Merge branch 'for-linus-clk' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

Pull clkdev updates from Russell King:
 "This series addresses some breakage in clkdev caused by a previous
  patch set from the clk tree which introduced per-user clk structures.
  This basically renamed the existing 'struct clk' to 'struct clk_hw',
  and introduced a new 'struct clk'.

  This change will break anyone using clk_add_alias() with the common
  clk code enabled.  Thankfully, the intersection of users of
  clk_add_alias() and those using the common clk code is practically
  zero, but this is something which should be fixed to keep the code
  sane.

  The problem is that clk_add_alias() does this:

        r = clk_get(...);
        l = clkdev_alloc(r, ...);
        clk_put(...);

  which causes the alias to store a pointer to 'r', which has been
  freed.

  The original patch set tried to work around this problem incorrectly -
  at clk_get() time, it tried to convert the struct clk to a struct
  clk_hw, and then creating a new struct clk from that.  Clearly, if the
  original struct clk has been freed, then we have a use-after-free bug.

  We have other places in the tree which do something similar, so this
  series also addresses those locations too.

  This series addresses this problem by converting clkdev to store and
  use the clk_hw pointer.  This allows clk_get() to only have to create
  it's per-user struct clk from the clk_hw.  We can also get to the
  desired clk_hw at clk_add_alias() or clk lookup creation time, when
  the struct clk is "alive".

  We also perform some cleanups of the code:

   - replacing looped calls to clkdev_add() with clkdev_add_table()

   - replacing open-coded lookup allocation (which should have been
     using clkdev_alloc()) and subsequent clkdev_add() with
     clkdev_create()

   - replacing open-coded clk_add_alias() with clk_add_alias()"

* 'for-linus-clk' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  clk: s2mps11: use clkdev_create()
  ASoC: migor: use clkdev_create()
  ARM: omap2: use clkdev_add_alias()
  ARM: omap2: use clkdev_create()
  ARM: orion: use clkdev_create()
  ARM: lpc32xx: convert to use clkdev_add_table()
  SH: use clkdev_add_table()
  clkdev: add clkdev_create() helper
  clkdev: const-ify connection id to clk_add_alias()
  clkdev: get rid of redundant clk_add_alias() prototype in linux/clk.h
  clkdev: drop __init from clkdev_add_table()
  clk: update clk API documentation to clarify clk_round_rate()
  clkdev: use clk_hw internally

2 files changed, 61 insertions, 26 deletions

diff --git a/drivers/clk/clk-s2mps11.c b/drivers/clk/clk-s2mps11.c
index bfa1e64e267d..9b13a303d3f8 100644
--- a/drivers/clk/clk-s2mps11.c
+++ b/drivers/clk/clk-s2mps11.c
@@ -242,14 +242,12 @@ static int s2mps11_clk_probe(struct platform_device *pdev)
 			goto err_reg;
 		}
 
-		s2mps11_clk->lookup = clkdev_alloc(s2mps11_clk->clk,
+		s2mps11_clk->lookup = clkdev_create(s2mps11_clk->clk,
 					s2mps11_name(s2mps11_clk), NULL);
 		if (!s2mps11_clk->lookup) {
 			ret = -ENOMEM;
 			goto err_lup;
 		}
-
-		clkdev_add(s2mps11_clk->lookup);
 	}
 
 	for (i = 0; i < S2MPS11_CLKS_NUM; i++) {
diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index 1fcb6ef2cdac..c0eaf0973bd2 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -177,7 +177,7 @@ struct clk *clk_get_sys(const char *dev_id, const char *con_id)
 	if (!cl)
 		goto out;
 
-	clk = __clk_create_clk(__clk_get_hw(cl->clk), dev_id, con_id);
+	clk = __clk_create_clk(cl->clk_hw, dev_id, con_id);
 	if (IS_ERR(clk))
 		goto out;
 
@@ -215,18 +215,26 @@ void clk_put(struct clk *clk)
 }
 EXPORT_SYMBOL(clk_put);
 
