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of: reserved_mem: add support for using more than one region for given device

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This patch allows device drivers to initialize more than one reserved
memory region assigned to given device. When driver needs to use more
than one reserved memory region, it should allocate child devices and
initialize regions by index for each of its child devices.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
This commit is contained in:
Marek Szyprowski 2016-05-24 15:31:24 +02:00 committed by Sylwester Nawrocki
parent 712b617e5e
commit 59ce403972
2 changed files with 89 additions and 27 deletions
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91
drivers/of/of_reserved_mem.c
View File

@ -21,6 +21,7 @@
#include <linux/sizes.h>
#include <linux/of_reserved_mem.h>
#include <linux/sort.h>
#include <linux/slab.h>
#define MAX_RESERVED_REGIONS 16
static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
@ -289,53 +290,95 @@ static inline struct reserved_mem *__find_rmem(struct device_node *node)
return NULL;
}
/**
* of_reserved_mem_device_init() - assign reserved memory region to given device
*
* This function assign memory region pointed by "memory-region" device tree
* property to the given device.
*/
int of_reserved_mem_device_init(struct device *dev)
{
struct rmem_assigned_device {
struct device *dev;
struct reserved_mem *rmem;
struct list_head list;
};
static LIST_HEAD(of_rmem_assigned_device_list);
static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
/**
* of_reserved_mem_device_init_by_idx() - assign reserved memory region to
* given device
* @dev: Pointer to the device to configure
* @np: Pointer to the device_node with 'reserved-memory' property
* @idx: Index of selected region
*
* This function assigns respective DMA-mapping operations based on reserved
* memory region specified by 'memory-region' property in @np node to the @dev
* device. When driver needs to use more than one reserved memory region, it
* should allocate child devices and initialize regions by name for each of
* child device.
*
* Returns error code or zero on success.
*/
int of_reserved_mem_device_init_by_idx(struct device *dev,
struct device_node *np, int idx)
{
struct rmem_assigned_device *rd;
struct device_node *target;
struct reserved_mem *rmem;
struct device_node *np;
int ret;
np = of_parse_phandle(dev->of_node, "memory-region", 0);
if (!np)
return -ENODEV;
if (!np || !dev)
return -EINVAL;
rmem = __find_rmem(np);
of_node_put(np);
target = of_parse_phandle(np, "memory-region", idx);
if (!target)
return -EINVAL;
rmem = __find_rmem(target);
of_node_put(target);
if (!rmem || !rmem->ops || !rmem->ops->device_init)
return -EINVAL;
rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
if (!rd)
return -ENOMEM;
ret = rmem->ops->device_init(rmem, dev);
if (ret == 0)
if (ret == 0) {
rd->dev = dev;
rd->rmem = rmem;
mutex_lock(&of_rmem_assigned_device_mutex);
list_add(&rd->list, &of_rmem_assigned_device_list);
mutex_unlock(&of_rmem_assigned_device_mutex);
dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
} else {
kfree(rd);
}
return ret;
}
EXPORT_SYMBOL_GPL(of_reserved_mem_device_init);
EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
/**
* of_reserved_mem_device_release() - release reserved memory device structures
* @dev: Pointer to the device to deconfigure
*
* This function releases structures allocated for memory region handling for
* the given device.
*/
void of_reserved_mem_device_release(struct device *dev)
{
struct reserved_mem *rmem;
struct device_node *np;
struct rmem_assigned_device *rd;
struct reserved_mem *rmem = NULL;
np = of_parse_phandle(dev->of_node, "memory-region", 0);
if (!np)
return;
rmem = __find_rmem(np);
of_node_put(np);
mutex_lock(&of_rmem_assigned_device_mutex);
list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
if (rd->dev == dev) {
rmem = rd->rmem;
list_del(&rd->list);
kfree(rd);
break;
}
}
mutex_unlock(&of_rmem_assigned_device_mutex);
if (!rmem || !rmem->ops || !rmem->ops->device_release)
return;

25
include/linux/of_reserved_mem.h
View File

@ -1,7 +1,8 @@
#ifndef __OF_RESERVED_MEM_H
#define __OF_RESERVED_MEM_H
struct device;
#include <linux/device.h>
struct of_phandle_args;
struct reserved_mem_ops;
@ -28,14 +29,17 @@ typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem);
_OF_DECLARE(reservedmem, name, compat, init, reservedmem_of_init_fn)
#ifdef CONFIG_OF_RESERVED_MEM
int of_reserved_mem_device_init(struct device *dev);
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);
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);
#else
static inline int of_reserved_mem_device_init(struct device *dev)
static inline int of_reserved_mem_device_init_by_idx(struct device *dev,
struct device_node *np, int idx)
{
return -ENOSYS;
}
@ -46,4 +50,19 @@ static inline void fdt_reserved_mem_save_node(unsigned long node,
const char *uname, phys_addr_t base, phys_addr_t size) { }
#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 */