From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

We currently duplicate the entire struct pinfunction object in
pinmux_generic_add_pinfunction(). While this is inevitable when the
arguments come in split through pinmux_generic_add_function(), users of
pinmux_generic_add_pinfunction() will typically pass addresses of
structures in .rodata, meaning we can try to avoid the duplication with
the help from kmemdup_const(). To that end: don't wrap the entire struct
pinfunction in struct function_desc but rather just store the address.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/pinctrl/freescale/pinctrl-imx.c   |  2 +-
 drivers/pinctrl/mediatek/pinctrl-airoha.c |  2 +-
 drivers/pinctrl/mediatek/pinctrl-moore.c  |  2 +-
 drivers/pinctrl/pinctrl-ingenic.c         |  2 +-
 drivers/pinctrl/pinmux.c                  | 18 ++++++++++++++----
 drivers/pinctrl/pinmux.h                  |  2 +-
 6 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/pinctrl/freescale/pinctrl-imx.c b/drivers/pinctrl/freescale/pinctrl-imx.c
index 56bfbf4c3575355bdda59cf7471bbf5b9babff4a..ad3bb8475c0c29e15dfc7a8e4afdeadf5ec8aaed 100644
--- a/drivers/pinctrl/freescale/pinctrl-imx.c
+++ b/drivers/pinctrl/freescale/pinctrl-imx.c
@@ -266,7 +266,7 @@ static int imx_pmx_set(struct pinctrl_dev *pctldev, unsigned selector,
 	npins = grp->grp.npins;
 
 	dev_dbg(ipctl->dev, "enable function %s group %s\n",
-		func->func.name, grp->grp.name);
+		func->func->name, grp->grp.name);
 
 	for (i = 0; i < npins; i++) {
 		/*
diff --git a/drivers/pinctrl/mediatek/pinctrl-airoha.c b/drivers/pinctrl/mediatek/pinctrl-airoha.c
index 2eed83f9f209cad79580082c274d4056231bd421..8fb3b65a1b775cf078d3c926af59480e9e09ab30 100644
--- a/drivers/pinctrl/mediatek/pinctrl-airoha.c
+++ b/drivers/pinctrl/mediatek/pinctrl-airoha.c
@@ -2456,7 +2456,7 @@ static int airoha_pinmux_set_mux(struct pinctrl_dev *pctrl_dev,
 		return -EINVAL;
 
 	dev_dbg(pctrl_dev->dev, "enable function %s group %s\n",
-		desc->func.name, grp->grp.name);
+		desc->func->name, grp->grp.name);
 
 	func = desc->data;
 	for (i = 0; i < func->group_size; i++) {
diff --git a/drivers/pinctrl/mediatek/pinctrl-moore.c b/drivers/pinctrl/mediatek/pinctrl-moore.c
index 17a08c73423fd089066e4894d2307c852bbbb661..11dc525eb3a2dc8ceabf2278ee1a2abaa425eec1 100644
--- a/drivers/pinctrl/mediatek/pinctrl-moore.c
+++ b/drivers/pinctrl/mediatek/pinctrl-moore.c
@@ -56,7 +56,7 @@ static int mtk_pinmux_set_mux(struct pinctrl_dev *pctldev,
 		return -EINVAL;
 
 	dev_dbg(pctldev->dev, "enable function %s group %s\n",
-		func->func.name, grp->grp.name);
+		func->func->name, grp->grp.name);
 
 	for (i = 0; i < grp->grp.npins; i++) {
 		const struct mtk_pin_desc *desc;
diff --git a/drivers/pinctrl/pinctrl-ingenic.c b/drivers/pinctrl/pinctrl-ingenic.c
index e13ef07850386e70cffc83011589ceaf70a70a41..e5b24fab12e11e443df25ffeb7b70d7c1a03c6bc 100644
--- a/drivers/pinctrl/pinctrl-ingenic.c
+++ b/drivers/pinctrl/pinctrl-ingenic.c
@@ -4015,7 +4015,7 @@ static int ingenic_pinmux_set_mux(struct pinctrl_dev *pctldev,
 		return -EINVAL;
 
 	dev_dbg(pctldev->dev, "enable function %s group %s\n",
-		func->func.name, grp->grp.name);
+		func->func->name, grp->grp.name);
 
 	mode = (uintptr_t)grp->data;
 	if (mode <= 3) {
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index 62bd4aa53b2b22cb09eacfb05398205f2fe391b9..6f5e3ede972bbfa78e279790df359632e2d63485 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -810,7 +810,7 @@ pinmux_generic_get_function_name(struct pinctrl_dev *pctldev,
 	if (!function)
 		return NULL;
 
-	return function->func.name;
+	return function->func->name;
 }
 EXPORT_SYMBOL_GPL(pinmux_generic_get_function_name);
 
@@ -835,8 +835,8 @@ int pinmux_generic_get_function_groups(struct pinctrl_dev *pctldev,
 			__func__, selector);
 		return -EINVAL;
 	}
-	*groups = function->func.groups;
-	*ngroups = function->func.ngroups;
+	*groups = function->func->groups;
+	*ngroups = function->func->ngroups;
 
 	return 0;
 }
@@ -903,7 +903,17 @@ int pinmux_generic_add_pinfunction(struct pinctrl_dev *pctldev,
 	if (!function)
 		return -ENOMEM;
 
-	function->func = *func;
+	/*
+	 * FIXME: It's generally a bad idea to use devres in subsystem core
+	 * code - managed interfaces are aimed at drivers - but pinctrl already
+	 * uses it all over the place so it's a larger piece of technical debt
+	 * to fix.
+	 */
+	function->func = devm_kmemdup_const(pctldev->dev, func,
+					    sizeof(*func), GFP_KERNEL);
+	if (!function->func)
+		return -ENOMEM;
+
 	function->data = data;
 
 	error = radix_tree_insert(&pctldev->pin_function_tree, selector, function);
diff --git a/drivers/pinctrl/pinmux.h b/drivers/pinctrl/pinmux.h
index 549ab10f7afbda32fadf4ad151401180bed2064f..653684290666d78fd725febb5f8bc987b66a1afb 100644
--- a/drivers/pinctrl/pinmux.h
+++ b/drivers/pinctrl/pinmux.h
@@ -137,7 +137,7 @@ static inline void pinmux_init_device_debugfs(struct dentry *devroot,
  * @data: pin controller driver specific data
  */
 struct function_desc {
-	struct pinfunction func;
+	const struct pinfunction *func;
 	void *data;
 };
 

-- 
2.48.1