[PATCH v6 05/12] bus: stm32_firewall: add stm32_firewall_get_grant_all_access() API
From: Gatien Chevallier <gatien.chevallier@foss.st.com>
Date: 2026-02-26 10:31:23
Also in:
linux-arm-kernel, linux-gpio, lkml
Subsystem:
st stm32 firewall, the rest · Maintainers:
Gatien Chevallier, Linus Torvalds
Add the stm32_firewall_get_grant_all_access() API to be able to fetch all firewall references in an access-controllers property and try to grant access to all of them. Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com> Reviewed-by: Linus Walleij <linusw@kernel.org> --- drivers/bus/stm32_firewall.c | 42 +++++++++++++++++++++++++++++++ include/linux/bus/stm32_firewall_device.h | 26 +++++++++++++++++++ 2 files changed, 68 insertions(+)
diff --git a/drivers/bus/stm32_firewall.c b/drivers/bus/stm32_firewall.c
index 41cc1e7190ed..0b22b8e2fdf2 100644
--- a/drivers/bus/stm32_firewall.c
+++ b/drivers/bus/stm32_firewall.c@@ -185,6 +185,48 @@ void stm32_firewall_release_access_by_id(struct stm32_firewall *firewall, u32 su } EXPORT_SYMBOL_GPL(stm32_firewall_release_access_by_id); +int stm32_firewall_get_grant_all_access(struct device *dev, struct stm32_firewall **firewall, + int *nb_firewall) +{ + struct stm32_firewall *loc_firewall; + int err; + int i; + + *nb_firewall = of_count_phandle_with_args(dev->of_node, "access-controllers", + "#access-controller-cells"); + if (*nb_firewall < 0) + return *nb_firewall; + + if (!*nb_firewall) { + *firewall = NULL; + return 0; + } + + loc_firewall = devm_kcalloc(dev, *nb_firewall, sizeof(*loc_firewall), GFP_KERNEL); + if (!loc_firewall) + return -ENOMEM; + + /* Get stm32 firewall information */ + err = stm32_firewall_get_firewall(dev->of_node, loc_firewall, *nb_firewall); + if (err) + return err; + + for (i = 0; i < *nb_firewall; i++) { + err = stm32_firewall_grant_access(&loc_firewall[i]); + if (err) { + while (i--) + stm32_firewall_release_access(&loc_firewall[i]); + + return err; + } + } + + *firewall = loc_firewall; + + return 0; +} +EXPORT_SYMBOL_GPL(stm32_firewall_get_grant_all_access); + /* Firewall controller API */ int stm32_firewall_controller_register(struct stm32_firewall_controller *firewall_controller)
diff --git a/include/linux/bus/stm32_firewall_device.h b/include/linux/bus/stm32_firewall_device.h
index eaa7a3f54450..6c878f3ca86f 100644
--- a/include/linux/bus/stm32_firewall_device.h
+++ b/include/linux/bus/stm32_firewall_device.h@@ -112,6 +112,25 @@ int stm32_firewall_grant_access_by_id(struct stm32_firewall *firewall, u32 subsy */ void stm32_firewall_release_access_by_id(struct stm32_firewall *firewall, u32 subsystem_id); +/** + * stm32_firewall_get_grant_all_access - Allocate and get all the firewall(s) associated to given + * device. Then, try to grant access rights for each element. + * This function is basically a helper function that wraps + * both stm32_firewall_get_firewall() and + * stm32_firewall_grant_access() on all firewall references of + * a device along with the allocation of the array. + * Realease access using stm32_firewall_release_access* APIs + * when done. + * + * @dev: Device performing the checks + * @firewall: Pointer to the array of firewall references to be allocated + * @nb_firewall: Number of allocated elements in @firewall + * + * Returns 0 on success, or appropriate errno code if error occurred. + */ +int stm32_firewall_get_grant_all_access(struct device *dev, struct stm32_firewall **firewall, + int *nb_firewall); + #else /* CONFIG_STM32_FIREWALL */ static inline int stm32_firewall_get_firewall(struct device_node *np,
@@ -141,5 +160,12 @@ static inline void stm32_firewall_release_access_by_id(struct stm32_firewall *fi { } +static inline int stm32_firewall_get_grant_all_access(struct device *dev, + struct stm32_firewall **firewall, + int *nb_firewall) +{ + return -ENODEV; +} + #endif /* CONFIG_STM32_FIREWALL */ #endif /* STM32_FIREWALL_DEVICE_H */
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2.43.0