[PATCH 4/5] memremap: don't use a separate devm action for devmap_managed_enable_get

Christoph Hellwig
2019-08-11T08:15:34Z

Just clean up for early failures and then piggy back on
devm_memremap_pages_release. This helps with a pending not device
managed version of devm_memremap_pages.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
mm/memremap.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/mm/memremap.c b/mm/memremap.c
index 600a14cbe663..09a087ca30ff 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -21,13 +21,13 @@ DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
EXPORT_SYMBOL(devmap_managed_key);
static atomic_t devmap_managed_enable;

-static void devmap_managed_enable_put(void *data)
+static void devmap_managed_enable_put(void)
{
if (atomic_dec_and_test(&devmap_managed_enable))
static_branch_disable(&devmap_managed_key);
}

-static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgmap)
+static int devmap_managed_enable_get(struct dev_pagemap *pgmap)
{
if (!pgmap->ops || !pgmap->ops->page_free) {
WARN(1, "Missing page_free method\n");
@@ -36,13 +36,16 @@ static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgm

if (atomic_inc_return(&devmap_managed_enable) == 1)
static_branch_enable(&devmap_managed_key);
- return devm_add_action_or_reset(dev, devmap_managed_enable_put, NULL);
+ return 0;
}
#else
-static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgmap)
+static int devmap_managed_enable_get(struct dev_pagemap *pgmap)
{
return -EINVAL;
}
+static void devmap_managed_enable_put(void)
+{
+}
#endif /* CONFIG_DEV_PAGEMAP_OPS */

static void pgmap_array_delete(struct resource *res)
@@ -123,6 +126,7 @@ static void devm_memremap_pages_release(void *data)
untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
pgmap_array_delete(res);
WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");
+ devmap_managed_enable_put();
}

static void dev_pagemap_percpu_release(struct percpu_ref *ref)
@@ -212,7 +216,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
}

if (need_devmap_managed) {
- error = devmap_managed_enable_get(dev, pgmap);
+ error = devmap_managed_enable_get(pgmap);
if (error)
return ERR_PTR(error);
}
@@ -321,6 +325,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
err_array:
dev_pagemap_kill(pgmap);
dev_pagemap_cleanup(pgmap);
+ devmap_managed_enable_put();
return ERR_PTR(error);
}
EXPORT_SYMBOL_GPL(devm_memremap_pages);
--
2.20.1