// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/mm/dma-mapping.c
*
* Copyright (C) 2000-2004 Russell King
*
* DMA uncached mapping support.
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/genalloc.h>
#include <linux/gfp.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/dma-direct.h>
#include <linux/dma-map-ops.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/cma.h>
#include <asm/page.h>
#include <asm/highmem.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/mach/arch.h>
#include <asm/dma-iommu.h>
#include <asm/mach/map.h>
#include <asm/system_info.h>
#include <asm/xen/xen-ops.h>
#include "dma.h"
#include "mm.h"
struct arm_dma_alloc_args {
struct device *dev;
size_t size;
gfp_t gfp;
pgprot_t prot;
const void *caller;
bool want_vaddr;
int coherent_flag;
};
struct arm_dma_free_args {
struct device *dev;
size_t size;
void *cpu_addr;
struct page *page;
bool want_vaddr;
};
#define NORMAL 0
#define COHERENT 1
struct arm_dma_allocator {
void *(*alloc)(struct arm_dma_alloc_args *args,
struct page **ret_page);
void (*free)(struct arm_dma_free_args *args);
};
struct arm_dma_buffer {
struct list_head list;
void *virt;
struct arm_dma_allocator *allocator;
};
static LIST_HEAD(arm_dma_bufs);
static DEFINE_SPINLOCK(arm_dma_bufs_lock);
static struct arm_dma_buffer *arm_dma_buffer_find(void *virt)
{
struct arm_dma_buffer *buf, *found = NULL;
unsigned long flags;
spin_lock_irqsave(&arm_dma_bufs_lock, flags);
list_for_each_entry(buf, &arm_dma_bufs, list) {
if (buf->virt == virt) {
list_del(&buf->list);
found = buf;
break;
}
}
spin_unlock_irqrestore(&arm_dma_bufs_lock, flags);
return found;
}
/*
* The DMA API is built upon the notion of "buffer ownership". A buffer
* is either exclusively owned by the CPU (and therefore may be accessed
* by it) or exclusively owned by the DMA device. These helper functions
* represent the transitions between these two ownership states.
*
* Note, however, that on later ARMs, this notion does not work due to
* speculative prefetches. We model our approach on the assumption that
* the CPU does do speculative prefetches, which means we clean caches
* before transfers and delay cache invalidation until transfer completion.
*
*/
static void __dma_clear_buffer(struct page *page, size_t size, int coherent_flag)
{
/*
* Ensure that the allocated pages are zeroed, and that any data
* lurking in the kernel direct-mapped region is invalidated.
*/
if (PageHighMem(page)) {
phys_addr_t base = __pfn_to_phys(page_to_pfn(page));
phys_addr_t end = base + size;
while (size > 0) {
void *ptr = kmap_atomic(page);
memset(ptr, 0, PAGE_SIZE);
if (coherent_flag != COHERENT)
dmac_flush_range(ptr, ptr + PAGE_SIZE);
kunmap_atomic(ptr);
page++;
size -= PAGE_SIZE;
}
if (coherent_flag != COHERENT)
outer_flush_range(base, end);
} else {
void *ptr = page_address(page);
memset(ptr, 0, size);
if (coherent_flag != COHERENT) {
dmac_flush_range(ptr, ptr + size);
outer_flush_range(__pa(ptr), __pa(ptr) + size);
}
}
}
/*
* Allocate a DMA buffer for 'dev' of size 'size' using the
* specified gfp mask. Note that 'size' must be page aligned.
*/
static struct page *__dma_alloc_buffer(struct device *dev, size_t size,
gfp_t gfp, int coherent_flag)
{
unsigned long order = get_order(size);
struct page *page, *p, *e;
page = alloc_pages(gfp, order);
if (!page)
return NULL;
/*
* Now split the huge page and free the excess pages
*/
split_page(page, order);
for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
__free_page(p);
__dma_clear_buffer(page, size, coherent_flag);
return page;
}
/*
* Free a DMA buffer. 'size' must be page aligned.
*/
static void __dma_free_buffer(struct page *page, size_t size)
{
struct page *e = page + (size >> PAGE_SHIFT);
while (page < e) {
__free_page(page);
page++;
}
}
static void *__alloc_from_contiguous(struct device *dev, size_t size,
pgprot_t prot, struct page **ret_page,
const void *caller, bool want_vaddr,
int coherent_flag, gfp_t gfp);
static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
pgprot_t prot, struct page **ret_page,
const void *caller, bool want_vaddr);
#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
static struct gen_pool *atomic_pool __ro_after_init;
static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
static int __init early_coherent_pool(char *p)
{
atomic_pool_size = memparse(p, &p);
return 0;
}
early_param("coherent_pool", early_coherent_pool);
/*
* Initialise the coherent pool for atomic allocations.
*/
static int __init atomic_pool_init(void)
{
pgprot_t prot = pgprot_dmacoherent(PAGE_KERNEL);
gfp_t gfp = GFP_KERNEL | GFP_DMA;
struct page *page;
void *ptr;
atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
if (!atomic_pool)
goto out;
/*
* The atomic pool is only used for non-coherent allocations
* so we must pass NORMAL for coherent_flag.
*/
if (dev_get_cma_area(NULL))
ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot,
&page, atomic_pool_init, true, NORMAL,
GFP_KERNEL);
else
ptr = __alloc_remap_buffer(NULL, atomic_pool_size, gfp, prot,
&page, atomic_pool_init, true);
if (ptr) {
int ret;
ret = gen_pool_add_virt(atomic_pool, (unsigned long)ptr,
page_to_phys(page),
atomic_pool_size, -1);
if (ret)
goto destroy_genpool;
gen_pool_set_algo(atomic_pool,
gen_pool_first_fit_order_align,
NULL);
pr_info("DMA: preallocated %zu KiB pool for atomic coherent allocations\n",
atomic_pool_size / 1024);
return 0;
}
destroy_genpool:
gen_pool_destroy(atomic_pool);
atomic_pool = NULL;
out:
pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
atomic_pool_size / 1024);
return -ENOMEM;
}
/*
* CMA is activated by core_initcall, so we must be called after it.
