From nobody Mon Nov 25 07:26:12 2024 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) (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 AC1E5208995; Tue, 29 Oct 2024 20:36:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.9 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730234179; cv=none; b=cuSnR62ILwEejyBGMUGGlnAQA2o6DZbLO2amaPSwO6iKEHaDGTKZDfcs6wb6zjzLKjEBIPwMs5s5C82e2EBIWZY87OdBhKQEAsGfYEMGp4asSVenmxmpLzQvo67PJuXz8Y6JeU0eTo5FLhiCfnDxEH1kfxJu+ddBLcefBkWHW38= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730234179; c=relaxed/simple; bh=DKFmxHzxPQkqD1psZKnNbadcZ1L7Hn+Mk6cweDGLsFs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=OU0ic3YtP5Mbu0jkvLVvruseaT66H6KwNWEfx98MnuF2sSIJX8giDxc0pTiBYzx08+eho9LZhaLOfXi8zquWon/5wd07GQghDRk5G2UggVWP6bIrhyj5Bsy/+eJEDpXq1Cvx7w90v8w/jXaI1RVLY8z9FnjmeUH99aizt/ui8sc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=CAiuf96s; arc=none smtp.client-ip=198.175.65.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="CAiuf96s" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1730234176; x=1761770176; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=DKFmxHzxPQkqD1psZKnNbadcZ1L7Hn+Mk6cweDGLsFs=; b=CAiuf96sqKIEw8ibGaVYDwIdOAy9aEN7GZbtc5hJEFYHgT01Up0ELfJe QMoQ+pG8RvvGWwoJfeTs8+YaNCVhH7Ctp82oJERF891YKduThe3D6qEOT Wr/d64kGpoo7vqOkdkBdhisnN0niq2p4bt2fBq91xkd7wc4S/q+BTeWfO YQ0YULRfQCY2L4voIfdEt/fJEV84gxoQeIXKN07mWfnx/g2el98MLaHmb ibxjULuKAl4Niw78Bfa54tmFbsqwU68UkAm0p/eiFgXf3PkpmcKA8LVTq eViSC2yB8od2CRK+AHJ85cKquiyfkp5R6VXaDNPmd+tNJMWXWzbF/8dOt Q==; X-CSE-ConnectionGUID: l3WgaUr6TEuUdd7XtAw+9Q== X-CSE-MsgGUID: WsLlbU8aSKqypdig1QHJNw== X-IronPort-AV: E=McAfee;i="6700,10204,11222"; a="52457671" X-IronPort-AV: E=Sophos;i="6.11,199,1725346800"; d="scan'208";a="52457671" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Oct 2024 13:36:16 -0700 X-CSE-ConnectionGUID: 54V+enRvQK6N3/FQvNMVtw== X-CSE-MsgGUID: 4VqZh1aFQNGORQC+xO2NtQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,243,1725346800"; d="scan'208";a="119561340" Received: from ldmartin-desk2.corp.intel.com (HELO localhost) ([10.125.108.77]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Oct 2024 13:36:14 -0700 From: ira.weiny@intel.com Date: Tue, 29 Oct 2024 15:34:59 -0500 Subject: [PATCH v5 24/27] cxl/region: Read existing extents on region creation Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20241029-dcd-type2-upstream-v5-24-8739cb67c374@intel.com> References: <20241029-dcd-type2-upstream-v5-0-8739cb67c374@intel.com> In-Reply-To: <20241029-dcd-type2-upstream-v5-0-8739cb67c374@intel.com> To: Dave Jiang , Fan Ni , Jonathan Cameron , Navneet Singh , Jonathan Corbet , Andrew Morton Cc: Dan Williams , Davidlohr Bueso , Alison Schofield , Vishal Verma , Ira Weiny , linux-cxl@vger.kernel.org, linux-doc@vger.kernel.org, nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org X-Mailer: b4 0.15-dev-2a633 X-Developer-Signature: v=1; a=ed25519-sha256; t=1730234086; l=8797; i=ira.weiny@intel.com; s=20221211; h=from:subject:message-id; bh=RuDglYW1Lv8McJ7c8J0fq4cx4MJ0RfCKTX4dw0NI7gM=; b=5n/a8ah3fzTFOW0DtNnpmd2Xf7agEKz02e66yUFZ4B1JZs3u0mtP9HIX5yOEDk+9Qpy6rkdQQ qsO7nJdvQsFD/DO9dxdiA1dLzOGyPIfKyq/v1BeVZ8aMEzAx97VvSJ3 X-Developer-Key: i=ira.weiny@intel.com; a=ed25519; pk=noldbkG+Wp1qXRrrkfY1QJpDf7QsOEthbOT7vm0PqsE= From: Navneet Singh Dynamic capacity device extents may be left in an accepted state on a device due to an unexpected host crash. In this case it is expected that the creation of a new region on top of a DC partition can read those extents and surface them for continued use. Once all endpoint decoders are part of a region and the region is being realized, a read of the 'devices extent list' can reveal these previously accepted extents. CXL r3.1 specifies the mailbox call Get Dynamic Capacity Extent List for this purpose. The call returns all the extents for all