xref: /linux/arch/csky/mm/dma-mapping.c (revision cfb24463)
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 <asm/cache.h>
13 
cache_op(phys_addr_t paddr,size_t size,void (* fn)(unsigned long start,unsigned long end))14 static inline void cache_op(phys_addr_t paddr, size_t size,
15 			    void (*fn)(unsigned long start, unsigned long end))
16 {
17 	struct page *page    = phys_to_page(paddr);
18 	void *start          = __va(page_to_phys(page));
19 	unsigned long offset = offset_in_page(paddr);
20 	size_t left          = size;
21 
22 	do {
23 		size_t len = left;
24 
25 		if (offset + len > PAGE_SIZE)
26 			len = PAGE_SIZE - offset;
27 
28 		if (PageHighMem(page)) {
29 			start = kmap_atomic(page);
30 
31 			fn((unsigned long)start + offset,
32 					(unsigned long)start + offset + len);
33 
34 			kunmap_atomic(start);
35 		} else {
36 			fn((unsigned long)start + offset,
37 					(unsigned long)start + offset + len);
38 		}
39 		offset = 0;
40 
41 		page++;
42 		start += PAGE_SIZE;
43 		left -= len;
44 	} while (left);
45 }
46 
dma_wbinv_set_zero_range(unsigned long start,unsigned long end)47 static void dma_wbinv_set_zero_range(unsigned long start, unsigned long end)
48 {
49 	memset((void *)start, 0, end - start);
50 	dma_wbinv_range(start, end);
51 }
52 
arch_dma_prep_coherent(struct page * page,size_t size)53 void arch_dma_prep_coherent(struct page *page, size_t size)
54 {
55 	cache_op(page_to_phys(page), size, dma_wbinv_set_zero_range);
56 }
57 
arch_sync_dma_for_device(phys_addr_t paddr,size_t size,enum dma_data_direction dir)58 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
59 		enum dma_data_direction dir)
60 {
61 	switch (dir) {
62 	case DMA_TO_DEVICE:
63 		cache_op(paddr, size, dma_wb_range);
64 		break;
65 	case DMA_FROM_DEVICE:
66 	case DMA_BIDIRECTIONAL:
67 		cache_op(paddr, size, dma_wbinv_range);
68 		break;
69 	default:
70 		BUG();
71 	}
72 }
73 
arch_sync_dma_for_cpu(phys_addr_t paddr,size_t size,enum dma_data_direction dir)74 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
75 		enum dma_data_direction dir)
76 {
77 	switch (dir) {
78 	case DMA_TO_DEVICE:
79 		return;
80 	case DMA_FROM_DEVICE:
81 	case DMA_BIDIRECTIONAL:
82 		cache_op(paddr, size, dma_inv_range);
83 		break;
84 	default:
85 		BUG();
86 	}
87 }
88