Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d9c9998b authored by Chris Goldsworthy's avatar Chris Goldsworthy
Browse files

of: reserved_mem: Check that memory reserved in device tree is in use 



Inside of dma_alloc_attrs(), verify that devices with a reserved memory
region are actually using the region, in order to prevent wastage of
memory.

Change-Id: I56852a761d3253ec2a3a7db0f6501c73983e55c6
Signed-off-by: default avatarChris Goldsworthy <cgoldswo@codeaurora.org>
parent b94e0753

drivers/of/Kconfig

+10 −0
Original line number Original line Diff line number Diff line
@@ -86,6 +86,16 @@ config OF_RESERVED_MEM 
	depends on OF_EARLY_FLATTREE

	depends on OF_EARLY_FLATTREE

	default y if DMA_DECLARE_COHERENT || DMA_CMA

	default y if DMA_DECLARE_COHERENT || DMA_CMA





config OF_RESERVED_MEM_CHECK

	bool "Reserved memory registration check"

	depends on OF_RESERVED_MEM

	help

	  If a device has a reserved memory region and allocates memory

	  through the DMA API, check to see if the device and region have been

	  associated through a call to of_reserved_mem_device_init_by_idx()

	  before performing an allocation. If the association hasn't occurred,

	  WARN_ON.



config OF_RESOLVE

config OF_RESOLVE

	bool

	bool

drivers/of/of_reserved_mem.c

+45 −0
Original line number Original line Diff line number Diff line
@@ -385,6 +385,51 @@ void of_reserved_mem_device_release(struct device *dev) 
}

}

EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);

EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);





#ifdef CONFIG_OF_RESERVED_MEM_CHECK

/**

 * of_reserved_mem_device_is_init() - test if a device's reserved memory

 *				      will be used in DMA allocations

 * @dev: device we want to perform test on

 *

 * Check if a device and its reserved memory region (if it has one) have

 * been associated with one another through a call to

 * of_reserved_mem_device_init_by_idx().

 *

 * Return false if the device has reserved memory and it's not in use, true

 * otherwise.

 */

bool of_reserved_mem_device_is_init(struct device *dev)

{

	struct device_node *mem_dev_node;

	struct rmem_assigned_device *rd;

	bool ret = false;



	if (!dev->of_node)

		return true;



	mem_dev_node = of_parse_phandle(dev->of_node, "memory-region", 0);

	if (!mem_dev_node)

		return true;



	if (!of_device_is_available(mem_dev_node) || !__find_rmem(mem_dev_node))

		goto exit;

	of_node_put(mem_dev_node);



	mutex_lock(&of_rmem_assigned_device_mutex);

	list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {

		if (rd->dev == dev) {

			ret = true;

			break;

		}

	}

	mutex_unlock(&of_rmem_assigned_device_mutex);

	return ret;

exit:

	of_node_put(mem_dev_node);

	return true;

}

#endif /* CONFIG_OF_RESERVED_MEM_CHECK */



/**

/**

 * of_reserved_mem_lookup() - acquire reserved_mem from a device node

 * of_reserved_mem_lookup() - acquire reserved_mem from a device node

 * @np:		node pointer of the desired reserved-memory region

 * @np:		node pointer of the desired reserved-memory region

include/linux/of_reserved_mem.h

+9 −0
Original line number Original line Diff line number Diff line
@@ -35,6 +35,15 @@ int of_reserved_mem_device_init_by_idx(struct device *dev, 
				       struct device_node *np, int idx);

				       struct device_node *np, int idx);

void of_reserved_mem_device_release(struct device *dev);

void of_reserved_mem_device_release(struct device *dev);





#ifdef CONFIG_OF_RESERVED_MEM_CHECK

bool of_reserved_mem_device_is_init(struct device *dev);

#else /* !CONFIG_OF_RESERVED_MEM_CHECK */

static inline bool of_reserved_mem_device_is_init(struct device *dev)

{

	return true;

}

#endif /* CONFIG_OF_RESERVED_MEM_CHECK */



void fdt_init_reserved_mem(void);

void fdt_init_reserved_mem(void);

void fdt_reserved_mem_save_node(unsigned long node, const char *uname,

void fdt_reserved_mem_save_node(unsigned long node, const char *uname,

			       phys_addr_t base, phys_addr_t size);

			       phys_addr_t base, phys_addr_t size);

kernel/dma/mapping.c

+3 −0
Original line number Original line Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <linux/export.h>

#include <linux/export.h>

#include <linux/gfp.h>

#include <linux/gfp.h>

#include <linux/of_device.h>

#include <linux/of_device.h>

#include <linux/of_reserved_mem.h>

#include <linux/slab.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/vmalloc.h>
@@ -284,6 +285,8 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, 




	WARN_ON_ONCE(!dev->coherent_dma_mask);

	WARN_ON_ONCE(!dev->coherent_dma_mask);





	WARN_ON(!of_reserved_mem_device_is_init(dev));



	if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))

	if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))

		return cpu_addr;

		return cpu_addr;