From patchwork Thu Dec 14 07:37:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13492519 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="BBgxT82k" Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D535B9; Wed, 13 Dec 2023 23:38:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702539493; x=1734075493; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=s2pn4yZl0XYTp65Nn5lvuI7n/QI1GItpUEXHrwpjM9A=; b=BBgxT82kFOUkxCI4MYyQPQKAfHIHKZc50MvaP7ltfnOxFpmZhuSHRYKN 3dgMT3TMoP3wzOM5EYuywcHiWCb8Vlw6za8Ub/c2Or9wX7R4T4+tKIi1T EIcV0k3QM2cz6v+Eo3PT1+0yIiM3eGtMwwm9YsB1yJinZYWU1ODSzqvvM uo5h5FL99MNf6RWdDckoa4eJvp7jr/E8mqTXSlGmu/sKJ5Ap5bDEK9hWB uenAHWK3DpeYlI7XZ6NhtNRnj/lgbYvhsmUifjG9d9mUwjyXYFcJ9RTHR hOm8EIbGwm+R55yfPw5aLevRddLquF/5jD8l/vpeEpK+vDHSobzx8r+/z w==; X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="481275512" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="481275512" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:12 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="723972059" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="723972059" Received: from llblake-mobl1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.213.191.124]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:11 -0800 From: Vishal Verma Date: Thu, 14 Dec 2023 00:37:54 -0700 Subject: [PATCH v5 1/4] Documentatiion/ABI: Add ABI documentation for sys-bus-dax Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231214-vv-dax_abi-v5-1-3f7b006960b4@intel.com> References: <20231214-vv-dax_abi-v5-0-3f7b006960b4@intel.com> In-Reply-To: <20231214-vv-dax_abi-v5-0-3f7b006960b4@intel.com> To: Dan Williams , Vishal Verma , Dave Jiang , Andrew Morton , Oscar Salvador Cc: linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, David Hildenbrand , Dave Hansen , Huang Ying , Greg Kroah-Hartman , linux-mm@kvack.org X-Mailer: b4 0.13-dev-433a8 X-Developer-Signature: v=1; a=openpgp-sha256; l=5934; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=s2pn4yZl0XYTp65Nn5lvuI7n/QI1GItpUEXHrwpjM9A=; b=owGbwMvMwCXGf25diOft7jLG02pJDKlVGx4VxXeVLzrzw/Rzevi5Y9KH3GbOf7RvZum9o3Ouq E1sv6TV21HKwiDGxSArpsjyd89HxmNy2/N5AhMcYeawMoEMYeDiFICJ2Isx/OHn+2U8ea3O/vwu Tesphzmq5lYYaJ1peJkQ9+FcOvPT7GhGhs2HTzq8qm+IF3kimLko9v/0y/bhllrfTy0IN5ZJ/lB 7hQsA X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Add the missing sysfs ABI documentation for the device DAX subsystem. Various ABI attributes under this have been present since v5.1, and more have been added over time. In preparation for adding a new attribute, add this file with the historical details. Cc: Dan Williams Signed-off-by: Vishal Verma --- Documentation/ABI/testing/sysfs-bus-dax | 136 ++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-dax b/Documentation/ABI/testing/sysfs-bus-dax new file mode 100644 index 000000000000..6359f7bc9bf4 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-dax @@ -0,0 +1,136 @@ +What: /sys/bus/dax/devices/daxX.Y/align +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RW) Provides a way to specify an alignment for a dax device. + Values allowed are constrained by the physical address ranges + that back the dax device, and also by arch requirements. + +What: /sys/bus/dax/devices/daxX.Y/mapping +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (WO) Provides a way to allocate a mapping range under a dax + device. Specified in the format -. + +What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/start +What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/end +What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/page_offset +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) A dax device may have multiple constituent discontiguous + address ranges. These are represented by the different + 'mappingX' subdirectories. The 'start' attribute indicates the + start physical address for the given range. The 'end' attribute + indicates the end physical address for the given range. The + 'page_offset' attribute indicates the offset of the current + range in the dax device. + +What: /sys/bus/dax/devices/daxX.Y/resource +Date: June, 2019 +KernelVersion: v5.3 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The resource attribute indicates the starting physical + address of a dax device. In case of a device with multiple + constituent ranges, it indicates the starting address of the + first range. + +What: /sys/bus/dax/devices/daxX.Y/size +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RW) The size attribute indicates the total size of a dax + device. For creating subdivided dax devices, or for resizing + an existing device, the new size can be written to this as + part of the reconfiguration process. + +What: /sys/bus/dax/devices/daxX.Y/numa_node +Date: November, 2019 +KernelVersion: v5.5 +Contact: nvdimm@lists.linux.dev +Description: + (RO) If NUMA is enabled and the platform has affinitized the + backing device for this dax device, emit the CPU node + affinity for this device. + +What: /sys/bus/dax/devices/daxX.Y/target_node +Date: February, 2019 +KernelVersion: v5.1 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The target-node attribute is the Linux numa-node that a + device-dax instance may create when it is online. Prior to + being online the device's 'numa_node' property reflects the + closest online cpu node which is the typical expectation of a + device 'numa_node'. Once it is online it becomes its own + distinct numa node. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/available_size +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The available_size attribute tracks available dax region + capacity. This only applies to volatile hmem devices, not pmem + devices, since pmem devices are defined by nvdimm namespace + boundaries. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/size +Date: July, 2017 +KernelVersion: v5.1 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The size attribute indicates the size of a given dax region + in bytes. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/align +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The align attribute indicates alignment of the dax region. + Changes on align may not always be valid, when say certain + mappings were created with 2M and then we switch to 1G. This + validates all ranges against the new value being attempted, post + resizing. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/seed +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The seed device is a concept for dynamic dax regions to be + able to split the region amongst multiple sub-instances. The + seed device, similar to libnvdimm seed devices, is a device + that starts with zero capacity allocated and unbound to a + driver. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/create +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RW) The create interface to the dax region provides a way to + create a new unconfigured dax device under the given region, which + can then be configured (with a size etc.) and then probed. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/delete +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (WO) The delete interface for a dax region provides for deletion + of any 0-sized and idle dax devices. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/id +Date: July, 2017 +KernelVersion: v5.1 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The id attribute indicates the region id of a dax region. From patchwork Thu Dec 14 07:37:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13492518 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="YwkX20FX" Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E04E107; Wed, 13 Dec 2023 23:38:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702539494; x=1734075494; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=g9l8RslOMp5ad/gXCRHw+j360xuk1nb3+acdwFrlL50=; b=YwkX20FX85WUILkbomoDirV2Z5k1yMSdUp9E6Ts3FuH6F4+nCsP3ZXni Q6+MC4fE0X40PmFY0j5bBzji/V7JskXvjHf8dn/apZIbAlQvdxWAcpcfN 