[PATCH v3 10/15] pinctrl: make struct pinfunction a pointer in struct function_desc

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski at 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 at 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                  | 23 +++++++++++++++++++----
 drivers/pinctrl/pinmux.h                  |  2 +-
 6 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/drivers/pinctrl/freescale/pinctrl-imx.c b/drivers/pinctrl/freescale/pinctrl-imx.c
index 9ed84479a5b43871861f46fe1326f1dfadc7f63c..0df7eba8ccd3209fbc4b2e67ffdea12b77b90858 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 9a95577439a1b50607427756a713c8122c7c4af1..148b6e235db53290c48d717a994d88cd53c3a135 100644
--- a/drivers/pinctrl/mediatek/pinctrl-airoha.c
+++ b/drivers/pinctrl/mediatek/pinctrl-airoha.c
@@ -2459,7 +2459,7 @@ 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 ec0005246c19a156079807acddc93bcb767d1222..8ebd731675f69c8b076a7e7767be8ff7c6d3dd79 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 f89f8ec06ac63227930a38dbc80f00333cc15b48..d81788aea5cb002a86869e22eaab430f7ad18e77 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..504dbb3e97cf334e39b49121137c6768081fcd40 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 +903,22 @@ int pinmux_generic_add_pinfunction(struct pinctrl_dev *pctldev,
 	if (!function)
 		return -ENOMEM;
 
-	function->func = *func;
+	function->func = kmemdup_const(func, sizeof(*func), GFP_KERNEL);
+	if (!function->func)
+		return -ENOMEM;
+
+	/*
+	 * 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.
+	 */
+	error = devm_add_action_or_reset(pctldev->dev,
+					 (void (*)(void *))kfree_const,
+					 (void *)function->func);
+	if (error)
+		return error;
+
 	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