memremap: don't use a separate devm action for devmap_managed_enable_get

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.

Link: https://lore.kernel.org/r/20190818090557.17853-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/kernel/memremap.c b/kernel/memremap.c
index 600a14c..09a087c 100644 (file)
--- a/kernel/memremap.c
+++ b/kernel/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);