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authorChristoph Hellwig <hch@lst.de>2015-08-17 16:00:35 +0200
committerDan Williams <dan.j.williams@intel.com>2015-08-27 19:40:58 -0400
commit41e94a851304f7acac840adec4004f8aeee53ad4 (patch)
treefe4c599d1263b7fdd92eb2838e5d223015066718 /kernel
parent033fbae988fcb67e5077203512181890848b8e90 (diff)
downloadop-kernel-dev-41e94a851304f7acac840adec4004f8aeee53ad4.zip
op-kernel-dev-41e94a851304f7acac840adec4004f8aeee53ad4.tar.gz
add devm_memremap_pages
This behaves like devm_memremap except that it ensures we have page structures available that can back the region. Signed-off-by: Christoph Hellwig <hch@lst.de> [djbw: catch attempts to remap RAM, drop flags] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/memremap.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 5c9b55e..72b0c66 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -14,6 +14,7 @@
#include <linux/types.h>
#include <linux/io.h>
#include <linux/mm.h>
+#include <linux/memory_hotplug.h>
#ifndef ioremap_cache
/* temporary while we convert existing ioremap_cache users to memremap */
@@ -135,3 +136,55 @@ void devm_memunmap(struct device *dev, void *addr)
memunmap(addr);
}
EXPORT_SYMBOL(devm_memunmap);
+
+#ifdef CONFIG_ZONE_DEVICE
+struct page_map {
+ struct resource res;
+};
+
+static void devm_memremap_pages_release(struct device *dev, void *res)
+{
+ struct page_map *page_map = res;
+
+ /* pages are dead and unused, undo the arch mapping */
+ arch_remove_memory(page_map->res.start, resource_size(&page_map->res));
+}
+
+void *devm_memremap_pages(struct device *dev, struct resource *res)
+{
+ int is_ram = region_intersects(res->start, resource_size(res),
+ "System RAM");
+ struct page_map *page_map;
+ int error, nid;
+
+ if (is_ram == REGION_MIXED) {
+ WARN_ONCE(1, "%s attempted on mixed region %pr\n",
+ __func__, res);
+ return ERR_PTR(-ENXIO);
+ }
+
+ if (is_ram == REGION_INTERSECTS)
+ return __va(res->start);
+
+ page_map = devres_alloc(devm_memremap_pages_release,
+ sizeof(*page_map), GFP_KERNEL);
+ if (!page_map)
+ return ERR_PTR(-ENOMEM);
+
+ memcpy(&page_map->res, res, sizeof(*res));
+
+ nid = dev_to_node(dev);
+ if (nid < 0)
+ nid = 0;
+
+ error = arch_add_memory(nid, res->start, resource_size(res), true);
+ if (error) {
+ devres_free(page_map);
+ return ERR_PTR(error);
+ }
+
+ devres_add(dev, page_map);
+ return __va(res->start);
+}
+EXPORT_SYMBOL(devm_memremap_pages);
+#endif /* CONFIG_ZONE_DEVICE */
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