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authorChristoph Hellwig <hch@lst.de>2019-06-26 14:27:06 +0200
committerJason Gunthorpe <jgg@mellanox.com>2019-07-02 19:32:44 +0200
commit0092908d16c604b8207c2141ec64b0fa4473bb03 (patch)
tree13b972659276b1deac4a9e93a7947432ba97a974 /kernel/resource.c
parentmm: export alloc_pages_vma (diff)
downloadlinux-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.c39
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"))