5E7QTbNdhA49T1oQURdDokk/HMz3rsnlf5X8PadOU70khIVYtyVEVWne+ RxeoGoAb4Wu9373+sQGqiguK1gDunZbmZIc5rg2cu2gVLlY3BGFOzolYu i4vDQ28vVIW5t/zf5TW/5fMs+jfoeZyuhRAcHo0qQA75ANmruLp1UswZG iWC6yin4mMoLMRvT1dDnblhP40FelKCnixVeTlMTbbgXNukYiohSnj4iK Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="481275522" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="481275522" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:13 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="723972064" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="723972064" Received: from llblake-mobl1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.213.191.124]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:12 -0800 From: Vishal Verma Date: Thu, 14 Dec 2023 00:37:55 -0700 Subject: [PATCH v5 2/4] dax/bus: Use guard(device) in sysfs attribute helpers Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231214-vv-dax_abi-v5-2-3f7b006960b4@intel.com> References: <20231214-vv-dax_abi-v5-0-3f7b006960b4@intel.com> In-Reply-To: <20231214-vv-dax_abi-v5-0-3f7b006960b4@intel.com> To: Dan Williams , Vishal Verma , Dave Jiang , Andrew Morton , Oscar Salvador Cc: linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, David Hildenbrand , Dave Hansen , Huang Ying , Greg Kroah-Hartman , linux-mm@kvack.org, Joao Martins X-Mailer: b4 0.13-dev-433a8 X-Developer-Signature: v=1; a=openpgp-sha256; l=7001; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=g9l8RslOMp5ad/gXCRHw+j360xuk1nb3+acdwFrlL50=; b=owGbwMvMwCXGf25diOft7jLG02pJDKlVGx4ZxJv18x/TfPRo6pLQrU05Fp3PElasO7C0qM1kr 5tHY3xlRykLgxgXg6yYIsvfPR8Zj8ltz+cJTHCEmcPKBDKEgYtTACZySoGRoZ9jz78FO0WOfBHN z7hkJdKzWZrxycoHdT8NjQSDuFZGHmZk+Kn/VmUD14viH/ymS1fZFjwx1PJr9J8nFCC9Yf3cLpa H7AA= X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Use the guard(device) macro to lock a 'struct device', and unlock it automatically when going out of scope using Scope Based Resource Management semantics. A lot of the sysfs attribute writes in drivers/dax/bus.c benefit from a cleanup using these, so change these where applicable. Cc: Joao Martins Cc: Dan Williams Signed-off-by: Vishal Verma --- drivers/dax/bus.c | 143 ++++++++++++++++++++++-------------------------------- 1 file changed, 59 insertions(+), 84 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 1ff1ab5fa105..6226de131d17 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -294,13 +294,10 @@ static ssize_t available_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct dax_region *dax_region = dev_get_drvdata(dev); - unsigned long long size; - device_lock(dev); - size = dax_region_avail_size(dax_region); - device_unlock(dev); + guard(device)(dev); - return sprintf(buf, "%llu\n", size); + return sprintf(buf, "%llu\n", dax_region_avail_size(dax_region)); } static DEVICE_ATTR_RO(available_size); @@ -309,17 +306,14 @@ static ssize_t seed_show(struct device *dev, { struct dax_region *dax_region = dev_get_drvdata(dev); struct device *seed; - ssize_t rc; if (is_static(dax_region)) return -EINVAL; - device_lock(dev); + guard(device)(dev); seed = dax_region->seed; - rc = sprintf(buf, "%s\n", seed ? dev_name(seed) : ""); - device_unlock(dev); - return rc; + return sprintf(buf, "%s\n", seed ? dev_name(seed) : ""); } static DEVICE_ATTR_RO(seed); @@ -328,24 +322,28 @@ static ssize_t create_show(struct device *dev, { struct dax_region *dax_region = dev_get_drvdata(dev); struct device *youngest; - ssize_t rc; if (is_static(dax_region)) return -EINVAL; - device_lock(dev); + guard(device)(dev); youngest = dax_region->youngest; - rc = sprintf(buf, "%s\n", youngest ? dev_name(youngest) : ""); - device_unlock(dev); - return rc; + return sprintf(buf, "%s\n", youngest ? dev_name(youngest) : ""); } static ssize_t create_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct dax_region *dax_region = dev_get_drvdata(dev); + struct dev_dax_data data = { + .dax_region = dax_region, + .size = 0, + .id = -1, + .memmap_on_memory = false, + }; unsigned long long avail; + struct dev_dax *dev_dax; ssize_t rc; int val; @@ -358,38 +356,25 @@ static ssize_t create_store(struct device *dev, struct device_attribute *attr, if (val != 1) return -EINVAL; - device_lock(dev); + guard(device)(dev); avail = dax_region_avail_size(dax_region); if (avail == 0) - rc = -ENOSPC; - else { - struct dev_dax_data data = { - .dax_region = dax_region, - .size = 0, - .id = -1, - .memmap_on_memory = false, - }; - struct dev_dax *dev_dax = devm_create_dev_dax(&data); + return -ENOSPC; - if (IS_ERR(dev_dax)) - rc = PTR_ERR(dev_dax); - else { - /* - * In support of crafting multiple new devices - * simultaneously multiple seeds can be created, - * but only the first one that has not been - * successfully bound is tracked as the region - * seed. - */ - if (!dax_region->seed) - dax_region->seed = &dev_dax->dev; - dax_region->youngest = &dev_dax->dev; - rc = len; - } - } - device_unlock(dev); + dev_dax = devm_create_dev_dax(&data); + if (IS_ERR(dev_dax)) + return PTR_ERR(dev_dax); - return rc; + /* + * In support of crafting multiple new devices simultaneously multiple + * seeds can be created, but only the first one that has not been + * successfully bound is tracked as the region seed. + */ + if (!dax_region->seed) + dax_region->seed = &dev_dax->dev; + dax_region->youngest = &dev_dax->dev; + + return len; } static DEVICE_ATTR_RW(create); @@ -481,12 +466,9 @@ static int __free_dev_dax_id(struct dev_dax *dev_dax) static int free_dev_dax_id(struct dev_dax *dev_dax) { struct device *dev = &dev_dax->dev; - int rc; - device_lock(dev); - rc = __free_dev_dax_id(dev_dax); - device_unlock(dev); - return rc; + guard(device)(dev); + return __free_dev_dax_id(dev_dax); } static int alloc_dev_dax_id(struct dev_dax *dev_dax) @@ -908,9 +890,8 @@ static ssize_t size_show(struct device *dev, struct dev_dax *dev_dax = to_dev_dax(dev); unsigned long long size; - device_lock(dev); + guard(device)(dev); size = dev_dax_size(dev_dax); - device_unlock(dev); return sprintf(buf, "%llu\n", size); } @@ -1080,17 +1061,16 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr, return -EINVAL; } - device_lock(dax_region->dev); - if (!dax_region->dev->driver) { - device_unlock(dax_region->dev); + guard(device)(dax_region->dev); + if (!dax_region->dev->driver) return -ENXIO; - } - device_lock(dev); + + guard(device)(dev); rc = dev_dax_resize(dax_region, dev_dax, val); - device_unlock(dev); - device_unlock(dax_region->dev); + if (rc) + return rc; - return rc == 0 ? len : rc; + return len; } static DEVICE_ATTR_RW(size); @@ -1137,21 +1117,20 @@ static ssize_t mapping_store(struct device *dev, struct device_attribute *attr, if (rc) return rc; - rc = -ENXIO; - device_lock(dax_region->dev); - if (!dax_region->dev->driver) { - device_unlock(dax_region->dev); - return rc; - } - device_lock(dev); + guard(device)(dax_region->dev); + if (!dax_region->dev->driver) + return -ENXIO; + guard(device)(dev); to_alloc = range_len(&r); - if (alloc_is_aligned(dev_dax, to_alloc)) - rc = alloc_dev_dax_range(dev_dax, r.start, to_alloc); - device_unlock(dev); - device_unlock(dax_region->dev); + if (!alloc_is_aligned(dev_dax, to_alloc)) + return -ENXIO; - return rc == 0 ? len : rc; + rc = alloc_dev_dax_range(dev_dax, r.start, to_alloc); + if (rc) + return rc; + + return len; } static DEVICE_ATTR_WO(mapping); @@ -1196,27 +1175,23 @@ static ssize_t align_store(struct device *dev, struct device_attribute *attr, if (!dax_align_valid(val)) return -EINVAL; - device_lock(dax_region->dev); - if (!dax_region->dev->driver) { - device_unlock(dax_region->dev); + guard(device)(dax_region->dev); + if (!dax_region->dev->driver) return -ENXIO; - } - device_lock(dev); - if (dev->driver) { - rc = -EBUSY; - goto out_unlock; - } + guard(device)(dev); + if (dev->driver) + return -EBUSY; align_save = dev_dax->align; dev_dax->align = val; rc = dev_dax_validate_align(dev_dax); - if (rc) + if (rc) { dev_dax->align = align_save; -out_unlock: - device_unlock(dev); - device_unlock(dax_region->dev); - return rc == 0 ? len : rc; + return rc; + } + + return len; } static DEVICE_ATTR_RW(align); From patchwork Thu Dec 14 07:37:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13492520 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="NR65oHmK" Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 103E810C; Wed, 13 Dec 2023 23:38:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702539495; x=1734075495; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=VTyAcMOb3p9TMnLFpPQVGZqQ3IoF/IW/eEzVelz5aSE=; b=NR65oHmKWkxWVng0q57WPxqK++qQv3W7WInG1m4wQPtZKAwlRsPpgKpI r3jONdZiEnbI7VW1BsLK522unvj8r3d92XzYEPxA/E5asvTTQdkaRSjYR Y4ZXZH7qgn6qn8LBzGAzhDjqW8PJhyxVKx7O0bLkQNqFz+1JiZfWGQBkC ordgTx7LsRmGV+wh3j+MBu6DVYLAHPmGtEYWd1NpNHNWE+R/Ci9ntXZOz kvdqGcb3Xj+aYk8gLHvWDKyJTMfm/O3EqebonNkTcnNZXARbT8Qrz09+w hjcs0zxPoMTD7vl2BrxLkHj2+0/8xvskBV3pvbKnqLtg0bhuD6lUKUj/l w==; X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="481275530" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="481275530" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:14 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="723972068" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="723972068" Received: from llblake-mobl1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.213.191.124]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:13 -0800 From: Vishal Verma Date: Thu, 14 Dec 2023 00:37:56 -0700 Subject: [PATCH v5 3/4] mm/memory_hotplug: export mhp_supports_memmap_on_memory() Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231214-vv-dax_abi-v5-3-3f7b006960b4@intel.com> References: <20231214-vv-dax_abi-v5-0-3f7b006960b4@intel.com> In-Reply-To: <20231214-vv-dax_abi-v5-0-3f7b006960b4@intel.com> To: Dan Williams , Vishal Verma , Dave Jiang , Andrew Morton , Oscar Salvador Cc: linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, David Hildenbrand , Dave Hansen , Huang Ying , Greg Kroah-Hartman , linux-mm@kvack.org, Michal Hocko X-Mailer: b4 0.13-dev-433a8 X-Developer-Signature: v=1; a=openpgp-sha256; l=4625; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=VTyAcMOb3p9TMnLFpPQVGZqQ3IoF/IW/eEzVelz5aSE=; b=owGbwMvMwCXGf25diOft7jLG02pJDKlVGx4pb98Uu1/qmbru9H/PH6bM1J0/7UV3iMK//UUCo ZtfqC/k7ihlYRDjYpAVU2T5u+cj4zG57fk8gQmOMHNYmUCGMHBxCsBEUiMYGVbuX/Wr9FcXs9aM oDlX6jRyr1fI/1s065G+YX6fQ+ehP6sYGV4/iDWrnHaq9Xa2THW3oGnTxgemL7ds3qmhVXMi5Nu BHB4A X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF In preparation for adding sysfs ABI to toggle memmap_on_memory semantics for drivers adding memory, export the mhp_supports_memmap_on_memory() helper. This allows drivers to check if memmap_on_memory support is available before trying to request it, and display an appropriate message if it isn't available. As part of this, remove the size argument to this - with recent updates to allow memmap_on_memory for larger ranges, and the internal splitting of altmaps into respective memory blocks, the size argument is meaningless. Cc: Andrew Morton Cc: David Hildenbrand Cc: Michal Hocko Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Suggested-by: David Hildenbrand Signed-off-by: Vishal Verma Acked-by: David Hildenbrand --- include/linux/memory_hotplug.h | 6 ++++++ mm/memory_hotplug.c | 17 ++++++----------- 2 files changed, 12 insertions(+), 11 deletions(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 7d2076583494..ebc9d528f00c 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -121,6 +121,7 @@ struct mhp_params { bool mhp_range_allowed(u64 start, u64 size, bool need_mapping); struct range mhp_get_pluggable_range(bool need_mapping); +bool mhp_supports_memmap_on_memory(void); /* * Zone resizing functions @@ -262,6 +263,11 @@ static inline bool movable_node_is_enabled(void) return false; } +static bool mhp_supports_memmap_on_memory(void) +{ + return false; +} + static inline void pgdat_kswapd_lock(pg_data_t *pgdat) {} static inline void pgdat_kswapd_unlock(pg_data_t *pgdat) {} static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat) {} diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 