[PATCHv2 0/5] pinctrl fixes for generic functions and groups

[PATCHv2 0/5] pinctrl fixes for generic functions and groups

[Tony Lindgren]

Here are fixes to the race issues for generic group and functions
reported by H. Nikolaus Schaller <hns@goldelico.com>. I have not seen
the issue here myself, so please test to see if this is sufficient.

I've also fixed rza1 in addition to pinctrl-single. Please also check
the drivers pinctrl-mt7622.c and pinctrl-ingenic.c if mutex fixes are
needed there.

Regards,

Tony

Changes since v1:

- Check if a function or group already exists as suggested by
  Andy Shevchenko

- Make sure we always have a valid name for functions and groups
  as suggested by Christ van Willegen

- Prettify rza1 variables as suggested by Jacopo Mondi


Tony Lindgren (5):
  pinctrl: core: Return selector to the pinctrl driver
  pinctrl: pinmux: Return selector to the pinctrl driver
  pinctrl: single: Fix group and function selector use
  pinctrl: rza1: Fix selector use for groups and functions
  pinctrl: core: Remove broken remove_last group and pinmux functions

 drivers/pinctrl/core.c           | 35 ++++++++++--
 drivers/pinctrl/core.h           |  6 ---
 drivers/pinctrl/pinctrl-rza1.c   | 24 +++++----
 drivers/pinctrl/pinctrl-single.c | 91 +++++++++++++++++++-------------
 drivers/pinctrl/pinmux.c         | 16 ++++--
 drivers/pinctrl/pinmux.h         |  7 ---
 6 files changed, 112 insertions(+), 67 deletions(-)

-- 
2.17.1

[PATCH 1/5] pinctrl: core: Return selector to the pinctrl driver

[Tony Lindgren]

We must return the selector from pinctrl_generic_add_group() so
pin controller device drivers can remove the right group if needed
for deferred probe for example. And we now must make sure that a
proper name is passed so we can use it to check if the entry already
exists.

Note that fixes are also needed for the pin controller drivers to
use the selector value.

Fixes: c7059c5ac70a ("pinctrl: core: Add generic pinctrl functions
for managing groups")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Christ van Willegen <cvwillegen@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/pinctrl/core.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -617,6 +617,26 @@ struct group_desc *pinctrl_generic_get_group(struct pinctrl_dev *pctldev,
 }
 EXPORT_SYMBOL_GPL(pinctrl_generic_get_group);
 
+static int pinctrl_generic_group_name_to_selector(struct pinctrl_dev *pctldev,
+						  const char *function)
+{
+	const struct pinctrl_ops *ops = pctldev->desc->pctlops;
+	int ngroups = ops->get_groups_count(pctldev);
+	int selector = 0;
+
+	/* See if this pctldev has this group */
+	while (selector < ngroups) {
+		const char *gname = ops->get_group_name(pctldev, selector);
+
+		if (!strcmp(function, gname))
+			return selector;
+
+		selector++;
+	}
+
+	return -EINVAL;
+}
+
 /**
  * pinctrl_generic_add_group() - adds a new pin group
  * @pctldev: pin controller device
@@ -631,6 +651,16 @@ int pinctrl_generic_add_group(struct pinctrl_dev *pctldev, const char *name,
 			      int *pins, int num_pins, void *data)
 {
 	struct group_desc *group;
+	int selector;
+
+	if (!name)
+		return -EINVAL;
+
+	selector = pinctrl_generic_group_name_to_selector(pctldev, name);
+	if (selector >= 0)
+		return selector;
+
+	selector = pctldev->num_groups;
 
 	group = devm_kzalloc(pctldev->dev, sizeof(*group), GFP_KERNEL);
 	if (!group)
@@ -641,12 +671,11 @@ int pinctrl_generic_add_group(struct pinctrl_dev *pctldev, const char *name,
 	group->num_pins = num_pins;
 	group->data = data;
 
-	radix_tree_insert(&pctldev->pin_group_tree, pctldev->num_groups,
-			  group);
+	radix_tree_insert(&pctldev->pin_group_tree, selector, group);
 
 	pctldev->num_groups++;
 
-	return 0;
+	return selector;
 }
 EXPORT_SYMBOL_GPL(pinctrl_generic_add_group);
 
-- 
2.17.1

[PATCH 2/5] pinctrl: pinmux: Return selector to the pinctrl driver

[Tony Lindgren]

We must return the selector from pinmux_generic_add_function() so
pin controller device drivers can remove the right group if needed
for deferred probe for example. And we now must make sure that a
proper name is passed so we can use it to check if the entry already
exists.