*/
postcore_initcall(atomic_pool_init);
#ifdef CONFIG_CMA_AREAS
struct dma_contig_early_reserve {
phys_addr_t base;
unsigned long size;
};
static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata;
static int dma_mmu_remap_num __initdata;
#ifdef CONFIG_DMA_CMA
void __init dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
{
dma_mmu_remap[dma_mmu_remap_num].base = base;
dma_mmu_remap[dma_mmu_remap_num].size = size;
dma_mmu_remap_num++;
}
#endif
void __init dma_contiguous_remap(void)
{
int i;
for (i = 0; i < dma_mmu_remap_num; i++) {
phys_addr_t start = dma_mmu_remap[i].base;
phys_addr_t end = start + dma_mmu_remap[i].size;
struct map_desc map;
unsigned long addr;
if (end > arm_lowmem_limit)
end = arm_lowmem_limit;
if (start >= end)
continue;
map.pfn = __phys_to_pfn(start);
map.virtual = __phys_to_virt(start);
map.length = end - start;
map.type = MT_MEMORY_DMA_READY;
/*
* Clear previous low-memory mapping to ensure that the
* TLB does not see any conflicting entries, then flush
* the TLB of the old entries before creating new mappings.
*
* This ensures that any speculatively loaded TLB entries
* (even though they may be rare) can not cause any problems,
* and ensures that this code is architecturally compliant.
*/
for (addr = __phys_to_virt(start); addr < __phys_to_virt(end);
addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
flush_tlb_kernel_range(__phys_to_virt(start),
__phys_to_virt(end));
iotable_init(&map, 1);
}
}
#endif
static int __dma_update_pte(pte_t *pte, unsigned long addr, void *data)
{
struct page *page = virt_to_page((void *)addr);
pgprot_t prot = *(pgprot_t *)data;
set_pte_ext(pte, mk_pte(page, prot), 0);
return 0;
}
static void __dma_remap(struct page *page, size_t size, pgprot_t prot)
{
unsigned long start = (unsigned long) page_address(page);
unsigned end = start + size;
apply_to_page_range(&init_mm, start, size, __dma_update_pte, &prot);
flush_tlb_kernel_range(start, end);
}
static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
pgprot_t prot, struct page **ret_page,
const void *caller, bool want_vaddr)
{
struct page *page;
void *ptr = NULL;
/*
* __alloc_remap_buffer is only called when the device is
* non-coherent
*/
page = __dma_alloc_buffer(dev, size, gfp, NORMAL);
if (!page)
return NULL;
if (!want_vaddr)
goto out;
ptr = dma_common_contiguous_remap(page, size, prot, caller);
if (!ptr) {
__dma_free_buffer(page, size);
return NULL;
}
out:
*ret_page = page;
return ptr;
}
static void *__alloc_from_pool(size_t size, struct page **ret_page)
{
unsigned long val;
void *ptr = NULL;
if (!atomic_pool) {
WARN(1, "coherent pool not initialised!\n");
return NULL;
}
val = gen_pool_alloc(atomic_pool, size);
if (val) {
phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
*ret_page = phys_to_page(phys);
ptr = (void *)val;
}
return ptr;
}
static bool __in_atomic_pool(void *start, size_t size)
{
return gen_pool_has_addr(atomic_pool, (unsigned long)start, size);
}
static int __free_from_pool(void *start, size_t size)
{
if (!__in_atomic_pool(start, size))
return 0;
gen_pool_free(atomic_pool, (unsigned long)start, size);
return 1;
}
static void *__alloc_from_contiguous(struct device *dev, size_t size,
pgprot_t prot, struct page **ret_page,
const void *caller, bool want_vaddr,
int coherent_flag, gfp_t gfp)
{
unsigned long order = get_order(size);
size_t count = size >> PAGE_SHIFT;
struct page *page;
void *ptr = NULL;
page = dma_alloc_from_contiguous(dev, count, order, gfp & __GFP_NOWARN);
if (!page)
return NULL;
__dma_clear_buffer(page, size, coherent_flag);
if (!want_vaddr)
goto out;
if (PageHighMem(page)) {
ptr = dma_common_contiguous_remap(page, size, prot, caller);
if (!ptr) {
dma_release_from_contiguous(dev, page, count);
return NULL;
}
} else {
__dma_remap(page, size, prot);
ptr = page_address(page);
}
out:
*ret_page = page;
return ptr;
}
static void __free_from_contiguous(struct device *dev, struct page *page,
void *cpu_addr, size_t size, bool want_vaddr)
{
if (want_vaddr) {
if (PageHighMem(page))
dma_common_free_remap(cpu_addr, size);
else
__dma_remap(page, size, PAGE_KERNEL);
}
dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
}
static inline pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot)
{
prot = (attrs & DMA_ATTR_WRITE_COMBINE) ?
