On Tue, 17 Jun 2025 18:09:38 +0530 Neeraj Kumar <[email protected]> wrote:
> Added exported cxl_create_pmem_region routine to create cxl pmem region For function names always add () after and drop 'function/routine' etc. Ends up shorter and easier to read. > from LSA parsed cxl region information. > Inspirition for the function is taken from ndctl device attribute > (_store) call. It allocates cxlr and fills information parsed from LSA > and calls device_add(&cxlr->dev) to initiates further region creation > porbes Spell check. > > Signed-off-by: Neeraj Kumar <[email protected]> > --- > drivers/cxl/core/port.c | 6 ++ > drivers/cxl/core/region.c | 208 ++++++++++++++++++++++++++++++++++++++ > drivers/cxl/cxl.h | 11 ++ > 3 files changed, 225 insertions(+) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index b98b1ccffd1c..8990e3c3474d 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -2522,6 +2522,214 @@ static ssize_t create_ram_region_show(struct device > *dev, > return __create_region_show(to_cxl_root_decoder(dev), buf); > } > > +static ssize_t update_region_size(struct cxl_region *cxlr, u64 val) > +{ > + int rc; > + > + rc = down_write_killable(&cxl_region_rwsem); ACQUIRE() as mentioned below. > + if (rc) > + return rc; > + > + if (val) > + rc = alloc_hpa(cxlr, val); > + else > + rc = free_hpa(cxlr); > + up_write(&cxl_region_rwsem); > + > + if (rc) > + return rc; return rc; > + > + return 0; > +} > + > +static ssize_t update_region_dpa_size(struct cxl_region *cxlr, > + struct cxl_decoder *cxld, > + unsigned long long size) > +{ > + int rc; > + struct cxl_endpoint_decoder *cxled = > + to_cxl_endpoint_decoder(&cxld->dev); > + > + if (!IS_ALIGNED(size, SZ_256M)) > + return -EINVAL; > + > + rc = cxl_dpa_free(cxled); > + if (rc) > + return rc; > + > + if (size == 0) > + return 0; > + > + rc = cxl_dpa_alloc(cxled, size); return cxl_dpa_alloc() Unless something more is getting added here in later patches in which case you can ignore this comment. > + if (rc) > + return rc; > + > + return 0; > +} > + > +static ssize_t update_region_dpa_mode(struct cxl_region *cxlr, > + struct cxl_decoder *cxld) > +{ > + int rc; > + struct cxl_endpoint_decoder *cxled = > + to_cxl_endpoint_decoder(&cxld->dev); Maybe don't bother with local variable and just put this below as the parameter. > + > + rc = cxl_dpa_set_mode(cxled, CXL_DECODER_PMEM); return cxl_dpa_set_mode() > + if (rc) > + return rc; > + > + return 0; > +} > + > +static size_t attach_region_target(struct cxl_region *cxlr, > + struct cxl_decoder *cxld, int pos) > +{ > + int rc; > + struct cxl_endpoint_decoder *cxled = > + to_cxl_endpoint_decoder(&cxld->dev); > + > + rc = attach_target(cxlr, cxled, pos, TASK_INTERRUPTIBLE); > + No blank line here > + if (rc < 0) Can it ever be > 0 ? If not, return attach_target() should be fine. > + return rc; > + > + return 0; > +} > + > +static ssize_t commit_region(struct cxl_region *cxlr) > +{ > + struct cxl_region_params *p = &cxlr->params; > + ssize_t rc; > + > + rc = down_write_killable(&cxl_region_rwsem); Maybe look at Dan's new ACQUIRE() series. The last patch in there is targeting code similar to this. > + if (rc) > + return rc; > + > + /* Already in the requested state? */ > + if (p->state >= CXL_CONFIG_COMMIT) > + goto out; > + > + /* Not ready to commit? */ > + if (p->state < CXL_CONFIG_ACTIVE) { > + rc = -ENXIO; > + goto out; > + } > + > + /* > + * Invalidate caches before region