From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932922AbdBHNQx (ORCPT ); Wed, 8 Feb 2017 08:16:53 -0500 Received: from mga11.intel.com ([192.55.52.93]:61712 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754447AbdBHNQt (ORCPT ); Wed, 8 Feb 2017 08:16:49 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,346,1477983600"; d="scan'208";a="41465749" Date: Wed, 8 Feb 2017 15:16:43 +0200 From: Jarkko Sakkinen To: Michal Suchanek Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Ashley Lai , Peter Huewe , Marcel Selhorst , Jason Gunthorpe , linuxppc-dev@lists.ozlabs.org, tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tpm: ibmvtpm: simplify crq initialization and document crq format Message-ID: <20170208131643.yb6ceb7tigxtu3b3@intel.com> References: <20170131141734.28534-1-msuchanek@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170131141734.28534-1-msuchanek@suse.de> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 31, 2017 at 03:17:34PM +0100, Michal Suchanek wrote: > > The crq is passed in registers so is the same on BE and LE hosts. 's/ so// ' ? > 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 > --- > drivers/char/tpm/tpm_ibmvtpm.c | 92 +++++++++++++++++++++++++----------------- > 1 file changed, 56 insertions(+), 36 deletions(-) > > diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c > index 946025a7413b..b6402b1b76fe 100644 > --- a/drivers/char/tpm/tpm_ibmvtpm.c > +++ b/drivers/char/tpm/tpm_ibmvtpm.c > @@ -39,18 +39,58 @@ 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 tmp crq (second word is reserved) > + * > + * Return value: > + * 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 > + * > + * 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 registar avoiding byteswap altogether. Endian only affects > + * memory loads and stores - registers are internally represented the same. > * > * Return value: > - * 0 -Sucess > + * 0 (H_SUCCESS) - Success > * Non-zero - Failure hould be "Return:" [1] [1] http://lxr.free-electrons.com/source/Documentation/kernel-doc-nano-HOWTO.txt > */ > -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); > } > > /** > @@ -106,8 +146,6 @@ 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) { > @@ -134,10 +172,6 @@ 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 > @@ -145,8 +179,9 @@ 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; > @@ -178,15 +213,10 @@ 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); > @@ -205,15 +235,10 @@ 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); > @@ -233,7 +258,7 @@ 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); > @@ -253,7 +278,7 @@ 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); > @@ -332,15 +357,10 @@ 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); > -- > 2.10.2 > Otherwise, I do not see any issues but can somebody test this? I cannot and I rather not merge it before it is peer tested. Reviewed-by: Jarkko Sakkinen /Jarkko