Note that fixes are also needed for the pin controller drivers to
use the selector value.

Fixes: a76edc89b100 ("pinctrl: core: Add generic pinctrl functions for
managing groups")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Christ van Willegen <cvwillegen@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/pinctrl/pinmux.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -308,7 +308,6 @@ static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
 		selector++;
 	}
 
-	dev_err(pctldev->dev, "function '%s' not supported\n", function);
 	return -EINVAL;
 }
 
@@ -775,6 +774,16 @@ int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
 				void *data)
 {
 	struct function_desc *function;
+	int selector;
+
+	if (!name)
+		return -EINVAL;
+
+	selector = pinmux_func_name_to_selector(pctldev, name);
+	if (selector >= 0)
+		return selector;
+
+	selector = pctldev->num_functions;
 
 	function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL);
 	if (!function)
@@ -785,12 +794,11 @@ int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
 	function->num_group_names = num_groups;
 	function->data = data;
 
-	radix_tree_insert(&pctldev->pin_function_tree, pctldev->num_functions,
-			  function);
+	radix_tree_insert(&pctldev->pin_function_tree, selector, function);
 
 	pctldev->num_functions++;
 
-	return 0;
+	return selector;
 }
 EXPORT_SYMBOL_GPL(pinmux_generic_add_function);
 
-- 
2.17.1

[PATCH 3/5] pinctrl: single: Fix group and function selector use

[Tony Lindgren]

We must use a mutex around the generic_add functions and save the
function and group selector in case we need to remove them. Otherwise
the selector use will be racy for deferred probe at least.

Note that struct device_node *np is unused in pcs_add_function() we
remove that too and fix a checkpatch warning for bare unsigned while
at it.

Fixes: 571aec4df5b7 ("pinctrl: single: Use generic pinmux helpers for
managing functions")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Christ van Willegen <cvwillegen@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/pinctrl/pinctrl-single.c | 91 +++++++++++++++++++-------------
 1 file changed, 55 insertions(+), 36 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -747,38 +747,44 @@ static int pcs_allocate_pin_table(struct pcs_device *pcs)
 /**
  * pcs_add_function() - adds a new function to the function list
  * @pcs: pcs driver instance
- * @np: device node of the mux entry
+ * @fcn: new function allocated
  * @name: name of the function
  * @vals: array of mux register value pairs used by the function
  * @nvals: number of mux register value pairs
  * @pgnames: array of pingroup names for the function
  * @npgnames: number of pingroup names
+ *
+ * Caller must take care of locking.
  */
-static struct pcs_function *pcs_add_function(struct pcs_device *pcs,
-					struct device_node *np,
-					const char *name,
-					struct pcs_func_vals *vals,
-					unsigned nvals,
-					const char **pgnames,
-					unsigned npgnames)
+static int pcs_add_function(struct pcs_device *pcs,
+			    struct pcs_function **fcn,
+			    const char *name,
+			    struct pcs_func_vals *vals,
+			    unsigned int nvals,
+			    const char **pgnames,
+			    unsigned int npgnames)
 {
 	struct pcs_function *function;
-	int res;
+	int selector;
 
 	function = devm_kzalloc(pcs->dev, sizeof(*function), GFP_KERNEL);
 	if (!function)
-		return NULL;
+		return -ENOMEM;
 
 	function->vals = vals;
 	function->nvals = nvals;
 
