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Commit 176d1169 authored by Masahiro Yamada's avatar Masahiro Yamada Committed by Stephen Boyd
Browse files

clk: move core->parents allocation to clk_register() 



Currently, __clk_core_init() allows failure of the kcalloc() for the
core->parents.  So, clk_fetch_parent_index() and __clk_init_parent()
also try to allocate core->parents in case it has not been allocated
yet.  Scattering memory allocation here and there makes things
complicated.

Like other clk_core members, allocate core->parents in clk_register()
and let it fail in case of memory shortage.  If we cannot allocate
such a small piece of memory, the system is already insane.  There is
no point to postpone the memory allocation.

Also, allocate core->parents regardless of core->num_parents.  We want
it even if core->num_parents == 1 because clk_fetch_parent_index()
might be called against the clk_core with a single parent.

If core->num_parents == 0, core->parents is set to ZERO_SIZE_PTR. It
is harmless because no access happens to core->parents in such a case.

Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: default avatarVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 3a6e8454

drivers/clk/clk.c

+19 −32
Original line number Diff line number Diff line
@@ -1067,13 +1067,6 @@ static int clk_fetch_parent_index(struct clk_core *core, 
{

	int i;



	if (!core->parents) {

		core->parents = kcalloc(core->num_parents,

					sizeof(*core->parents), GFP_KERNEL);

		if (!core->parents)

			return -ENOMEM;

	}



	/*

	 * find index of new parent clock using cached parent ptrs,

	 * or if not yet cached, use string name comparison and cache
@@ -1718,11 +1711,6 @@ static struct clk_core *__clk_init_parent(struct clk_core *core) 


	index = core->ops->get_parent(core->hw);



	if (!core->parents)

		core->parents =

			kcalloc(core->num_parents, sizeof(*core->parents),

					GFP_KERNEL);



	ret = clk_core_get_parent_by_index(core, index);



out:
@@ -2360,16 +2348,6 @@ static int __clk_core_init(struct clk_core *core) 
				"%s: invalid NULL in %s's .parent_names\n",

				__func__, core->name);



	/*

	 * Allocate an array of struct clk *'s to avoid unnecessary string

	 * look-ups of clk's possible parents.  This can fail for clocks passed

	 * in to clk_init during early boot; thus any access to core->parents[]

	 * must always check for a NULL pointer and try to populate it if

	 * necessary.

	 */

	if (core->num_parents > 1) {

		core->parents = kcalloc(core->num_parents,

					sizeof(*core->parents), GFP_KERNEL);

	/*

	 * clk_core_lookup returns NULL for parents that have not been

	 * clk_init'd; thus any access to clk->parents[] must check
@@ -2380,7 +2358,6 @@ static int __clk_core_init(struct clk_core *core) 
		for (i = 0; i < core->num_parents; i++)

			core->parents[i] =

				clk_core_lookup(core->parent_names[i]);

	}



	core->parent = __clk_init_parent(core);
@@ -2578,12 +2555,20 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) 
		}

	}



	/* avoid unnecessary string look-ups of clk_core's possible parents. */

	core->parents = kcalloc(core->num_parents, sizeof(*core->parents),

				GFP_KERNEL);

	if (!core->parents) {

		ret = -ENOMEM;

		goto fail_parents;

	};



	INIT_HLIST_HEAD(&core->clks);



	hw->clk = __clk_create_clk(hw, NULL, NULL);

	if (IS_ERR(hw->clk)) {

		ret = PTR_ERR(hw->clk);

		goto fail_parent_names_copy;

		goto fail_parents;

	}



	ret = __clk_core_init(core);
@@ -2593,6 +2578,8 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) 
	__clk_free_clk(hw->clk);

	hw->clk = NULL;



fail_parents:

	kfree(core->parents);

fail_parent_names_copy:

	while (--i >= 0)

		kfree_const(core->parent_names[i]);