xref: /openbmc/linux/arch/csky/mm/dma-mapping.c (revision e15a5365)
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-map-ops.h>
6 #include <linux/genalloc.h>
7 #include <linux/highmem.h>
8 #include <linux/io.h>
9 #include <linux/mm.h>
10 #include <linux/scatterlist.h>
11 #include <linux/types.h>
12 #include <linux/version.h>
13 #include <asm/cache.h>
14 
15 static inline void cache_op(phys_addr_t paddr, size_t size,
16 			    void (*fn)(unsigned long start, unsigned long end))
17 {
18 	struct page *page    = phys_to_page(paddr);
19 	void *start          = __va(page_to_phys(page));
20 	unsigned long offset = offset_in_page(paddr);
21 	size_t left          = size;
22 
23 	do {
24 		size_t len = left;
25 
26 		if (offset + len > PAGE_SIZE)
27 			len = PAGE_SIZE - offset;
28 
29 		if (PageHighMem(page)) {
30 			start = kmap_atomic(page);
31 
32 			fn((unsigned long)start + offset,
33 					(unsigned long)start + offset + len);
34 
35 			kunmap_atomic(start);
36 		} else {
37 			fn((unsigned long)start + offset,
38 					(unsigned long)start + offset + len);
39 		}
40 		offset = 0;
41 
42 		page++;
43 		start += PAGE_SIZE;
44 		left -= len;
45 	} while (left);
46 }
47 
48 static void dma_wbinv_set_zero_range(unsigned long start, unsigned long end)
49 {
50 	memset((void *)start, 0, end - start);
51 	dma_wbinv_range(start, end);
52 }
53 
54 void arch_dma_prep_coherent(struct page *page, size_t size)
55 {
56 	cache_op(page_to_phys(page), size, dma_wbinv_set_zero_range);
57 }
58 
59 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
60 		enum dma_data_direction dir)
61 {
62 	switch (dir) {
63 	case DMA_TO_DEVICE:
64 		cache_op(paddr, size, dma_wb_range);
65 		break;
66 	case DMA_FROM_DEVICE:
67 	case DMA_BIDIRECTIONAL:
68 		cache_op(paddr, size, dma_wbinv_range);
69 		break;
70 	default:
71 		BUG();
72 	}
73 }
74 
75 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
76 		enum dma_data_direction dir)
77 {
78 	switch (dir) {
79 	case DMA_TO_DEVICE:
80 		return;
81 	case DMA_FROM_DEVICE:
82 	case DMA_BIDIRECTIONAL:
83 		cache_op(paddr, size, dma_inv_range);
84 		break;
85 	default:
86 		BUG();
87 	}
88 }
89