linux_dsm_epyc7002/include/linux/fwnode.h
Saravana Kannan 8375e74f2b driver core: Add fw_devlink kernel commandline option
fwnode_operations.add_links allows creating device links from
information provided by firmware.

fwnode_operations.add_links is currently implemented only by
OF/devicetree code and a specific case of efi. However, there's nothing
preventing ACPI or other firmware types from implementing it.

The OF implementation is currently controlled by a kernel commandline
parameter called of_devlink.

Since this feature is generic isn't limited to OF, add a generic
fw_devlink kernel commandline parameter to control this feature across
firmware types.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200222014038.180923-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-04 17:58:48 +01:00

176 lines
6.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* fwnode.h - Firmware device node object handle type definition.
*
* Copyright (C) 2015, Intel Corporation
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*/
#ifndef _LINUX_FWNODE_H_
#define _LINUX_FWNODE_H_
#include <linux/types.h>
struct fwnode_operations;
struct device;
struct fwnode_handle {
struct fwnode_handle *secondary;
const struct fwnode_operations *ops;
struct device *dev;
};
/**
* struct fwnode_endpoint - Fwnode graph endpoint
* @port: Port number
* @id: Endpoint id
* @local_fwnode: reference to the related fwnode
*/
struct fwnode_endpoint {
unsigned int port;
unsigned int id;
const struct fwnode_handle *local_fwnode;
};
#define NR_FWNODE_REFERENCE_ARGS 8
/**
* struct fwnode_reference_args - Fwnode reference with additional arguments
* @fwnode:- A reference to the base fwnode
* @nargs: Number of elements in @args array
* @args: Integer arguments on the fwnode
*/
struct fwnode_reference_args {
struct fwnode_handle *fwnode;
unsigned int nargs;
u64 args[NR_FWNODE_REFERENCE_ARGS];
};
/**
* struct fwnode_operations - Operations for fwnode interface
* @get: Get a reference to an fwnode.
* @put: Put a reference to an fwnode.
* @device_is_available: Return true if the device is available.
* @device_get_match_data: Return the device driver match data.
* @property_present: Return true if a property is present.
* @property_read_int_array: Read an array of integer properties. Return zero on
* success, a negative error code otherwise.
* @property_read_string_array: Read an array of string properties. Return zero
* on success, a negative error code otherwise.
* @get_name: Return the name of an fwnode.
* @get_name_prefix: Get a prefix for a node (for printing purposes).
* @get_parent: Return the parent of an fwnode.
* @get_next_child_node: Return the next child node in an iteration.
* @get_named_child_node: Return a child node with a given name.
* @get_reference_args: Return a reference pointed to by a property, with args
* @graph_get_next_endpoint: Return an endpoint node in an iteration.
* @graph_get_remote_endpoint: Return the remote endpoint node of a local
* endpoint node.
* @graph_get_port_parent: Return the parent node of a port node.
* @graph_parse_endpoint: Parse endpoint for port and endpoint id.
* @add_links: Called after the device corresponding to the fwnode is added
* using device_add(). The function is expected to create device
* links to all the suppliers of the device that are available at
* the time this function is called. The function must NOT stop
* at the first failed device link if other unlinked supplier
* devices are present in the system. This is necessary for the
* driver/bus sync_state() callbacks to work correctly.
*
* For example, say Device-C depends on suppliers Device-S1 and
* Device-S2 and the dependency is listed in that order in the
* firmware. Say, S1 gets populated from the firmware after
* late_initcall_sync(). Say S2 is populated and probed way
* before that in device_initcall(). When C is populated, if this
* add_links() function doesn't continue past a "failed linking to
* S1" and continue linking C to S2, then S2 will get a
* sync_state() callback before C is probed. This is because from
* the perspective of S2, C was never a consumer when its
* sync_state() evaluation is done. To avoid this, the add_links()
* function has to go through all available suppliers of the
* device (that corresponds to this fwnode) and link to them
* before returning.
*
* If some suppliers are not yet available (indicated by an error
* return value), this function will be called again when other
* devices are added to allow creating device links to any newly
* available suppliers.
*
* Return 0 if device links have been successfully created to all
* the known suppliers of this device or if the supplier
* information is not known.
*
* Return -ENODEV if the suppliers needed for probing this device
* have not been registered yet (because device links can only be
* created to devices registered with the driver core).
*
* Return -EAGAIN if some of the suppliers of this device have not
* been registered yet, but none of those suppliers are necessary
* for probing the device.
*/
struct fwnode_operations {
struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);
void (*put)(struct fwnode_handle *fwnode);
bool (*device_is_available)(const struct fwnode_handle *fwnode);
const void *(*device_get_match_data)(const struct fwnode_handle *fwnode,
const struct device *dev);
bool (*property_present)(const struct fwnode_handle *fwnode,
const char *propname);
int (*property_read_int_array)(const struct fwnode_handle *fwnode,
const char *propname,
unsigned int elem_size, void *val,
size_t nval);
int
(*property_read_string_array)(const struct fwnode_handle *fwnode_handle,
const char *propname, const char **val,
size_t nval);
const char *(*get_name)(const struct fwnode_handle *fwnode);
const char *(*get_name_prefix)(const struct fwnode_handle *fwnode);
struct fwnode_handle *(*get_parent)(const struct fwnode_handle *fwnode);
struct fwnode_handle *
(*get_next_child_node)(const struct fwnode_handle *fwnode,
struct fwnode_handle *child);
struct fwnode_handle *
(*get_named_child_node)(const struct fwnode_handle *fwnode,
const char *name);
int (*get_reference_args)(const struct fwnode_handle *fwnode,
const char *prop, const char *nargs_prop,
unsigned int nargs, unsigned int index,
struct fwnode_reference_args *args);
struct fwnode_handle *
(*graph_get_next_endpoint)(const struct fwnode_handle *fwnode,
struct fwnode_handle *prev);
struct fwnode_handle *
(*graph_get_remote_endpoint)(const struct fwnode_handle *fwnode);
struct fwnode_handle *
(*graph_get_port_parent)(struct fwnode_handle *fwnode);
int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode,
struct fwnode_endpoint *endpoint);
int (*add_links)(const struct fwnode_handle *fwnode,
struct device *dev);
};
#define fwnode_has_op(fwnode, op) \
((fwnode) && (fwnode)->ops && (fwnode)->ops->op)
#define fwnode_call_int_op(fwnode, op, ...) \
(fwnode ? (fwnode_has_op(fwnode, op) ? \
(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : -ENXIO) : \
-EINVAL)
#define fwnode_call_bool_op(fwnode, op, ...) \
(fwnode_has_op(fwnode, op) ? \
(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : false)
#define fwnode_call_ptr_op(fwnode, op, ...) \
(fwnode_has_op(fwnode, op) ? \
(fwnode)->ops->op(fwnode, ## __VA_ARGS__) : NULL)
#define fwnode_call_void_op(fwnode, op, ...) \
do { \
if (fwnode_has_op(fwnode, op)) \
(fwnode)->ops->op(fwnode, ## __VA_ARGS__); \
} while (false)
#define get_dev_from_fwnode(fwnode) get_device((fwnode)->dev)
extern u32 fw_devlink_get_flags(void);
#endif