1 files changed, 451 insertions, 0 deletions

diff --git a/drivers/base/dma-removed.c b/drivers/base/dma-removed.c
new file mode 100644
index 000000000000..87c743995a50
--- /dev/null
+++ b/drivers/base/dma-removed.c
@@ -0,0 +1,451 @@
+/*
+ *
+ *  Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
+ *  Copyright (C) 2000-2004 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/bootmem.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/list.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-contiguous.h>
+#include <linux/highmem.h>
+#include <linux/memblock.h>
+#include <linux/slab.h>
+#include <linux/iommu.h>
+#include <linux/io.h>
+#include <linux/vmalloc.h>
+#include <linux/sizes.h>
+#include <linux/spinlock.h>
+#include <asm/dma-contiguous.h>
+#include <asm/tlbflush.h>
+
+struct removed_region {
+	phys_addr_t	base;
+	int		nr_pages;
+	unsigned long	*bitmap;
+	int		fixup;
+	struct mutex	lock;
+};
+
+#define NO_KERNEL_MAPPING_DUMMY	0x2222
+
+static int dma_init_removed_memory(phys_addr_t phys_addr, size_t size,
+				struct removed_region **mem)
+{
+	struct removed_region *dma_mem = NULL;
+	int pages = size >> PAGE_SHIFT;
+	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
+
+	dma_mem = kzalloc(sizeof(struct removed_region), GFP_KERNEL);
+	if (!dma_mem)
+		goto out;
+	dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+	if (!dma_mem->bitmap)
+		goto free1_out;
+
+	dma_mem->base = phys_addr;
+	dma_mem->nr_pages = pages;
+	mutex_init(&dma_mem->lock);
+
+	*mem = dma_mem;
+
+	return 0;
+
+free1_out:
+	kfree(dma_mem);
+out:
+	return -ENOMEM;
+}
+
+static int dma_assign_removed_region(struct device *dev,
+					struct removed_region *mem)
+{
+	if (dev->removed_mem)
+		return -EBUSY;
+
+	dev->removed_mem = mem;
+	return 0;
+}
+
+static void adapt_iomem_resource(unsigned long base_pfn, unsigned long end_pfn)
+{
+	struct resource *res, *conflict;
+	resource_size_t cstart, cend;
+
+	res = kzalloc(sizeof(*res), GFP_KERNEL);
+	if (!res)
+		return;
+
+	res->name  = "System RAM";
+	res->start = __pfn_to_phys(base_pfn);
+	res->end = __pfn_to_phys(end_pfn) - 1;
+	res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+
+	conflict = request_resource_conflict(&iomem_resource, res);
+	if (!conflict) {
+		pr_err("Removed memory: no conflict resource found\n");
+		kfree(res);
+		goto done;
+	}
+
+	cstart = conflict->start;
+	cend = conflict->end;
+	if ((cstart == res->start) && (cend == res->end)) {
+		release_resource(conflict);
+	} else if ((res->start >= cstart) && (res->start <= cend)) {
+		if (res->start == cstart) {
+			adjust_resource(conflict, res->end + 1,
+					cend - res->end);
+		} else if (res->end == cend) {
+			adjust_resource(conflict, cstart,
+					res->start - cstart);
+		} else {
+			adjust_resource(conflict, cstart,
+					res->start - cstart);
+			res->start = res->end + 1;
+			res->end = cend;
+			request_resource(&iomem_resource, res);
+			goto done;
+		}
+	} else {
+		pr_err("Removed memory: incorrect resource conflict start=%llx end=%llx\n",
+				(unsigned long long) conflict->start,
+				(unsigned long long) conflict->end);
+	}
+
+	kfree(res);
+done:
+	return;
+}
+
+#ifdef CONFIG_FLATMEM
+static void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
+{
+	struct page *start_pg, *end_pg;
+	unsigned long pg, pgend;
+
+	start_pfn = ALIGN(start_pfn, pageblock_nr_pages);
+	end_pfn = round_down(end_pfn, pageblock_nr_pages);
+	/*
+	 * Convert start_pfn/end_pfn to a struct page pointer.
+	 */
+	start_pg = pfn_to_page(start_pfn - 1) + 1;
+	end_pg = pfn_to_page(end_pfn - 1) + 1;
+
+	/*
+	 * Convert to physical addresses, and round start upwards and end
+	 * downwards.
+	 */
+	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
+	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
+
+	/*
+	 * If there are free pages between these, free the section of the
+	 * memmap array.
