Files
kernel_xiaomi_mt6785/include/linux/of_reserved_mem.h
ot_hankjh.chen 0ead3dd333 [ALPS05544164] BACKPORT: porting of_reserved_mem API
of: reserved_mem: Accessor for acquiring reserved_mem

In some cases drivers referencing a reserved-memory region might want to
remap the entire region, but when defining the reserved-memory by "size"
of: reserved_mem: Accessor for acquiring reserved_mem

In some cases drivers referencing a reserved-memory region might want to
remap the entire region, but when defining the reserved-memory by "size"
the client driver has no means to know the associated base address of
the reserved memory region.

This patch adds an accessor for such drivers to acquire a handle to
their associated reserved-memory for this purpose.

A complicating factor for the implementation is that the reserved_mem
objects are created from the flattened DeviceTree, as such we cant
use the device_node address for comparison. Fortunately the name of the
node will be used as "name" of the reserved_mem and will be used when
building the full_name, so we can compare the "name" with the basename
of the full_name to find the match.

the client driver has no means to know the associated base address of
the reserved memory region.

This patch adds an accessor for such drivers to acquire a handle to
their associated reserved-memory for this purpose.

A complicating factor for the implementation is that the reserved_mem
objects are created from the flattened DeviceTree, as such we cant
use the device_node address for comparison. Fortunately the name of the
node will be used as "name" of the reserved_mem and will be used when
building the full_name, so we can compare the "name" with the basename
of the full_name to find the match.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

MTK-Commit-Id: 2b34e97a0e4025458496b31b415852f218ea3e75

Change-Id: Ia721d144b1a2e6885436a3869886d3b2f1f5f241
Signed-off-by: ot_hankjh.chen <ot_hankjh.chen@mediatek.com>
CR-Id: ALPS05544164
Feature: Memory RAM Dump (MRDUMP)
2021-05-13 11:55:51 +08:00

85 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __OF_RESERVED_MEM_H
#define __OF_RESERVED_MEM_H
#include <linux/device.h>
struct of_phandle_args;
struct reserved_mem_ops;
struct reserved_mem {
const char *name;
unsigned long fdt_node;
unsigned long phandle;
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);
#define RESERVEDMEM_OF_DECLARE(name, compat, init) \
_OF_DECLARE(reservedmem, name, compat, init, reservedmem_of_init_fn)
int get_reserved_mem_count(void);
struct reserved_mem *get_reserved_mem(int num);
#ifdef CONFIG_OF_RESERVED_MEM
int of_reserved_mem_device_init_by_idx(struct device *dev,
struct device_node *np, int idx);
void of_reserved_mem_device_release(struct device *dev);
int early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
phys_addr_t align,
phys_addr_t start,
phys_addr_t end,
bool nomap,
phys_addr_t *res_base);
void fdt_init_reserved_mem(void);
void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
phys_addr_t base, phys_addr_t size);
struct reserved_mem *of_reserved_mem_lookup(struct device_node *np);
#else
static inline int of_reserved_mem_device_init_by_idx(struct device *dev,
struct device_node *np, int idx)
{
return -ENOSYS;
}
static inline void of_reserved_mem_device_release(struct device *pdev) { }
static inline void fdt_init_reserved_mem(void) { }
static inline void fdt_reserved_mem_save_node(unsigned long node,
const char *uname, phys_addr_t base, phys_addr_t size) { }
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 */