blob: f7a61e7b7734eb5e1a2e13beb3588531be08900c [file] [log] [blame]
/*
*
* Copyright (c) 2013-2017, 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 {
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;
unsigned int pageno;
unsigned long order;
void __iomem *addr = NULL;
struct removed_region *dma_mem = dev->removed_mem;
unsigned 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