pgprot_writecombine(prot) :
pgprot_dmacoherent(prot);
return prot;
}
static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp,
struct page **ret_page)
{
struct page *page;
/* __alloc_simple_buffer is only called when the device is coherent */
page = __dma_alloc_buffer(dev, size, gfp, COHERENT);
if (!page)
return NULL;
*ret_page = page;
return page_address(page);
}
static void *simple_allocator_alloc(struct arm_dma_alloc_args *args,
struct page **ret_page)
{
return __alloc_simple_buffer(args->dev, args->size, args->gfp,
ret_page);
}
static void simple_allocator_free(struct arm_dma_free_args *args)
{
__dma_free_buffer(args->page, args->size);
}
static struct arm_dma_allocator simple_allocator = {
.alloc = simple_allocator_alloc,
.free = simple_allocator_free,
};
static void *cma_allocator_alloc(struct arm_dma_alloc_args *args,
struct page **ret_page)
{
return __alloc_from_contiguous(args->dev, args->size, args->prot,
ret_page, args->caller,
args->want_vaddr, args->coherent_flag,
args->gfp);
}
static void cma_allocator_free(struct arm_dma_free_args *args)
{
__free_from_contiguous(args->dev, args->page, args->cpu_addr,
args->size, args->want_vaddr);
}
static struct arm_dma_allocator cma_allocator = {
.alloc = cma_allocator_alloc,
.free = cma_allocator_free,
};
static void *pool_allocator_alloc(struct arm_dma_alloc_args *args,
struct page **ret_page)
{
return __alloc_from_pool(args->size, ret_page);
}
static void pool_allocator_free(struct arm_dma_free_args *args)
{
__free_from_pool(args->cpu_addr, args->size);
}
static struct arm_dma_allocator pool_allocator = {
.alloc = pool_allocator_alloc,
.free = pool_allocator_free,
};
static void *remap_allocator_alloc(struct arm_dma_alloc_args *args,
struct page **ret_page)
{
return __alloc_remap_buffer(args->dev, args->size, args->gfp,
args->prot, ret_page, args->caller,
args->want_vaddr);
}
static void remap_allocator_free(struct arm_dma_free_args *args)
{
if (args->want_vaddr)
dma_common_free_remap(args->cpu_addr, args->size);
__dma_free_buffer(args->page, args->size);
}
static struct arm_dma_allocator remap_allocator = {
.alloc = remap_allocator_alloc,
.free = remap_allocator_free,
};
static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
gfp_t gfp, pgprot_t prot, bool is_coherent,
unsigned long attrs, const void *caller)
{
u64 mask = min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
struct page *page = NULL;
void *addr;
bool allowblock, cma;
struct arm_dma_buffer *buf;
struct arm_dma_alloc_args args = {
.dev = dev,
.size = PAGE_ALIGN(size),
.gfp = gfp,
.prot = prot,
.caller = caller,
.want_vaddr = ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0),
.coherent_flag = is_coherent ? COHERENT : NORMAL,
};
#ifdef CONFIG_DMA_API_DEBUG
u64 limit = (mask + 1) & ~mask;
if (limit && size >= limit) {
dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n",
size, mask);
return NULL;
}
#endif
buf = kzalloc(sizeof(*buf),
gfp & ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM));
if (!buf)
return NULL;
if (mask < 0xffffffffULL)
gfp |= GFP_DMA;
args.gfp = gfp;
*handle = DMA_MAPPING_ERROR;
allowblock = gfpflags_allow_blocking(gfp);
cma = allowblock ? dev_get_cma_area(dev) : NULL;
if (cma)
buf->allocator = &cma_allocator;
else if (is_coherent)
buf->allocator = &simple_allocator;
else if (allowblock)
buf->allocator = &remap_allocator;
else
buf->allocator = &pool_allocator;
addr = buf->allocator->alloc(&args, &page);
if (page) {
unsigned long flags;
*handle = phys_to_dma(dev, page_to_phys(page));
buf->virt = args.want_vaddr ? addr : page;
spin_lock_irqsave(&arm_dma_bufs_lock, flags);
list_add(&buf->list, &arm_dma_bufs);
spin_unlock_irqrestore(&arm_dma_bufs_lock, flags);
} else {
kfree(buf);
}
return args.want_vaddr ? addr : page;
}
/*
* Free a buffer as defined by the above mapping.
*/
static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t handle, unsigned long attrs,
bool is_coherent)
{
struct page *page = phys_to_page(dma_to_phys(dev, handle));
struct arm_dma_buffer *buf;
struct arm_dma_free_args args = {
.dev = dev,
.size = PAGE_ALIGN(size),
.cpu_addr = cpu_addr,
.page = page,
.want_vaddr = ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0),
};
buf = arm_dma_buffer_find(cpu_addr);
if (WARN(!buf, "Freeing invalid buffer %p\n", cpu_addr))
return;
buf->allocator->free(&args);
kfree(buf);
}
static void dma_cache_maint_page(struct page *page, unsigned long offset,
size_t size, enum dma_data_direction dir,
void (*op)(const void *, size_t, int))
{
unsigned long pfn;
size_t left = size;
pfn = page_to_pfn(page) + offset / PAGE_SIZE;
offset %= PAGE_SIZE;
/*
* A single sg entry may refer to multiple physically contiguous
* pages. But we still need to process highmem pages individually.
* If highmem is not configured then the bulk of this loop gets
* optimized out.
*/
do {
size_t len = left;
void *vaddr;
page = pfn_to_page(pfn);
if (PageHighMem(page)) {
if (len + offset > PAGE_SIZE)
len = PAGE_SIZE - offset;
if (cache_is_vipt_nonaliasing()) {
vaddr = kmap_atomic(page);
op(vaddr + offset, len, dir);
kunmap_atomic(vaddr);
} else {
vaddr = kmap_high_get(page);
if (vaddr) {
op(vaddr + offset, len, dir);
kunmap_high(page);
}
}
} else {
vaddr = page_address(page) + offset;
op(vaddr, len, dir);
}
offset = 0;
pfn++;
left -= len;
} while (left);
}
/*
* Make an area consistent for devices.
* Note: Drivers should NOT use this function directly.