926e1cfb10e9..751664c519f7 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1325,7 +1325,7 @@ static inline bool arch_supports_memmap_on_memory(unsigned long vmemmap_size) } #endif -static bool mhp_supports_memmap_on_memory(unsigned long size) +bool mhp_supports_memmap_on_memory(void) { unsigned long vmemmap_size = memory_block_memmap_size(); unsigned long memmap_pages = memory_block_memmap_on_memory_pages(); @@ -1334,17 +1334,11 @@ static bool mhp_supports_memmap_on_memory(unsigned long size) * Besides having arch support and the feature enabled at runtime, we * need a few more assumptions to hold true: * - * a) We span a single memory block: memory onlining/offlinin;g happens - * in memory block granularity. We don't want the vmemmap of online - * memory blocks to reside on offline memory blocks. In the future, - * we might want to support variable-sized memory blocks to make the - * feature more versatile. - * - * b) The vmemmap pages span complete PMDs: We don't want vmemmap code + * a) The vmemmap pages span complete PMDs: We don't want vmemmap code * to populate memory from the altmap for unrelated parts (i.e., * other memory blocks) * - * c) The vmemmap pages (and thereby the pages that will be exposed to + * b) The vmemmap pages (and thereby the pages that will be exposed to * the buddy) have to cover full pageblocks: memory onlining/offlining * code requires applicable ranges to be page-aligned, for example, to * set the migratetypes properly. @@ -1356,7 +1350,7 @@ static bool mhp_supports_memmap_on_memory(unsigned long size) * altmap as an alternative source of memory, and we do not exactly * populate a single PMD. */ - if (!mhp_memmap_on_memory() || size != memory_block_size_bytes()) + if (!mhp_memmap_on_memory()) return false; /* @@ -1379,6 +1373,7 @@ static bool mhp_supports_memmap_on_memory(unsigned long size) return arch_supports_memmap_on_memory(vmemmap_size); } +EXPORT_SYMBOL_GPL(mhp_supports_memmap_on_memory); static void __ref remove_memory_blocks_and_altmaps(u64 start, u64 size) { @@ -1512,7 +1507,7 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) * Self hosted memmap array */ if ((mhp_flags & MHP_MEMMAP_ON_MEMORY) && - mhp_supports_memmap_on_memory(memory_block_size_bytes())) { + mhp_supports_memmap_on_memory()) { ret = create_altmaps_and_memory_blocks(nid, group, start, size); if (ret) goto error; From patchwork Thu Dec 14 07:37:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13492521 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ADwO/gQ3" Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D98EA3; Wed, 13 Dec 2023 23:38:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702539496; x=1734075496; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=jYMqTdWolji6J2rYKSsSVwH7OXLij+oakPFuQznWwJY=; b=ADwO/gQ3mOTOcE4xSwYOzyfhLCfYfPsYd3LZ5c71TNmXiQoDARXJtebF zdp+eb3yCGs+dzBjEAxGzqLyyXUtZQp+S9wBUizms6Sus0P1FPXV2kUKS Y9c65u6ge5R3I62bEFR5fUCpHT2DtvFAgXn6Oibd04jZuIHSvLcpGYZpK QnhwA9NgQe09rA7ycbo7FffxGFbG+sgCTEN3sxySyA826KVZI47uo9Kp9 8p3Jwzgf6y2hd01x+K2vuQCxsdhNABKvcj34M6uzvtu/WtxsdmN/MLqVO yGuJScFb3HjzKq+ZA34drmwl8++Liejg/B8R7/+IbRsFZU463Sv0x2yoP w==; X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="481275541" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="481275541" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:15 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="723972075" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="723972075" Received: from llblake-mobl1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.213.191.124]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:14 -0800 From: Vishal Verma Date: Thu, 14 Dec 2023 00:37:57 -0700 Subject: [PATCH v5 4/4] dax: add a sysfs knob to control memmap_on_memory behavior Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231214-vv-dax_abi-v5-4-3f7b006960b4@intel.com> References: <20231214-vv-dax_abi-v5-0-3f7b006960b4@intel.com> In-Reply-To: <20231214-vv-dax_abi-v5-0-3f7b006960b4@intel.com> To: Dan Williams , Vishal Verma , Dave Jiang , Andrew Morton , Oscar Salvador Cc: linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, David Hildenbrand , Dave Hansen , Huang Ying , Greg Kroah-Hartman , linux-mm@kvack.org, Li Zhijian , Jonathan Cameron X-Mailer: b4 0.13-dev-433a8 X-Developer-Signature: v=1; a=openpgp-sha256; l=3902; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=jYMqTdWolji6J2rYKSsSVwH7OXLij+oakPFuQznWwJY=; b=owGbwMvMwCXGf25diOft7jLG02pJDKlVGx4xGLwMeT8h+dTH8ILmoEoW649mq5eJfrI008iZd dHkQLRRRykLgxgXg6yYIsvfPR8Zj8ltz+cJTHCEmcPKBDaEi1MAJhKYxsgw/8ehpzXc1V8u7tt1 7WqTeHdgvEtK+ZM+7val85Qn6ao7MjLsucZTNdV7da/OS+73H804o1XEmnZ7n/p5accFhRezdDU 4AA== X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Add a sysfs knob for dax devices to control the memmap_on_memory setting if the dax device were to be hotplugged as system memory. The default memmap_on_memory setting for dax devices originating via pmem or hmem is set to 'false' - i.e. no memmap_on_memory semantics, to preserve legacy behavior. For dax devices via CXL, the default is on. The sysfs control allows the administrator to override the above defaults if needed. Cc: David Hildenbrand Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Tested-by: Li Zhijian Reviewed-by: Jonathan Cameron Reviewed-by: David Hildenbrand Signed-off-by: Vishal Verma --- drivers/dax/bus.c | 38 +++++++++++++++++++++++++++++++++ Documentation/ABI/testing/sysfs-bus-dax | 17 +++++++++++++++ 2 files changed, 55 insertions(+) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 6226de131d17..f4d3beec507c 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -1245,6 +1245,43 @@ static ssize_t numa_node_show(struct device *dev, } static DEVICE_ATTR_RO(numa_node); +static ssize_t memmap_on_memory_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + + return sprintf(buf, "%d\n", dev_dax->memmap_on_memory); +} + +static ssize_t memmap_on_memory_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_device_driver *dax_drv; + ssize_t rc; + bool val; + + rc = kstrtobool(buf, &val); + if (rc) + return rc; + + if (val == true && !mhp_supports_memmap_on_memory()) { + dev_dbg(dev, "memmap_on_memory is not available\n"); + return -EOPNOTSUPP; + } + + guard(device)(dev); + dax_drv = to_dax_drv(dev->driver); + if (dax_drv && dev_dax->memmap_on_memory != val && + dax_drv->type == DAXDRV_KMEM_TYPE) + return -EBUSY; + dev_dax->memmap_on_memory = val; + + return len; +} +static DEVICE_ATTR_RW(memmap_on_memory); + static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = container_of(kobj, struct device, kobj); @@ -1271,6 +1308,7 @@ static struct attribute *dev_dax_attributes[] = { &dev_attr_align.attr, &dev_attr_resource.attr, &dev_attr_numa_node.attr, + &dev_attr_memmap_on_memory.attr, NULL, }; diff --git a/Documentation/ABI/testing/sysfs-bus-dax b/Documentation/ABI/testing/sysfs-bus-dax index 6359f7bc9bf4..40d9965733b2 100644 --- a/Documentation/ABI/testing/sysfs-bus-dax +++ b/Documentation/ABI/testing/sysfs-bus-dax @@ -134,3 +134,20 @@ KernelVersion: v5.1 Contact: nvdimm@lists.linux.dev Description: (RO) The id attribute indicates the region id of a dax region. + +What: /sys/bus/dax/devices/daxX.Y/memmap_on_memory +Date: October, 2023 +KernelVersion: v6.8 +Contact: nvdimm@lists.linux.dev +Description: + (RW) Control the memmap_on_memory setting if the dax device + were to be hotplugged as system memory. This determines whether + the 'altmap' for the hotplugged memory will be placed on the + device being hotplugged (memmap_on_memory=1) or if it will be + placed on regular memory (memmap_on_memory=0). This attribute + must be set before the device is handed over to the 'kmem' + driver (i.e. hotplugged into system-ram). Additionally, this + depends on CONFIG_MHP_MEMMAP_ON_MEMORY, and a globally enabled + memmap_on_memory parameter for memory_hotplug. This is + typically set on the kernel command line - + memory_hotplug.memmap_on_memory set to 'true' or 'force'."