-	res = pinmux_generic_add_function(pcs->pctl, name,
-					  pgnames, npgnames,
-					  function);
-	if (res)
-		return NULL;
+	selector = pinmux_generic_add_function(pcs->pctl, name,
+					       pgnames, npgnames,
+					       function);
+	if (selector < 0) {
+		devm_kfree(pcs->dev, function);
+		*fcn = NULL;
+	} else {
+		*fcn = function;
+	}
 
-	return function;
+	return selector;
 }
 
 /**
@@ -979,8 +985,8 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 {
 	const char *name = "pinctrl-single,pins";
 	struct pcs_func_vals *vals;
-	int rows, *pins, found = 0, res = -ENOMEM, i;
-	struct pcs_function *function;
+	int rows, *pins, found = 0, res = -ENOMEM, i, fsel, gsel;
+	struct pcs_function *function = NULL;
 
 	rows = pinctrl_count_index_with_args(np, name);
 	if (rows <= 0) {
@@ -1030,21 +1036,25 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 	}
 
 	pgnames[0] = np->name;
-	function = pcs_add_function(pcs, np, np->name, vals, found, pgnames, 1);
-	if (!function) {
-		res = -ENOMEM;
+	mutex_lock(&pcs->mutex);
+	fsel = pcs_add_function(pcs, &function, np->name, vals, found,
+				pgnames, 1);
+	if (fsel < 0) {
+		res = fsel;
 		goto free_pins;
 	}
 
-	res = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
-	if (res < 0)
+	gsel = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
+	if (gsel < 0) {
+		res = gsel;
 		goto free_function;
+	}
 
 	(*map)->type = PIN_MAP_TYPE_MUX_GROUP;
 	(*map)->data.mux.group = np->name;
 	(*map)->data.mux.function = np->name;
 
-	if (PCS_HAS_PINCONF) {
+	if (PCS_HAS_PINCONF && function) {
 		res = pcs_parse_pinconf(pcs, np, function, map);
 		if (res)
 			goto free_pingroups;
@@ -1052,14 +1062,16 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 	} else {
 		*num_maps = 1;
 	}
+	mutex_unlock(&pcs->mutex);
+
 	return 0;
 
 free_pingroups:
-	pinctrl_generic_remove_last_group(pcs->pctl);
+	pinctrl_generic_remove_group(pcs->pctl, gsel);
 	*num_maps = 1;
 free_function:
-	pinmux_generic_remove_last_function(pcs->pctl);
-
+	pinmux_generic_remove_function(pcs->pctl, fsel);
+	mutex_unlock(&pcs->mutex);
 free_pins:
 	devm_kfree(pcs->dev, pins);
 
@@ -1077,9 +1089,9 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
 {
 	const char *name = "pinctrl-single,bits";
 	struct pcs_func_vals *vals;
-	int rows, *pins, found = 0, res = -ENOMEM, i;
+	int rows, *pins, found = 0, res = -ENOMEM, i, fsel, gsel;
 	int npins_in_row;
-	struct pcs_function *function;
+	struct pcs_function *function = NULL;
 
 	rows = pinctrl_count_index_with_args(np, name);
 	if (rows <= 0) {
@@ -1166,15 +1178,19 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
 	}
 
 	pgnames[0] = np->name;
-	function = pcs_add_function(pcs, np, np->name, vals, found, pgnames, 1);
-	if (!function) {
-		res = -ENOMEM;
+	mutex_lock(&pcs->mutex);
+	fsel = pcs_add_function(pcs, &function, np->name, vals, found,
+				pgnames, 1);
+	if (fsel < 0) {
+		res = fsel;
 		goto free_pins;
 	}
 
-	res = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
-	if (res < 0)
+	gsel = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
+	if (gsel < 0) {
+		res = gsel;
 		goto free_function;
+	}
 
 	(*map)->type = PIN_MAP_TYPE_MUX_GROUP;
 	(*map)->data.mux.group = np->name;
@@ -1186,13 +1202,16 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
 	}
 