* Use the driver DMA support - see dma-mapping.h (dma_sync_*)
*/
static void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
size_t size, enum dma_data_direction dir)
{
phys_addr_t paddr;
dma_cache_maint_page(page, off, size, dir, dmac_map_area);
paddr = page_to_phys(page) + off;
if (dir == DMA_FROM_DEVICE) {
outer_inv_range(paddr, paddr + size);
} else {
outer_clean_range(paddr, paddr + size);
}
/* FIXME: non-speculating: flush on bidirectional mappings? */
}
static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
size_t size, enum dma_data_direction dir)
{
phys_addr_t paddr = page_to_phys(page) + off;
/* FIXME: non-speculating: not required */
/* in any case, don't bother invalidating if DMA to device */
if (dir != DMA_TO_DEVICE) {
outer_inv_range(paddr, paddr + size);
dma_cache_maint_page(page, off, size, dir, dmac_unmap_area);
}
/*
* Mark the D-cache clean for these pages to avoid extra flushing.
*/
if (dir != DMA_TO_DEVICE && size >= PAGE_SIZE) {
struct folio *folio = pfn_folio(paddr / PAGE_SIZE);
size_t offset = offset_in_folio(folio, paddr);
for (;;) {
size_t sz = folio_size(folio) - offset;
if (size < sz)
break;
if (!offset)
set_bit(PG_dcache_clean, &folio->flags);
offset = 0;
size -= sz;
if (!size)
break;
folio = folio_next(folio);
}
}
}
#ifdef CONFIG_ARM_DMA_USE_IOMMU
static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)
{
int prot = 0;
if (attrs & DMA_ATTR_PRIVILEGED)
prot |= IOMMU_PRIV;
switch (dir) {
case DMA_BIDIRECTIONAL:
return prot | IOMMU_READ | IOMMU_WRITE;
case DMA_TO_DEVICE:
return prot | IOMMU_READ;
case DMA_FROM_DEVICE:
return prot | IOMMU_WRITE;
default:
return prot;
}
}
/* IOMMU */
static int extend_iommu_mapping(struct dma_iommu_mapping *mapping);
static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping,
size_t size)
{
unsigned int order = get_order(size);
unsigned int align = 0;
unsigned int count, start;
size_t mapping_size = mapping->bits << PAGE_SHIFT;
unsigned long flags;
dma_addr_t iova;
int i;
if (order > CONFIG_ARM_DMA_IOMMU_ALIGNMENT)
order = CONFIG_ARM_DMA_IOMMU_ALIGNMENT;
count = PAGE_ALIGN(size) >> PAGE_SHIFT;
align = (1 << order) - 1;
spin_lock_irqsave(&mapping->lock, flags);
for (i = 0; i < mapping->nr_bitmaps; i++) {
start = bitmap_find_next_zero_area(mapping->bitmaps[i],
mapping->bits, 0, count, align);
if (start > mapping->bits)
continue;
bitmap_set(mapping->bitmaps[i], start, count);
break;
}
/*
* No unused range found. Try to extend the existing mapping
* and perform a second attempt to reserve an IO virtual
* address range of size bytes.
*/
if (i == mapping->nr_bitmaps) {
if (extend_iommu_mapping(mapping)) {
spin_unlock_irqrestore(&mapping->lock, flags);
return DMA_MAPPING_ERROR;
}
start = bitmap_find_next_zero_area(mapping->bitmaps[i],
mapping->bits, 0, count, align);
if (start > mapping->bits) {
spin_unlock_irqrestore(&mapping->lock, flags);
return DMA_MAPPING_ERROR;
}
bitmap_set(mapping->bitmaps[i], start, count);
}
spin_unlock_irqrestore(&mapping->lock, flags);
iova = mapping->base + (mapping_size * i);
iova += start << PAGE_SHIFT;
return iova;
}
static inline void __free_iova(struct dma_iommu_mapping *mapping,
dma_addr_t addr, size_t size)
{
unsigned int start, count;
size_t mapping_size = mapping->bits << PAGE_SHIFT;
unsigned long flags;
dma_addr_t bitmap_base;
u32 bitmap_index;
if (!size)
return;
bitmap_index = (u32) (addr - mapping->base) / (u32) mapping_size;
BUG_ON(addr < mapping->base || bitmap_index > mapping->extensions);
bitmap_base = mapping->base + mapping_size * bitmap_index;
start = (addr - bitmap_base) >> PAGE_SHIFT;
if (addr + size > bitmap_base + mapping_size) {
/*
* The address range to be freed reaches into the iova
* range of the next bitmap. This should not happen as
* we don't allow this in __alloc_iova (at the
* moment).
