From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AC40C72 for ; Thu, 2 Sep 2021 18:22:29 +0000 (UTC) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4H0q434mNJz67N2l; Fri, 3 Sep 2021 02:20:51 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Thu, 2 Sep 2021 20:22:26 +0200 Received: from localhost (10.52.127.69) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Thu, 2 Sep 2021 19:22:25 +0100 Date: Thu, 2 Sep 2021 19:22:27 +0100 From: Jonathan Cameron To: Dan Williams CC: , Ben Widawsky , , , , Subject: Re: [PATCH v3 21/28] cxl/pmem: Translate NVDIMM label commands to CXL label commands Message-ID: <20210902192227.00006dc8@Huawei.com> In-Reply-To: <162982123813.1124374.3721946437291753388.stgit@dwillia2-desk3.amr.corp.intel.com> References: <162982112370.1124374.2020303588105269226.stgit@dwillia2-desk3.amr.corp.intel.com> <162982123813.1124374.3721946437291753388.stgit@dwillia2-desk3.amr.corp.intel.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; i686-w64-mingw32) Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.52.127.69] X-ClientProxiedBy: lhreml715-chm.china.huawei.com (10.201.108.66) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected On Tue, 24 Aug 2021 09:07:18 -0700 Dan Williams wrote: > The LIBNVDIMM IOCTL UAPI calls back to the nvdimm-bus-provider to > translate the Linux command payload to the device native command format. > The LIBNVDIMM commands get-config-size, get-config-data, and > set-config-data, map to the CXL memory device commands device-identify, > get-lsa, and set-lsa. Recall that the label-storage-area (LSA) on an > NVDIMM device arranges for the provisioning of namespaces. Additionally > for CXL the LSA is used for provisioning regions as well. > > The data from device-identify is already cached in the 'struct cxl_mem' > instance associated with @cxl_nvd, so that payload return is simply > crafted and no CXL command is issued. The conversion for get-lsa is > straightforward, but the conversion for set-lsa requires an allocation > to append the set-lsa header in front of the payload. > > Acked-by: Ben Widawsky > Signed-off-by: Dan Williams Minor query inline. > --- > drivers/cxl/pmem.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 117 insertions(+), 4 deletions(-) > > diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c > index 469b984176a2..6cc76302c8f8 100644 > --- a/drivers/cxl/pmem.c > +++ b/drivers/cxl/pmem.c > @@ -52,10 +52,10 @@ static int cxl_nvdimm_probe(struct device *dev) > +static int cxl_pmem_get_config_size(struct cxl_mem *cxlm, > + struct nd_cmd_get_config_size *cmd, > + unsigned int buf_len, int *cmd_rc) > +{ > + if (sizeof(*cmd) > buf_len) > + return -EINVAL; > + > + *cmd = (struct nd_cmd_get_config_size) { > + .config_size = cxlm->lsa_size, > + .max_xfer = cxlm->payload_size, > + }; > + *cmd_rc = 0; > + > + return 0; > +} > + > +static int cxl_pmem_get_config_data(struct cxl_mem *cxlm, > + struct nd_cmd_get_config_data_hdr *cmd, > + unsigned int buf_len, int *cmd_rc) > +{ > + struct cxl_mbox_get_lsa { > + u32 offset; > + u32 length; > + } get_lsa; > + int rc; > + > + if (sizeof(*cmd) > buf_len) > + return -EINVAL; > + if (struct_size(cmd, out_buf, cmd->in_length) > buf_len) > + return -EINVAL; > + > + get_lsa = (struct cxl_mbox_get_lsa) { > + .offset = cmd->in_offset, > + .length = cmd->in_length, > + }; > + > + rc = cxl_mem_mbox_send_cmd(cxlm, CXL_MBOX_OP_GET_LSA, &get_lsa, > + sizeof(get_lsa), cmd->out_buf, > + cmd->in_length); > + cmd->status = 0; > + *cmd_rc = 0; > + > + return rc; > +} > + > +static int cxl_pmem_set_config_data(struct cxl_mem *cxlm, > + struct nd_cmd_set_config_hdr *cmd, > + unsigned int buf_len, int *cmd_rc) > +{ > + struct cxl_mbox_set_lsa { > + u32 offset; > + u32 reserved; > + u8 data[]; > + } *set_lsa; > + int rc; > + > + if (sizeof(*cmd) > buf_len) > + return -EINVAL; > + > + /* 4-byte status follows the input data in the payload */ > + if (struct_size(cmd, in_buf, cmd->in_length) + 4 > buf_len) > + return -EINVAL; > + > + set_lsa = > + kvzalloc(struct_size(set_lsa, data, cmd->in_length), GFP_KERNEL); > + if (!set_lsa) > + return -ENOMEM; > + > + *set_lsa = (struct cxl_mbox_set_lsa) { > + .offset = cmd->in_offset, > + }; > + memcpy(set_lsa->data, cmd->in_buf, cmd->in_length); > + > + rc = cxl_mem_mbox_send_cmd(cxlm, CXL_MBOX_OP_SET_LSA, set_lsa, > + struct_size(set_lsa, data, cmd->in_length), > + NULL, 0); > + > + /* set "firmware" status */ > + *(u32 *) &cmd->in_buf[cmd->in_length] = 0; Are we guaranteed this is aligned? Not 'locally' obvious so maybe a comment? > + *cmd_rc = 0; > + kvfree(set_lsa); > + > + return rc; > +} > +