 	*num_maps = 1;
+	mutex_unlock(&pcs->mutex);
+
 	return 0;
 
 free_pingroups:
-	pinctrl_generic_remove_last_group(pcs->pctl);
+	pinctrl_generic_remove_group(pcs->pctl, gsel);
 	*num_maps = 1;
 free_function:
-	pinmux_generic_remove_last_function(pcs->pctl);
+	pinmux_generic_remove_function(pcs->pctl, fsel);
+	mutex_unlock(&pcs->mutex);
 free_pins:
 	devm_kfree(pcs->dev, pins);
 
-- 
2.17.1

[PATCH 4/5] pinctrl: rza1: Fix selector use for groups and functions

[Tony Lindgren]

We must use a mutex around the generic_add functions and save the
function and group selector in case we need to remove them. Otherwise
the selector use will be racy for deferred probe at least.

Fixes: 5a49b644b307 ("pinctrl: Renesas RZ/A1 pin and gpio controller")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Christ van Willegen <cvwillegen@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Wang <sean.wang@mediatek.com>
Acked-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/pinctrl/pinctrl-rza1.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-rza1.c b/drivers/pinctrl/pinctrl-rza1.c
--- a/drivers/pinctrl/pinctrl-rza1.c
+++ b/drivers/pinctrl/pinctrl-rza1.c
@@ -1006,6 +1006,7 @@ static int rza1_dt_node_to_map(struct pinctrl_dev *pctldev,
 	const char *grpname;
 	const char **fngrps;
 	int ret, npins;
+	int gsel, fsel;
 
 	npins = rza1_dt_node_pin_count(np);
 	if (npins < 0) {
@@ -1055,18 +1056,19 @@ static int rza1_dt_node_to_map(struct pinctrl_dev *pctldev,
 	fngrps[0] = grpname;
 
 	mutex_lock(&rza1_pctl->mutex);
-	ret = pinctrl_generic_add_group(pctldev, grpname, grpins, npins,
-					NULL);
-	if (ret) {
+	gsel = pinctrl_generic_add_group(pctldev, grpname, grpins, npins,
+					 NULL);
+	if (gsel < 0) {
 		mutex_unlock(&rza1_pctl->mutex);
-		return ret;
+		return gsel;
 	}
 
-	ret = pinmux_generic_add_function(pctldev, grpname, fngrps, 1,
-					  mux_confs);
-	if (ret)
+	fsel = pinmux_generic_add_function(pctldev, grpname, fngrps, 1,
+					   mux_confs);
+	if (fsel < 0) {
+		ret = fsel;
 		goto remove_group;
-	mutex_unlock(&rza1_pctl->mutex);
+	}
 
 	dev_info(rza1_pctl->dev, "Parsed function and group %s with %d pins\n",
 				 grpname, npins);
@@ -1083,15 +1085,15 @@ static int rza1_dt_node_to_map(struct pinctrl_dev *pctldev,
 	(*map)->data.mux.group = np->name;
 	(*map)->data.mux.function = np->name;
 	*num_maps = 1;
+	mutex_unlock(&rza1_pctl->mutex);
 
 	return 0;
 
 remove_function:
-	mutex_lock(&rza1_pctl->mutex);
-	pinmux_generic_remove_last_function(pctldev);
+	pinmux_generic_remove_function(pctldev, fsel);
 
 remove_group:
-	pinctrl_generic_remove_last_group(pctldev);
+	pinctrl_generic_remove_group(pctldev, gsel);
 	mutex_unlock(&rza1_pctl->mutex);
 
 	dev_info(rza1_pctl->dev, "Unable to parse function and group %s\n",
-- 
2.17.1

[PATCH 5/5] pinctrl: core: Remove broken remove_last group and pinmux functions

[Tony Lindgren]

With no users left for these functions let's remove them.

Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Christ van Willegen <cvwillegen@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/pinctrl/core.h   | 6 ------
 drivers/pinctrl/pinmux.h | 7 -------
 2 files changed, 13 deletions(-)

diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h
--- a/drivers/pinctrl/core.h
+++ b/drivers/pinctrl/core.h
@@ -218,12 +218,6 @@ int pinctrl_generic_add_group(struct pinctrl_dev *pctldev, const char *name,
 int pinctrl_generic_remove_group(struct pinctrl_dev *pctldev,
 				 unsigned int group_selector);
 
-static inline int
-pinctrl_generic_remove_last_group(struct pinctrl_dev *pctldev)
-{
-	return pinctrl_generic_remove_group(pctldev, pctldev->num_groups - 1);
-}
-
 #endif	/* CONFIG_GENERIC_PINCTRL_GROUPS */
 
 struct pinctrl_dev *get_pinctrl_dev_from_devname(const char *dev_name);
diff --git a/drivers/pinctrl/pinmux.h b/drivers/pinctrl/pinmux.h
--- a/drivers/pinctrl/pinmux.h
+++ b/drivers/pinctrl/pinmux.h
@@ -150,13 +150,6 @@ int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
 int pinmux_generic_remove_function(struct pinctrl_dev *pctldev,
 				   unsigned int selector);
 
-static inline int
-pinmux_generic_remove_last_function(struct pinctrl_dev *pctldev)
-{
-	return pinmux_generic_remove_function(pctldev,
-					      pctldev->num_functions - 1);
-}
-
 void pinmux_generic_free_functions(struct pinctrl_dev *pctldev);
 
 #else
-- 
2.17.1

Re: [PATCHv2 0/5] pinctrl fixes for generic functions and groups

[Linus Walleij]

On Tue, Jun 19, 2018 at 11:31 AM Tony Lindgren <tony@atomide.com> wrote:

> Here are fixes to the race issues for generic group and functions
> reported by H. Nikolaus Schaller <hns@goldelico.com>. I have not seen
> the issue here myself, so please test to see if this is sufficient.

It looks sane to me, it'd be great to have some Tested-by: from
H. Nikolaus, can we get that?

Else I guess I just queue them, but if I should queue them for
fixes it'd be great if it actually can be verified to fix something :D

Yours,
Linus Walleij

Re: [PATCHv2 0/5] pinctrl fixes for generic functions and groups

[Tony Lindgren]

* Linus Walleij <linus.walleij@linaro.org> [180628 13:57]:
> On Tue, Jun 19, 2018 at 11:31 AM Tony Lindgren <tony@atomide.com> wrote:
> 
> > Here are fixes to the race issues for generic group and functions
> > reported by H. Nikolaus Schaller <hns@goldelico.com>. I have not seen
> > the issue here myself, so please test to see if this is sufficient.
> 
> It looks sane to me, it'd be great to have some Tested-by: from
> H. Nikolaus, can we get that?
> 
> Else I guess I just queue them, but if I should queue them for
> fixes it'd be great if it actually can be verified to fix something :D

Looks like git did not add Reported-by to Cc or I messed up
something as Nikolaus did not see this set. I'll resend
these patches one more time so Nikolaus can test.

Regards,

Tony

[PATCH 3/5] pinctrl: single: Fix group and function selector use

[Tony Lindgren]

We must use a mutex around the generic_add functions and save the
function and group selector in case we need to remove them. Otherwise
the selector use will be racy for deferred probe at least.

Note that struct device_node *np is unused in pcs_add_function() we
remove that too and fix a checkpatch warning for bare unsigned while
at it.

Fixes: 571aec4df5b7 ("pinctrl: single: Use generic pinmux helpers for
managing functions")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Christ van Willegen <cvwillegen@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/pinctrl/pinctrl-single.c | 91 +++++++++++++++++++-------------
 1 file changed, 55 insertions(+), 36 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -747,38 +747,44 @@ static int pcs_allocate_pin_table(struct pcs_device *pcs)
 /**
  * pcs_add_function() - adds a new function to the function list
  * @pcs: pcs driver instance
- * @np: device node of the mux entry
+ * @fcn: new function allocated
  * @name: name of the function
  * @vals: array of mux register value pairs used by the function
  * @nvals: number of mux register value pairs
  * @pgnames: array of pingroup names for the function
  * @npgnames: number of pingroup names
+ *
+ * Caller must take care of locking.
  */
-static struct pcs_function *pcs_add_function(struct pcs_device *pcs,
-					struct device_node *np,
-					const char *name,
-					struct pcs_func_vals *vals,
-					unsigned nvals,
-					const char **pgnames,
-					unsigned npgnames)
+static int pcs_add_function(struct pcs_device *pcs,
+			    struct pcs_function **fcn,
+			    const char *name,
+			    struct pcs_func_vals *vals,
+			    unsigned int nvals,
+			    const char **pgnames,
+			    unsigned int npgnames)
 {
 	struct pcs_function *function;
-	int res;
+	int selector;
 