-void clkdev_add(struct clk_lookup *cl)
+static void __clkdev_add(struct clk_lookup *cl)
 {
 	mutex_lock(&clocks_mutex);
 	list_add_tail(&cl->node, &clocks);
 	mutex_unlock(&clocks_mutex);
 }
+
+void clkdev_add(struct clk_lookup *cl)
+{
+	if (!cl->clk_hw)
+		cl->clk_hw = __clk_get_hw(cl->clk);
+	__clkdev_add(cl);
+}
 EXPORT_SYMBOL(clkdev_add);
 
-void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
+void clkdev_add_table(struct clk_lookup *cl, size_t num)
 {
 	mutex_lock(&clocks_mutex);
 	while (num--) {
+		cl->clk_hw = __clk_get_hw(cl->clk);
 		list_add_tail(&cl->node, &clocks);
 		cl++;
 	}
@@ -243,7 +251,7 @@ struct clk_lookup_alloc {
 };
 
 static struct clk_lookup * __init_refok
-vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,
+vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
 	va_list ap)
 {
 	struct clk_lookup_alloc *cla;
@@ -252,7 +260,7 @@ vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,
 	if (!cla)
 		return NULL;
 
-	cla->cl.clk = clk;
+	cla->cl.clk_hw = hw;
 	if (con_id) {
 		strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
 		cla->cl.con_id = cla->con_id;
@@ -266,6 +274,19 @@ vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,
 	return &cla->cl;
 }
 
+static struct clk_lookup *
+vclkdev_create(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
+	va_list ap)
+{
+	struct clk_lookup *cl;
+
+	cl = vclkdev_alloc(hw, con_id, dev_fmt, ap);
+	if (cl)
+		__clkdev_add(cl);
+
+	return cl;
+}
+
 struct clk_lookup * __init_refok
 clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
 {
@@ -273,28 +294,49 @@ clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
 	va_list ap;
 
 	va_start(ap, dev_fmt);
-	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
+	cl = vclkdev_alloc(__clk_get_hw(clk), con_id, dev_fmt, ap);
 	va_end(ap);
 
 	return cl;
 }
 EXPORT_SYMBOL(clkdev_alloc);
 
-int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
-	struct device *dev)
+/**
+ * clkdev_create - allocate and add a clkdev lookup structure
+ * @clk: struct clk to associate with all clk_lookups
+ * @con_id: connection ID string on device
+ * @dev_fmt: format string describing device name
+ *
+ * Returns a clk_lookup structure, which can be later unregistered and
+ * freed.
+ */
+struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id,
+	const char *dev_fmt, ...)
 {
-	struct clk *r = clk_get(dev, id);
+	struct clk_lookup *cl;
+	va_list ap;
+
+	va_start(ap, dev_fmt);
+	cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);
+	va_end(ap);
+
+	return cl;
+}
+EXPORT_SYMBOL_GPL(clkdev_create);
+
+int clk_add_alias(const char *alias, const char *alias_dev_name,
+	const char *con_id, struct device *dev)
+{
+	struct clk *r = clk_get(dev, con_id);
 	struct clk_lookup *l;
 
 	if (IS_ERR(r))
 		return PTR_ERR(r);
 
-	l = clkdev_alloc(r, alias, alias_dev_name);
+	l = clkdev_create(r, alias, "%s", alias_dev_name);
 	clk_put(r);
-	if (!l)
-		return -ENODEV;
-	clkdev_add(l);
-	return 0;
+
+	return l ? 0 : -ENODEV;
 }
 EXPORT_SYMBOL(clk_add_alias);
 
@@ -334,15 +376,10 @@ int clk_register_clkdev(struct clk *clk, const char *con_id,
 		return PTR_ERR(clk);
 
 	va_start(ap, dev_fmt);
-	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
+	cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);
 	va_end(ap);
 
-	if (!cl)
-		return -ENOMEM;
-
-	clkdev_add(cl);
-
-	return 0;
+	return cl ? 0 : -ENOMEM;
 }
 EXPORT_SYMBOL(clk_register_clkdev);
 
@@ -365,8 +402,8 @@ int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num)
 		return PTR_ERR(clk);
 
 	for (i = 0; i < num; i++, cl++) {
-		cl->clk = clk;
-		clkdev_add(cl);
+		cl->clk_hw = __clk_get_hw(clk);
+		__clkdev_add(cl);
 	}
 
 	return 0;