--- /dev/null
+/*
+ * Copyright(c) 2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#include <linux/device.h>
+#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 */
+__weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size)
+{
+ return ioremap(offset, size);
+}
+#endif
+
+static void *try_ram_remap(resource_size_t offset, size_t size)
+{
+ struct page *page = pfn_to_page(offset >> PAGE_SHIFT);
+
+ /* In the simple case just return the existing linear address */
+ if (!PageHighMem(page))
+ return __va(offset);
+ return NULL; /* fallback to ioremap_cache */
+}
+
+/**
+ * memremap() - remap an iomem_resource as cacheable memory
+ * @offset: iomem resource start address
+ * @size: size of remap
+ * @flags: either MEMREMAP_WB or MEMREMAP_WT
+ *
+ * memremap() is "ioremap" for cases where it is known that the resource
+ * being mapped does not have i/o side effects and the __iomem
+ * annotation is not applicable.
+ *
+ * MEMREMAP_WB - matches the default mapping for "System RAM" on
+ * the architecture. This is usually a read-allocate write-back cache.
+ * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM
+ * memremap() will bypass establishing a new mapping and instead return
+ * a pointer into the direct map.
+ *
+ * MEMREMAP_WT - establish a mapping whereby writes either bypass the
+ * cache or are written through to memory and never exist in a
+ * cache-dirty state with respect to program visibility. Attempts to
+ * map "System RAM" with this mapping type will fail.
+ */
+void *memremap(resource_size_t offset, size_t size, unsigned long flags)
+{
+ int is_ram = region_intersects(offset, size, "System RAM");
+ void *addr = NULL;
+
+ if (is_ram == REGION_MIXED) {
+ WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n",
+ &offset, (unsigned long) size);
+ return NULL;
+ }
+
+ /* Try all mapping types requested until one returns non-NULL */
+ if (flags & MEMREMAP_WB) {
+ flags &= ~MEMREMAP_WB;
+ /*
+ * MEMREMAP_WB is special in that it can be satisifed
+ * from the direct map. Some archs depend on the
+ * capability of memremap() to autodetect cases where
+ * the requested range is potentially in "System RAM"
+ */
+ if (is_ram == REGION_INTERSECTS)
+ addr = try_ram_remap(offset, size);
+ if (!addr)
+ addr = ioremap_cache(offset, size);
+ }
+
+ /*
+ * If we don't have a mapping yet and more request flags are
+ * pending then we will be attempting to establish a new virtual
+ * address mapping. Enforce that this mapping is not aliasing
+ * "System RAM"
+ */
+ if (!addr && is_ram == REGION_INTERSECTS && flags) {
+ WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n",
+ &offset, (unsigned long) size);
+ return NULL;
+ }
+
+ if (!addr && (flags & MEMREMAP_WT)) {
+ flags &= ~MEMREMAP_WT;
+ addr = ioremap_wt(offset, size);
+ }
+
+ return addr;
+}
+EXPORT_SYMBOL(memremap);
+
+void memunmap(void *addr)
+{
+ if (is_vmalloc_addr(addr))
+ iounmap((void __iomem *) addr);
+}
+EXPORT_SYMBOL(memunmap);
+
+static void devm_memremap_release(struct device *dev, void *res)
+{
+ memunmap(*(void **)res);
+}
+
+static int devm_memremap_match(struct device *dev, void *res, void *match_data)
+{
+ return *(void **)res == match_data;
+}
+
+void *devm_memremap(struct device *dev, resource_size_t offset,
+ size_t size, unsigned long flags)
+{
+ void **ptr, *addr;
+
+ ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL,
+ dev_to_node(dev));
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ addr = memremap(offset, size, flags);
+ if (addr) {
+ *ptr = addr;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ return ERR_PTR(-ENXIO);
+ }
+
+ return addr;
+}
+EXPORT_SYMBOL(devm_memremap);
+
+void devm_memunmap(struct device *dev, void *addr)
+{
+ WARN_ON(devres_release(dev, devm_memremap_release,
+ devm_memremap_match, 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_node(devm_memremap_pages_release,
+ sizeof(*page_map), GFP_KERNEL, dev_to_node(dev));
+ if (!page_map)
+ return ERR_PTR(-ENOMEM);
+
+ memcpy(&page_map->res, res, sizeof(*res));
+
+ nid = dev_to_node(dev);
+ if (nid < 0)
+ nid = numa_mem_id();
+
+ 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 */
Code Review / kvmfornfv.git / blobdiff