xref: /openbmc/linux/kernel/dma/mapping.c (revision 05887cb610a54bf568de7f0bc07c4a64e45ac6f9)

// 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-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_alloc_coherent - Managed dma_alloc_coherent()
 * @dev: Device to allocate coherent memory for
 * @size: Size of allocation
 * @dma_handle: Out argument for allocated DMA handle
 * @gfp: Allocation flags
 *
 * Managed dma_alloc_coherent().  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_coherent(struct device *dev, size_t size,
			   dma_addr_t *dma_handle, gfp_t gfp)
{
	struct dma_devres *dr;
	void *vaddr;

	dr = devres_alloc(dmam_release, sizeof(*dr), gfp);
	if (!dr)
		return NULL;

	vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
	if (!vaddr) {
		devres_free(dr);
		return NULL;
	}

	dr->vaddr = vaddr;
	dr->dma_handle = *dma_handle;
	dr->size = size;

	devres_add(dev, dr);

	return vaddr;
}
EXPORT_SYMBOL(dmam_alloc_coherent);

/**
 * 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);

#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT

static void dmam_coherent_decl_release(struct device *dev, void *res)
{
	dma_release_declared_memory(dev);
}

/**
 * dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
 * @dev: Device to declare coherent memory for
 * @phys_addr: Physical address of coherent memory to be declared
 * @device_addr: Device address of coherent memory to be declared
 * @size: Size of coherent memory to be declared
 * @flags: Flags
 *
 * Managed dma_declare_coherent_memory().
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
int dmam_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
				 dma_addr_t device_addr, size_t size, int flags)
{
	void *res;
	int rc;

	res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
	if (!res)
		return -ENOMEM;

	rc = dma_declare_coherent_memory(dev, phys_addr, device_addr, size,
					 flags);
	if (!rc)
		devres_add(dev, res);
	else
		devres_free(res);

	return rc;
}
EXPORT_SYMBOL(dmam_declare_coherent_memory);

/**
 * dmam_release_declared_memory - Managed dma_release_declared_memory().
 * @dev: Device to release declared coherent memory for
 *
 * Managed dmam_release_declared_memory().
 */
void dmam_release_declared_memory(struct device *dev)
{
	WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
}
EXPORT_SYMBOL(dmam_release_declared_memory);

#endif

/*
 * 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;
	int ret;

	if (!dev_is_dma_coherent(dev)) {
		if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
			return -ENXIO;

		page = pfn_to_page(arch_dma_coherent_to_pfn(dev, cpu_addr,
				dma_addr));
	} else {
		page = virt_to_page(cpu_addr);
	}

	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
	if (!ret)
		sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
	return ret;
}
EXPORT_SYMBOL(dma_common_get_sgtable);

/*
 * 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)
{
#ifndef CONFIG_ARCH_NO_COHERENT_DMA_MMAP
	unsigned long user_count = vma_pages(vma);
	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
	unsigned long off = vma->vm_pgoff;
	unsigned long pfn;
	int ret = -ENXIO;

	vma->vm_page_prot = arch_dma_mmap_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;

	if (!dev_is_dma_coherent(dev)) {
		if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
			return -ENXIO;
		pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr);
	} else {
		pfn = page_to_pfn(virt_to_page(cpu_addr));
	}

	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
			user_count << PAGE_SHIFT, vma->vm_page_prot);
#else
	return -ENXIO;
#endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */
}
EXPORT_SYMBOL(dma_common_mmap);

#ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
static u64 dma_default_get_required_mask(struct device *dev)
{
	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
	u64 mask;

	if (!high_totalram) {
		/* convert to mask just covering totalram */
		low_totalram = (1 << (fls(low_totalram) - 1));
		low_totalram += low_totalram - 1;
		mask = low_totalram;
	} else {
		high_totalram = (1 << (fls(high_totalram) - 1));
		high_totalram += high_totalram - 1;
		mask = (((u64)high_totalram) << 32) + 0xffffffff;
	}
	return mask;
}

u64 dma_get_required_mask(struct device *dev)
{
	const struct dma_map_ops *ops = get_dma_ops(dev);

	if (ops->get_required_mask)
		return ops->get_required_mask(dev);
	return dma_default_get_required_mask(dev);
}
EXPORT_SYMBOL_GPL(dma_get_required_mask);
#endif