WSL2-Linux-Kernel/arch/arm64/mm/dma-mapping.c

438 строки
11 KiB
C

/*
* SWIOTLB-based DMA API implementation
*
* Copyright (C) 2012 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.com>
*
* 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.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/gfp.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/genalloc.h>
#include <linux/dma-mapping.h>
#include <linux/dma-contiguous.h>
#include <linux/vmalloc.h>
#include <linux/swiotlb.h>
#include <asm/cacheflush.h>
struct dma_map_ops *dma_ops;
EXPORT_SYMBOL(dma_ops);
static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot,
bool coherent)
{
if (!coherent || dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
return pgprot_writecombine(prot);
return prot;
}
static struct gen_pool *atomic_pool;
#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
static size_t atomic_pool_size = 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);
static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
{
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;
if (flags & __GFP_ZERO)
memset(ptr, 0, size);
}
return ptr;
}
static bool __in_atomic_pool(void *start, size_t size)
{
return addr_in_gen_pool(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 *__dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
struct dma_attrs *attrs)
{
if (dev == NULL) {
WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
return NULL;
}
if (IS_ENABLED(CONFIG_ZONE_DMA) &&
dev->coherent_dma_mask <= DMA_BIT_MASK(32))
flags |= GFP_DMA;
if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_WAIT)) {
struct page *page;
void *addr;
size = PAGE_ALIGN(size);
page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
get_order(size));
if (!page)
return NULL;
*dma_handle = phys_to_dma(dev, page_to_phys(page));
addr = page_address(page);
if (flags & __GFP_ZERO)
memset(addr, 0, size);
return addr;
} else {
return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
}
}
static void __dma_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
bool freed;
phys_addr_t paddr = dma_to_phys(dev, dma_handle);
if (dev == NULL) {
WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
return;
}
freed = dma_release_from_contiguous(dev,
phys_to_page(paddr),
size >> PAGE_SHIFT);
if (!freed)
swiotlb_free_coherent(dev, size, vaddr, dma_handle);
}
static void *__dma_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
struct dma_attrs *attrs)
{
struct page *page;
void *ptr, *coherent_ptr;
bool coherent = is_device_dma_coherent(dev);
size = PAGE_ALIGN(size);
if (!coherent && !(flags & __GFP_WAIT)) {
struct page *page = NULL;
void *addr = __alloc_from_pool(size, &page, flags);
if (addr)
*dma_handle = phys_to_dma(dev, page_to_phys(page));
return addr;
}
ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
if (!ptr)
goto no_mem;
/* no need for non-cacheable mapping if coherent */
if (coherent)
return ptr;
/* remove any dirty cache lines on the kernel alias */
__dma_flush_range(ptr, ptr + size);
/* create a coherent mapping */
page = virt_to_page(ptr);
coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,
__get_dma_pgprot(attrs,
__pgprot(PROT_NORMAL_NC), false),
NULL);
if (!coherent_ptr)
goto no_map;
return coherent_ptr;
no_map:
__dma_free_coherent(dev, size, ptr, *dma_handle, attrs);
no_mem:
*dma_handle = DMA_ERROR_CODE;
return NULL;
}
static void __dma_free(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
if (!is_device_dma_coherent(dev)) {
if (__free_from_pool(vaddr, size))
return;
vunmap(vaddr);
}
__dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs);
}
static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir,
struct dma_attrs *attrs)
{
dma_addr_t dev_addr;
dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
if (!is_device_dma_coherent(dev))
__dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
return dev_addr;
}
static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
if (!is_device_dma_coherent(dev))
__dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
}
static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
int nelems, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
struct scatterlist *sg;
int i, ret;
ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
if (!is_device_dma_coherent(dev))
for_each_sg(sgl, sg, ret, i)
__dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
sg->length, dir);
return ret;
}
static void __swiotlb_unmap_sg_attrs(struct device *dev,
struct scatterlist *sgl, int nelems,
