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authorFrank Rowand <frank.rowand@sony.com>2018-07-12 14:00:07 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-08-24 13:07:10 +0200
commitc62357ffc469ffec3a9363493a24196c539390c4 (patch)
treea8bc4819e4729c4c465f8c731991ac9f3e389317
parent926fb5fe74d20370657c446f0fccb9b6bc7ea49c (diff)
downloadlinux-c62357ffc469ffec3a9363493a24196c539390c4.tar.gz
of: overlay: update phandle cache on overlay apply and remove
[ Upstream commit b9952b5218added5577e4a3443969bc20884cea9 ] A comment in the review of the patch adding the phandle cache said that the cache would have to be updated when modules are applied and removed. This patch implements the cache updates. Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()") Reported-by: Alan Tull <atull@kernel.org> Suggested-by: Alan Tull <atull@kernel.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/of/base.c6
-rw-r--r--drivers/of/of_private.h2
-rw-r--r--drivers/of/overlay.c11
3 files changed, 16 insertions, 3 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 848f549164cd04..466e3c8582f0fd 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -102,7 +102,7 @@ static u32 phandle_cache_mask;
* - the phandle lookup overhead reduction provided by the cache
* will likely be less
*/
-static void of_populate_phandle_cache(void)
+void of_populate_phandle_cache(void)
{
unsigned long flags;
u32 cache_entries;
@@ -134,8 +134,7 @@ out:
raw_spin_unlock_irqrestore(&devtree_lock, flags);
}
-#ifndef CONFIG_MODULES
-static int __init of_free_phandle_cache(void)
+int of_free_phandle_cache(void)
{
unsigned long flags;
@@ -148,6 +147,7 @@ static int __init of_free_phandle_cache(void)
return 0;
}
+#if !defined(CONFIG_MODULES)
late_initcall_sync(of_free_phandle_cache);
#endif
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 891d780c076a12..216175d11d3dc2 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -79,6 +79,8 @@ int of_resolve_phandles(struct device_node *tree);
#if defined(CONFIG_OF_OVERLAY)
void of_overlay_mutex_lock(void);
void of_overlay_mutex_unlock(void);
+int of_free_phandle_cache(void);
+void of_populate_phandle_cache(void);
#else
static inline void of_overlay_mutex_lock(void) {};
static inline void of_overlay_mutex_unlock(void) {};
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 7baa53e5b1d74d..eda57ef12fd057 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -804,6 +804,8 @@ static int of_overlay_apply(const void *fdt, struct device_node *tree,
goto err_free_overlay_changeset;
}
+ of_populate_phandle_cache();
+
ret = __of_changeset_apply_notify(&ovcs->cset);
if (ret)
pr_err("overlay changeset entry notify error %d\n", ret);
@@ -1046,8 +1048,17 @@ int of_overlay_remove(int *ovcs_id)
list_del(&ovcs->ovcs_list);
+ /*
+ * Disable phandle cache. Avoids race condition that would arise
+ * from removing cache entry when the associated node is deleted.
+ */
+ of_free_phandle_cache();
+
ret_apply = 0;
ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply);
+
+ of_populate_phandle_cache();
+
if (ret) {
if (ret_apply)
devicetree_state_flags |= DTSF_REVERT_FAIL;