From patchwork Fri Jun 24 04:19:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 12893628 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) (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 49E2223A0; Fri, 24 Jun 2022 04:20:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656044411; x=1687580411; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=d8ij3u11o75oSSOGptJFkUuJ7uZDU0gk5H3Gjw/F+sU=; b=PNzPbtIdNAEyXuaUW/DebK3L/7pYmMotr1yJj6fKRpG2ezC+A1FMmx0E K46C6M9+IPIXGByJwcXFV3H7Bb3VjWtbZEbe0HqIQdU2e/fnsXq/Tul/u BtqUhmZOTzAIuKSGk/34RNM+CxydW3p1lWARYofqIW/oUa+j3c7pfGzJY reQh3lwZUN/zaU6dpSExiop0CsRkLFDI3J/3PthhPZxDacV7qM2PQSoaG pvkwrULlOF6OZwoRY1OISK9zPSaYWngdxF50q8cXSBfVzTWLXdp31EGwT NjLVEraJnfKeN04uguDJ/B3985jcW3lSN+USc7gXpwoXBBWUAnvOi1vvT A==; X-IronPort-AV: E=McAfee;i="6400,9594,10387"; a="344912781" X-IronPort-AV: E=Sophos;i="5.92,218,1650956400"; d="scan'208";a="344912781" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jun 2022 21:20:09 -0700 X-IronPort-AV: E=Sophos;i="5.92,218,1650956400"; d="scan'208";a="645092899" Received: from daharell-mobl2.amr.corp.intel.com (HELO dwillia2-xfh.intel.com) ([10.209.66.176]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jun 2022 21:20:09 -0700 From: Dan Williams To: linux-cxl@vger.kernel.org Cc: nvdimm@lists.linux.dev, linux-pci@vger.kernel.org, patches@lists.linux.dev, hch@lst.de, Dan Williams Subject: [PATCH 27/46] cxl/port: Move 'cxl_ep' references to an xarray per port Date: Thu, 23 Jun 2022 21:19:31 -0700 Message-Id: <20220624041950.559155-2-dan.j.williams@intel.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <165603869943.551046.3498980330327696732.stgit@dwillia2-xfh> References: <165603869943.551046.3498980330327696732.stgit@dwillia2-xfh> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In preparation for region provisioning that needs to walk the topology by endpoints, use an xarray to record endpoint interest in a given port. In addition to being more space and time efficient it also reduces the complexity of the implementation by moving locking internal to the xarray implementation. It also allows for a single cxl_ep reference to be recorded in multiple xarrays. Signed-off-by: Dan Williams Reviewed-by: Jonathan Cameron --- drivers/cxl/core/port.c | 60 ++++++++++++++++++++--------------------- drivers/cxl/cxl.h | 4 +-- 2 files changed, 30 insertions(+), 34 deletions(-) diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 8f53f59dd0fa..ea3ab9baf232 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -431,22 +431,27 @@ static struct cxl_switch_decoder *to_cxl_switch_decoder(struct device *dev) static void cxl_ep_release(struct cxl_ep *ep) { - if (!ep) - return; - list_del(&ep->list); put_device(ep->ep); kfree(ep); } +static void cxl_ep_remove(struct cxl_port *port, struct cxl_ep *ep) +{ + if (!ep) + return; + xa_erase(&port->endpoints, (unsigned long) ep->ep); + cxl_ep_release(ep); +} + static void cxl_port_release(struct device *dev) { struct cxl_port *port = to_cxl_port(dev); - struct cxl_ep *ep, *_e; + unsigned long index; + struct cxl_ep *ep; - device_lock(dev); - list_for_each_entry_safe(ep, _e, &port->endpoints, list) - cxl_ep_release(ep); - device_unlock(dev); + xa_for_each(&port->endpoints, index, ep) + cxl_ep_remove(port, ep); + xa_destroy(&port->endpoints); ida_free(&cxl_port_ida, port->id); kfree(port); } @@ -562,7 +567,7 @@ static struct cxl_port *cxl_port_alloc(struct device *uport, ida_init(&port->decoder_ida); port->dpa_end = -1; INIT_LIST_HEAD(&port->dports); - INIT_LIST_HEAD(&port->endpoints); + xa_init(&port->endpoints); device_initialize(dev); lockdep_set_class_and_subclass(&dev->mutex, &cxl_port_key, port->depth); @@ -858,33 +863,21 @@ struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port, } EXPORT_SYMBOL_NS_GPL(devm_cxl_add_dport, CXL); -static struct cxl_ep *find_ep(struct cxl_port *port, struct device *ep_dev) -{ - struct cxl_ep *ep; - - device_lock_assert(&port->dev); - list_for_each_entry(ep, &port->endpoints, list) - if (ep->ep == ep_dev) - return ep; - return NULL; -} - static int add_ep(struct cxl_ep *new) { struct cxl_port *port = new->dport->port; - struct cxl_ep *dup; + int rc; device_lock(&port->dev); if (port->dead) { device_unlock(&port->dev); return -ENXIO; } - dup = find_ep(port, new->ep); - if (!dup) - list_add_tail(&new->list, &port->endpoints); + rc = xa_insert(&port->endpoints, (unsigned long)new->ep, new, + GFP_KERNEL); device_unlock(&port->dev); - return dup ? -EEXIST : 0; + return rc; } /** @@ -905,7 +898,6 @@ static int cxl_add_ep(struct cxl_dport *dport, struct device *ep_dev) if (!ep) return -ENOMEM; - INIT_LIST_HEAD(&ep->list); ep->ep = get_device(ep_dev); ep->dport = dport; @@ -1048,6 +1040,12 @@ static void delete_switch_port(struct cxl_port *port, struct list_head *dports) devm_release_action(port->dev.parent, unregister_port, port); } +static struct cxl_ep *cxl_ep_load(struct cxl_port *port, + struct cxl_memdev *cxlmd) +{ + return xa_load(&port->endpoints, (unsigned long)&cxlmd->dev); +} + static void cxl_detach_ep(void *data) { struct cxl_memdev *cxlmd = data; @@ -1086,11 +1084,11 @@ static void cxl_detach_ep(void *data) } device_lock(&port->dev); - ep = find_ep(port, &cxlmd->dev); + ep = cxl_ep_load(port, cxlmd); dev_dbg(&cxlmd->dev, "disconnect %s from %s\n", ep ? dev_name(ep->ep) : "", dev_name(&port->dev)); - cxl_ep_release(ep); - if (ep && !port->dead && list_empty(&port->endpoints) && + cxl_ep_remove(port, ep); + if (ep && !port->dead && xa_empty(&port->endpoints) && !is_cxl_root(parent_port)) { /* * This was the last ep attached to a dynamically @@ -1184,7 +1182,7 @@ static int add_port_attach_ep(struct cxl_memdev *cxlmd, dev_dbg(&cxlmd->dev, "add to new port %s:%s\n", dev_name(&port->dev), dev_name(port->uport)); rc = cxl_add_ep(dport, &cxlmd->dev); - if (rc == -EEXIST) { + if (rc == -EBUSY) { /* * "can't" happen, but this error code means * something to the caller, so translate it. @@ -1247,7 +1245,7 @@ int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd) * the parent_port lock as the current port may be being * reaped. */ - if (rc && rc != -EEXIST) { + if (rc && rc != -EBUSY) { put_device(&port->dev); return rc; } diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 55d34b1576f1..3d149780d724 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -337,7 +337,7 @@ struct cxl_port { struct device *uport; int id; struct list_head dports; - struct list_head endpoints; + struct xarray endpoints; struct cxl_dport *parent_dport; struct ida decoder_ida; int dpa_end; @@ -366,12 +366,10 @@ struct cxl_dport { * struct cxl_ep - track an endpoint's interest in a port * @ep: device that hosts a generic CXL endpoint (expander or accelerator) * @dport: which dport routes to this endpoint on this port - * @list: node on port->endpoints list */ struct cxl_ep { struct device *ep; struct cxl_dport *dport; - struct list_head list; }; /*