Re: [RFT PATCH] tpm: ibmvtpm: simplify crq initialization and document crq format

[Jarkko Sakkinen]

Ugh. I'll apply this. My apologies.

/Jarkko

On Fri, Aug 18, 2017 at 12:21:45AM +0200, msuchanek wrote:
> ping?
> 
> On Fri, 24 Feb 2017 20:35:16 +0100
> Michal Suchanek <msuchanek@xxxxxxx> wrote:
> 
> > The crq is passed in registers and is the same on BE and LE hosts.
> > However, current implementation allocates a structure on-stack to
> > represent the crq, initializes the members swapping them to BE, and
> > loads the structure swapping it from BE. This is pointless and causes
> > GCC warnings about ununitialized members. Get rid of the structure and
> > the warnings.
> > 
> > Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> > ---
> > v2
> > 
> > fix typos and spelling in comments
> > ---
> >  drivers/char/tpm/tpm_ibmvtpm.c | 96
> > ++++++++++++++++++++++++++---------------- 1 file changed, 60
> > insertions(+), 36 deletions(-)
> > 
> > diff --git a/drivers/char/tpm/tpm_ibmvtpm.c
> > b/drivers/char/tpm/tpm_ibmvtpm.c index 1b9d61ffe991..89027339d55f
> > 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c
> > +++ b/drivers/char/tpm/tpm_ibmvtpm.c
> > @@ -39,19 +39,63 @@ static struct vio_device_id
> > tpm_ibmvtpm_device_table[] = { MODULE_DEVICE_TABLE(vio,
> > tpm_ibmvtpm_device_table); 
> >  /**
> > + *
> > + * ibmvtpm_send_crq_word - Send a CRQ request
> > + * @vdev:	vio device struct
> > + * @w1:		pre-constructed first word of tpm crq (second
> > word is reserved)
> > + *
> > + * Return:
> > + *	0 - Success
> > + *	Non-zero - Failure
> > + */
> > +static int ibmvtpm_send_crq_word(struct vio_dev *vdev, u64 w1)
> > +{
> > +	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address,
> > w1, 0); +}
> > +
> > +/**
> > + *
> >   * ibmvtpm_send_crq - Send a CRQ request
> >   *
> >   * @vdev:	vio device struct
> > - * @w1:		first word
> > - * @w2:		second word
> > + * @valid:	Valid field
> > + * @msg:	Type field
> > + * @len:	Length field
> > + * @data:	Data field
> > + *
> > + * The ibmvtpm crq is defined as follows:
> > + *
> > + * Byte  |   0   |   1   |   2   |   3   |   4   |   5   |   6   |
> > 7
> > + *
> > -----------------------------------------------------------------------
> > + * Word0 | Valid | Type  |     Length    |              Data
> > + *
> > -----------------------------------------------------------------------
> > + * Word1 |                Reserved
> > + *
> > -----------------------------------------------------------------------
> > + *
> > + * Which matches the following structure (on bigendian host):
> > + *
> > + * struct ibmvtpm_crq {
> > + *         u8 valid;
> > + *         u8 msg;
> > + *         __be16 len;
> > + *         __be32 data;
> > + *         __be64 reserved;
> > + * } __attribute__((packed, aligned(8)));
> > + *
> > + * However, the value is passed in a register so just compute the
> > numeric value
> > + * to load into the register avoiding byteswap altogether. Endian
> > only affects
> > + * memory loads and stores - registers are internally represented
> > the same. *
> >   * Return:
> > - *	0 -Sucess
> > + *	0 (H_SUCCESS) - Success
> >   *	Non-zero - Failure
> >   */
> > -static int ibmvtpm_send_crq(struct vio_dev *vdev, u64 w1, u64 w2)
> > +static int ibmvtpm_send_crq(struct vio_dev *vdev,
> > +		u8 valid, u8 msg, u16 len, u32 data)
> >  {
> > -	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address,
> > w1, w2);
> > +	u64 w1 = ((u64)valid << 56) | ((u64)msg << 48) | ((u64)len
> > << 32) |
> > +		(u64)data;
> > +	return ibmvtpm_send_crq_word(vdev, w1);
> >  }
> >  
> >  /**
> > @@ -109,8 +153,6 @@ static int tpm_ibmvtpm_recv(struct tpm_chip
> > *chip, u8 *buf, size_t count) static int tpm_ibmvtpm_send(struct
> > tpm_chip *chip, u8 *buf, size_t count) {
> >  	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
> > -	struct ibmvtpm_crq crq;