 	function = devm_kzalloc(pcs->dev, sizeof(*function), GFP_KERNEL);
 	if (!function)
-		return NULL;
+		return -ENOMEM;
 
 	function->vals = vals;
 	function->nvals = nvals;
 
-	res = pinmux_generic_add_function(pcs->pctl, name,
-					  pgnames, npgnames,
-					  function);
-	if (res)
-		return NULL;
+	selector = pinmux_generic_add_function(pcs->pctl, name,
+					       pgnames, npgnames,
+					       function);
+	if (selector < 0) {
+		devm_kfree(pcs->dev, function);
+		*fcn = NULL;
+	} else {
+		*fcn = function;
+	}
 
-	return function;
+	return selector;
 }
 
 /**
@@ -979,8 +985,8 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 {
 	const char *name = "pinctrl-single,pins";
 	struct pcs_func_vals *vals;
-	int rows, *pins, found = 0, res = -ENOMEM, i;
-	struct pcs_function *function;
+	int rows, *pins, found = 0, res = -ENOMEM, i, fsel, gsel;
+	struct pcs_function *function = NULL;
 
 	rows = pinctrl_count_index_with_args(np, name);
 	if (rows <= 0) {
@@ -1030,21 +1036,25 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 	}
 
 	pgnames[0] = np->name;
-	function = pcs_add_function(pcs, np, np->name, vals, found, pgnames, 1);
-	if (!function) {
-		res = -ENOMEM;
+	mutex_lock(&pcs->mutex);
+	fsel = pcs_add_function(pcs, &function, np->name, vals, found,
+				pgnames, 1);
+	if (fsel < 0) {
+		res = fsel;
 		goto free_pins;
 	}
 
-	res = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
-	if (res < 0)
+	gsel = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
+	if (gsel < 0) {
+		res = gsel;
 		goto free_function;
+	}
 
 	(*map)->type = PIN_MAP_TYPE_MUX_GROUP;
 	(*map)->data.mux.group = np->name;
 	(*map)->data.mux.function = np->name;
 
-	if (PCS_HAS_PINCONF) {
+	if (PCS_HAS_PINCONF && function) {
 		res = pcs_parse_pinconf(pcs, np, function, map);
 		if (res)
 			goto free_pingroups;
@@ -1052,14 +1062,16 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 	} else {
 		*num_maps = 1;
 	}
+	mutex_unlock(&pcs->mutex);
+
 	return 0;
 
 free_pingroups:
-	pinctrl_generic_remove_last_group(pcs->pctl);
+	pinctrl_generic_remove_group(pcs->pctl, gsel);
 	*num_maps = 1;
 free_function:
-	pinmux_generic_remove_last_function(pcs->pctl);
-
+	pinmux_generic_remove_function(pcs->pctl, fsel);
+	mutex_unlock(&pcs->mutex);
 free_pins:
 	devm_kfree(pcs->dev, pins);
 
