[PATCH 5.15 430/779] memremap: remove support for external pgmap refcounts
From: Greg Kroah-Hartman
Date: Mon Aug 15 2022 - 15:14:32 EST
From: Christoph Hellwig <hch@xxxxxx>
[ Upstream commit b80892ca022e9eb484771a66eb68e12364695a2a ]
No driver is left using the external pgmap refcount, so remove the
code to support it.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211028151017.50234-1-hch@xxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/pci/p2pdma.c | 2 +-
include/linux/memremap.h | 18 ++--------
mm/memremap.c | 59 +++++++------------------------
tools/testing/nvdimm/test/iomap.c | 43 +++++++---------------
4 files changed, 28 insertions(+), 94 deletions(-)
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 50cdde3e9a8b..316fd2f44df4 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -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;
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index c0e9d35889e8..a8bc588fe7aa 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -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_ */
diff --git a/mm/memremap.c b/mm/memremap.c
index e77487375c8e..a638a27d89f5 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -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);
- 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);
- }
- }
+ init_completion(&pgmap->done);
+ error = percpu_ref_init(&pgmap->ref, dev_pagemap_percpu_release, 0,
+ GFP_KERNEL);
+ if (error)
+ return ERR_PTR(error);
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();
diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c
index ed563bdd88f3..b752ce47ead3 100644
--- a/tools/testing/nvdimm/test/iomap.c
+++ b/tools/testing/nvdimm/test/iomap.c
@@ -100,25 +100,17 @@ static void nfit_test_kill(void *_pgmap)
{
struct dev_pagemap *pgmap = _pgmap;
- WARN_ON(!pgmap || !pgmap->ref);
-
- if (pgmap->ops && pgmap->ops->kill)
- pgmap->ops->kill(pgmap);
- else
- 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);
- }
+ WARN_ON(!pgmap);
+
+ percpu_ref_kill(&pgmap->ref);
+
+ wait_for_completion(&pgmap->done);
+ 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);
- 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);
- }
- }
+ init_completion(&pgmap->done);
+ error = percpu_ref_init(&pgmap->ref, dev_pagemap_percpu_release, 0,
+ GFP_KERNEL);
+ if (error)
+ return ERR_PTR(error);
error = devm_add_action_or_reset(dev, nfit_test_kill, pgmap);
if (error)
--
2.35.1