swh:1:snp:77163734605b0ec556b01d897b7bb4a7e30d46b6
Tip revision: 92ed301919932f777713b9172e525674157e983d authored by Linus Torvalds on 26 July 2020, 21:14:06 UTC
Linux 5.8-rc7
Linux 5.8-rc7
Tip revision: 92ed301
mapping.c
// SPDX-License-Identifier: GPL-2.0
/*
* arch-independent dma-mapping routines
*
* Copyright (c) 2006 SUSE Linux Products GmbH
* Copyright (c) 2006 Tejun Heo <teheo@suse.de>
*/
#include <linux/memblock.h> /* for max_pfn */
#include <linux/acpi.h>
#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
#include <linux/export.h>
#include <linux/gfp.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
/*
* Managed DMA API
*/
struct dma_devres {
size_t size;
void *vaddr;
dma_addr_t dma_handle;
unsigned long attrs;
};
static void dmam_release(struct device *dev, void *res)
{
struct dma_devres *this = res;
dma_free_attrs(dev, this->size, this->vaddr, this->dma_handle,
this->attrs);
}
static int dmam_match(struct device *dev, void *res, void *match_data)
{
struct dma_devres *this = res, *match = match_data;
if (this->vaddr == match->vaddr) {
WARN_ON(this->size != match->size ||
this->dma_handle != match->dma_handle);
return 1;
}
return 0;
}
/**
* dmam_free_coherent - Managed dma_free_coherent()
* @dev: Device to free coherent memory for
* @size: Size of allocation
* @vaddr: Virtual address of the memory to free
* @dma_handle: DMA handle of the memory to free
*
* Managed dma_free_coherent().
*/
void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle)
{
struct dma_devres match_data = { size, vaddr, dma_handle };
dma_free_coherent(dev, size, vaddr, dma_handle);
WARN_ON(devres_destroy(dev, dmam_release, dmam_match, &match_data));
}
EXPORT_SYMBOL(dmam_free_coherent);
/**
* dmam_alloc_attrs - Managed dma_alloc_attrs()
* @dev: Device to allocate non_coherent memory for
* @size: Size of allocation
* @dma_handle: Out argument for allocated DMA handle
* @gfp: Allocation flags
* @attrs: Flags in the DMA_ATTR_* namespace.
*
* Managed dma_alloc_attrs(). Memory allocated using this function will be
* automatically released on driver detach.
*
* RETURNS:
* Pointer to allocated memory on success, NULL on failure.
*/
void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs)
{
struct dma_devres *dr;
void *vaddr;
dr = devres_alloc(dmam_release, sizeof(*dr), gfp);
if (!dr)
return NULL;
vaddr = dma_alloc_attrs(dev, size, dma_handle, gfp, attrs);
if (!vaddr) {
devres_free(dr);
return NULL;
}
dr->vaddr = vaddr;
dr->dma_handle = *dma_handle;
dr->size = size;
dr->attrs = attrs;
devres_add(dev, dr);
return vaddr;
}
EXPORT_SYMBOL(dmam_alloc_attrs);
/*
* Create scatter-list for the already allocated DMA buffer.
*/
int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
struct page *page = virt_to_page(cpu_addr);
int ret;
ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
if (!ret)
sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
return ret;
}
/*
* The whole dma_get_sgtable() idea is fundamentally unsafe - it seems
* that the intention is to allow exporting memory allocated via the
* coherent DMA APIs through the dma_buf API, which only accepts a
* scattertable. This presents a couple of problems:
* 1. Not all memory allocated via the coherent DMA APIs is backed by
* a struct page
* 2. Passing coherent DMA memory into the streaming APIs is not allowed
* as we will try to flush the memory through a different alias to that
* actually being used (and the flushes are redundant.)
*/
int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
if (dma_is_direct(ops))
return dma_direct_get_sgtable(dev, sgt, cpu_addr, dma_addr,
size, attrs);
if (!ops->get_sgtable)
return -ENXIO;
return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs);
}
EXPORT_SYMBOL(dma_get_sgtable_attrs);
#ifdef CONFIG_MMU
/*
* Return the page attributes used for mapping dma_alloc_* memory, either in
* kernel space if remapping is needed, or to userspace through dma_mmap_*.
*/
pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs)
{
if (force_dma_unencrypted(dev))
prot = pgprot_decrypted(prot);
if (dev_is_dma_coherent(dev) ||
(IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) &&
(attrs & DMA_ATTR_NON_CONSISTENT)))
return prot;
#ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE
if (attrs & DMA_ATTR_WRITE_COMBINE)
return pgprot_writecombine(prot);
#endif
return pgprot_dmacoherent(prot);
}
#endif /* CONFIG_MMU */
/*
* Create userspace mapping for the DMA-coherent memory.
*/
int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
#ifdef CONFIG_MMU
unsigned long user_count = vma_pages(vma);
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
int ret = -ENXIO;
vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (off >= count || user_count > count - off)
return -ENXIO;
return remap_pfn_range(vma, vma->vm_start,
page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff,
user_count << PAGE_SHIFT, vma->vm_page_prot);
#else
return -ENXIO;
#endif /* CONFIG_MMU */
}
/**
* dma_can_mmap - check if a given device supports dma_mmap_*
* @dev: device to check
*
* Returns %true if @dev supports dma_mmap_coherent() and dma_mmap_attrs() to
* map DMA allocations to userspace.