*/
BUG();
} else
count = size >> PAGE_SHIFT;
spin_lock_irqsave(&mapping->lock, flags);
bitmap_clear(mapping->bitmaps[bitmap_index], start, count);
spin_unlock_irqrestore(&mapping->lock, flags);
}
/* We'll try 2M, 1M, 64K, and finally 4K; array must end with 0! */
static const int iommu_order_array[] = { 9, 8, 4, 0 };
static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
gfp_t gfp, unsigned long attrs,
int coherent_flag)
{
struct page **pages;
int count = size >> PAGE_SHIFT;
int array_size = count * sizeof(struct page *);
int i = 0;
int order_idx = 0;
pages = kvzalloc(array_size, GFP_KERNEL);
if (!pages)
return NULL;
if (attrs & DMA_ATTR_FORCE_CONTIGUOUS)
{
unsigned long order = get_order(size);
struct page *page;
page = dma_alloc_from_contiguous(dev, count, order,
gfp & __GFP_NOWARN);
if (!page)
goto error;
__dma_clear_buffer(page, size, coherent_flag);
for (i = 0; i < count; i++)
pages[i] = page + i;
return pages;
}
/* Go straight to 4K chunks if caller says it's OK. */
if (attrs & DMA_ATTR_ALLOC_SINGLE_PAGES)
order_idx = ARRAY_SIZE(iommu_order_array) - 1;
/*
* IOMMU can map any pages, so himem can also be used here
*/
gfp |= __GFP_NOWARN | __GFP_HIGHMEM;
while (count) {
int j, order;
order = iommu_order_array[order_idx];
/* Drop down when we get small */
if (__fls(count) < order) {
order_idx++;
continue;
}
if (order) {
/* See if it's easy to allocate a high-order chunk */
pages[i] = alloc_pages(gfp | __GFP_NORETRY, order);
/* Go down a notch at first sign of pressure */
if (!pages[i]) {
order_idx++;
continue;
}
} else {
pages[i] = alloc_pages(gfp, 0);
if (!pages[i])
goto error;
}
if (order) {
split_page(pages[i], order);
j = 1 << order;
while (--j)
pages[i + j] = pages[i] + j;
}
__dma_clear_buffer(pages[i], PAGE_SIZE << order, coherent_flag);
i += 1 << order;
count -= 1 << order;
}
return pages;
error:
while (i--)
if (pages[i])
__free_pages(pages[i], 0);
kvfree(pages);
return NULL;
}
static int __iommu_free_buffer(struct device *dev, struct page **pages,
size_t size, unsigned long attrs)
{
int count = size >> PAGE_SHIFT;
int i;
if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
dma_release_from_contiguous(dev, pages[0], count);
} else {
for (i = 0; i < count; i++)
if (pages[i])
__free_pages(pages[i], 0);
}
kvfree(pages);
return 0;
}
/*
* Create a mapping in device IO address space for specified pages
*/
static dma_addr_t
__iommu_create_mapping(struct device *dev, struct page **pages, size_t size,
unsigned long attrs)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
dma_addr_t dma_addr, iova;
int i;
dma_addr = __alloc_iova(mapping, size);
if (dma_addr == DMA_MAPPING_ERROR)
return dma_addr;
iova = dma_addr;
for (i = 0; i < count; ) {
int ret;
unsigned int next_pfn = page_to_pfn(pages[i]) + 1;
phys_addr_t phys = page_to_phys(pages[i]);
unsigned int len, j;
for (j = i + 1; j < count; j++, next_pfn++)
if (page_to_pfn(pages[j]) != next_pfn)
break;
len = (j - i) << PAGE_SHIFT;
ret = iommu_map(mapping->domain, iova, phys, len,
__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs),
GFP_KERNEL);
if (ret < 0)
goto fail;
iova += len;
i = j;
}
return dma_addr;
fail:
iommu_unmap(mapping->domain, dma_addr, iova-dma_addr);
__free_iova(mapping, dma_addr, size);
return DMA_MAPPING_ERROR;
}
static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t size)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
/*
* add optional in-page offset from iova to size and align
* result to page size
*/
size = PAGE_ALIGN((iova & ~PAGE_MASK) + size);
iova &= PAGE_MASK;
iommu_unmap(mapping->domain, iova, size);
__free_iova(mapping, iova, size);
return 0;
}
static struct page **__atomic_get_pages(void *addr)
{
struct page *page;
phys_addr_t phys;
phys = gen_pool_virt_to_phys(atomic_pool, (unsigned long)addr);
page = phys_to_page(phys);
return (struct page **)page;
}
static struct page **__iommu_get_pages(void *cpu_addr, unsigned long attrs)
{
if (__in_atomic_pool(cpu_addr, PAGE_SIZE))
return __atomic_get_pages(cpu_addr);
if (attrs & DMA_ATTR_NO_KERNEL_MAPPING)
return cpu_addr;
return dma_common_find_pages(cpu_addr);
}
static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
dma_addr_t *handle, int coherent_flag,
unsigned long attrs)
{
struct page *page;
void *addr;
if (coherent_flag == COHERENT)
addr = __alloc_simple_buffer(dev, size, gfp, &page);
else
addr = __alloc_from_pool(size, &page);
if (!addr)
return NULL;
*handle = __iommu_create_mapping(dev, &page, size, attrs);
if (*handle == DMA_MAPPING_ERROR)
goto err_mapping;
return addr;
err_mapping:
__free_from_pool(addr, size);
return NULL;
}
static void __iommu_free_atomic(struct device *dev, void *cpu_addr,
dma_addr_t handle, size_t size, int coherent_flag)
{
__iommu_remove_mapping(dev, handle, size);
if (coherent_flag == COHERENT)
__dma_free_buffer(virt_to_page(cpu_addr), size);
else
__free_from_pool(cpu_addr, size);
}
static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
{
pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL);
struct page **pages;
void *addr = NULL;
int coherent_flag = dev->dma_coherent ? COHERENT : NORMAL;
*handle = DMA_MAPPING_ERROR;
size = PAGE_ALIGN(size);
if (coherent_flag == COHERENT || !gfpflags_allow_blocking(gfp))
return __iommu_alloc_simple(dev, size, gfp, handle,
coherent_flag, attrs);
pages = __iommu_alloc_buffer(dev, size, gfp, attrs, coherent_flag);
if (!pages)
return NULL;
*handle = __iommu_create_mapping(dev, pages, size, attrs);
if (*handle == DMA_MAPPING_ERROR)
goto err_buffer;
if (attrs & DMA_ATTR_NO_KERNEL_MAPPING)
return pages;
addr = dma_common_pages_remap(pages, size, prot,
__builtin_return_address(0));
if (!addr)
goto err_mapping;
return addr;
err_mapping:
__iommu_remove_mapping(dev, *handle, size);
err_buffer:
__iommu_free_buffer(dev, pages, size, attrs);
return NULL;
}
static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
struct page **pages = __iommu_get_pages(cpu_addr, attrs);
unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
int err;
if (!pages)
return -ENXIO;
if (vma->vm_pgoff >= nr_pages)
return -ENXIO;
if (!dev->dma_coherent)
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
err = vm_map_pages(vma, pages, nr_pages);
if (err)
pr_err("Remapping memory failed: %d\n", err);
return err;
}
/*
* free a page as defined by the above mapping.
* Must not be called with IRQs disabled.