@@ -1077,9 +1089,9 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
 {
 	const char *name = "pinctrl-single,bits";
 	struct pcs_func_vals *vals;
-	int rows, *pins, found = 0, res = -ENOMEM, i;
+	int rows, *pins, found = 0, res = -ENOMEM, i, fsel, gsel;
 	int npins_in_row;
-	struct pcs_function *function;
+	struct pcs_function *function = NULL;
 
 	rows = pinctrl_count_index_with_args(np, name);
 	if (rows <= 0) {
@@ -1166,15 +1178,19 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
 	}
 
 	pgnames[0] = np->name;
-	function = pcs_add_function(pcs, np, np->name, vals, found, pgnames, 1);
-	if (!function) {
-		res = -ENOMEM;
+	mutex_lock(&pcs->mutex);
+	fsel = pcs_add_function(pcs, &function, np->name, vals, found,
+				pgnames, 1);
+	if (fsel < 0) {
+		res = fsel;
 		goto free_pins;
 	}
 
-	res = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
-	if (res < 0)
+	gsel = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
+	if (gsel < 0) {
+		res = gsel;
 		goto free_function;
+	}
 
 	(*map)->type = PIN_MAP_TYPE_MUX_GROUP;
 	(*map)->data.mux.group = np->name;
@@ -1186,13 +1202,16 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
 	}
 
 	*num_maps = 1;
+	mutex_unlock(&pcs->mutex);
+
 	return 0;
 
 free_pingroups:
-	pinctrl_generic_remove_last_group(pcs->pctl);
+	pinctrl_generic_remove_group(pcs->pctl, gsel);
 	*num_maps = 1;
 free_function:
-	pinmux_generic_remove_last_function(pcs->pctl);
+	pinmux_generic_remove_function(pcs->pctl, fsel);
+	mutex_unlock(&pcs->mutex);
 free_pins:
 	devm_kfree(pcs->dev, pins);
 
-- 
2.17.1

[PATCH 3/5] pinctrl: single: Fix group and function selector use

[Tony Lindgren]

We must use a mutex around the generic_add functions and save the
function and group selector in case we need to remove them. Otherwise
the selector use will be racy for deferred probe at least.

Note that struct device_node *np is unused in pcs_add_function() we
remove that too and fix a checkpatch warning for bare unsigned while
at it.

Fixes: 571aec4df5b7 ("pinctrl: single: Use generic pinmux helpers for
managing functions")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/pinctrl/pinctrl-single.c | 91 +++++++++++++++++++-------------
 1 file changed, 55 insertions(+), 36 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -747,38 +747,44 @@ static int pcs_allocate_pin_table(struct pcs_device *pcs)
 /**
  * pcs_add_function() - adds a new function to the function list
  * @pcs: pcs driver instance
- * @np: device node of the mux entry
+ * @fcn: new function allocated
  * @name: name of the function
  * @vals: array of mux register value pairs used by the function
  * @nvals: number of mux register value pairs
  * @pgnames: array of pingroup names for the function
  * @npgnames: number of pingroup names
+ *
+ * Caller must take care of locking.
  */
-static struct pcs_function *pcs_add_function(struct pcs_device *pcs,
-					struct device_node *np,
-					const char *name,
-					struct pcs_func_vals *vals,
-					unsigned nvals,
-					const char **pgnames,
-					unsigned npgnames)
+static int pcs_add_function(struct pcs_device *pcs,
+			    struct pcs_function **fcn,
+			    const char *name,
+			    struct pcs_func_vals *vals,
+			    unsigned int nvals,
+			    const char **pgnames,
+			    unsigned int npgnames)
 {
 	struct pcs_function *function;
-	int res;
+	int selector;
 
 	function = devm_kzalloc(pcs->dev, sizeof(*function), GFP_KERNEL);
 	if (!function)
-		return NULL;
+		return -ENOMEM;
 
 	function->vals = vals;
 	function->nvals = nvals;
 
-	res = pinmux_generic_add_function(pcs->pctl, name,
-					  pgnames, npgnames,
-					  function);
-	if (res)
-		return NULL;
+	selector = pinmux_generic_add_function(pcs->pctl, name,
+					       pgnames, npgnames,
+					       function);
+	if (selector < 0) {
+		devm_kfree(pcs->dev, function);
+		*fcn = NULL;
+	} else {
+		*fcn = function;
+	}
 
