blob: 4281801b5b61a6472ac296c79483cf9874fa41eb [file] [log] [blame]
/*
*
* 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, 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 *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,
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;
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)
{
}
void *removed_remap(struct device *dev, void *cpu_addr, dma_addr_t handle,
size_t size, unsigned long attrs)
{
return ioremap(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;
}
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