Commit b80892ca authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Dan Williams
Browse files

memremap: remove support for external pgmap refcounts 



No driver is left using the external pgmap refcount, so remove the
code to support it.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211028151017.50234-1-hch@lst.de


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent b842f1d1

drivers/pci/p2pdma.c

+1 −1
Original line number Diff line number Diff line
@@ -219,7 +219,7 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size, 
	error = gen_pool_add_owner(p2pdma->pool, (unsigned long)addr,

			pci_bus_address(pdev, bar) + offset,

			range_len(&pgmap->range), dev_to_node(&pdev->dev),

			pgmap->ref);

			&pgmap->ref);

	if (error)

		goto pages_free;

include/linux/memremap.h

+3 −15
Original line number Diff line number Diff line
@@ -72,16 +72,6 @@ struct dev_pagemap_ops { 
	 */

	void (*page_free)(struct page *page);



	/*

	 * Transition the refcount in struct dev_pagemap to the dead state.

	 */

	void (*kill)(struct dev_pagemap *pgmap);



	/*

	 * Wait for refcount in struct dev_pagemap to be idle and reap it.

	 */

	void (*cleanup)(struct dev_pagemap *pgmap);



	/*

	 * Used for private (un-addressable) device memory only.  Must migrate

	 * the page back to a CPU accessible page.
@@ -95,8 +85,7 @@ struct dev_pagemap_ops { 
 * struct dev_pagemap - metadata for ZONE_DEVICE mappings

 * @altmap: pre-allocated/reserved memory for vmemmap allocations

 * @ref: reference count that pins the devm_memremap_pages() mapping

 * @internal_ref: internal reference if @ref is not provided by the caller

 * @done: completion for @internal_ref

 * @done: completion for @ref

 * @type: memory type: see MEMORY_* in memory_hotplug.h

 * @flags: PGMAP_* flags to specify defailed behavior

 * @ops: method table
@@ -109,8 +98,7 @@ struct dev_pagemap_ops { 
 */

struct dev_pagemap {

	struct vmem_altmap altmap;

	struct percpu_ref *ref;

	struct percpu_ref internal_ref;

	struct percpu_ref ref;

	struct completion done;

	enum memory_type type;

	unsigned int flags;
@@ -191,7 +179,7 @@ static inline unsigned long memremap_compat_align(void) 
static inline void put_dev_pagemap(struct dev_pagemap *pgmap)

{

	if (pgmap)

		percpu_ref_put(pgmap->ref);

		percpu_ref_put(&pgmap->ref);

}



#endif /* _LINUX_MEMREMAP_H_ */

mm/memremap.c

+12 −47
Original line number Diff line number Diff line
@@ -112,30 +112,6 @@ static unsigned long pfn_next(unsigned long pfn) 
#define for_each_device_pfn(pfn, map, i) \

	for (pfn = pfn_first(map, i); pfn < pfn_end(map, i); pfn = pfn_next(pfn))



static void dev_pagemap_kill(struct dev_pagemap *pgmap)

{

	if (pgmap->ops && pgmap->ops->kill)

		pgmap->ops->kill(pgmap);

	else

		percpu_ref_kill(pgmap->ref);

}



static void dev_pagemap_cleanup(struct dev_pagemap *pgmap)

{

	if (pgmap->ops && pgmap->ops->cleanup) {

		pgmap->ops->cleanup(pgmap);

	} else {

		wait_for_completion(&pgmap->done);

		percpu_ref_exit(pgmap->ref);

	}

	/*

	 * Undo the pgmap ref assignment for the internal case as the

	 * caller may re-enable the same pgmap.

	 */

	if (pgmap->ref == &pgmap->internal_ref)

		pgmap->ref = NULL;

}



static void pageunmap_range(struct dev_pagemap *pgmap, int range_id)

{

	struct range *range = &pgmap->ranges[range_id];
@@ -167,11 +143,12 @@ void memunmap_pages(struct dev_pagemap *pgmap) 
	unsigned long pfn;

	int i;



	dev_pagemap_kill(pgmap);

	percpu_ref_kill(&pgmap->ref);

	for (i = 0; i < pgmap->nr_range; i++)

		for_each_device_pfn(pfn, pgmap, i)

			put_page(pfn_to_page(pfn));

	dev_pagemap_cleanup(pgmap);

	wait_for_completion(&pgmap->done);

	percpu_ref_exit(&pgmap->ref);



	for (i = 0; i < pgmap->nr_range; i++)

		pageunmap_range(pgmap, i);
@@ -188,8 +165,7 @@ static void devm_memremap_pages_release(void *data) 


static void dev_pagemap_percpu_release(struct percpu_ref *ref)

