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Commit e890a867 authored by Dan Williams's avatar Dan Williams Committed by Greg Kroah-Hartman
Browse files

mm, hmm: use devm semantics for hmm_devmem_{add, remove} 

commit 58ef15b765af0d2cbe6799ec564f1dc485010ab8 upstream.

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.

Note that devm_kzalloc() automatically handles allocating node-local
memory.

Link: http://lkml.kernel.org/r/154275559545.76910.9186690723515469051.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>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Balbir Singh <bsingharora@gmail.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>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c215c66c

include/linux/hmm.h

+1 −3
Original line number Diff line number Diff line
@@ -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

mm/hmm.c

+24 −103
Original line number Diff line number Diff line
@@ -945,7 +945,6 @@ static void hmm_devmem_ref_exit(void *data) 


	devmem = container_of(ref, struct hmm_devmem, ref);

	percpu_ref_exit(ref);

	devm_remove_action(devmem->device, &hmm_devmem_ref_exit, data);

}



static void hmm_devmem_ref_kill(void *data)
@@ -956,7 +955,6 @@ static void hmm_devmem_ref_kill(void *data) 
	devmem = container_of(ref, struct hmm_devmem, ref);

	percpu_ref_kill(ref);

	wait_for_completion(&devmem->completion);

	devm_remove_action(devmem->device, &hmm_devmem_ref_kill, data);

}



static int hmm_devmem_fault(struct vm_area_struct *vma,
@@ -994,7 +992,7 @@ 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 resource *resource = devmem->resource;
@@ -1002,11 +1000,6 @@ static void hmm_devmem_release(struct device *dev, void *data) 
	struct zone *zone;

	struct page *page;



	if (percpu_ref_tryget_live(&devmem->ref)) {

		dev_WARN(dev, "%s: page mapping is still live!\n", __func__);

		percpu_ref_put(&devmem->ref);

	}



	/* 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;
@@ -1130,19 +1123,6 @@ 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

 *
@@ -1170,8 +1150,7 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, 


	dev_pagemap_get_ops();



	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);
@@ -1185,11 +1164,11 @@ 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,
@@ -1209,16 +1188,12 @@ 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;
@@ -1227,28 +1202,13 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, 


	ret = hmm_devmem_pages_create(devmem);

	if (ret)

		goto error_pages;



	devres_add(device, devmem);

		return ERR_PTR(ret);



	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_release, devmem);

	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);
@@ -1264,8 +1224,7 @@ struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, 


	dev_pagemap_get_ops();



	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);
@@ -1279,12 +1238,12 @@ 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 +
@@ -1292,59 +1251,21 @@ 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);



	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