On Tue, 24 Aug 2021 09:07:18 -0700 Dan Williams <[email protected]> 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 <[email protected]> > Signed-off-by: Dan Williams <[email protected]> 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; > +} > +