-	return function;
+	return selector;
 }
 
 /**
@@ -979,8 +985,8 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 {
 	const char *name = "pinctrl-single,pins";
 	struct pcs_func_vals *vals;
-	int rows, *pins, found = 0, res = -ENOMEM, i;
-	struct pcs_function *function;
+	int rows, *pins, found = 0, res = -ENOMEM, i, fsel, gsel;
+	struct pcs_function *function = NULL;
 
 	rows = pinctrl_count_index_with_args(np, name);
 	if (rows <= 0) {
@@ -1030,21 +1036,25 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 	}
 
 	pgnames[0] = np->name;
-	function = pcs_add_function(pcs, np, np->name, vals, found, pgnames, 1);
-	if (!function) {
-		res = -ENOMEM;
+	mutex_lock(&pcs->mutex);
+	fsel = pcs_add_function(pcs, &function, np->name, vals, found,
+				pgnames, 1);
+	if (fsel < 0) {
+		res = fsel;
 		goto free_pins;
 	}
 
-	res = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
-	if (res < 0)
+	gsel = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
+	if (gsel < 0) {
+		res = gsel;
 		goto free_function;
+	}
 
 	(*map)->type = PIN_MAP_TYPE_MUX_GROUP;
 	(*map)->data.mux.group = np->name;
 	(*map)->data.mux.function = np->name;
 
-	if (PCS_HAS_PINCONF) {
+	if (PCS_HAS_PINCONF && function) {
 		res = pcs_parse_pinconf(pcs, np, function, map);
 		if (res)
 			goto free_pingroups;
@@ -1052,14 +1062,16 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 	} else {
 		*num_maps = 1;
 	}
+	mutex_unlock(&pcs->mutex);
+
 	return 0;
 
 free_pingroups:
-	pinctrl_generic_remove_last_group(pcs->pctl);
+	pinctrl_generic_remove_group(pcs->pctl, gsel);
 	*num_maps = 1;
 free_function:
-	pinmux_generic_remove_last_function(pcs->pctl);
-
+	pinmux_generic_remove_function(pcs->pctl, fsel);
+	mutex_unlock(&pcs->mutex);
 free_pins:
 	devm_kfree(pcs->dev, pins);
 
@@ -1077,9 +1089,9 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
 {
 	const char *name = "pinctrl-single,bits";
 	struct pcs_func_vals *vals;
-	int rows, *pins, found = 0, res = -ENOMEM, i;
+	int rows, *pins, found = 0, res = -ENOMEM, i, fsel, gsel;
 	int npins_in_row;
-	struct pcs_function *function;
+	struct pcs_function *function = NULL;
 
 	rows = pinctrl_count_index_with_args(np, name);
 	if (rows <= 0) {
@@ -1166,15 +1178,19 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
 	}
 
 	pgnames[0] = np->name;
-	function = pcs_add_function(pcs, np, np->name, vals, found, pgnames, 1);
-	if (!function) {
-		res = -ENOMEM;
+	mutex_lock(&pcs->mutex);
+	fsel = pcs_add_function(pcs, &function, np->name, vals, found,
+				pgnames, 1);
+	if (fsel < 0) {
+		res = fsel;
 		goto free_pins;
 	}
 
-	res = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
-	if (res < 0)
+	gsel = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
+	if (gsel < 0) {
+		res = gsel;
 		goto free_function;
+	}
 
 	(*map)->type = PIN_MAP_TYPE_MUX_GROUP;
 	(*map)->data.mux.group = np->name;
@@ -1186,13 +1202,16 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
 	}
 
 	*num_maps = 1;
+	mutex_unlock(&pcs->mutex);
+
 	return 0;
 
 free_pingroups:
-	pinctrl_generic_remove_last_group(pcs->pctl);
+	pinctrl_generic_remove_group(pcs->pctl, gsel);
 	*num_maps = 1;
 free_function:
-	pinmux_generic_remove_last_function(pcs->pctl);
+	pinmux_generic_remove_function(pcs->pctl, fsel);
+	mutex_unlock(&pcs->mutex);
 free_pins:
 	devm_kfree(pcs->dev, pins);
 
-- 
2.17.1