linux-kernel - Re: [PATCH v5 05/10] tpm, tpm_tis: Store result of interrupt capability query

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Date:   Thu, 16 Jun 2022 00:07:41 +0200
From:   Lino Sanfilippo <LinoSanfilippo@....de>
To:     Jarkko Sakkinen <jarkko@...nel.org>
Cc:     peterhuewe@....de, jgg@...pe.ca, stefanb@...ux.vnet.ibm.com,
        linux@...ewoehner.de, linux-integrity@...r.kernel.org,
        linux-kernel@...r.kernel.org, l.sanfilippo@...bus.com,
        lukas@...ner.de, p.rosenberger@...bus.com
Subject: Re: [PATCH v5 05/10] tpm, tpm_tis: Store result of interrupt
 capability query

On 15.06.22 at 20:18, Jarkko Sakkinen wrote:
> On Fri, Jun 10, 2022 at 01:08:41PM +0200, LinoSanfilippo@....de wrote:
>> From: Lino Sanfilippo <l.sanfilippo@...bus.com>
>>
>> According to the TPM Interface Specification (TIS) support for "stsValid"
>> and "commandReady" interrupts is only optional.
>> This has to be taken into account when handling the interrupts in functions
>> like wait_for_tpm_stat(). So query the set of supported interrupts and
>> store it in a global variable so that it can be accessed later.
>>
>> Signed-off-by: Lino Sanfilippo <l.sanfilippo@...bus.com>
>> ---
>>  drivers/char/tpm/tpm_tis_core.c | 73 +++++++++++++++++----------------
>>  drivers/char/tpm/tpm_tis_core.h |  1 +
>>  2 files changed, 38 insertions(+), 36 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
>> index 718525fcadc0..2f03fefa1706 100644
>> --- a/drivers/char/tpm/tpm_tis_core.c
>> +++ b/drivers/char/tpm/tpm_tis_core.c
>> @@ -1007,8 +1007,39 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>  	if (rc < 0)
>>  		goto out_err;
>>
>> -	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
>> -		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
>> +	/* Figure out the capabilities */
>> +	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
>> +	if (rc < 0)
>> +		goto out_err;
>> +
>> +	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
>> +		intfcaps);
>> +	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
>> +		dev_dbg(dev, "\tBurst Count Static\n");
>> +	if (intfcaps & TPM_INTF_CMD_READY_INT) {
>> +		intmask |= TPM_INTF_CMD_READY_INT;
>> +		dev_dbg(dev, "\tCommand Ready Int Support\n");
>> +	}
>> +	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
>> +		dev_dbg(dev, "\tInterrupt Edge Falling\n");
>> +	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
>> +		dev_dbg(dev, "\tInterrupt Edge Rising\n");
>> +	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
>> +		dev_dbg(dev, "\tInterrupt Level Low\n");
>> +	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
>> +		dev_dbg(dev, "\tInterrupt Level High\n");
>> +	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
>> +		intmask |= TPM_INTF_LOCALITY_CHANGE_INT;
>> +		dev_dbg(dev, "\tLocality Change Int Support\n");
>> +	if (intfcaps & TPM_INTF_STS_VALID_INT) {
>> +		intmask |= TPM_INTF_STS_VALID_INT;
>> +		dev_dbg(dev, "\tSts Valid Int Support\n");
>> +	}
>> +	if (intfcaps & TPM_INTF_DATA_AVAIL_INT) {
>> +		intmask |= TPM_INTF_DATA_AVAIL_INT;
>> +		dev_dbg(dev, "\tData Avail Int Support\n");
>> +	}
>> +
>>  	intmask &= ~TPM_GLOBAL_INT_ENABLE;
>>
>>  	rc = request_locality(chip, 0);
>> @@ -1042,32 +1073,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>  		goto out_err;
>>  	}
>>
>> -	/* Figure out the capabilities */
>> -	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
>> -	if (rc < 0)
>> -		goto out_err;
>> -
>> -	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
>> -		intfcaps);
>> -	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
>> -		dev_dbg(dev, "\tBurst Count Static\n");
>> -	if (intfcaps & TPM_INTF_CMD_READY_INT)
>> -		dev_dbg(dev, "\tCommand Ready Int Support\n");
>> -	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
>> -		dev_dbg(dev, "\tInterrupt Edge Falling\n");
>> -	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
>> -		dev_dbg(dev, "\tInterrupt Edge Rising\n");
>> -	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
>> -		dev_dbg(dev, "\tInterrupt Level Low\n");
>> -	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
>> -		dev_dbg(dev, "\tInterrupt Level High\n");
>> -	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
>> -		dev_dbg(dev, "\tLocality Change Int Support\n");
>> -	if (intfcaps & TPM_INTF_STS_VALID_INT)
>> -		dev_dbg(dev, "\tSts Valid Int Support\n");
>> -	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
>> -		dev_dbg(dev, "\tData Avail Int Support\n");
>> -
>>  	/* INTERRUPT Setup */
>>  	init_waitqueue_head(&priv->read_queue);
>>  	init_waitqueue_head(&priv->int_queue);
>> @@ -1098,7 +1103,9 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>  		else
>>  			tpm_tis_probe_irq(chip, intmask);
>>
>> -		if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
>> +		if (chip->flags & TPM_CHIP_FLAG_IRQ) {
>> +			priv->irqs_in_use = intmask;
>> +		} else {
>>  			dev_err(&chip->dev, FW_BUG
>>  					"TPM interrupt not working, polling instead\n");
>>
>> @@ -1145,13 +1152,7 @@ static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
>>  	if (rc < 0)
>>  		goto out;
>>
>> -	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
>> -	if (rc < 0)
>> -		goto out;
>> -
>> -	intmask |= TPM_INTF_CMD_READY_INT
>> -	    | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
>> -	    | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
>> +	intmask = priv->irqs_in_use | TPM_GLOBAL_INT_ENABLE;
>>
>>  	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
>>
>> diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h
>> index 0f29d0b68c3e..8e02faa4079d 100644
>> --- a/drivers/char/tpm/tpm_tis_core.h
>> +++ b/drivers/char/tpm/tpm_tis_core.h
>> @@ -96,6 +96,7 @@ struct tpm_tis_data {
>>  	u16 manufacturer_id;
>>  	int locality;
>>  	int irq;
>> +	unsigned int irqs_in_use;
>>  	unsigned long irqtest_flags;
>>  	unsigned long flags;
>>  	void __iomem *ilb_base_addr;
>> --
>> 2.36.1
>>
>
> int_mask would be imho a better name.
>
> Can you squash this and the following patch? It's good to slice in
> small patches but here I think it would make sense to tie the field
> to use case, in order for it to make sense.
>

Sure, will do so.

Regards,
Lino