/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Internals of the DMA direct mapping implementation.  Only for use by the
 * DMA mapping code and IOMMU drivers.
 */
#ifndef _LINUX_DMA_DIRECT_H
#define _LINUX_DMA_DIRECT_H 1

#include <linux/dma-mapping.h>
#include <linux/dma-map-ops.h>
#include <linux/memblock.h> /* for min_low_pfn */
#include <linux/mem_encrypt.h>
#include <linux/swiotlb.h>

extern u64 zone_dma_limit;

/*
 * Record the mapping of CPU physical to DMA addresses for a given region.
 */
struct bus_dma_region {
        phys_addr_t     cpu_start;
        dma_addr_t      dma_start;
        u64             size;
};

static inline dma_addr_t translate_phys_to_dma(struct device *dev,
                phys_addr_t paddr)
{
        const struct bus_dma_region *m;

        for (m = dev->dma_range_map; m->size; m++) {
                u64 offset = paddr - m->cpu_start;

                if (paddr >= m->cpu_start && offset < m->size)
                        return m->dma_start + offset;
        }

        /* make sure dma_capable fails when no translation is available */
        return DMA_MAPPING_ERROR;
}

static inline phys_addr_t translate_dma_to_phys(struct device *dev,
                dma_addr_t dma_addr)
{
        const struct bus_dma_region *m;

        for (m = dev->dma_range_map; m->size; m++) {
                u64 offset = dma_addr - m->dma_start;

                if (dma_addr >= m->dma_start && offset < m->size)
                        return m->cpu_start + offset;
        }

        return (phys_addr_t)-1;
}

static inline dma_addr_t dma_range_map_min(const struct bus_dma_region *map)
{
        dma_addr_t ret = (dma_addr_t)U64_MAX;

        for (; map->size; map++)
                ret = min(ret, map->dma_start);
        return ret;
}

static inline dma_addr_t dma_range_map_max(const struct bus_dma_region *map)
{
        dma_addr_t ret = 0;

        for (; map->size; map++)
                ret = max(ret, map->dma_start + map->size - 1);
        return ret;
}

#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
#include <asm/dma-direct.h>
#ifndef phys_to_dma_unencrypted
#define phys_to_dma_unencrypted         phys_to_dma
#endif
#else
static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
{
        if (dev->dma_range_map)
                return translate_phys_to_dma(dev, paddr);
        return paddr;
}

static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev,
                                                phys_addr_t paddr)
{
        return dma_addr_unencrypted(__phys_to_dma(dev, paddr));
}
/*
 * If memory encryption is supported, phys_to_dma will set the memory encryption
 * bit in the DMA address, and dma_to_phys will clear it.
 * phys_to_dma_unencrypted is for use on special unencrypted memory like swiotlb
 * buffers.
 */
static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
{
        return dma_addr_encrypted(__phys_to_dma(dev, paddr));
}

static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
{
        phys_addr_t paddr;

        dma_addr = dma_addr_canonical(dma_addr);
        if (dev->dma_range_map)
                paddr = translate_dma_to_phys(dev, dma_addr);
        else
                paddr = dma_addr;

        return paddr;
}
#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */

#ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
bool force_dma_unencrypted(struct device *dev);
#else
static inline bool force_dma_unencrypted(struct device *dev)
{
        return false;
}
#endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */

static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
                bool is_ram)
{
        dma_addr_t end = addr + size - 1;

        if (addr == DMA_MAPPING_ERROR)
                return false;
        if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
            min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
                return false;

        return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit);
}

u64 dma_direct_get_required_mask(struct device *dev);
void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
                gfp_t gfp, unsigned long attrs);
void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
                dma_addr_t dma_addr, unsigned long attrs);
struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
                dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
void dma_direct_free_pages(struct device *dev, size_t size,
                struct page *page, dma_addr_t dma_addr,
                enum dma_data_direction dir);
int dma_direct_supported(struct device *dev, u64 mask);

#endif /* _LINUX_DMA_DIRECT_H */