// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.

#include <linux/cache.h>
#include <linux/dma-map-ops.h>
#include <linux/genalloc.h>
#include <linux/highmem.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/types.h>
#include <asm/cache.h>

static inline void cache_op(phys_addr_t paddr, size_t size,
                            void (*fn)(unsigned long start, unsigned long end))
{
        struct page *page    = phys_to_page(paddr);
        void *start          = __va(page_to_phys(page));
        unsigned long offset = offset_in_page(paddr);
        size_t left          = size;

        do {
                size_t len = left;

                if (offset + len > PAGE_SIZE)
                        len = PAGE_SIZE - offset;

                if (PageHighMem(page)) {
                        start = kmap_atomic(page);

                        fn((unsigned long)start + offset,
                                        (unsigned long)start + offset + len);

                        kunmap_atomic(start);
                } else {
                        fn((unsigned long)start + offset,
                                        (unsigned long)start + offset + len);
                }
                offset = 0;

                page++;
                start += PAGE_SIZE;
                left -= len;
        } while (left);
}

static void dma_wbinv_set_zero_range(unsigned long start, unsigned long end)
{
        memset((void *)start, 0, end - start);
        dma_wbinv_range(start, end);
}

void arch_dma_prep_coherent(struct page *page, size_t size)
{
        cache_op(page_to_phys(page), size, dma_wbinv_set_zero_range);
}

void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
                enum dma_data_direction dir)
{
        switch (dir) {
        case DMA_TO_DEVICE:
                cache_op(paddr, size, dma_wb_range);
                break;
        case DMA_FROM_DEVICE:
        case DMA_BIDIRECTIONAL:
                cache_op(paddr, size, dma_wbinv_range);
                break;
        default:
                BUG();
        }
}

void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
                enum dma_data_direction dir)
{
        switch (dir) {
        case DMA_TO_DEVICE:
                return;
        case DMA_FROM_DEVICE:
        case DMA_BIDIRECTIONAL:
                cache_op(paddr, size, dma_inv_range);
                break;
        default:
                BUG();
        }
}