From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f199.google.com (mail-qt0-f199.google.com [209.85.216.199]) by kanga.kvack.org (Postfix) with ESMTP id C8DD08E0001 for ; Tue, 18 Sep 2018 16:35:42 -0400 (EDT) Received: by mail-qt0-f199.google.com with SMTP id e88-v6so2407634qtb.1 for ; Tue, 18 Sep 2018 13:35:42 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id a8-v6si7301934qvn.86.2018.09.18.13.35.41 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Sep 2018 13:35:41 -0700 (PDT) Date: Tue, 18 Sep 2018 16:35:37 -0400 From: Jerome Glisse Subject: Re: [PATCH v5 6/7] mm, hmm: Replace hmm_devmem_pages_create() with devm_memremap_pages() Message-ID: <20180918203537.GF14689@redhat.com> References: <153680531988.453305.8080706591516037706.stgit@dwillia2-desk3.amr.corp.intel.com> <153680535314.453305.11205770267271657025.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <153680535314.453305.11205770267271657025.stgit@dwillia2-desk3.amr.corp.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dan Williams Cc: akpm@linux-foundation.org, Christoph Hellwig , Logan Gunthorpe , alexander.h.duyck@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Wed, Sep 12, 2018 at 07:22:33PM -0700, Dan Williams wrote: > Commit e8d513483300 "memremap: change devm_memremap_pages interface to > use struct dev_pagemap" refactored devm_memremap_pages() to allow a > dev_pagemap instance to be supplied. Passing in a dev_pagemap interface > simplifies the design of pgmap type drivers in that they can rely on > container_of() to lookup any private data associated with the given > dev_pagemap instance. > > In addition to the cleanups this also gives hmm users multi-order-radix > improvements that arrived with commit ab1b597ee0e4 "mm, > devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups" > > As part of the conversion to the devm_memremap_pages() method of > handling the percpu_ref relative to when pages are put, the percpu_ref > completion needs to move to hmm_devmem_ref_exit(). See commit > 71389703839e ("mm, zone_device: Replace {get, put}_zone_device_page...") > for details. > > Reviewed-by: Christoph Hellwig Reviewed-by: Jerome Glisse > Cc: Logan Gunthorpe > Signed-off-by: Dan Williams > --- > mm/hmm.c | 194 ++++++++------------------------------------------------------ > 1 file changed, 26 insertions(+), 168 deletions(-) > > diff --git a/mm/hmm.c b/mm/hmm.c > index ec1d9eccf176..c6cab5205b99 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -938,17 +938,16 @@ static void hmm_devmem_ref_exit(void *data) > struct hmm_devmem *devmem; > > devmem = container_of(ref, struct hmm_devmem, ref); > + wait_for_completion(&devmem->completion); > percpu_ref_exit(ref); > } > > -static void hmm_devmem_ref_kill(void *data) > +static void hmm_devmem_ref_kill(struct percpu_ref *ref) > { > - struct percpu_ref *ref = data; > struct hmm_devmem *devmem; > > devmem = container_of(ref, struct hmm_devmem, ref); > percpu_ref_kill(ref); > - wait_for_completion(&devmem->completion); > } > > static int hmm_devmem_fault(struct vm_area_struct *vma, > @@ -971,152 +970,6 @@ static void hmm_devmem_free(struct page *page, void *data) > devmem->ops->free(devmem, page); > } > > -static DEFINE_MUTEX(hmm_devmem_lock); > -static RADIX_TREE(hmm_devmem_radix, GFP_KERNEL); > - > -static void hmm_devmem_radix_release(struct resource *resource) > -{ > - resource_size_t key; > - > - mutex_lock(&hmm_devmem_lock); > - for (key = resource->start; > - key <= resource->end; > - key += PA_SECTION_SIZE) > - radix_tree_delete(&hmm_devmem_radix, key >> PA_SECTION_SHIFT); > - mutex_unlock(&hmm_devmem_lock); > -} > - > -static void hmm_devmem_release(void *data) > -{ > - struct hmm_devmem *devmem = data; > - struct resource *resource = devmem->resource; > - unsigned long start_pfn, npages; > - struct zone *zone; > - struct page *page; > - > - /* pages are dead and unused, undo the arch mapping */ > - start_pfn = (resource->start & ~(PA_SECTION_SIZE - 1)) >> PAGE_SHIFT; > - npages = ALIGN(resource_size(resource), PA_SECTION_SIZE) >> PAGE_SHIFT; > - > - page = pfn_to_page(start_pfn); > - zone = page_zone(page); > - > - mem_hotplug_begin(); > - if (resource->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) > - __remove_pages(zone, start_pfn, npages, NULL); > - else > - arch_remove_memory(start_pfn << PAGE_SHIFT, > - npages << PAGE_SHIFT, NULL); > - mem_hotplug_done(); > - > - hmm_devmem_radix_release(resource); > -} > - > -static int hmm_devmem_pages_create(struct hmm_devmem *devmem) > -{ > - resource_size_t key, align_start, align_size, align_end; > - struct device *device = devmem->device; > - int ret, nid, is_ram; > - unsigned long pfn; > - > - align_start = devmem->resource->start & ~(PA_SECTION_SIZE - 1); > - align_size = ALIGN(devmem->resource->start + > - resource_size(devmem->resource), > - PA_SECTION_SIZE) - align_start; > - > - is_ram = region_intersects(align_start, align_size, > - IORESOURCE_SYSTEM_RAM, > - IORES_DESC_NONE); > - if (is_ram == REGION_MIXED) { > - WARN_ONCE(1, "%s attempted on mixed region %pr\n", > - __func__, devmem->resource); > - return -ENXIO; > - } > - if (is_ram == REGION_INTERSECTS) > - return -ENXIO; > - > - 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; > - devmem->pagemap.dev = devmem->device; > - devmem->pagemap.ref = &devmem->ref; > - devmem->pagemap.data = devmem; > - > - mutex_lock(&hmm_devmem_lock); > - align_end = align_start + align_size - 1; > - for (key = align_start; key <= align_end; key += PA_SECTION_SIZE) { > - struct hmm_devmem *dup; > - > - dup = radix_tree_lookup(&hmm_devmem_radix, > - key >> PA_SECTION_SHIFT); > - if (dup) { > - dev_err(device, "%s: collides with mapping for %s\n", > - __func__, dev_name(dup->device)); > - mutex_unlock(&hmm_devmem_lock); > - ret = -EBUSY; > - goto error; > - } > - ret = radix_tree_insert(&hmm_devmem_radix, > - key >> PA_SECTION_SHIFT, > - devmem); > - if (ret) { > - dev_err(device, "%s: failed: %d\n", __func__, ret); > - mutex_unlock(&hmm_devmem_lock); > - goto error_radix; > - } > - } > - mutex_unlock(&hmm_devmem_lock); > - > - nid = dev_to_node(device); > - if (nid < 0) > - nid = numa_mem_id(); > - > - mem_hotplug_begin(); > - /* > - * For device private memory we call add_pages() as we only need to > - * allocate and initialize struct page for the device memory. More- > - * 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(). > - */ > - if (devmem->pagemap.type == MEMORY_DEVICE_PUBLIC) > - ret = arch_add_memory(nid, align_start, align_size, NULL, > - false); > - else > - ret = add_pages(nid, align_start >> PAGE_SHIFT, > - align_size >> PAGE_SHIFT, NULL, false); > - if (ret) { > - mem_hotplug_done(); > - goto error_add_memory; > - } > - move_pfn_range_to_zone(&NODE_DATA(nid)->node_zones[ZONE_DEVICE], > - align_start >> PAGE_SHIFT, > - align_size >> PAGE_SHIFT, NULL); > - mem_hotplug_done(); > - > - for (pfn = devmem->pfn_first; pfn < devmem->pfn_last; pfn++) { > - struct page *page = pfn_to_page(pfn); > - > - page->pgmap = &devmem->pagemap; > - } > - return 0; > - > -error_add_memory: > - untrack_pfn(NULL, PHYS_PFN(align_start), align_size); > -error_radix: > - hmm_devmem_radix_release(devmem->resource); > -error: > - return ret; > -} > - > /* > * hmm_devmem_add() - hotplug ZONE_DEVICE memory for device memory > * > @@ -1140,6 +993,7 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, > { > struct hmm_devmem *devmem; > resource_size_t addr; > + void *result; > int ret; > > dev_pagemap_get_ops(); > @@ -1194,14 +1048,18 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, > devmem->pfn_last = devmem->pfn_first + > (resource_size(devmem->resource) >> PAGE_SHIFT); > > - ret = hmm_devmem_pages_create(devmem); > - if (ret) > - return ERR_PTR(ret); > - > - ret = devm_add_action_or_reset(device, hmm_devmem_release, devmem); > - if (ret) > - return ERR_PTR(ret); > + 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; > + devmem->pagemap.altmap_valid = false; > + devmem->pagemap.ref = &devmem->ref; > + devmem->pagemap.data = devmem; > > + result = devm_memremap_pages(devmem->device, &devmem->pagemap, > + hmm_devmem_ref_kill); > + if (IS_ERR(result)) > + return result; > return devmem; > } > EXPORT_SYMBOL(hmm_devmem_add); > @@ -1211,6 +1069,7 @@ struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, > struct resource *res) > { > struct hmm_devmem *devmem; > + void *result; > int ret; > > if (res->desc != IORES_DESC_DEVICE_PUBLIC_MEMORY) > @@ -1243,19 +1102,18 @@ struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, > devmem->pfn_last = devmem->pfn_first + > (resource_size(devmem->resource) >> PAGE_SHIFT); > > - ret = hmm_devmem_pages_create(devmem); > - if (ret) > - return ERR_PTR(ret); > - > - ret = devm_add_action_or_reset(device, hmm_devmem_release, devmem); > - if (ret) > - return ERR_PTR(ret); > - > - ret = devm_add_action_or_reset(device, hmm_devmem_ref_kill, > - &devmem->ref); > - if (ret) > - return ERR_PTR(ret); > + devmem->pagemap.type = MEMORY_DEVICE_PUBLIC; > + devmem->pagemap.res = *devmem->resource; > + devmem->pagemap.page_fault = hmm_devmem_fault; > + devmem->pagemap.page_free = hmm_devmem_free; > + devmem->pagemap.altmap_valid = false; > + devmem->pagemap.ref = &devmem->ref; > + devmem->pagemap.data = devmem; > > + result = devm_memremap_pages(devmem->device, &devmem->pagemap, > + hmm_devmem_ref_kill); > + if (IS_ERR(result)) > + return result; > return devmem; > } > EXPORT_SYMBOL(hmm_devmem_add_resource); >