> > -	__be64 *word = (__be64 *)&crq;
> >  	int rc, sig;
> >  
> >  	if (!ibmvtpm->rtce_buf) {
> > @@ -137,10 +179,6 @@ static int tpm_ibmvtpm_send(struct tpm_chip
> > *chip, u8 *buf, size_t count) spin_lock(&ibmvtpm->rtce_lock);
> >  	ibmvtpm->res_len = 0;
> >  	memcpy((void *)ibmvtpm->rtce_buf, (void *)buf, count);
> > -	crq.valid = (u8)IBMVTPM_VALID_CMD;
> > -	crq.msg = (u8)VTPM_TPM_COMMAND;
> > -	crq.len = cpu_to_be16(count);
> > -	crq.data = cpu_to_be32(ibmvtpm->rtce_dma_handle);
> >  
> >  	/*
> >  	 * set the processing flag before the Hcall, since we may
> > get the @@ -148,8 +186,9 @@ static int tpm_ibmvtpm_send(struct
> > tpm_chip *chip, u8 *buf, size_t count) */
> >  	ibmvtpm->tpm_processing_cmd = true;
> >  
> > -	rc = ibmvtpm_send_crq(ibmvtpm->vdev, be64_to_cpu(word[0]),
> > -			      be64_to_cpu(word[1]));
> > +	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
> > +			IBMVTPM_VALID_CMD, VTPM_TPM_COMMAND,
> > +			count, ibmvtpm->rtce_dma_handle);
> >  	if (rc != H_SUCCESS) {
> >  		dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed
> > rc=%d\n", rc); rc = 0;
> > @@ -182,15 +221,10 @@ static u8 tpm_ibmvtpm_status(struct tpm_chip
> > *chip) */
> >  static int ibmvtpm_crq_get_rtce_size(struct ibmvtpm_dev *ibmvtpm)
> >  {
> > -	struct ibmvtpm_crq crq;
> > -	u64 *buf = (u64 *) &crq;
> >  	int rc;
> >  
> > -	crq.valid = (u8)IBMVTPM_VALID_CMD;
> > -	crq.msg = (u8)VTPM_GET_RTCE_BUFFER_SIZE;
> > -
> > -	rc = ibmvtpm_send_crq(ibmvtpm->vdev, cpu_to_be64(buf[0]),
> > -			      cpu_to_be64(buf[1]));
> > +	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
> > +			IBMVTPM_VALID_CMD,
> > VTPM_GET_RTCE_BUFFER_SIZE, 0, 0); if (rc != H_SUCCESS)
> >  		dev_err(ibmvtpm->dev,
> >  			"ibmvtpm_crq_get_rtce_size failed rc=%d\n",
> > rc); @@ -210,15 +244,10 @@ static int
> > ibmvtpm_crq_get_rtce_size(struct ibmvtpm_dev *ibmvtpm) */
> >  static int ibmvtpm_crq_get_version(struct ibmvtpm_dev *ibmvtpm)
> >  {
> > -	struct ibmvtpm_crq crq;
> > -	u64 *buf = (u64 *) &crq;
> >  	int rc;
> >  
> > -	crq.valid = (u8)IBMVTPM_VALID_CMD;
> > -	crq.msg = (u8)VTPM_GET_VERSION;
> > -
> > -	rc = ibmvtpm_send_crq(ibmvtpm->vdev, cpu_to_be64(buf[0]),
> > -			      cpu_to_be64(buf[1]));
> > +	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
> > +			IBMVTPM_VALID_CMD, VTPM_GET_VERSION, 0, 0);
> >  	if (rc != H_SUCCESS)
> >  		dev_err(ibmvtpm->dev,
> >  			"ibmvtpm_crq_get_version failed rc=%d\n",
> > rc); @@ -238,7 +267,7 @@ static int
> > ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm) {
> >  	int rc;
> >  
> > -	rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_COMP_CMD, 0);
> > +	rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_COMP_CMD);
> >  	if (rc != H_SUCCESS)
> >  		dev_err(ibmvtpm->dev,
> >  			"ibmvtpm_crq_send_init_complete failed
> > rc=%d\n", rc); @@ -258,7 +287,7 @@ static int
> > ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm) {
> >  	int rc;
> >  
> > -	rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_CMD, 0);
> > +	rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_CMD);
> >  	if (rc != H_SUCCESS)
> >  		dev_err(ibmvtpm->dev,
> >  			"ibmvtpm_crq_send_init failed rc=%d\n", rc);
> > @@ -336,15 +365,10 @@ static int tpm_ibmvtpm_suspend(struct device
> > *dev) {
> >  	struct tpm_chip *chip = dev_get_drvdata(dev);
> >  	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
> > -	struct ibmvtpm_crq crq;
> > -	u64 *buf = (u64 *) &crq;
> >  	int rc = 0;
> >  
> > -	crq.valid = (u8)IBMVTPM_VALID_CMD;
> > -	crq.msg = (u8)VTPM_PREPARE_TO_SUSPEND;
> > -
> > -	rc = ibmvtpm_send_crq(ibmvtpm->vdev, cpu_to_be64(buf[0]),
> > -			      cpu_to_be64(buf[1]));
> > +	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
> > +			IBMVTPM_VALID_CMD, VTPM_PREPARE_TO_SUSPEND,
> > 0, 0); if (rc != H_SUCCESS)
> >  		dev_err(ibmvtpm->dev,
> >  			"tpm_ibmvtpm_suspend failed rc=%d\n", rc);
>