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[192.55.52.151]) by mx.google.com with ESMTPS id o24-v6si11348838pgv.80.2018.05.21.15.45.26 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 21 May 2018 15:45:27 -0700 (PDT) Received-SPF: pass (google.com: domain of dan.j.williams@intel.com designates 192.55.52.151 as permitted sender) client-ip=192.55.52.151; Authentication-Results: mx.google.com; spf=pass (google.com: domain of dan.j.williams@intel.com designates 192.55.52.151 as permitted sender) smtp.mailfrom=dan.j.williams@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 May 2018 15:45:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,427,1520924400"; d="scan'208";a="42785606" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga007.jf.intel.com with ESMTP; 21 May 2018 15:45:26 -0700 Subject: [PATCH 3/5] mm, hmm: use devm semantics for hmm_devmem_{add, remove} From: Dan Williams To: akpm@linux-foundation.org Cc: Christoph Hellwig , =?utf-8?b?SsOpcsO0bWU=?= Glisse , Logan Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Mon, 21 May 2018 15:35:29 -0700 Message-ID: <152694212973.5484.9009059511258430529.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <152694211402.5484.2277538346144115181.stgit@dwillia2-desk3.amr.corp.intel.com> References: <152694211402.5484.2277538346144115181.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: X-Virus-Scanned: ClamAV using ClamSMTP devm semantics arrange for resources to be torn down when device-driver-probe fails or when device-driver-release completes. Similar to devm_memremap_pages() there is no need to support an explicit remove operation when the users properly adhere to devm semantics. Cc: Christoph Hellwig Cc: "Jérôme Glisse" Cc: Logan Gunthorpe Signed-off-by: Dan Williams Reviewed-by: Christoph Hellwig --- Documentation/vm/hmm.txt | 1 include/linux/hmm.h | 4 - mm/hmm.c | 127 +++++++++++----------------------------------- 3 files changed, 32 insertions(+), 100 deletions(-) diff --git a/Documentation/vm/hmm.txt b/Documentation/vm/hmm.txt index 2d1d6f69e91b..b2f944b87c5e 100644 --- a/Documentation/vm/hmm.txt +++ b/Documentation/vm/hmm.txt @@ -285,7 +285,6 @@ region needing a struct page. This is offered through a very simple API: struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, struct device *device, unsigned long size); - void hmm_devmem_remove(struct hmm_devmem *devmem); The hmm_devmem_ops is where most of the important things are: diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 39988924de3a..880f6bb9485c 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -499,8 +499,7 @@ struct hmm_devmem { * enough and allocate struct page for it. * * The device driver can wrap the hmm_devmem struct inside a private device - * driver struct. The device driver must call hmm_devmem_remove() before the - * device goes away and before freeing the hmm_devmem struct memory. + * driver struct. */ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, struct device *device, @@ -508,7 +507,6 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, struct device *device, struct resource *res); -void hmm_devmem_remove(struct hmm_devmem *devmem); /* * hmm_devmem_page_set_drvdata - set per-page driver data field diff --git a/mm/hmm.c b/mm/hmm.c index 486dc394a5a3..8aa9d9fbb87b 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -993,15 +993,17 @@ static void hmm_devmem_radix_release(struct resource *resource) mutex_unlock(&hmm_devmem_lock); } -static void hmm_devmem_release(struct device *dev, void *data) +static void hmm_devmem_release(void *data) { struct hmm_devmem *devmem = data; + struct device *dev = devmem->device; struct resource *resource = devmem->resource; + struct dev_pagemap *pgmap = &devmem->pagemap; unsigned long start_pfn, npages; struct zone *zone; struct page *page; - if (percpu_ref_tryget_live(&devmem->ref)) { + if (pgmap->registered && percpu_ref_tryget_live(&devmem->ref)) { dev_WARN(dev, "%s: page mapping is still live!\n", __func__); percpu_ref_put(&devmem->ref); } @@ -1129,19 +1131,6 @@ static int hmm_devmem_pages_create(struct hmm_devmem *devmem) return ret; } -static int hmm_devmem_match(struct device *dev, void *data, void *match_data) -{ - struct hmm_devmem *devmem = data; - - return devmem->resource == match_data; -} - -static void hmm_devmem_pages_remove(struct hmm_devmem *devmem) -{ - devres_release(devmem->device, &hmm_devmem_release, - &hmm_devmem_match, devmem->resource); -} - /* * hmm_devmem_add() - hotplug ZONE_DEVICE memory for device memory * @@ -1169,8 +1158,7 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, static_branch_enable(&device_private_key); - devmem = devres_alloc_node(&hmm_devmem_release, sizeof(*devmem), - GFP_KERNEL, dev_to_node(device)); + devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL); if (!devmem) return ERR_PTR(-ENOMEM); @@ -1184,11 +1172,11 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release, 0, GFP_KERNEL); if (ret) - goto error_percpu_ref; + return ERR_PTR(ret); - ret = devm_add_action(device, hmm_devmem_ref_exit, &devmem->ref); + ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit, &devmem->ref); if (ret) - goto error_devm_add_action; + return ERR_PTR(ret); size = ALIGN(size, PA_SECTION_SIZE); addr = min((unsigned long)iomem_resource.end, @@ -1208,16 +1196,12 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, devmem->resource = devm_request_mem_region(device, addr, size, dev_name(device)); - if (!devmem->resource) { - ret = -ENOMEM; - goto error_no_resource; - } + if (!devmem->resource) + return ERR_PTR(-ENOMEM); break; } - if (!devmem->resource) { - ret = -ERANGE; - goto error_no_resource; - } + if (!devmem->resource) + return ERR_PTR(-ERANGE); devmem->resource->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY; devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; @@ -1226,28 +1210,18 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, ret = hmm_devmem_pages_create(devmem); if (ret) - goto error_pages; + return ERR_PTR(ret); - devres_add(device, devmem); + ret = devm_add_action_or_reset(device, hmm_devmem_release, devmem); + if (ret) + return ERR_PTR(ret); + devmem->pagemap.registered = true; - ret = devm_add_action(device, hmm_devmem_ref_kill, &devmem->ref); - if (ret) { - hmm_devmem_remove(devmem); + ret = devm_add_action_or_reset(device, hmm_devmem_ref_kill, &devmem->ref); + if (ret) return ERR_PTR(ret); - } return devmem; - -error_pages: - devm_release_mem_region(device, devmem->resource->start, - resource_size(devmem->resource)); -error_no_resource: -error_devm_add_action: - hmm_devmem_ref_kill(&devmem->ref); - hmm_devmem_ref_exit(&devmem->ref); -error_percpu_ref: - devres_free(devmem); - return ERR_PTR(ret); } EXPORT_SYMBOL(hmm_devmem_add); @@ -1263,8 +1237,7 @@ struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, static_branch_enable(&device_private_key); - devmem = devres_alloc_node(&hmm_devmem_release, sizeof(*devmem), - GFP_KERNEL, dev_to_node(device)); + devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL); if (!devmem) return ERR_PTR(-ENOMEM); @@ -1278,12 +1251,12 @@ struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release, 0, GFP_KERNEL); if (ret) - goto error_percpu_ref; + return ERR_PTR(ret); - ret = devm_add_action(device, hmm_devmem_ref_exit, &devmem->ref); + ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit, + &devmem->ref); if (ret) - goto error_devm_add_action; - + return ERR_PTR(ret); devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; devmem->pfn_last = devmem->pfn_first + @@ -1291,60 +1264,22 @@ struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, ret = hmm_devmem_pages_create(devmem); if (ret) - goto error_devm_add_action; + return ERR_PTR(ret); - devres_add(device, devmem); + ret = devm_add_action_or_reset(device, hmm_devmem_release, devmem); + if (ret) + return ERR_PTR(ret); + devmem->pagemap.registered = true; - ret = devm_add_action(device, hmm_devmem_ref_kill, &devmem->ref); - if (ret) { - hmm_devmem_remove(devmem); + ret = devm_add_action_or_reset(device, hmm_devmem_ref_kill, &devmem->ref); + if (ret) return ERR_PTR(ret); - } return devmem; - -error_devm_add_action: - hmm_devmem_ref_kill(&devmem->ref); - hmm_devmem_ref_exit(&devmem->ref); -error_percpu_ref: - devres_free(devmem); - return ERR_PTR(ret); } EXPORT_SYMBOL(hmm_devmem_add_resource); /* - * hmm_devmem_remove() - remove device memory (kill and free ZONE_DEVICE) - * - * @devmem: hmm_devmem struct use to track and manage the ZONE_DEVICE memory - * - * This will hot-unplug memory that was hotplugged by hmm_devmem_add on behalf - * of the device driver. It will free struct page and remove the resource that - * reserved the physical address range for this device memory. - */ -void hmm_devmem_remove(struct hmm_devmem *devmem) -{ - resource_size_t start, size; - struct device *device; - bool cdm = false; - - if (!devmem) - return; - - device = devmem->device; - start = devmem->resource->start; - size = resource_size(devmem->resource); - - cdm = devmem->resource->desc == IORES_DESC_DEVICE_PUBLIC_MEMORY; - hmm_devmem_ref_kill(&devmem->ref); - hmm_devmem_ref_exit(&devmem->ref); - hmm_devmem_pages_remove(devmem); - - if (!cdm) - devm_release_mem_region(device, start, size); -} -EXPORT_SYMBOL(hmm_devmem_remove); - -/* * A device driver that wants to handle multiple devices memory through a * single fake device can use hmm_device to do so. This is purely a helper * and it is not needed to make use of any HMM functionality.