From patchwork Tue Oct 29 20:34:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 13855453 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 388F420E320; Tue, 29 Oct 2024 20:36:11 +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=1730234173; cv=none; b=Wck6V5Az6oQOKwaEvdaYcRXl/fFqIZiV82gTnocRGhww6z1MxEVCcCuzW1SIsTBOf3XsQuqwckBAJd2VRf+bnxt2ilfkR1pl0U+Z8WV6juOal/IU/kjLxmtFMZcNDPiQh2+rjXGkpgXGAJiEyryhF8CW/Ip/mDYh3kNX8eLE/uk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730234173; c=relaxed/simple; bh=Vx9nmkDR6TYif3/NmresoXniXFEfFK8D/F7cGxg/7wE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ZeqifIALmxuAci5Y+RRPbdiQ0z9A6aQqhfwc+C9PbEElhffd9OH3BYA+pRPvUXGSrEKj9tFMaywgs9CKKWmgMzRhAHSGRwnD3Q6ed/Vv8kuHinoZ3P1rPmYa/EXKHfoHbBxeA0MU9sXPVT/sEF06+ehCFjj9fqxljLyL6/YDwTg= 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=jRbYv7Ot; 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="jRbYv7Ot" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1730234171; x=1761770171; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=Vx9nmkDR6TYif3/NmresoXniXFEfFK8D/F7cGxg/7wE=; b=jRbYv7OtEfTQWAghWV7B/I13zO0atT5hlDPdcQXKW7138n4NnkXCFwnq pTdtFgxnxfUK1JVUsuoIG2lhVamUj2p794HielEkbOKosaqZm3rDWJFBa 2UE/9h3EZ8XZWw4BNyE2+SF4Fy12vBb5DQSm8EJd2UQBTW6kNl/WNcInC 4bCtkJtNoBw20x7z1wvbTPoxvRsq9NHp7OPfjFHEpd3zl8gH9tL307M1Y QAuYCFMr7wM59kkCX5fM9wZpXuih6iReP/osQQ2lJ7hUauAzYsi06Vifa OK8NgE2q9I6GjEg0UA6zh1iFSavCxmAm4qgV6DPnW3uInaXh+l9G0joLR A==; X-CSE-ConnectionGUID: e3XtMdfCRAeclmoUwIuNcg== X-CSE-MsgGUID: /DsVRHpvRUibgRImGCmnQg== X-IronPort-AV: E=McAfee;i="6700,10204,11222"; a="52457648" X-IronPort-AV: E=Sophos;i="6.11,199,1725346800"; d="scan'208";a="52457648" 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 13:36:11 -0700 X-CSE-ConnectionGUID: k8nMvlPPQ8Gs76Bcv6TBVw== X-CSE-MsgGUID: 1d0KujcjQVSP0T3ATojTEw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,243,1725346800"; d="scan'208";a="119561327" 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 13:36:09 -0700 From: Ira Weiny Date: Tue, 29 Oct 2024 15:34:57 -0500 Subject: [PATCH v5 22/27] dax/bus: Factor out dev dax resize logic Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241029-dcd-type2-upstream-v5-22-8739cb67c374@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=8873; i=ira.weiny@intel.com; s=20221211; h=from:subject:message-id; bh=Vx9nmkDR6TYif3/NmresoXniXFEfFK8D/F7cGxg/7wE=; b=zxXGspUdrzYMaLYQtpP6NZHZFPeg950FEIeO21TzbLAoR9/E3GZVrL7ZoCNvPd7KGYuDu2paE KX1BFsZkyUJA71zniTIptBmUWCcZCNj/WPdAsmubxaClKwpTdSdCLWF X-Developer-Key: i=ira.weiny@intel.com; a=ed25519; pk=noldbkG+Wp1qXRrrkfY1QJpDf7QsOEthbOT7vm0PqsE= Dynamic Capacity regions must limit dev dax resources to those areas which have extents backing real memory. Such DAX regions are dubbed 'sparse' regions. In order to manage where memory is available four alternatives were considered: 1) Create a single region resource child on region creation which reserves the entire region. Then as extents are added punch holes in this reservation. This requires new resource manipulation to punch the holes and still requires an additional iteration over the extent areas which may already have existing dev dax resources used. 2) Maintain an ordered xarray of extents which can be queried while processing the resize logic. The issue is that existing region->res children may artificially limit the allocation size sent to alloc_dev_dax_range(). IE the resource children can't be directly used in the resize logic to find where space in the region is. This also poses a problem of managing the available size in 2 places. 