xref: /openbmc/linux/arch/csky/mm/dma-mapping.c (revision b08918fb)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3 
4 #include <linux/cache.h>
5 #include <linux/dma-mapping.h>
6 #include <linux/dma-contiguous.h>
7 #include <linux/dma-noncoherent.h>
8 #include <linux/genalloc.h>
9 #include <linux/highmem.h>
10 #include <linux/io.h>
11 #include <linux/mm.h>
12 #include <linux/scatterlist.h>
13 #include <linux/types.h>
14 #include <linux/version.h>
15 #include <asm/cache.h>
16 
17 void arch_dma_prep_coherent(struct page *page, size_t size)
18 {
19 	if (PageHighMem(page)) {
20 		unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
21 
22 		do {
23 			void *ptr = kmap_atomic(page);
24 			size_t _size = (size < PAGE_SIZE) ? size : PAGE_SIZE;
25 
26 			memset(ptr, 0, _size);
27 			dma_wbinv_range((unsigned long)ptr,
28 					(unsigned long)ptr + _size);
29 
30 			kunmap_atomic(ptr);
31 
32 			page++;
33 			size -= PAGE_SIZE;
34 			count--;
35 		} while (count);
36 	} else {
37 		void *ptr = page_address(page);
38 
39 		memset(ptr, 0, size);
40 		dma_wbinv_range((unsigned long)ptr, (unsigned long)ptr + size);
41 	}
42 }
43 
44 static inline void cache_op(phys_addr_t paddr, size_t size,
45 			    void (*fn)(unsigned long start, unsigned long end))
46 {
47 	struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
48 	unsigned int offset = paddr & ~PAGE_MASK;
49 	size_t left = size;
50 	unsigned long start;
51 
52 	do {
53 		size_t len = left;
54 
55 		if (PageHighMem(page)) {
56 			void *addr;
57 
58 			if (offset + len > PAGE_SIZE) {
59 				if (offset >= PAGE_SIZE) {
60 					page += offset >> PAGE_SHIFT;
61 					offset &= ~PAGE_MASK;
62 				}
63 				len = PAGE_SIZE - offset;
64 			}
65 
66 			addr = kmap_atomic(page);
67 			start = (unsigned long)(addr + offset);
68 			fn(start, start + len);
69 			kunmap_atomic(addr);
70 		} else {
71 			start = (unsigned long)phys_to_virt(paddr);
72 			fn(start, start + size);
73 		}
74 		offset = 0;
75 		page++;
76 		left -= len;
77 	} while (left);
78 }
79 
80 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
81 			      size_t size, enum dma_data_direction dir)
82 {
83 	switch (dir) {
84 	case DMA_TO_DEVICE:
85 		cache_op(paddr, size, dma_wb_range);
86 		break;
87 	case DMA_FROM_DEVICE:
88 	case DMA_BIDIRECTIONAL:
89 		cache_op(paddr, size, dma_wbinv_range);
90 		break;
91 	default:
92 		BUG();
93 	}
94 }
95 
96 void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
97 			   size_t size, enum dma_data_direction dir)
98 {
99 	switch (dir) {
100 	case DMA_TO_DEVICE:
101 		cache_op(paddr, size, dma_wb_range);
102 		break;
103 	case DMA_FROM_DEVICE:
104 	case DMA_BIDIRECTIONAL:
105 		cache_op(paddr, size, dma_wbinv_range);
106 		break;
107 	default:
108 		BUG();
109 	}
110 }
111