Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d06f4207 authored by Laura Abbott's avatar Laura Abbott
Browse files

drivers: Add dma-removed dma_ops 



The current set of dma_ops only supports memory that's actually
backed by struct pages. In the general case this is what we want,
but there are some use cases where it's useful to allocate
removed memory through dma APIs (through CMA region for example).
Add a limited set of dma operations to accomplish this. This is
only the allocate/free version of the APIs which is all that is
necessary for these purposes.

Change-Id: I518e6965d63f3c95697f59c089b95219f8e6d96e
Signed-off-by: default avatarLaura Abbott <lauraa@codeaurora.org>
parent 84361a5f

drivers/base/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ obj-y := core.o bus.o dd.o syscore.o \ 
			   attribute_container.o transport_class.o \

			   topology.o

obj-$(CONFIG_DEVTMPFS)	+= devtmpfs.o

obj-$(CONFIG_CMA) += dma-contiguous.o

obj-$(CONFIG_CMA) += dma-contiguous.o dma-removed.o

obj-y			+= power/

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

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

drivers/base/dma-removed.c

0 → 100644
+153 −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>



#define NO_KERNEL_MAPPING_DUMMY	0x2222



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);

	unsigned long pfn;

	unsigned long order = get_order(size);

	void *addr = NULL;



	size = PAGE_ALIGN(size);



	if (!(gfp & __GFP_WAIT))

		return NULL;



	pfn = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT, order);



	if (pfn) {

		addr = ioremap(__pfn_to_phys(pfn), size);

		memset(addr, 0, size);

		if (no_kernel_mapping) {

			iounmap(addr);

			addr = (void *)NO_KERNEL_MAPPING_DUMMY;

		}

		if (addr)

			*handle = __pfn_to_phys(pfn);



	}



	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);



	if (!no_kernel_mapping)

		iounmap(cpu_addr);

	dma_release_from_contiguous(dev, __phys_to_pfn(handle),

					size >> PAGE_SHIFT);

}



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;

}



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,

};

EXPORT_SYMBOL(removed_dma_ops);

include/linux/dma-removed.h

0 → 100644
+16 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 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/dma-mapping.h>



extern struct dma_map_ops removed_dma_ops;