Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit bbecd94e authored by Dan Williams's avatar Dan Williams Committed by Linus Torvalds
Browse files

mm, hmm: replace hmm_devmem_pages_create() with devm_memremap_pages() 

Commit e8d51348 ("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 ab1b597e "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 71389703
("mm, zone_device: Replace {get, put}_zone_device_page...") for details.

Link: http://lkml.kernel.org/r/154275560053.76910.10870962637383152392.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJérôme Glisse <jglisse@redhat.com>
Acked-by: default avatarBalbir Singh <bsingharora@gmail.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 58ef15b7

mm/hmm.c

+26 −170
Original line number Diff line number Diff line
@@ -986,17 +986,16 @@ 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,
@@ -1019,154 +1018,6 @@ 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;



	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();



	/*

	 * Initialization of the pages has been deferred until now in order

	 * to allow us to do the work while not holding the hotplug lock.

	 */

	memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],

				align_start >> PAGE_SHIFT,

				align_size >> PAGE_SHIFT, &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

 *
@@ -1190,6 +1041,7 @@ 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();
@@ -1244,14 +1096,18 @@ 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;

	devmem->pagemap.kill = hmm_devmem_ref_kill;



	result = devm_memremap_pages(devmem->device, &devmem->pagemap);

	if (IS_ERR(result))

		return result;

	return devmem;

}

EXPORT_SYMBOL(hmm_devmem_add);
@@ -1261,6 +1117,7 @@ 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)
@@ -1293,19 +1150,18 @@ 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;

	devmem->pagemap.kill = hmm_devmem_ref_kill;



	result = devm_memremap_pages(devmem->device, &devmem->pagemap);

	if (IS_ERR(result))

		return result;

	return devmem;

}

EXPORT_SYMBOL(hmm_devmem_add_resource);