+	 */
+	if (pg < pgend)
+		free_bootmem_late(pg, pgend - pg);
+}
+#else
+static void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
+{
+}
+#endif
+
+static int _clear_pte(pte_t *pte, pgtable_t token, unsigned long addr,
+			    void *data)
+{
+	pte_clear(&init_mm, addr, pte);
+	return 0;
+}
+
+static void clear_mapping(unsigned long addr, unsigned long size)
+{
+	apply_to_page_range(&init_mm, addr, size, _clear_pte, NULL);
+	/* ensure ptes are updated */
+	mb();
+	flush_tlb_kernel_range(addr, addr + size);
+}
+
+static void removed_region_fixup(struct removed_region *dma_mem, int index)
+{
+	unsigned long fixup_size;
+	unsigned long base_pfn;
+	unsigned long flags;
+
+	if (index > dma_mem->nr_pages)
+		return;
+
+	/* carve-out */
+	flags = memblock_region_resize_late_begin();
+	memblock_free(dma_mem->base, dma_mem->nr_pages * PAGE_SIZE);
+	memblock_remove(dma_mem->base, index * PAGE_SIZE);
+	memblock_region_resize_late_end(flags);
+
+	/* clear page-mappings */
+	base_pfn = dma_mem->base >> PAGE_SHIFT;
+	if (!PageHighMem(pfn_to_page(base_pfn))) {
+		clear_mapping((unsigned long) phys_to_virt(dma_mem->base),
+				index * PAGE_SIZE);
+	}
+
+	/* free page objects */
+	free_memmap(base_pfn, base_pfn + index);
+
+	/* return remaining area to system */
+	fixup_size = (dma_mem->nr_pages - index) * PAGE_SIZE;
+	free_bootmem_late(dma_mem->base + index * PAGE_SIZE, fixup_size);
+
+	/*
+	 * release freed resource region so as to show up under iomem resource
+	 * list
+	 */
+	adapt_iomem_resource(base_pfn, base_pfn + index);
+
+	/* limit the fixup region */
+	dma_mem->nr_pages = index;
+}
+
+void *removed_alloc(struct device *dev, size_t size, dma_addr_t *handle,
+		    gfp_t gfp, struct dma_attrs *attrs)
+{
+	bool no_kernel_mapping = dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING,
+					attrs);
+	bool skip_zeroing = dma_get_attr(DMA_ATTR_SKIP_ZEROING, attrs);
+	int pageno;
+	unsigned long order;
+	void *addr = NULL;
+	struct removed_region *dma_mem = dev->removed_mem;
+	int nbits;
+	unsigned int align;
+
+	if (!gfpflags_allow_blocking(gfp))
+		return NULL;
+
+	size = PAGE_ALIGN(size);
+	nbits = size >> PAGE_SHIFT;
+	order = get_order(size);
+
+	if (order > get_order(SZ_1M))
+		order = get_order(SZ_1M);
+
+	align = (1 << order) - 1;
+
+
+	mutex_lock(&dma_mem->lock);
+	pageno = bitmap_find_next_zero_area(dma_mem->bitmap, dma_mem->nr_pages,
+						0, nbits, align);
+
+	if (pageno < dma_mem->nr_pages) {
+		phys_addr_t base = dma_mem->base + pageno * PAGE_SIZE;
+		*handle = base;
+
+		bitmap_set(dma_mem->bitmap, pageno, nbits);
+
+		if (dma_mem->fixup) {
+			removed_region_fixup(dma_mem, pageno + nbits);
+			dma_mem->fixup = 0;
+		}
+
+		if (no_kernel_mapping && skip_zeroing) {
+			addr = (void *)NO_KERNEL_MAPPING_DUMMY;
+			goto out;
+		}
+
+		addr = ioremap(base, size);
+		if (WARN_ON(!addr)) {
+			bitmap_clear(dma_mem->bitmap, pageno, nbits);
+		} else {
+			if (!skip_zeroing)
+				memset_io(addr, 0, size);
+			if (no_kernel_mapping) {
+				iounmap(addr);
+				addr = (void *)NO_KERNEL_MAPPING_DUMMY;
+			}
+			*handle = base;
+		}
+	}
+
+out:
+	mutex_unlock(&dma_mem->lock);
+	return addr;
+}
+
+
+int removed_mmap(struct device *dev, struct vm_area_struct *vma,
+		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		 struct dma_attrs *attrs)
+{
+	return -ENXIO;
+}
+
+void removed_free(struct device *dev, size_t size, void *cpu_addr,
+		  dma_addr_t handle, struct dma_attrs *attrs)
+{
+	bool no_kernel_mapping = dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING,
+					attrs);
+	struct removed_region *dma_mem = dev->removed_mem;
+
+	if (!no_kernel_mapping)
+		iounmap(cpu_addr);
+	mutex_lock(&dma_mem->lock);
+	bitmap_clear(dma_mem->bitmap, (handle - dma_mem->base) >> PAGE_SHIFT,
+				size >> PAGE_SHIFT);
+	mutex_unlock(&dma_mem->lock);
+}
+
+static dma_addr_t removed_map_page(struct device *dev, struct page *page,
