Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752510AbdHQAGa (ORCPT ); Wed, 16 Aug 2017 20:06:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39424 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752465AbdHQAG1 (ORCPT ); Wed, 16 Aug 2017 20:06:27 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 9275C1C13D3 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=jglisse@redhat.com From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: John Hubbard , Dan Williams , David Nellans , Balbir Singh , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Subject: [HMM-v25 19/19] mm/hmm: add new helper to hotplug CDM memory region v3 Date: Wed, 16 Aug 2017 20:05:48 -0400 Message-Id: <20170817000548.32038-20-jglisse@redhat.com> In-Reply-To: <20170817000548.32038-1-jglisse@redhat.com> References: <20170817000548.32038-1-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 17 Aug 2017 00:06:26 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5220 Lines: 172 Unlike unaddressable memory, coherent device memory has a real resource associated with it on the system (as CPU can address it). Add a new helper to hotplug such memory within the HMM framework. Changed since v2: - s/host/public Changed since v1: - s/public/host Signed-off-by: Jérôme Glisse Reviewed-by: Balbir Singh --- include/linux/hmm.h | 3 ++ mm/hmm.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 86 insertions(+), 5 deletions(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 79e63178fd87..5866f3194c26 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -443,6 +443,9 @@ struct hmm_devmem { struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, struct device *device, unsigned long size); +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); /* diff --git a/mm/hmm.c b/mm/hmm.c index 1a1e79d390c1..3faa4d40295e 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -854,7 +854,11 @@ static void hmm_devmem_release(struct device *dev, void *data) zone = page_zone(page); mem_hotplug_begin(); - __remove_pages(zone, start_pfn, npages); + if (resource->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) + __remove_pages(zone, start_pfn, npages); + else + arch_remove_memory(start_pfn << PAGE_SHIFT, + npages << PAGE_SHIFT); mem_hotplug_done(); hmm_devmem_radix_release(resource); @@ -890,7 +894,11 @@ static int hmm_devmem_pages_create(struct hmm_devmem *devmem) if (is_ram == REGION_INTERSECTS) return -ENXIO; - devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; + if (devmem->resource->desc == IORES_DESC_DEVICE_PUBLIC_MEMORY) + devmem->pagemap.type = MEMORY_DEVICE_PUBLIC; + else + devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; + devmem->pagemap.res = devmem->resource; devmem->pagemap.page_fault = hmm_devmem_fault; devmem->pagemap.page_free = hmm_devmem_free; @@ -935,9 +943,15 @@ static int hmm_devmem_pages_create(struct hmm_devmem *devmem) * over the device memory is un-accessible thus we do not want to * create a linear mapping for the memory like arch_add_memory() * would do. + * + * For device public memory, which is accesible by the CPU, we do + * want the linear mapping and thus use arch_add_memory(). */ - ret = add_pages(nid, align_start >> PAGE_SHIFT, - align_size >> PAGE_SHIFT, false); + if (devmem->pagemap.type == MEMORY_DEVICE_PUBLIC) + ret = arch_add_memory(nid, align_start, align_size, false); + else + ret = add_pages(nid, align_start >> PAGE_SHIFT, + align_size >> PAGE_SHIFT, false); if (ret) { mem_hotplug_done(); goto error_add_memory; @@ -1084,6 +1098,67 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, } EXPORT_SYMBOL(hmm_devmem_add); +struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, + struct device *device, + struct resource *res) +{ + struct hmm_devmem *devmem; + int ret; + + if (res->desc != IORES_DESC_DEVICE_PUBLIC_MEMORY) + return ERR_PTR(-EINVAL); + + static_branch_enable(&device_private_key); + + devmem = devres_alloc_node(&hmm_devmem_release, sizeof(*devmem), + GFP_KERNEL, dev_to_node(device)); + if (!devmem) + return ERR_PTR(-ENOMEM); + + init_completion(&devmem->completion); + devmem->pfn_first = -1UL; + devmem->pfn_last = -1UL; + devmem->resource = res; + devmem->device = device; + devmem->ops = ops; + + ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release, + 0, GFP_KERNEL); + if (ret) + goto error_percpu_ref; + + ret = devm_add_action(device, hmm_devmem_ref_exit, &devmem->ref); + if (ret) + goto error_devm_add_action; + + + devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; + devmem->pfn_last = devmem->pfn_first + + (resource_size(devmem->resource) >> PAGE_SHIFT); + + ret = hmm_devmem_pages_create(devmem); + if (ret) + goto error_devm_add_action; + + devres_add(device, devmem); + + ret = devm_add_action(device, hmm_devmem_ref_kill, &devmem->ref); + if (ret) { + hmm_devmem_remove(devmem); + 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) * @@ -1097,6 +1172,7 @@ void hmm_devmem_remove(struct hmm_devmem *devmem) { resource_size_t start, size; struct device *device; + bool cdm = false; if (!devmem) return; @@ -1105,11 +1181,13 @@ void hmm_devmem_remove(struct hmm_devmem *devmem) 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); - devm_release_mem_region(device, start, size); + if (!cdm) + devm_release_mem_region(device, start, size); } EXPORT_SYMBOL(hmm_devmem_remove); -- 2.13.4