* 15C */
> +		return TPM_MEDIUM;
> +	case TPM2_CC_SEQUENCE_COMPLETE:       /* 13E */
> +		return TPM_MEDIUM;
> +	case TPM2_CC_EVENT_SEQUENCE_COMPLETE: /* 185 */
> +		return TPM_MEDIUM;
> +	case TPM2_CC_HASH_SEQUENCE_START:     /* 186 */
> +		return TPM_MEDIUM;
> +
> +	case TPM2_CC_VERIFY_SIGNATURE:        /* 177 */
> +		return TPM_LONG;
> +
> +	case TPM2_CC_PCR_EXTEND:              /* 182 */
> +		return TPM_MEDIUM;
> +
> +	case TPM2_CC_HIERARCHY_CONTROL:       /* 121 */
> +		return TPM_LONG;
> +	case TPM2_CC_HIERARCHY_CHANGE_AUTH:   /* 129 */
> +		return TPM_LONG;
> +
> +	case TPM2_CC_GET_CAPABILITY:          /* 17A */
> +		return TPM_MEDIUM;
> +
> +	case TPM2_CC_NV_READ:                 /* 14E */
> +		return TPM_LONG;
> +
> +	case TPM2_CC_CREATE_PRIMARY:          /* 131 */
> +		return TPM_LONG_LONG;
> +	case TPM2_CC_CREATE:                  /* 153 */
> +		return TPM_LONG_LONG;
> +	case TPM2_CC_CREATE_LOADED:           /* 191 */
> +		return TPM_LONG_LONG;
> +
> +	default:
> +		return TPM_UNDEFINED;
> +	}
> +}
> +
> +/**
> + * tpm2_calc_ordinal_duration() - returns the maximum amount of time
> + * the chip could take to return the result for a particular ordinal
> + * in jiffies.
> + *
> + * @chip:    TPM chip to use.
> + * @ordinal: TPM command ordinal.
> + *
> + * Return: A maxiaml duration time for an ordinal in jiffies.
> + */

Ditto.

The short summary could be just like:

  tpm2_calc_ordinal_duration() - calculate the maximum command duration

And then move everything there to the long description.

> +unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
> +{
> +	unsigned int index;
> +
> +	index = tpm2_ordinal_duration_index(ordinal);
> +
> +	if (index != TPM_UNDEFINED)
> +		return chip->duration[index];
> +	else
> +		return msecs_to_jiffies(TPM2_DURATION_DEFAULT);
> +}
> +EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration);
> +
>  
>  struct tpm2_pcr_read_out {
>  	__be32	update_cnt;
> @@ -748,32 +714,6 @@ void tpm2_shutdown(struct tpm_chip *chip, u16
> shutdown_type)
>  	tpm_buf_destroy(&buf);
>  }
>  
> -/*
> - * tpm2_calc_ordinal_duration() - maximum duration for a command
> - *
> - * @chip:	TPM chip to use.
> - * @ordinal:	command code number.
> - *
> - * Return: maximum duration for a command
> - */

This is almost correct but there should not be an empty line between the
parameters and the short summary.

> -unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
> -{
> -	int index = TPM_UNDEFINED;
> -	int duration = 0;
> -
> -	if (ordinal >= TPM2_CC_FIRST && ordinal <= TPM2_CC_LAST)
> -		index = tpm2_ordinal_duration[ordinal - TPM2_CC_FIRST];
> -
> -	if (index != TPM_UNDEFINED)
> -		duration = chip->duration[index];
> -
> -	if (duration <= 0)
> -		duration = msecs_to_jiffies(TPM2_DURATION_DEFAULT);
> -
> -	return duration;
> -}
> -EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration);
> -
>  /**
>   * tpm2_do_selftest() - ensure that all self tests have passed
>   *

/Jarkko