setup to drop any speculative > + * consumption of this address space > + */ > + rc = cxl_region_invalidate_memregion(cxlr); > + if (rc) > + goto out; > + > + rc = cxl_region_decode_commit(cxlr); > + if (rc == 0) With AQUIRE() stuff you can just do if (rc) return rc; here > + p->state = CXL_CONFIG_COMMIT; > +out: > + up_write(&cxl_region_rwsem); > + if (rc) > + return rc; > + return 0; > +} > + > +static struct cxl_region * > +devm_cxl_pmem_add_region(struct cxl_root_decoder *cxlrd, > + struct cxl_decoder *cxld, > + struct cxl_pmem_region_params *params, int id, > + enum cxl_decoder_mode mode, enum cxl_decoder_type type) > +{ > + struct cxl_port *port; > + struct cxl_region *cxlr; > + struct cxl_region_params *p; > + struct device *dev; > + int rc; > + > + if (!cxlrd) > + return ERR_PTR(-EINVAL); For a check like this, add a comment on why it might be NULL. If it can't be, then drop the check. > + > + port = to_cxl_port(cxlrd->cxlsd.cxld.dev.parent); Maybe add a comment on which port this actually is. These long indirections can make that hard to figure out! > + > + cxlr = cxl_region_alloc(cxlrd, id); > + if (IS_ERR(cxlr)) > + return cxlr; > + cxlr->mode = mode; > + cxlr->type = type; > + > + dev = &cxlr->dev; > + rc = dev_set_name(dev, "region%d", id); > + if (rc) > + goto err; > + > + p = &cxlr->params; > + p->uuid = params->uuid; > + p->interleave_ways = params->nlabel; > + p->interleave_granularity = params->ig; > + > + /* Update region size */ > + if (update_region_size(cxlr, params->rawsize)) > + goto err; > + > + /* Flush cxl wq */ Much more useful to say 'why' you are flushing it. It's obvious from the code that you are. > + cxl_wq_flush(); > + > + /* Clear DPA Size */ I'd look at all these comments and where they are obvious, drop the comment and let the code speak for itself. > + if (update_region_dpa_size(cxlr, cxld, 0)) > + goto err; > + > + /* Update DPA mode */ > + if (update_region_dpa_mode(cxlr, cxld)) > + goto err; > + > + /* Update DPA Size */ > + if (update_region_dpa_size(cxlr, cxld, params->rawsize)) > + goto err; > + > + /* Attach region targets */ It's attaching just one by the look of it. I'd just drop the comment. > + if (attach_region_target(cxlr, cxld, params->position)) > + goto err; > + > + /* Commit Region */ > + if (commit_region(cxlr)) > + goto err; > + > + rc = device_add(dev); > + if (rc) > + goto err; > + > + rc = devm_add_action_or_reset(port->uport_dev, unregister_region, cxlr); > + if (rc) > + return ERR_PTR(rc); > + > + dev_dbg(port->uport_dev, "%s: created %s\n", > + dev_name(&cxlrd->cxlsd.cxld.dev), dev_name(dev)); > + return cxlr; > + > +err: > + put_device(dev); > + return ERR_PTR(rc); > +} > + > +struct cxl_region *cxl_create_pmem_region(struct cxl_root_decoder *cxlrd, > + struct cxl_decoder *cxld, > + struct cxl_pmem_region_params *params, int id) > +{ > + int rc; > + > + rc = memregion_alloc(GFP_KERNEL); > + if (rc < 0) > + return ERR_PTR(rc); > + > + if (atomic_cmpxchg(&cxlrd->region_id, id, rc) != id) { > + memregion_free(rc); > + return ERR_PTR(-EBUSY); > + } I'm a little surprised not to see cleanup of the memregion via devm somewhere here. > + > + return devm_cxl_pmem_add_region(cxlrd, cxld, params, id, > + CXL_DECODER_PMEM, CXL_DECODER_HOSTONLYMEM); > +} > +EXPORT_SYMBOL_NS_GPL(cxl_create_pmem_region, "CXL"); > + > static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd, > enum cxl_decoder_mode mode, int id) > {