dynamic capacity partitions. If the fabric manager is adding extents to any DCD partition, the extent list for the recovered region may change. In this case the query must retry. Upon retry the query could encounter extents which were accepted on a previous list query. Adding such extents is ignored without error because they are entirely within a previous accepted extent. Instead warn on this case to allow for differentiating bad devices from this normal condition. Latch any errors to be bubbled up to ensure notification to the user even if individual errors are rate limited or otherwise ignored. The scan for existing extents races with the dax_cxl driver. This is synchronized through the region device lock. Extents which are found after the driver has loaded will surface through the normal notification path while extents seen prior to the driver are read during driver load. Signed-off-by: Navneet Singh Reviewed-by: Jonathan Cameron Reviewed-by: Fan Ni Co-developed-by: Ira Weiny Signed-off-by: Ira Weiny --- Changes: [Jonathan: fix kfree/kvfree bug] [Jonathan: bubble up errors and print an error] [Jonathan: change rescan message from debug to warn] --- drivers/cxl/core/core.h | 1 + drivers/cxl/core/mbox.c | 108 ++++++++++++++++++++++++++++++++++++++++++= ++++ drivers/cxl/core/region.c | 25 +++++++++++ drivers/cxl/cxlmem.h | 21 +++++++++ 4 files changed, 155 insertions(+) diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index c5951018f8ff590627676eeb7a430b6acbf516d8..feb00bbe98c9b59d2c7fceb3ad5= fed3885b59753 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -21,6 +21,7 @@ cxled_to_mds(struct cxl_endpoint_decoder *cxled) return container_of(cxlds, struct cxl_memdev_state, cxlds); } =20 +int cxl_process_extent_list(struct cxl_endpoint_decoder *cxled); int cxl_region_invalidate_memregion(struct cxl_region *cxlr); =20 #ifdef CONFIG_CXL_REGION diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index 770d966dfd180c569fd492ab503e0aa12676ceeb..5cfa5e34e679b5665650d8b2ada= 47018e5facb1c 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -1699,6 +1699,114 @@ int cxl_dev_dynamic_capacity_identify(struct cxl_me= mdev_state *mds) } EXPORT_SYMBOL_NS_GPL(cxl_dev_dynamic_capacity_identify, CXL); =20 +/* Return -EAGAIN if the extent list changes while reading */ +static int __cxl_process_extent_list(struct cxl_endpoint_decoder *cxled) +{ + u32 current_index, total_read, total_expected, initial_gen_num; + struct cxl_memdev_state *mds =3D cxled_to_mds(cxled); + struct cxl_mailbox *cxl_mbox =3D &mds->cxlds.cxl_mbox; + struct device *dev =3D mds->cxlds.dev; + struct cxl_mbox_cmd mbox_cmd; + u32 max_extent_count; + int latched_rc =3D 0; + bool first =3D true; + + struct cxl_mbox_get_extent_out *extents __free(kvfree) =3D + kvmalloc(cxl_mbox->payload_size, GFP_KERNEL); + if (!extents) + return -ENOMEM; + + total_read =3D 0; + current_index =3D 0; + total_expected =3D 0; + max_extent_count =3D (cxl_mbox->payload_size - sizeof(*extents)) / + sizeof(struct cxl_extent); + do { + struct cxl_mbox_get_extent_in get_extent; + u32 nr_returned, current_total, current_gen_num; + int rc; + + get_extent =3D (struct cxl_mbox_get_extent_in) { + .extent_cnt =3D max(max_extent_count, + total_expected - current_index), + .start_extent_index =3D cpu_to_le32(current_index), + }; + + mbox_cmd =3D (struct cxl_mbox_cmd) { + .opcode =3D CXL_MBOX_OP_GET_DC_EXTENT_LIST, + .payload_in =3D &get_extent, + .size_in =3D sizeof(get_extent), + .size_out =3D cxl_mbox->payload_size, + .payload_out =3D extents, + .min_out =3D 1, + }; + + rc =3D cxl_internal_send_cmd(cxl_mbox, &mbox_cmd); + if (rc < 0) + return rc; + + /* Save initial data */ + if (first) { + total_expected =3D le32_to_cpu(extents->total_extent_count); + initial_gen_num =3D le32_to_cpu(extents->generation_num); + first =3D false; + } + + nr_returned =3D le32_to_cpu(extents->returned_extent_count); + total_read +=3D nr_returned; + current_total =3D le32_to_cpu(extents->total_extent_count); + current_gen_num =3D le32_to_cpu(extents->generation_num); + + dev_dbg(dev, "Got extent list %d-%d of %d generation Num:%d\n", + current_index, total_read - 1, current_total, current_gen_num); + + if (current_gen_num !