*/
static void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t handle, unsigned long attrs)
{
int coherent_flag = dev->dma_coherent ? COHERENT : NORMAL;
struct page **pages;
size = PAGE_ALIGN(size);
if (coherent_flag == COHERENT || __in_atomic_pool(cpu_addr, size)) {
__iommu_free_atomic(dev, cpu_addr, handle, size, coherent_flag);
return;
}
pages = __iommu_get_pages(cpu_addr, attrs);
if (!pages) {
WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
return;
}
if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0)
dma_common_free_remap(cpu_addr, size);
__iommu_remove_mapping(dev, handle, size);
__iommu_free_buffer(dev, pages, size, attrs);
}
static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr,
size_t size, unsigned long attrs)
{
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct page **pages = __iommu_get_pages(cpu_addr, attrs);
if (!pages)
return -ENXIO;
return sg_alloc_table_from_pages(sgt, pages, count, 0, size,
GFP_KERNEL);
}
/*
* Map a part of the scatter-gather list into contiguous io address space
*/
static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
size_t size, dma_addr_t *handle,
enum dma_data_direction dir, unsigned long attrs)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
dma_addr_t iova, iova_base;
int ret = 0;
unsigned int count;
struct scatterlist *s;
int prot;
size = PAGE_ALIGN(size);
*handle = DMA_MAPPING_ERROR;
iova_base = iova = __alloc_iova(mapping, size);
if (iova == DMA_MAPPING_ERROR)
return -ENOMEM;
for (count = 0, s = sg; count < (size >> PAGE_SHIFT); s = sg_next(s)) {
phys_addr_t phys = page_to_phys(sg_page(s));
unsigned int len = PAGE_ALIGN(s->offset + s->length);
if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
prot = __dma_info_to_prot(dir, attrs);
ret = iommu_map(mapping->domain, iova, phys, len, prot,
GFP_KERNEL);
if (ret < 0)
goto fail;
count += len >> PAGE_SHIFT;
iova += len;
}
*handle = iova_base;
return 0;
fail:
iommu_unmap(mapping->domain, iova_base, count * PAGE_SIZE);
__free_iova(mapping, iova_base, size);
return ret;
}
/**
* arm_iommu_map_sg - map a set of SG buffers for streaming mode DMA
* @dev: valid struct device pointer
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Map a set of buffers described by scatterlist in streaming mode for DMA.
* The scatter gather list elements are merged together (if possible) and
* tagged with the appropriate dma address and length. They are obtained via
* sg_dma_{address,length}.
*/
static int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir, unsigned long attrs)
{
struct scatterlist *s = sg, *dma = sg, *start = sg;
int i, count = 0, ret;
unsigned int offset = s->offset;
unsigned int size = s->offset + s->length;
unsigned int max = dma_get_max_seg_size(dev);
for (i = 1; i < nents; i++) {
s = sg_next(s);
s->dma_length = 0;
if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) {
ret = __map_sg_chunk(dev, start, size,
&dma->dma_address, dir, attrs);
if (ret < 0)
goto bad_mapping;
dma->dma_address += offset;
dma->dma_length = size - offset;
size = offset = s->offset;
start = s;
dma = sg_next(dma);
count += 1;
}
size += s->length;
}
ret = __map_sg_chunk(dev, start, size, &dma->dma_address, dir, attrs);
if (ret < 0)
goto bad_mapping;
dma->dma_address += offset;
dma->dma_length = size - offset;
return count+1;
bad_mapping:
for_each_sg(sg, s, count, i)
__iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s));
if (ret == -ENOMEM)
return ret;
return -EINVAL;
}
/**
* arm_iommu_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
* @dev: valid struct device pointer
* @sg: list of buffers
* @nents: number of buffers to unmap (same as was passed to dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*
* Unmap a set of streaming mode DMA translations. Again, CPU access
* rules concerning calls here are the same as for dma_unmap_single().
*/
static void arm_iommu_unmap_sg(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir,
unsigned long attrs)
{
struct scatterlist *s;
int i;
for_each_sg(sg, s, nents, i) {
if (sg_dma_len(s))
__iommu_remove_mapping(dev, sg_dma_address(s),
sg_dma_len(s));
if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_page_dev_to_cpu(sg_page(s), s->offset,
s->length, dir);
}
}
/**
* arm_iommu_sync_sg_for_cpu
* @dev: valid struct device pointer
* @sg: list of buffers
* @nents: number of buffers to map (returned from dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*/
static void arm_iommu_sync_sg_for_cpu(struct device *dev,
struct scatterlist *sg,
int nents, enum dma_data_direction dir)
{
struct scatterlist *s;
int i;
if (dev->dma_coherent)
return;
for_each_sg(sg, s, nents, i)
__dma_page_dev_to_cpu(sg_page(s), s->offset, s->length, dir);
}
/**
* arm_iommu_sync_sg_for_device
* @dev: valid struct device pointer
* @sg: list of buffers
* @nents: number of buffers to map (returned from dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*/
static void arm_iommu_sync_sg_for_device(struct device *dev,
