Commit 0092908d authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jason Gunthorpe
Browse files

mm: factor out a devm_request_free_mem_region helper 



Keep the physical address allocation that hmm_add_device does with the
rest of the resource code, and allow future reuse of it without the hmm
wrapper.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 69262215

include/linux/ioport.h

+2 −0
Original line number Diff line number Diff line
@@ -285,6 +285,8 @@ static inline bool resource_overlaps(struct resource *r1, struct resource *r2) 
       return (r1->start <= r2->end && r1->end >= r2->start);

}



struct resource *devm_request_free_mem_region(struct device *dev,

		struct resource *base, unsigned long size);



#endif /* __ASSEMBLY__ */

#endif	/* _LINUX_IOPORT_H */

kernel/resource.c

+39 −0
Original line number Diff line number Diff line
@@ -1628,6 +1628,45 @@ void resource_list_free(struct list_head *head) 
}

EXPORT_SYMBOL(resource_list_free);



#ifdef CONFIG_DEVICE_PRIVATE

/**

 * devm_request_free_mem_region - find free region for device private memory

 *

 * @dev: device struct to bind the resource to

 * @size: size in bytes of the device memory to add

 * @base: resource tree to look in

 *

 * This function tries to find an empty range of physical address big enough to

 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE

 * memory, which in turn allocates struct pages.

 */

struct resource *devm_request_free_mem_region(struct device *dev,

		struct resource *base, unsigned long size)

{

	resource_size_t end, addr;

	struct resource *res;



	size = ALIGN(size, 1UL << PA_SECTION_SHIFT);

	end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);

	addr = end - size + 1UL;



	for (; addr > size && addr >= base->start; addr -= size) {

		if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=

				REGION_DISJOINT)

			continue;



		res = devm_request_mem_region(dev, addr, size, dev_name(dev));

		if (!res)

			return ERR_PTR(-ENOMEM);

		res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;

		return res;

	}



	return ERR_PTR(-ERANGE);

}

EXPORT_SYMBOL_GPL(devm_request_free_mem_region);

#endif /* CONFIG_DEVICE_PRIVATE */



static int __init strict_iomem(char *str)

{

	if (strstr(str, "relaxed"))

mm/hmm.c

+4 −29
Original line number Diff line number Diff line
@@ -25,8 +25,6 @@ 
#include <linux/mmu_notifier.h>

#include <linux/memory_hotplug.h>



#define PA_SECTION_SIZE (1UL << PA_SECTION_SHIFT)



#if IS_ENABLED(CONFIG_HMM_MIRROR)

static const struct mmu_notifier_ops hmm_mmu_notifier_ops;
@@ -1408,7 +1406,6 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, 
				  unsigned long size)

{

	struct hmm_devmem *devmem;

	resource_size_t addr;

	void *result;

	int ret;
@@ -1430,32 +1427,10 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, 
	if (ret)

		return ERR_PTR(ret);



	size = ALIGN(size, PA_SECTION_SIZE);

	addr = min((unsigned long)iomem_resource.end,

		   (1UL << MAX_PHYSMEM_BITS) - 1);

	addr = addr - size + 1UL;



	/*

	 * FIXME add a new helper to quickly walk resource tree and find free

	 * range

	 *

	 * FIXME what about ioport_resource resource ?

	 */

	for (; addr > size && addr >= iomem_resource.start; addr -= size) {

		ret = region_intersects(addr, size, 0, IORES_DESC_NONE);

		if (ret != REGION_DISJOINT)

			continue;



		devmem->resource = devm_request_mem_region(device, addr, size,

							   dev_name(device));

		if (!devmem->resource)

			return ERR_PTR(-ENOMEM);

		break;

	}

	if (!devmem->resource)

		return ERR_PTR(-ERANGE);



	devmem->resource->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;

	devmem->resource = devm_request_free_mem_region(device, &iomem_resource,

			size);

	if (IS_ERR(devmem->resource))

		return ERR_CAST(devmem->resource);

	devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT;

	devmem->pfn_last = devmem->pfn_first +

			   (resource_size(devmem->resource) >> PAGE_SHIFT);