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Commit cedb55eb authored by Laura Abbott's avatar Laura Abbott Committed by Matt Wagantall
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drivers: Add dma removed ops 



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

Change-Id: Ie4f1e9bdf57b79699fa8fa7e7a6087e6d88ebbfa
Signed-off-by: default avatarLaura Abbott <lauraa@codeaurora.org>
parent c3b4e280

drivers/base/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ obj-$(CONFIG_DEVTMPFS) += devtmpfs.o 
obj-$(CONFIG_DMA_CMA) += dma-contiguous.o

obj-y			+= power/

obj-$(CONFIG_HAS_DMA)	+= dma-mapping.o

obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o

obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o dma-removed.o

obj-$(CONFIG_ISA)	+= isa.o

obj-$(CONFIG_FW_LOADER)	+= firmware_class.o

obj-$(CONFIG_NUMA)	+= node.o

drivers/base/dma-removed.c

0 → 100644
+280 −0
Original line number Diff line number Diff line 
/*

 *

 *  Copyright (c) 2013-2014, 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/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 {

	dma_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, 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 = get_order(size);

	void *addr = NULL;

	struct removed_region *dma_mem = dev->removed_mem;

	int nbits = size >> PAGE_SHIFT;

	unsigned int align;



	size = PAGE_ALIGN(size);



	if (!(gfp & __GFP_WAIT))

		return NULL;



	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(base, size);

		if (WARN_ON(!addr)) {

			bitmap_clear(dma_mem->bitmap, pageno, nbits);

		} else {

			if (!skip_zeroing)

				memset(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;

        }

	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

include/linux/device.h

+1 −0
Original line number Diff line number Diff line
@@ -775,6 +775,7 @@ 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;