On Tue, Jul 25, 2023 at 06:40:58PM +0200, Gatien Chevallier wrote:
> 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@xxxxxxxxxxx>
...
> diff --git a/drivers/bus/stm32_firewall.c b/drivers/bus/stm32_firewall.c
...
> +int stm32_firewall_populate_bus(struct stm32_firewall_controller *firewall_controller)
> +{
> + struct stm32_firewall *firewalls;
> + struct device_node *child;
> + struct device *parent;
> + unsigned int i;
> + int len;
> + int err;
> +
> + parent = firewall_controller->dev;
> +
> + dev_dbg(parent, "Populating %s system bus\n", dev_name(firewall_controller->dev));
> +
> + for_each_available_child_of_node(dev_of_node(parent), child) {
> + /* The feature-domains property is mandatory for firewall bus devices */
> + len = of_count_phandle_with_args(child, "feature-domains", "#feature-domain-cells");
> + if (len <= 0)
Coccinelle says that, due to breaking out of a
for_each_available_child_of_node() loop, a call to of_node_put()
is needed here
> + return -EINVAL;
> +
> + firewalls = kcalloc(len, sizeof(*firewalls), GFP_KERNEL);
> + if (!firewalls)
And here.
> + return -ENOMEM;
> +
> + err = stm32_firewall_get_firewall(child, firewalls, (unsigned int)len);
> + if (err) {
> + kfree(firewalls);
And here.
> + return err;
> + }
> +
> + for (i = 0; i < len; i++) {
> + if (firewall_controller->grant_access(firewall_controller,
> + firewalls[i].firewall_id)) {
> + /*
> + * Peripheral access not allowed or not defined.
> + * Mark the node as populated so platform bus won't probe it
> + */
> + of_node_set_flag(child, OF_POPULATED);
> + dev_err(parent, "%s: Device driver will not be probed\n",
> + child->full_name);
> + }
> + }
> +
> + kfree(firewalls);
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(stm32_firewall_populate_bus);
> diff --git a/drivers/bus/stm32_firewall.h b/drivers/bus/stm32_firewall.h
...
> +/**
> + * struct stm32_firewall_controller - Information on firewall controller supplying services
> + *
> + * @name Name of the firewall controller
kernel-doc complains that name and the other fields of
struct stm32_firewall_controller are not documented.
I believe this is because a ':' is needed after the name of
the parameter (in this case 'name').
* @name: Name of the firewall controller
Likewise, elsewhere.
> + * @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);
> +};
> +
> +/**
> + * int stm32_firewall_controller_register - Register a firewall controller to the STM32 firewall
kernel-doc seems unhappy about the presence of 'int' on this line.
* stm32_firewall_controller_register - Register a firewall controller to the STM32 firewall
Likewise, elsewhere.
> + * 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);
...
> diff --git a/include/linux/bus/stm32_firewall_device.h b/include/linux/bus/stm32_firewall_device.h
> new file mode 100644
> index 000000000000..9bdc4060154c
> --- /dev/null
> +++ b/include/linux/bus/stm32_firewall_device.h
> @@ -0,0 +1,140 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2023, STMicroelectronics - All Rights Reserved
> + */
> +
> +#ifndef STM32_FIREWALL_DEVICE_H
> +#define STM32_FIREWALL_DEVICE_H
> +
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/types.h>
> +
> +#define STM32_FIREWALL_MAX_EXTRA_ARGS 5
> +
> +/* Opaque reference to stm32_firewall_controller */
> +struct stm32_firewall_controller;
> +
> +/**
> + * stm32_firewall - Information on a device's firewall. Each device can have more than one firewall.
kernel-doc seems unhappy about the absence of struct on this line.
* struct stm32_firewall - Information on a device's firewall. Each device can have more than one firewall.
> + *
> + * @firewall_ctrl Pointer referencing a firewall controller of the device. It is
> + * opaque so a device cannot manipulate the controller's ops or access
> + * the controller's data
> + * @extra_args Extra arguments that are implementation dependent
> + * @entry Name of the firewall entry
> + * @extra_args_size Number of extra arguments
> + * @firewall_id Firewall ID associated the device for this firewall controller
> + */
> +struct stm32_firewall {
> + struct stm32_firewall_controller *firewall_ctrl;
> + u32 extra_args[STM32_FIREWALL_MAX_EXTRA_ARGS];
> + const char *entry;
> + size_t extra_args_size;
> + u32 firewall_id;
> +};
...
--
pw-bot: changes-requested
