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Date:   Wed, 15 Jun 2022 21:18:01 +0300
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     LinoSanfilippo@gmx.de
Cc:     peterhuewe@gmx.de, jgg@ziepe.ca, stefanb@linux.vnet.ibm.com,
        linux@mniewoehner.de, linux-integrity@vger.kernel.org,
        linux-kernel@vger.kernel.org, l.sanfilippo@kunbus.com,
        lukas@wunner.de, p.rosenberger@kunbus.com
Subject: Re: [PATCH v5 05/10] tpm, tpm_tis: Store result of interrupt
 capability query
Message-ID: <YqoiWdwcds6AZgoO@iki.fi>
References: <20220610110846.8307-1-LinoSanfilippo@gmx.de>
 <20220610110846.8307-6-LinoSanfilippo@gmx.de>
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In-Reply-To: <20220610110846.8307-6-LinoSanfilippo@gmx.de>
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On Fri, Jun 10, 2022 at 01:08:41PM +0200, LinoSanfilippo@gmx.de wrote:
> From: Lino Sanfilippo <l.sanfilippo@kunbus.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@kunbus.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.

BR, Jarkko