+			unsigned long offset, size_t size,
+			enum dma_data_direction dir,
+			struct dma_attrs *attrs)
+{
+	return ~(dma_addr_t)0;
+}
+
+static void removed_unmap_page(struct device *dev, dma_addr_t dma_handle,
+		size_t size, enum dma_data_direction dir,
+		struct dma_attrs *attrs)
+{
+	return;
+}
+
+static int removed_map_sg(struct device *dev, struct scatterlist *sg,
+			int nents, enum dma_data_direction dir,
+			struct dma_attrs *attrs)
+{
+	return 0;
+}
+
+static void removed_unmap_sg(struct device *dev,
+			struct scatterlist *sg, int nents,
+			enum dma_data_direction dir,
+			struct dma_attrs *attrs)
+{
+	return;
+}
+
+static void removed_sync_single_for_cpu(struct device *dev,
+			dma_addr_t dma_handle, size_t size,
+			enum dma_data_direction dir)
+{
+	return;
+}
+
+void removed_sync_single_for_device(struct device *dev,
+			dma_addr_t dma_handle, size_t size,
+			enum dma_data_direction dir)
+{
+	return;
+}
+
+void removed_sync_sg_for_cpu(struct device *dev,
+			struct scatterlist *sg, int nents,
+			enum dma_data_direction dir)
+{
+	return;
+}
+
+void removed_sync_sg_for_device(struct device *dev,
+			struct scatterlist *sg, int nents,
+			enum dma_data_direction dir)
+{
+	return;
+}
+
+void *removed_remap(struct device *dev, void *cpu_addr, dma_addr_t handle,
+			size_t size, struct dma_attrs *attrs)
+{
+	return ioremap(handle, size);
+}
+
+void removed_unremap(struct device *dev, void *remapped_address, size_t size)
+{
+	iounmap(remapped_address);
+}
+
+struct dma_map_ops removed_dma_ops = {
+	.alloc			= removed_alloc,
+	.free			= removed_free,
+	.mmap			= removed_mmap,
+	.map_page		= removed_map_page,
+	.unmap_page		= removed_unmap_page,
+	.map_sg			= removed_map_sg,
+	.unmap_sg		= removed_unmap_sg,
+	.sync_single_for_cpu	= removed_sync_single_for_cpu,
+	.sync_single_for_device	= removed_sync_single_for_device,
+	.sync_sg_for_cpu	= removed_sync_sg_for_cpu,
+	.sync_sg_for_device	= removed_sync_sg_for_device,
+	.remap			= removed_remap,
+	.unremap		= removed_unremap,
+};
+EXPORT_SYMBOL(removed_dma_ops);
+
+#ifdef CONFIG_OF_RESERVED_MEM
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+
+static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
+{
+        struct removed_region *mem = rmem->priv;
+        if (!mem && dma_init_removed_memory(rmem->base, rmem->size, &mem)) {
+                pr_info("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
+                        &rmem->base, (unsigned long)rmem->size / SZ_1M);
+                return -EINVAL;
+        }
+	mem->fixup = rmem->fixup;
+	set_dma_ops(dev, &removed_dma_ops);
+        rmem->priv = mem;
+        dma_assign_removed_region(dev, mem);
+	return 0;
+}
+
+static void rmem_dma_device_release(struct reserved_mem *rmem,
+                                    struct device *dev)
+{
+        dev->dma_mem = NULL;
+}
+
+static const struct reserved_mem_ops removed_mem_ops = {
+        .device_init    = rmem_dma_device_init,
+        .device_release = rmem_dma_device_release,
+};
+
+static int __init removed_dma_setup(struct reserved_mem *rmem)
+{
+	unsigned long node = rmem->fdt_node;
+	int nomap, fixup;
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+	fixup = of_get_flat_dt_prop(node, "no-map-fixup", NULL) != NULL;
+
+	if (nomap && fixup) {
+		pr_err("Removed memory: nomap & nomap-fixup can't co-exist\n");
+		return -EINVAL;
+	}
+
+	rmem->fixup = fixup;
+	if (rmem->fixup) {
+		/* Architecture specific contiguous memory fixup only for
+		 * no-map-fixup to split mappings
+		 */
+		dma_contiguous_early_fixup(rmem->base, rmem->size);
+	}
+
+        rmem->ops = &removed_mem_ops;
+        pr_info("Removed memory: created DMA memory pool at %pa, size %ld MiB\n",
+                &rmem->base, (unsigned long)rmem->size / SZ_1M);
+        return 0;
+}
+RESERVEDMEM_OF_DECLARE(dma, "removed-dma-pool", removed_dma_setup);
+#endif