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author | Christoph Hellwig <hch@lst.de> | 2019-06-26 14:27:06 +0200 |
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committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-07-02 19:32:44 +0200 |
commit | 0092908d16c604b8207c2141ec64b0fa4473bb03 (patch) | |
tree | 13b972659276b1deac4a9e93a7947432ba97a974 /kernel/resource.c | |
parent | mm: export alloc_pages_vma (diff) | |
download | linux-0092908d16c604b8207c2141ec64b0fa4473bb03.tar.xz linux-0092908d16c604b8207c2141ec64b0fa4473bb03.zip |
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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'kernel/resource.c')
-rw-r--r-- | kernel/resource.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 158f04ec1d4f..d22423e85cf8 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -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")) |