linux-stable/include/linux/of_reserved_mem.h
Oreoluwa Babatunde c56436ef17 of: reserved_mem: Remove the use of phandle from the reserved_mem APIs
The __find_rmem() function is the only place that references the phandle
field of the reserved_mem struct. __find_rmem() is used to match a
device_node object to its corresponding entry in the reserved_mem array
using its phandle value. But, there is already a function called
of_reserved_mem_lookup() which carries out the same action using the
name of the node.

Using the of_reserved_mem_lookup() function is more reliable because
every node is guaranteed to have a name, but not all nodes will have a
phandle.

Nodes are only assigned a phandle if they are explicitly defined in the
DT using "phandle = <phandle_number>", or if they are referenced by
another node in the DT. Hence, If the phandle field is empty, then
__find_rmem() will return a false negative.

Hence, delete the __find_rmem() function and switch to using the
of_reserved_mem_lookup() function to find the corresponding entry of a
device_node in the reserved_mem array. Since the phandle field of the
reserved_mem struct is now unused, delete that as well.

Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com>
Link: https://lore.kernel.org/r/20240502192403.3307277-1-quic_obabatun@quicinc.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2024-05-03 07:49:13 -05:00

84 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __OF_RESERVED_MEM_H
#define __OF_RESERVED_MEM_H
#include <linux/device.h>
#include <linux/of.h>
struct of_phandle_args;
struct reserved_mem_ops;
struct reserved_mem {
const char *name;
unsigned long fdt_node;
const struct reserved_mem_ops *ops;
phys_addr_t base;
phys_addr_t size;
void *priv;
};
struct reserved_mem_ops {
int (*device_init)(struct reserved_mem *rmem,
struct device *dev);
void (*device_release)(struct reserved_mem *rmem,
struct device *dev);
};
typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem);
#ifdef CONFIG_OF_RESERVED_MEM
#define RESERVEDMEM_OF_DECLARE(name, compat, init) \
_OF_DECLARE(reservedmem, name, compat, init, reservedmem_of_init_fn)
int of_reserved_mem_device_init_by_idx(struct device *dev,
struct device_node *np, int idx);
int of_reserved_mem_device_init_by_name(struct device *dev,
struct device_node *np,
const char *name);
void of_reserved_mem_device_release(struct device *dev);
struct reserved_mem *of_reserved_mem_lookup(struct device_node *np);
#else
#define RESERVEDMEM_OF_DECLARE(name, compat, init) \
_OF_DECLARE_STUB(reservedmem, name, compat, init, reservedmem_of_init_fn)
static inline int of_reserved_mem_device_init_by_idx(struct device *dev,
struct device_node *np, int idx)
{
return -ENOSYS;
}
static inline int of_reserved_mem_device_init_by_name(struct device *dev,
struct device_node *np,
const char *name)
{
return -ENOSYS;
}
static inline void of_reserved_mem_device_release(struct device *pdev) { }
static inline struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
{
return NULL;
}
#endif
/**
* of_reserved_mem_device_init() - assign reserved memory region to given device
* @dev: Pointer to the device to configure
*
* This function assigns respective DMA-mapping operations based on the first
* reserved memory region specified by 'memory-region' property in device tree
* node of the given device.
*
* Returns error code or zero on success.
*/
static inline int of_reserved_mem_device_init(struct device *dev)
{
return of_reserved_mem_device_init_by_idx(dev, dev->of_node, 0);
}
#endif /* __OF_RESERVED_MEM_H */