*/
bool dma_can_mmap(struct device *dev)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
if (dma_is_direct(ops))
return dma_direct_can_mmap(dev);
return ops->mmap != NULL;
}
EXPORT_SYMBOL_GPL(dma_can_mmap);
/**
* dma_mmap_attrs - map a coherent DMA allocation into user space
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @vma: vm_area_struct describing requested user mapping
* @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs
* @dma_addr: device-view address returned from dma_alloc_attrs
* @size: size of memory originally requested in dma_alloc_attrs
* @attrs: attributes of mapping properties requested in dma_alloc_attrs
*
* Map a coherent DMA buffer previously allocated by dma_alloc_attrs into user
* space. The coherent DMA buffer must not be freed by the driver until the
* user space mapping has been released.
*/
int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
if (dma_is_direct(ops))
return dma_direct_mmap(dev, vma, cpu_addr, dma_addr, size,
attrs);
if (!ops->mmap)
return -ENXIO;
return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
}
EXPORT_SYMBOL(dma_mmap_attrs);
u64 dma_get_required_mask(struct device *dev)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
if (dma_is_direct(ops))
return dma_direct_get_required_mask(dev);
if (ops->get_required_mask)
return ops->get_required_mask(dev);
/*
* We require every DMA ops implementation to at least support a 32-bit
* DMA mask (and use bounce buffering if that isn't supported in
* hardware). As the direct mapping code has its own routine to
* actually report an optimal mask we default to 32-bit here as that
* is the right thing for most IOMMUs, and at least not actively
* harmful in general.
*/
return DMA_BIT_MASK(32);
}
EXPORT_SYMBOL_GPL(dma_get_required_mask);
void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t flag, unsigned long attrs)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
void *cpu_addr;
WARN_ON_ONCE(!dev->coherent_dma_mask);
if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
return cpu_addr;
/* let the implementation decide on the zone to allocate from: */
flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
if (dma_is_direct(ops))
cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs);
else if (ops->alloc)
cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
else
return NULL;
debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr);
return cpu_addr;
}
EXPORT_SYMBOL(dma_alloc_attrs);
void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_handle, unsigned long attrs)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr))
return;
/*
* On non-coherent platforms which implement DMA-coherent buffers via
* non-cacheable remaps, ops->free() may call vunmap(). Thus getting
* this far in IRQ context is a) at risk of a BUG_ON() or trying to
* sleep on some machines, and b) an indication that the driver is
* probably misusing the coherent API anyway.
*/
WARN_ON(irqs_disabled());
if (!cpu_addr)
return;
debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
if (dma_is_direct(ops))
dma_direct_free(dev, size, cpu_addr, dma_handle, attrs);
else if (ops->free)
ops->free(dev, size, cpu_addr, dma_handle, attrs);
}
EXPORT_SYMBOL(dma_free_attrs);
int dma_supported(struct device *dev, u64 mask)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
if (dma_is_direct(ops))
return dma_direct_supported(dev, mask);
if (!ops->dma_supported)
return 1;
return ops->dma_supported(dev, mask);
}
EXPORT_SYMBOL(dma_supported);
#ifdef CONFIG_ARCH_HAS_DMA_SET_MASK
void arch_dma_set_mask(struct device *dev, u64 mask);
#else
#define arch_dma_set_mask(dev, mask) do { } while (0)
#endif
int dma_set_mask(struct device *dev, u64 mask)
{
/*
* Truncate the mask to the actually supported dma_addr_t width to
* avoid generating unsupportable addresses.
*/
mask = (dma_addr_t)mask;
if (!dev->dma_mask || !dma_supported(dev, mask))
return -EIO;
arch_dma_set_mask(dev, mask);
*dev->dma_mask = mask;
return 0;
}
EXPORT_SYMBOL(dma_set_mask);
#ifndef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK
int dma_set_coherent_mask(struct device *dev, u64 mask)
{
/*
* Truncate the mask to the actually supported dma_addr_t width to
* avoid generating unsupportable addresses.
*/
mask = (dma_addr_t)mask;
if (!dma_supported(dev, mask))
return -EIO;
dev->coherent_dma_mask = mask;
return 0;
}
EXPORT_SYMBOL(dma_set_coherent_mask);
#endif
void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction dir)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
BUG_ON(!valid_dma_direction(dir));
if (dma_is_direct(ops))
arch_dma_cache_sync(dev, vaddr, size, dir);
else if (ops->cache_sync)
ops->cache_sync(dev, vaddr, size, dir);
}
EXPORT_SYMBOL(dma_cache_sync);
size_t dma_max_mapping_size(struct device *dev)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
size_t size = SIZE_MAX;
if (dma_is_direct(ops))
size = dma_direct_max_mapping_size(dev);
else if (ops && ops->max_mapping_size)
size = ops->max_mapping_size(dev);
return size;
}
EXPORT_SYMBOL_GPL(dma_max_mapping_size);
bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
if (dma_is_direct(ops))
return dma_direct_need_sync(dev, dma_addr);
return ops->sync_single_for_cpu || ops->sync_single_for_device;
}
EXPORT_SYMBOL_GPL(dma_need_sync);
unsigned long dma_get_merge_boundary(struct device *dev)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
if (!ops || !ops->get_merge_boundary)
return 0; /* can't merge */
return ops->get_merge_boundary(dev);
}
EXPORT_SYMBOL_GPL(dma_get_merge_boundary);