{

	struct dev_pagemap *pgmap =

		container_of(ref, struct dev_pagemap, internal_ref);

	struct dev_pagemap *pgmap = container_of(ref, struct dev_pagemap, ref);



	complete(&pgmap->done);

}
@@ -295,8 +271,8 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params, 
	memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],

				PHYS_PFN(range->start),

				PHYS_PFN(range_len(range)), pgmap);

	percpu_ref_get_many(pgmap->ref, pfn_end(pgmap, range_id)

			- pfn_first(pgmap, range_id));

	percpu_ref_get_many(&pgmap->ref,

		pfn_end(pgmap, range_id) - pfn_first(pgmap, range_id));

	return 0;



err_add_memory:
@@ -362,22 +338,11 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) 
		break;

	}



	if (!pgmap->ref) {

		if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup))

			return ERR_PTR(-EINVAL);



	init_completion(&pgmap->done);

		error = percpu_ref_init(&pgmap->internal_ref,

				dev_pagemap_percpu_release, 0, GFP_KERNEL);

	error = percpu_ref_init(&pgmap->ref, dev_pagemap_percpu_release, 0,

				GFP_KERNEL);

	if (error)

		return ERR_PTR(error);

		pgmap->ref = &pgmap->internal_ref;

	} else {

		if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) {

			WARN(1, "Missing reference count teardown definition\n");

			return ERR_PTR(-EINVAL);

		}

	}



	devmap_managed_enable_get(pgmap);
@@ -486,7 +451,7 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn, 
	/* fall back to slow path lookup */

	rcu_read_lock();

	pgmap = xa_load(&pgmap_array, PHYS_PFN(phys));

	if (pgmap && !percpu_ref_tryget_live(pgmap->ref))

	if (pgmap && !percpu_ref_tryget_live(&pgmap->ref))

		pgmap = NULL;

	rcu_read_unlock();

tools/testing/nvdimm/test/iomap.c

+12 −31
Original line number Diff line number Diff line
@@ -100,25 +100,17 @@ static void nfit_test_kill(void *_pgmap) 
{

	struct dev_pagemap *pgmap = _pgmap;



	WARN_ON(!pgmap || !pgmap->ref);

	WARN_ON(!pgmap);



	if (pgmap->ops && pgmap->ops->kill)

		pgmap->ops->kill(pgmap);

	else

		percpu_ref_kill(pgmap->ref);

	percpu_ref_kill(&pgmap->ref);



	if (pgmap->ops && pgmap->ops->cleanup) {

		pgmap->ops->cleanup(pgmap);

	} else {

	wait_for_completion(&pgmap->done);

		percpu_ref_exit(pgmap->ref);

	}

	percpu_ref_exit(&pgmap->ref);

}



static void dev_pagemap_percpu_release(struct percpu_ref *ref)

{

	struct dev_pagemap *pgmap =

		container_of(ref, struct dev_pagemap, internal_ref);

	struct dev_pagemap *pgmap = container_of(ref, struct dev_pagemap, ref);



	complete(&pgmap->done);

}
@@ -132,22 +124,11 @@ void *__wrap_devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) 
	if (!nfit_res)

		return devm_memremap_pages(dev, pgmap);



	if (!pgmap->ref) {

		if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup))

			return ERR_PTR(-EINVAL);



	init_completion(&pgmap->done);

		error = percpu_ref_init(&pgmap->internal_ref,

				dev_pagemap_percpu_release, 0, GFP_KERNEL);

	error = percpu_ref_init(&pgmap->ref, dev_pagemap_percpu_release, 0,

				GFP_KERNEL);

	if (error)

		return ERR_PTR(error);

		pgmap->ref = &pgmap->internal_ref;

	} else {

		if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) {

			WARN(1, "Missing reference count teardown definition\n");

			return ERR_PTR(-EINVAL);

		}

	}



	error = devm_add_action_or_reset(dev, nfit_test_kill, pgmap);

	if (error)