=3D initial_gen_num || total_expected !=3D current_= total) { + dev_warn(dev, "Extent list change detected; gen %u !=3D %u : cnt %u != =3D %u\n", + current_gen_num, initial_gen_num, + total_expected, current_total); + return -EAGAIN; + } + + for (int i =3D 0; i < nr_returned ; i++) { + struct cxl_extent *extent =3D &extents->extent[i]; + + dev_dbg(dev, "Processing extent %d/%d\n", + current_index + i, total_expected); + + rc =3D validate_add_extent(mds, extent); + if (rc) + latched_rc =3D rc; + } + + current_index +=3D nr_returned; + } while (total_expected > total_read); + + return latched_rc; +} + +/** + * cxl_process_extent_list() - Read existing extents + * @cxled: Endpoint decoder which is part of a region + * + * Issue the Get Dynamic Capacity Extent List command to the device + * and add existing extents if found. + * + * A retry of 10 is somewhat arbitrary, however, extent changes should be + * relatively rare while bringing up a region. So 10 should be plenty. + */ +#define CXL_READ_EXTENT_LIST_RETRY 10 +int cxl_process_extent_list(struct cxl_endpoint_decoder *cxled) +{ + int retry =3D CXL_READ_EXTENT_LIST_RETRY; + int rc; + + do { + rc =3D __cxl_process_extent_list(cxled); + } while (rc =3D=3D -EAGAIN && retry--); + + return rc; +} + static int add_dpa_res(struct device *dev, struct resource *parent, struct resource *res, resource_size_t start, resource_size_t size, const char *type) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 7de9d7bd85a3d45567885874cc1d61cb10b816a5..b160f8a95cd7d4415c6252b3a9f= 36b06490ddf45 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -3190,6 +3190,26 @@ static int devm_cxl_add_pmem_region(struct cxl_regio= n *cxlr) return rc; } =20 +static int cxlr_add_existing_extents(struct cxl_region *cxlr) +{ + struct cxl_region_params *p =3D &cxlr->params; + int i, latched_rc =3D 0; + + for (i =3D 0; i < p->nr_targets; i++) { + struct device *dev =3D &p->targets[i]->cxld.dev; + int rc; + + rc =3D cxl_process_extent_list(p->targets[i]); + if (rc) { + dev_err(dev, "Existing extent processing failed %d\n", + rc); + latched_rc =3D rc; + } + } + + return latched_rc; +} + static void cxlr_dax_unregister(void *_cxlr_dax) { struct cxl_dax_region *cxlr_dax =3D _cxlr_dax; @@ -3224,6 +3244,11 @@ static int devm_cxl_add_dax_region(struct cxl_region= *cxlr) dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent), dev_name(dev)); =20 + if (cxlr->mode =3D=3D CXL_REGION_DC) + if (cxlr_add_existing_extents(cxlr)) + dev_err(&cxlr->dev, "Existing extent processing failed %d\n", + rc); + return devm_add_action_or_reset(&cxlr->dev, cxlr_dax_unregister, cxlr_dax); err: diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index 85b30a74a6fa5de1dd99c08c8318edd204e3e19d..6f7f93056ed0b4062a22eeea356= 987f338c7f438 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -626,6 +626,27 @@ struct cxl_mbox_dc_response { } __packed extent_list[]; } __packed; =20 +/* + * Get Dynamic Capacity Extent List; Input Payload + * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-166 + */ +struct cxl_mbox_get_extent_in { + __le32 extent_cnt; + __le32 start_extent_index; +} __packed; + +/* + * Get Dynamic Capacity Extent List; Output Payload + * CXL rev 3.1 section 8.2.9.9.9.2; Table 8-167 + */ +struct cxl_mbox_get_extent_out { + __le32 returned_extent_count; + __le32 total_extent_count; + __le32 generation_num; + u8 rsvd[4]; + struct cxl_extent extent[]; +} __packed; + struct cxl_mbox_get_supported_logs { __le16 entries; u8 rsvd[6]; --=20 2.47.0