struct scatterlist *sg,
int nents, enum dma_data_direction dir)
{
struct scatterlist *s;
int i;
if (dev->dma_coherent)
return;
for_each_sg(sg, s, nents, i)
__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
}
/**
* arm_iommu_map_page
* @dev: valid struct device pointer
* @page: page that buffer resides in
* @offset: offset into page for start of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* IOMMU aware version of arm_dma_map_page()
*/
static dma_addr_t arm_iommu_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
dma_addr_t dma_addr;
int ret, prot, len = PAGE_ALIGN(size + offset);
if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_page_cpu_to_dev(page, offset, size, dir);
dma_addr = __alloc_iova(mapping, len);
if (dma_addr == DMA_MAPPING_ERROR)
return dma_addr;
prot = __dma_info_to_prot(dir, attrs);
ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len,
prot, GFP_KERNEL);
if (ret < 0)
goto fail;
return dma_addr + offset;
fail:
__free_iova(mapping, dma_addr, len);
return DMA_MAPPING_ERROR;
}
/**
* arm_iommu_unmap_page
* @dev: valid struct device pointer
* @handle: DMA address of buffer
* @size: size of buffer (same as passed to dma_map_page)
* @dir: DMA transfer direction (same as passed to dma_map_page)
*
* IOMMU aware version of arm_dma_unmap_page()
*/
static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
dma_addr_t iova = handle & PAGE_MASK;
struct page *page;
int offset = handle & ~PAGE_MASK;
int len = PAGE_ALIGN(size + offset);
if (!iova)
return;
if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
__dma_page_dev_to_cpu(page, offset, size, dir);
}
iommu_unmap(mapping->domain, iova, len);
__free_iova(mapping, iova, len);
}
/**
* arm_iommu_map_resource - map a device resource for DMA
* @dev: valid struct device pointer
* @phys_addr: physical address of resource
* @size: size of resource to map
* @dir: DMA transfer direction
*/
static dma_addr_t arm_iommu_map_resource(struct device *dev,
phys_addr_t phys_addr, size_t size,
enum dma_data_direction dir, unsigned long attrs)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
dma_addr_t dma_addr;
int ret, prot;
phys_addr_t addr = phys_addr & PAGE_MASK;
unsigned int offset = phys_addr & ~PAGE_MASK;
size_t len = PAGE_ALIGN(size + offset);
dma_addr = __alloc_iova(mapping, len);
if (dma_addr == DMA_MAPPING_ERROR)
return dma_addr;
prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO;
ret = iommu_map(mapping->domain, dma_addr, addr, len, prot, GFP_KERNEL);
if (ret < 0)
goto fail;
return dma_addr + offset;
fail:
__free_iova(mapping, dma_addr, len);
return DMA_MAPPING_ERROR;
}
/**
* arm_iommu_unmap_resource - unmap a device DMA resource
* @dev: valid struct device pointer
* @dma_handle: DMA address to resource
* @size: size of resource to map
* @dir: DMA transfer direction
*/
static void arm_iommu_unmap_resource(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
dma_addr_t iova = dma_handle & PAGE_MASK;
unsigned int offset = dma_handle & ~PAGE_MASK;
size_t len = PAGE_ALIGN(size + offset);
if (!iova)
return;
iommu_unmap(mapping->domain, iova, len);
__free_iova(mapping, iova, len);
}
static void arm_iommu_sync_single_for_cpu(struct device *dev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
dma_addr_t iova = handle & PAGE_MASK;
struct page *page;
unsigned int offset = handle & ~PAGE_MASK;
if (dev->dma_coherent || !iova)
return;
page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
__dma_page_dev_to_cpu(page, offset, size, dir);
}
static void arm_iommu_sync_single_for_device(struct device *dev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
dma_addr_t iova = handle & PAGE_MASK;
struct page *page;
unsigned int offset = handle & ~PAGE_MASK;
if (dev->dma_coherent || !iova)
return;
page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
__dma_page_cpu_to_dev(page, offset, size, dir);
}
static const struct dma_map_ops iommu_ops = {
.alloc = arm_iommu_alloc_attrs,
.free = arm_iommu_free_attrs,
.mmap = arm_iommu_mmap_attrs,
.get_sgtable = arm_iommu_get_sgtable,
.map_page = arm_iommu_map_page,
.unmap_page = arm_iommu_unmap_page,
.sync_single_for_cpu = arm_iommu_sync_single_for_cpu,
.sync_single_for_device = arm_iommu_sync_single_for_device,
.map_sg = arm_iommu_map_sg,
.unmap_sg = arm_iommu_unmap_sg,
.sync_sg_for_cpu = arm_iommu_sync_sg_for_cpu,
.sync_sg_for_device = arm_iommu_sync_sg_for_device,
.map_resource = arm_iommu_map_resource,
.unmap_resource = arm_iommu_unmap_resource,
};
/**
* arm_iommu_create_mapping
* @bus: pointer to the bus holding the client device (for IOMMU calls)
* @base: start address of the valid IO address space
* @size: maximum size of the valid IO address space
*
* Creates a mapping structure which holds information about used/unused
* IO address ranges, which is required to perform memory allocation and
* mapping with IOMMU aware functions.
*
* The client device need to be attached to the mapping with
* arm_iommu_attach_device function.
