ANDROID: GKI: drivers: Add dma removed ops

The current DMA coherent pool assumes that there is a kernel
mapping at all times for the entire pool. This may not be
what we want for the entire times. Add the dma_removed ops to
support this use case.

Bug: 145617272
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
Signed-off-by: Liam Mark <lmark@codeaurora.org>
Signed-off-by: Swathi Sridhar <swatsrid@codeaurora.org>

[surenb Squashed the following commits:
a478a8bf78ad "drivers: Add dma removed ops"
8510985ae320 "dma: removed: Merge dma removed changes from 4.14"
and removed-dma-pool driver changes from
9d4b7d641556 "iommu: arm-smmu: Merge for ..."]

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: Ie4f1e9bdf57b79699fa8fa7e7a6087e6d88ebbfa

include/linux/device.h

@@ -1053,6 +1053,7 @@ struct device {
 	struct cma *cma_area;		/* contiguous memory area for dma
 					   allocations */
 #endif
+	struct removed_region *removed_mem;
 	/* arch specific additions */
 	struct dev_archdata	archdata;
 

kernel/dma/Makefile

@@ -2,7 +2,7 @@
 
 obj-$(CONFIG_HAS_DMA)			+= mapping.o
 obj-$(CONFIG_DMA_CMA)			+= contiguous.o
-obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += coherent.o
+obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += coherent.o removed.o
 obj-$(CONFIG_DMA_DIRECT_OPS)		+= direct.o
 obj-$(CONFIG_DMA_NONCOHERENT_OPS)	+= noncoherent.o
 obj-$(CONFIG_DMA_VIRT_OPS)		+= virt.o

kernel/dma/removed.c

@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (c) 2013-2014,2018 The Linux Foundation. All rights reserved.
+ *  Copyright (C) 2000-2004 Russell King
+ */
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/errno.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>
+
+struct removed_region {
+	phys_addr_t	base;
+	int		nr_pages;
+	unsigned long	*bitmap;
+	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;
+}
+
+void *removed_alloc(struct device *dev, size_t size, dma_addr_t *handle,
+		    gfp_t gfp, unsigned long attrs)
+{
+	bool no_kernel_mapping = attrs & DMA_ATTR_NO_KERNEL_MAPPING;
+	bool skip_zeroing = attrs & DMA_ATTR_SKIP_ZEROING;
+	int pageno;
+	unsigned long order;
+	void __iomem *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 (no_kernel_mapping && skip_zeroing) {
+			addr = (void *)NO_KERNEL_MAPPING_DUMMY;
+			goto out;
+		}
+
+		addr = ioremap_wc(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,
+		 unsigned long attrs)
+{
+	return -ENXIO;
+}
+
+void removed_free(struct device *dev, size_t size, void *cpu_addr,
+		  dma_addr_t handle, unsigned long attrs)
+{
+	bool no_kernel_mapping = attrs & DMA_ATTR_NO_KERNEL_MAPPING;
+	struct removed_region *dma_mem = dev->removed_mem;
+
+	size = PAGE_ALIGN(size);
+	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,
+			unsigned long 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,
+		unsigned long attrs)
+{
+}
+
+static int removed_map_sg(struct device *dev, struct scatterlist *sg,
+			int nents, enum dma_data_direction dir,
+			unsigned long attrs)
+{
+	return 0;
+}
+
+static void removed_unmap_sg(struct device *dev,
+			struct scatterlist *sg, int nents,
+			enum dma_data_direction dir,
+			unsigned long attrs)
+{
+}
+
+static void removed_sync_single_for_cpu(struct device *dev,
+			dma_addr_t dma_handle, size_t size,
+			enum dma_data_direction dir)
+{
+}
+
+void removed_sync_single_for_device(struct device *dev,
+			dma_addr_t dma_handle, size_t size,
+			enum dma_data_direction dir)
+{
+}
+
+void removed_sync_sg_for_cpu(struct device *dev,
+			struct scatterlist *sg, int nents,
+			enum dma_data_direction dir)
+{
+}
+
+void removed_sync_sg_for_device(struct device *dev,
+			struct scatterlist *sg, int nents,
+			enum dma_data_direction dir)
+{
+}
+
+static void __iomem *removed_remap(struct device *dev, void *cpu_addr,
+			dma_addr_t handle, size_t size, unsigned long attrs)
+{
+	return ioremap_wc(handle, size);
+}
+
+void removed_unremap(struct device *dev, void *remapped_address, size_t size)
+{
+	iounmap(remapped_address);
+}
+
+const 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;
+	}
+	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)
+{
+	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