diff options
author | Gatien Chevallier <gatien.chevallier@foss.st.com> | 2024-01-05 14:03:56 +0100 |
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committer | Alexandre Torgue <alexandre.torgue@foss.st.com> | 2024-04-05 16:49:14 +0200 |
commit | 5c9668cfc6d7c7de30fa57fa0a6c0ddc93462969 (patch) | |
tree | ba9617ce9b6aaa5b1285f538c7601d4944ac0020 /drivers/bus/stm32_firewall.h | |
parent | c1c67654df0713539f9b5e8f84ce8fc573465efb (diff) |
firewall: introduce stm32_firewall framework
Introduce a STM32 firewall framework that offers to firewall consumers
different firewall services such as the ability to check their access
rights against their firewall controller(s).
The STM32 firewall framework offers a generic API for STM32 firewall
controllers that is defined in their drivers to best fit the
specificity of each firewall.
There are various types of firewalls:
-Peripheral firewalls that filter accesses to peripherals
-Memory firewalls that filter accesses to memories or memory regions
-No type for undefined type of firewall
Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>
Diffstat (limited to 'drivers/bus/stm32_firewall.h')
-rw-r--r-- | drivers/bus/stm32_firewall.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/drivers/bus/stm32_firewall.h b/drivers/bus/stm32_firewall.h new file mode 100644 index 000000000000..e5fac85fe346 --- /dev/null +++ b/drivers/bus/stm32_firewall.h @@ -0,0 +1,83 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2023, STMicroelectronics - All Rights Reserved + */ + +#ifndef _STM32_FIREWALL_H +#define _STM32_FIREWALL_H + +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/types.h> + +/** + * STM32_PERIPHERAL_FIREWALL: This type of firewall protects peripherals + * STM32_MEMORY_FIREWALL: This type of firewall protects memories/subsets of memory + * zones + * STM32_NOTYPE_FIREWALL: Undefined firewall type + */ + +#define STM32_PERIPHERAL_FIREWALL BIT(1) +#define STM32_MEMORY_FIREWALL BIT(2) +#define STM32_NOTYPE_FIREWALL BIT(3) + +/** + * struct stm32_firewall_controller - Information on firewall controller supplying services + * + * @name: Name of the firewall controller + * @dev: Device reference of the firewall controller + * @mmio: Base address of the firewall controller + * @entry: List entry of the firewall controller list + * @type: Type of firewall + * @max_entries: Number of entries covered by the firewall + * @grant_access: Callback used to grant access for a device access against a + * firewall controller + * @release_access: Callback used to release resources taken by a device when access was + * granted + * @grant_memory_range_access: Callback used to grant access for a device to a given memory region + */ +struct stm32_firewall_controller { + const char *name; + struct device *dev; + void __iomem *mmio; + struct list_head entry; + unsigned int type; + unsigned int max_entries; + + int (*grant_access)(struct stm32_firewall_controller *ctrl, u32 id); + void (*release_access)(struct stm32_firewall_controller *ctrl, u32 id); + int (*grant_memory_range_access)(struct stm32_firewall_controller *ctrl, phys_addr_t paddr, + size_t size); +}; + +/** + * stm32_firewall_controller_register - Register a firewall controller to the STM32 firewall + * framework + * @firewall_controller: Firewall controller to register + * + * Returns 0 in case of success or -ENODEV if no controller was given. + */ +int stm32_firewall_controller_register(struct stm32_firewall_controller *firewall_controller); + +/** + * stm32_firewall_controller_unregister - Unregister a firewall controller from the STM32 + * firewall framework + * @firewall_controller: Firewall controller to unregister + */ +void stm32_firewall_controller_unregister(struct stm32_firewall_controller *firewall_controller); + +/** + * stm32_firewall_populate_bus - Populate device tree nodes that have a correct firewall + * configuration. This is used at boot-time only, as a sanity check + * between device tree and firewalls hardware configurations to + * prevent a kernel crash when a device driver is not granted access + * + * @firewall_controller: Firewall controller which nodes will be populated or not + * + * Returns 0 in case of success or appropriate errno code if error occurred. + */ +int stm32_firewall_populate_bus(struct stm32_firewall_controller *firewall_controller); + +#endif /* _STM32_FIREWALL_H */ |