3) Maintain a separate resource tree with extents. This option is the same as 2) but with the different data structure. Most ideally there should be a unified representation of the resource tree not two places to look for space. 4) Create region resource children for each extent. Manage the dax dev resize logic in the same way as before but use a region child (extent) resource as the parents to find space within each extent. Option 4 can leverage the existing resize algorithm to find space within the extents. It manages the available space in a singular resource tree which is less complicated for finding space. In preparation for this change, factor out the dev_dax_resize logic. For static regions use dax_region->res as the parent to find space for the dax ranges. Future patches will use the same algorithm with individual extent resources as the parent. Reviewed-by: Jonathan Cameron Reviewed-by: Dave Jiang Signed-off-by: Ira Weiny --- Changes: [Jonathan: Adjust declaration of to_alloc] --- drivers/dax/bus.c | 130 +++++++++++++++++++++++++++++++++--------------------- 1 file changed, 80 insertions(+), 50 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index d8cb5195a227c0f6194cb210510e006327e1b35b..c25942a3d1255cb5e5bf8d213e62933281ff3e4f 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -844,11 +844,9 @@ static int devm_register_dax_mapping(struct dev_dax *dev_dax, int range_id) return 0; } -static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start, - resource_size_t size) +static int alloc_dev_dax_range(struct resource *parent, struct dev_dax *dev_dax, + u64 start, resource_size_t size) { - struct dax_region *dax_region = dev_dax->region; - struct resource *res = &dax_region->res; struct device *dev = &dev_dax->dev; struct dev_dax_range *ranges; unsigned long pgoff = 0; @@ -866,14 +864,14 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start, return 0; } - alloc = __request_region(res, start, size, dev_name(dev), 0); + alloc = __request_region(parent, start, size, dev_name(dev), 0); if (!alloc) return -ENOMEM; ranges = krealloc(dev_dax->ranges, sizeof(*ranges) * (dev_dax->nr_range + 1), GFP_KERNEL); if (!ranges) { - __release_region(res, alloc->start, resource_size(alloc)); + __release_region(parent, alloc->start, resource_size(alloc)); return -ENOMEM; } @@ -1026,50 +1024,45 @@ static bool adjust_ok(struct dev_dax *dev_dax, struct resource *res) return true; } -static ssize_t dev_dax_resize(struct dax_region *dax_region, - struct dev_dax *dev_dax, resource_size_t size) +/** + * dev_dax_resize_static - Expand the device into the unused portion of the + * region. This may involve adjusting the end of an existing resource, or + * allocating a new resource. + * + * @parent: parent resource to allocate this range in + * @dev_dax: DAX device to be expanded + * @to_alloc: amount of space to alloc; must be <= space available in @parent + * + * Return the amount of space allocated or -ERRNO on failure + */ +static ssize_t dev_dax_resize_static(struct resource *parent, + struct dev_dax *dev_dax, + resource_size_t to_alloc) { - resource_size_t avail = dax_region_avail_size(dax_region), to_alloc; - resource_size_t dev_size = dev_dax_size(dev_dax); - struct resource *region_res = &dax_region->res; - struct device *dev = &dev_dax->dev; struct resource *res, *first; - resource_size_t alloc = 0; int rc; - if (dev->driver) - return -EBUSY; - if (size == dev_size) - return 0; - if (size > dev_size && size - dev_size > avail) - return -ENOSPC; - if (size < dev_size) - return dev_dax_shrink(dev_dax, size); - - to_alloc = size - dev_size; - if (dev_WARN_ONCE(dev, !alloc_is_aligned(dev_dax, to_alloc), - "resize of %pa misaligned\n", &to_alloc)) - return -ENXIO; - - /* - * Expand the device into the unused portion of the region. This - * may involve adjusting the end of an existing resource, or - * allocating a new resource. - */ -retry: - first = region_res->child; - if (!first) - return alloc_dev_dax_range(dev_dax, dax_region->res.start, to_alloc); + first = parent->child; + if (!first) { + rc = alloc_dev_dax_range(parent, dev_dax, + parent->start, to_alloc); + if (rc) + return rc; + return to_alloc; + } - rc = -ENOSPC; for (res = first; res; res = res->sibling) { struct resource *next = res->sibling; + resource_size_t alloc; /* space at the beginning of the region */ - if (res == first && res->start > dax_region->res.start) { - alloc = min(res->start - dax_region->res.start, to_alloc); - rc = alloc_dev_dax_range(dev_dax, dax_region->res.start, alloc); - break; + if (res == first && res->start > parent->start) { + alloc = min(res->start - parent->start, to_alloc); + rc = alloc_dev_dax_range(parent, dev_dax, + parent->start, alloc); + if (rc) + return rc; + return alloc; } alloc = 0; @@ -1078,21 +1071,56 @@ static ssize_t dev_dax_resize(struct dax_region *dax_region, alloc = min(next->start - (res->end + 1), to_alloc); /* space at the end of the region */ - if (!alloc && !next && res->end < region_res->end) - alloc = min(region_res->end - res->end, to_alloc); + if (!alloc && !next && res->end < parent->end) + alloc = min(parent->end - res->end, to_alloc); if (!alloc) continue; if (adjust_ok(dev_dax, res)) { rc = adjust_dev_dax_range(dev_dax, res, resource_size(res) + alloc); - break; + if (rc) + return rc; + return alloc; } - rc = alloc_dev_dax_range(dev_dax, res->end + 1, alloc); - break; + rc = alloc_dev_dax_range(parent, dev_dax, res->end + 1, alloc); + if (rc) + return rc; + return alloc; } - if (rc) - return rc; + + /* available was already calculated and should never be an issue */ + dev_WARN_ONCE(&dev_dax->dev, 1, "space not found?"); + return 0; +} + +static ssize_t dev_dax_resize(struct dax_region *dax_region, + struct dev_dax *dev_dax, resource_size_t size) +{ + resource_size_t avail = dax_region_avail_size(dax_region); + resource_size_t dev_size = dev_dax_size(dev_dax); + struct device *dev = &dev_dax->dev; + resource_size_t to_alloc; + resource_size_t alloc; + + if (dev->driver) + return -EBUSY; + if (size == dev_size) + return 0; + if (size > dev_size && size - dev_size > avail) + return -ENOSPC; + if (size < dev_size) + return dev_dax_shrink(dev_dax, size); + + to_alloc = size - dev_size; + if (dev_WARN_ONCE(dev, !alloc_is_aligned(dev_dax, to_alloc), + "resize of %pa misaligned\n", &to_alloc)) + return -ENXIO; + +retry: + alloc = dev_dax_resize_static(&dax_region->res, dev_dax, to_alloc); + if (alloc <= 0) + return alloc; to_alloc -= alloc; if (to_alloc) goto retry; @@ -1198,7 +1226,8 @@ static ssize_t mapping_store(struct device *dev, struct device_attribute *attr, to_alloc = range_len(&r); if (alloc_is_aligned(dev_dax, to_alloc)) - rc = alloc_dev_dax_range(dev_dax, r.start, to_alloc); + rc = alloc_dev_dax_range(&dax_region->res, dev_dax, r.start, + to_alloc); up_write(&dax_dev_rwsem); up_write(&dax_region_rwsem); @@ -1466,7 +1495,8 @@ static struct dev_dax *__devm_create_dev_dax(struct dev_dax_data *data) device_initialize(dev); dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id); - rc = alloc_dev_dax_range(dev_dax, dax_region->res.start, data->size); + rc = alloc_dev_dax_range(&dax_region->res, dev_dax, dax_region->res.start, + data->size); if (rc) goto err_range;