From mboxrd@z Thu Jan 1 00:00:00 1970 From: msuchanek Subject: Re: [RFT PATCH] tpm: ibmvtpm: simplify crq initialization and document crq format Date: Fri, 18 Aug 2017 00:21:45 +0200 Message-ID: <20170818002145.62fb72eb@naga> References: <20170729072433.13194-1-sz.lin@moxa.com> <20170224193516.9342-1-msuchanek@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170224193516.9342-1-msuchanek@suse.de> Sender: linux-kernel-owner@vger.kernel.org To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Ashley Lai , Peter Huewe , Marcel Selhorst , Jarkko Sakkinen , Jason Gunthorpe , linuxppc-dev@lists.ozlabs.org, tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Cc: tpmdd@selhorst.ne List-Id: tpmdd-devel@lists.sourceforge.net ping? On Fri, 24 Feb 2017 20:35:16 +0100 Michal Suchanek 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 > Reviewed-by: Jarkko Sakkinen > --- > 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);