1 files changed, 254 insertions, 0 deletions
diff --git a/arch/csky/mm/dma-mapping.c b/arch/csky/mm/dma-mapping.c
new file mode 100644
index 0000000000000..85437b21e045d
--- /dev/null
+++ b/arch/csky/mm/dma-mapping.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/cache.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-contiguous.h>
+#include <linux/dma-noncoherent.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 <linux/version.h>
+#include <asm/cache.h>
+
+static struct gen_pool *atomic_pool;
+static size_t atomic_pool_size __initdata = SZ_256K;
+
+static int __init early_coherent_pool(char *p)
+{
+	atomic_pool_size = memparse(p, &p);
+	return 0;
+}
+early_param("coherent_pool", early_coherent_pool);
+
+static int __init atomic_pool_init(void)
+{
+	struct page *page;
+	size_t size = atomic_pool_size;
+	void *ptr;
+	int ret;
+
+	atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
+	if (!atomic_pool)
+		BUG();
+
+	page = alloc_pages(GFP_KERNEL | GFP_DMA, get_order(size));
+	if (!page)
+		BUG();
+
+	ptr = dma_common_contiguous_remap(page, size, VM_ALLOC,
+					  pgprot_noncached(PAGE_KERNEL),
+					  __builtin_return_address(0));
+	if (!ptr)
+		BUG();
+
+	ret = gen_pool_add_virt(atomic_pool, (unsigned long)ptr,
+				page_to_phys(page), atomic_pool_size, -1);
+	if (ret)
+		BUG();
+
+	gen_pool_set_algo(atomic_pool, gen_pool_first_fit_order_align, NULL);
+
+	pr_info("DMA: preallocated %zu KiB pool for atomic coherent pool\n",
+		atomic_pool_size / 1024);
+
+	pr_info("DMA: vaddr: 0x%x phy: 0x%lx,\n", (unsigned int)ptr,
+		page_to_phys(page));
+
+	return 0;
+}
+postcore_initcall(atomic_pool_init);
+
+static void *csky_dma_alloc_atomic(struct device *dev, size_t size,
+				   dma_addr_t *dma_handle)
+{
+	unsigned long addr;
+
+	addr = gen_pool_alloc(atomic_pool, size);
+	if (addr)
+		*dma_handle = gen_pool_virt_to_phys(atomic_pool, addr);
+
+	return (void *)addr;
+}
+
+static void csky_dma_free_atomic(struct device *dev, size_t size, void *vaddr,
+				 dma_addr_t dma_handle, unsigned long attrs)
+{
+	gen_pool_free(atomic_pool, (unsigned long)vaddr, size);
+}
+
+static void __dma_clear_buffer(struct page *page, size_t size)
+{
+	if (PageHighMem(page)) {
+		unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+		do {
+			void *ptr = kmap_atomic(page);
+			size_t _size = (size < PAGE_SIZE) ? size : PAGE_SIZE;
+
+			memset(ptr, 0, _size);
+			dma_wbinv_range((unsigned long)ptr,
+					(unsigned long)ptr + _size);
+
+			kunmap_atomic(ptr);
+
+			page++;
+			size -= PAGE_SIZE;
+			count--;
+		} while (count);
+	} else {
+		void *ptr = page_address(page);
+
+		memset(ptr, 0, size);
+		dma_wbinv_range((unsigned long)ptr, (unsigned long)ptr + size);
+	}
+}
+
+static void *csky_dma_alloc_nonatomic(struct device *dev, size_t size,
+				      dma_addr_t *dma_handle, gfp_t gfp,
+				      unsigned long attrs)
+{
+	void  *vaddr;
+	struct page *page;
+	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+	if (DMA_ATTR_NON_CONSISTENT & attrs) {
+		pr_err("csky %s can't support DMA_ATTR_NON_CONSISTENT.\n", __func__);
+		return NULL;
+	}
+
+	if (IS_ENABLED(CONFIG_DMA_CMA))
+		page = dma_alloc_from_contiguous(dev, count, get_order(size),
+						 gfp);
+	else
+		page = alloc_pages(gfp, get_order(size));
+
+	if (!page) {
+		pr_err("csky %s no more free pages.\n", __func__);
+		return NULL;
+	}
+
+	*dma_handle = page_to_phys(page);
+
+	__dma_clear_buffer(page, size);
+
+	if (attrs & DMA_ATTR_NO_KERNEL_MAPPING)
+		return page;
+
+	vaddr = dma_common_contiguous_remap(page, PAGE_ALIGN(size), VM_USERMAP,
+		pgprot_noncached(PAGE_KERNEL), __builtin_return_address(0));
+	if (!vaddr)
+		BUG();
+
+	return vaddr;
+}
+
+static void csky_dma_free_nonatomic(
+	struct device *dev,
+	size_t size,
+	void *vaddr,
+	dma_addr_t dma_handle,
+	unsigned long attrs
+	)
+{
+	struct page *page = phys_to_page(dma_handle);
+	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+	if ((unsigned int)vaddr >= VMALLOC_START)
+		dma_common_free_remap(vaddr, size, VM_USERMAP);
+
+	if (IS_ENABLED(CONFIG_DMA_CMA))
+		dma_release_from_contiguous(dev, page, count);
+	else
+		__free_pages(page, get_order(size));
+}
+
+void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		     gfp_t gfp, unsigned long attrs)
+{
+	if (gfpflags_allow_blocking(gfp))
+		return csky_dma_alloc_nonatomic(dev, size, dma_handle, gfp,
+						attrs);
+	else
+		return csky_dma_alloc_atomic(dev, size, dma_handle);
+}
+
+void arch_dma_free(struct device *dev, size_t size, void *vaddr,
+		   dma_addr_t dma_handle, unsigned long attrs)
+{
+	if (!addr_in_gen_pool(atomic_pool, (unsigned int) vaddr, size))
+		csky_dma_free_nonatomic(dev, size, vaddr, dma_handle, attrs);
+	else
+		csky_dma_free_atomic(dev, size, vaddr, dma_handle, attrs);
+}
+
+static inline void cache_op(phys_addr_t paddr, size_t size,
+			    void (*fn)(unsigned long start, unsigned long end))
+{
+	struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
+	unsigned int offset = paddr & ~PAGE_MASK;
+	size_t left = size;
+	unsigned long start;
+
+	do {
+		size_t len = left;
+
+		if (PageHighMem(page)) {
+			void *addr;
+
+			if (offset + len > PAGE_SIZE) {
+				if (offset >= PAGE_SIZE) {
+					page += offset >> PAGE_SHIFT;
+					offset &= ~PAGE_MASK;
+				}
+				len = PAGE_SIZE - offset;
+			}
+
+			addr = kmap_atomic(page);
+			start = (unsigned long)(addr + offset);
+			fn(start, start + len);
+			kunmap_atomic(addr);
+		} else {
+			start = (unsigned long)phys_to_virt(paddr);
+			fn(start, start + size);
+		}
+		offset = 0;
+		page++;
+		left -= len;
+	} while (left);
+}
+
+void arch_sync_dma_for_device(struct device *dev, 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(struct device *dev, 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();
+	}
+}