enum dma_data_direction dir,
struct dma_attrs *attrs)
{
struct scatterlist *sg;
int i;
if (!is_device_dma_coherent(dev))
for_each_sg(sgl, sg, nelems, i)
__dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
sg->length, dir);
swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
}
static void __swiotlb_sync_single_for_cpu(struct device *dev,
dma_addr_t dev_addr, size_t size,
enum dma_data_direction dir)
{
if (!is_device_dma_coherent(dev))
__dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
}
static void __swiotlb_sync_single_for_device(struct device *dev,
dma_addr_t dev_addr, size_t size,
enum dma_data_direction dir)
{
swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
if (!is_device_dma_coherent(dev))
__dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
}
static void __swiotlb_sync_sg_for_cpu(struct device *dev,
struct scatterlist *sgl, int nelems,
enum dma_data_direction dir)
{
struct scatterlist *sg;
int i;
if (!is_device_dma_coherent(dev))
for_each_sg(sgl, sg, nelems, i)
__dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
sg->length, dir);
swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
}
static void __swiotlb_sync_sg_for_device(struct device *dev,
struct scatterlist *sgl, int nelems,
enum dma_data_direction dir)
{
struct scatterlist *sg;
int i;
swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
if (!is_device_dma_coherent(dev))
for_each_sg(sgl, sg, nelems, i)
__dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
sg->length, dir);
}
/* vma->vm_page_prot must be set appropriately before calling this function */
static int __dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
int ret = -ENXIO;
unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
PAGE_SHIFT;
unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
ret = remap_pfn_range(vma, vma->vm_start,
pfn + off,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
}
return ret;
}
static int __swiotlb_mmap(struct device *dev,
struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
struct dma_attrs *attrs)
{
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
is_device_dma_coherent(dev));
return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
}
static struct dma_map_ops swiotlb_dma_ops = {
.alloc = __dma_alloc,
.free = __dma_free,
.mmap = __swiotlb_mmap,
.map_page = __swiotlb_map_page,
.unmap_page = __swiotlb_unmap_page,
.map_sg = __swiotlb_map_sg_attrs,
.unmap_sg = __swiotlb_unmap_sg_attrs,
.sync_single_for_cpu = __swiotlb_sync_single_for_cpu,
.sync_single_for_device = __swiotlb_sync_single_for_device,
.sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu,
.sync_sg_for_device = __swiotlb_sync_sg_for_device,
.dma_supported = swiotlb_dma_supported,
.mapping_error = swiotlb_dma_mapping_error,
};
static int __init atomic_pool_init(void)
{
pgprot_t prot = __pgprot(PROT_NORMAL_NC);
unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
struct page *page;
void *addr;
unsigned int pool_size_order = get_order(atomic_pool_size);
if (dev_get_cma_area(NULL))
page = dma_alloc_from_contiguous(NULL, nr_pages,
pool_size_order);
else
page = alloc_pages(GFP_DMA, pool_size_order);
if (page) {
int ret;
void *page_addr = page_address(page);
memset(page_addr, 0, atomic_pool_size);
__dma_flush_range(page_addr, page_addr + atomic_pool_size);
atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
if (!atomic_pool)
goto free_page;
addr = dma_common_contiguous_remap(page, atomic_pool_size,
VM_USERMAP, prot, atomic_pool_init);
if (!addr)
goto destroy_genpool;
ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
page_to_phys(page),
atomic_pool_size, -1);
if (ret)
goto remove_mapping;
gen_pool_set_algo(atomic_pool,
gen_pool_first_fit_order_align,
(void *)PAGE_SHIFT);
pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
atomic_pool_size / 1024);
return 0;
}
goto out;
remove_mapping:
dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
destroy_genpool:
gen_pool_destroy(atomic_pool);
atomic_pool = NULL;
free_page:
if (!dma_release_from_contiguous(NULL, page, nr_pages))
__free_pages(page, pool_size_order);
out:
pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
atomic_pool_size / 1024);
return -ENOMEM;
}
static int __init arm64_dma_init(void)
{
int ret;
dma_ops = &swiotlb_dma_ops;
ret = atomic_pool_init();
return ret;
}
arch_initcall(arm64_dma_init);
#define PREALLOC_DMA_DEBUG_ENTRIES 4096
static int __init dma_debug_do_init(void)
{
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}
fs_initcall(dma_debug_do_init);