*/
struct dma_iommu_mapping *
arm_iommu_create_mapping(const struct bus_type *bus, dma_addr_t base, u64 size)
{
unsigned int bits = size >> PAGE_SHIFT;
unsigned int bitmap_size = BITS_TO_LONGS(bits) * sizeof(long);
struct dma_iommu_mapping *mapping;
int extensions = 1;
int err = -ENOMEM;
/* currently only 32-bit DMA address space is supported */
if (size > DMA_BIT_MASK(32) + 1)
return ERR_PTR(-ERANGE);
if (!bitmap_size)
return ERR_PTR(-EINVAL);
if (bitmap_size > PAGE_SIZE) {
extensions = bitmap_size / PAGE_SIZE;
bitmap_size = PAGE_SIZE;
}
mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
if (!mapping)
goto err;
mapping->bitmap_size = bitmap_size;
mapping->bitmaps = kcalloc(extensions, sizeof(unsigned long *),
GFP_KERNEL);
if (!mapping->bitmaps)
goto err2;
mapping->bitmaps[0] = kzalloc(bitmap_size, GFP_KERNEL);
if (!mapping->bitmaps[0])
goto err3;
mapping->nr_bitmaps = 1;
mapping->extensions = extensions;
mapping->base = base;
mapping->bits = BITS_PER_BYTE * bitmap_size;
spin_lock_init(&mapping->lock);
mapping->domain = iommu_domain_alloc(bus);
if (!mapping->domain)
goto err4;
kref_init(&mapping->kref);
return mapping;
err4:
kfree(mapping->bitmaps[0]);
err3:
kfree(mapping->bitmaps);
err2:
kfree(mapping);
err:
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(arm_iommu_create_mapping);
static void release_iommu_mapping(struct kref *kref)
{
int i;
struct dma_iommu_mapping *mapping =
container_of(kref, struct dma_iommu_mapping, kref);
iommu_domain_free(mapping->domain);
for (i = 0; i < mapping->nr_bitmaps; i++)
kfree(mapping->bitmaps[i]);
kfree(mapping->bitmaps);
kfree(mapping);
}
static int extend_iommu_mapping(struct dma_iommu_mapping *mapping)
{
int next_bitmap;
if (mapping->nr_bitmaps >= mapping->extensions)
return -EINVAL;
next_bitmap = mapping->nr_bitmaps;
mapping->bitmaps[next_bitmap] = kzalloc(mapping->bitmap_size,
GFP_ATOMIC);
if (!mapping->bitmaps[next_bitmap])
return -ENOMEM;
mapping->nr_bitmaps++;
return 0;
}
void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping)
{
if (mapping)
kref_put(&mapping->kref, release_iommu_mapping);
}
EXPORT_SYMBOL_GPL(arm_iommu_release_mapping);
static int __arm_iommu_attach_device(struct device *dev,
struct dma_iommu_mapping *mapping)
{
int err;
err = iommu_attach_device(mapping->domain, dev);
if (err)
return err;
kref_get(&mapping->kref);
to_dma_iommu_mapping(dev) = mapping;
pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev));
return 0;
}
/**
* arm_iommu_attach_device
* @dev: valid struct device pointer
* @mapping: io address space mapping structure (returned from
* arm_iommu_create_mapping)
*
* Attaches specified io address space mapping to the provided device.
* This replaces the dma operations (dma_map_ops pointer) with the
* IOMMU aware version.
*
* More than one client might be attached to the same io address space
* mapping.
*/
int arm_iommu_attach_device(struct device *dev,
struct dma_iommu_mapping *mapping)
{
int err;
err = __arm_iommu_attach_device(dev, mapping);
if (err)
return err;
set_dma_ops(dev, &iommu_ops);
return 0;
}
EXPORT_SYMBOL_GPL(arm_iommu_attach_device);
/**
* arm_iommu_detach_device
* @dev: valid struct device pointer
*
* Detaches the provided device from a previously attached map.
* This overwrites the dma_ops pointer with appropriate non-IOMMU ops.
*/
void arm_iommu_detach_device(struct device *dev)
{
struct dma_iommu_mapping *mapping;
mapping = to_dma_iommu_mapping(dev);
if (!mapping) {
dev_warn(dev, "Not attached\n");
return;
}
iommu_detach_device(mapping->domain, dev);
kref_put(&mapping->kref, release_iommu_mapping);
to_dma_iommu_mapping(dev) = NULL;
set_dma_ops(dev, NULL);
pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));
}
EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
static void arm_setup_iommu_dma_ops(struct device *dev)
{
struct dma_iommu_mapping *mapping;
u64 dma_base = 0, size = 1ULL << 32;
if (dev->dma_range_map) {
dma_base = dma_range_map_min(dev->dma_range_map);
size = dma_range_map_max(dev->dma_range_map) - dma_base;
}
mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
if (IS_ERR(mapping)) {
pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
size, dev_name(dev));
return;
}
if (__arm_iommu_attach_device(dev, mapping)) {
pr_warn("Failed to attached device %s to IOMMU_mapping\n",
dev_name(dev));
arm_iommu_release_mapping(mapping);
return;
}
set_dma_ops(dev, &iommu_ops);
}
static void arm_teardown_iommu_dma_ops(struct device *dev)
{
struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
if (!mapping)
return;
arm_iommu_detach_device(dev);
arm_iommu_release_mapping(mapping);
}
#else
static void arm_setup_iommu_dma_ops(struct device *dev)
{
}
static void arm_teardown_iommu_dma_ops(struct device *dev) { }
#endif /* CONFIG_ARM_DMA_USE_IOMMU */
void arch_setup_dma_ops(struct device *dev, bool coherent)
{
/*
* Due to legacy code that sets the ->dma_coherent flag from a bus
* notifier we can't just assign coherent to the ->dma_coherent flag
* here, but instead have to make sure we only set but never clear it
* for now.
*/
if (coherent)
dev->dma_coherent = true;
/*
* Don't override the dma_ops if they have already been set. Ideally
* this should be the only location where dma_ops are set, remove this
* check when all other callers of set_dma_ops will have disappeared.
*/
if (dev->dma_ops)
return;
if (device_iommu_mapped(dev))
arm_setup_iommu_dma_ops(dev);
xen_setup_dma_ops(dev);
dev->archdata.dma_ops_setup = true;
}
void arch_teardown_dma_ops(struct device *dev)
{
if (!dev->archdata.dma_ops_setup)
return;
arm_teardown_iommu_dma_ops(dev);
/* Let arch_setup_dma_ops() start again from scratch upon re-probe */
set_dma_ops(dev, NULL);
}
void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
enum dma_data_direction dir)
{
__dma_page_cpu_to_dev(phys_to_page(paddr), paddr & (PAGE_SIZE - 1),
size, dir);
}
void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
enum dma_data_direction dir)
{
__dma_page_dev_to_cpu(phys_to_page(paddr), paddr & (PAGE_SIZE - 1),
size, dir);
}
void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs)
{
return __dma_alloc(dev, size, dma_handle, gfp,
__get_dma_pgprot(attrs, PAGE_KERNEL), false,
attrs, __builtin_return_address(0));
}
void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_handle, unsigned long attrs)
{
__arm_dma_free(dev, size, cpu_addr, dma_handle, attrs, false);
}
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