summaryrefslogtreecommitdiff
path: root/arch/m68k/sun3x/dvma.c
blob: 89e630e6655579b61bcadeba1ae1c4a1f403de0c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
// SPDX-License-Identifier: GPL-2.0
/*
 * Virtual DMA allocation
 *
 * (C) 1999 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
 *
 * 11/26/2000 -- disabled the existing code because it didn't work for
 * me in 2.4.  Replaced with a significantly more primitive version
 * similar to the sun3 code.  the old functionality was probably more
 * desirable, but....   -- Sam Creasey (sammy@oh.verio.com)
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/vmalloc.h>

#include <asm/sun3x.h>
#include <asm/dvma.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>

/* IOMMU support */

#define IOMMU_ADDR_MASK            0x03ffe000
#define IOMMU_CACHE_INHIBIT        0x00000040
#define IOMMU_FULL_BLOCK           0x00000020
#define IOMMU_MODIFIED             0x00000010
#define IOMMU_USED                 0x00000008
#define IOMMU_WRITE_PROTECT        0x00000004
#define IOMMU_DT_MASK              0x00000003
#define IOMMU_DT_INVALID           0x00000000
#define IOMMU_DT_VALID             0x00000001
#define IOMMU_DT_BAD               0x00000002


static volatile unsigned long *iommu_pte = (unsigned long *)SUN3X_IOMMU;


#define dvma_entry_paddr(index)		(iommu_pte[index] & IOMMU_ADDR_MASK)
#define dvma_entry_vaddr(index,paddr)	((index << DVMA_PAGE_SHIFT) |  \
					 (paddr & (DVMA_PAGE_SIZE-1)))
#if 0
#define dvma_entry_set(index,addr)	(iommu_pte[index] =            \
					    (addr & IOMMU_ADDR_MASK) | \
				             IOMMU_DT_VALID | IOMMU_CACHE_INHIBIT)
#else
#define dvma_entry_set(index,addr)	(iommu_pte[index] =            \
					    (addr & IOMMU_ADDR_MASK) | \
				             IOMMU_DT_VALID)
#endif
#define dvma_entry_clr(index)		(iommu_pte[index] = IOMMU_DT_INVALID)
#define dvma_entry_hash(addr)		((addr >> DVMA_PAGE_SHIFT) ^ \
					 ((addr & 0x03c00000) >>     \
						(DVMA_PAGE_SHIFT+4)))

#ifdef DEBUG
/* code to print out a dvma mapping for debugging purposes */
void dvma_print (unsigned long dvma_addr)
{

	unsigned long index;

	index = dvma_addr >> DVMA_PAGE_SHIFT;

	pr_info("idx %lx dvma_addr %08lx paddr %08lx\n", index, dvma_addr,
		dvma_entry_paddr(index));
}
#endif


/* create a virtual mapping for a page assigned within the IOMMU
   so that the cpu can reach it easily */
inline int dvma_map_cpu(unsigned long kaddr,
			       unsigned long vaddr, int len)
{
	pgd_t *pgd;
	unsigned long end;
	int ret = 0;

	kaddr &= PAGE_MASK;
	vaddr &= PAGE_MASK;

	end = PAGE_ALIGN(vaddr + len);

	pr_debug("dvma: mapping kern %08lx to virt %08lx\n", kaddr, vaddr);
	pgd = pgd_offset_k(vaddr);

	do {
		pmd_t *pmd;
		unsigned long end2;

		if((pmd = pmd_alloc(&init_mm, pgd, vaddr)) == NULL) {
			ret = -ENOMEM;
			goto out;
		}

		if((end & PGDIR_MASK) > (vaddr & PGDIR_MASK))
			end2 = (vaddr + (PGDIR_SIZE-1)) & PGDIR_MASK;
		else
			end2 = end;

		do {
			pte_t *pte;
			unsigned long end3;

			if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) {
				ret = -ENOMEM;
				goto out;
			}

			if((end2 & PMD_MASK) > (vaddr & PMD_MASK))
				end3 = (vaddr + (PMD_SIZE-1)) & PMD_MASK;
			else
				end3 = end2;

			do {
				pr_debug("mapping %08lx phys to %08lx\n",
					 __pa(kaddr), vaddr);
				set_pte(pte, pfn_pte(virt_to_pfn(kaddr),
						     PAGE_KERNEL));
				pte++;
				kaddr += PAGE_SIZE;
				vaddr += PAGE_SIZE;
			} while(vaddr < end3);

		} while(vaddr < end2);

	} while(vaddr < end);

	flush_tlb_all();

 out:
	return ret;
}


inline int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
				 int len)
{
	unsigned long end, index;

	index = baddr >> DVMA_PAGE_SHIFT;
	end = ((baddr+len) >> DVMA_PAGE_SHIFT);

	if(len & ~DVMA_PAGE_MASK)
		end++;

	for(; index < end ; index++) {
//		if(dvma_entry_use(index))
//			BUG();
//		pr_info("mapping pa %lx to ba %lx\n", __pa(kaddr),
//			index << DVMA_PAGE_SHIFT);

		dvma_entry_set(index, __pa(kaddr));

		iommu_pte[index] |= IOMMU_FULL_BLOCK;
//		dvma_entry_inc(index);

		kaddr += DVMA_PAGE_SIZE;
	}

#ifdef DEBUG
	for(index = (baddr >> DVMA_PAGE_SHIFT); index < end; index++)
		dvma_print(index << DVMA_PAGE_SHIFT);
#endif
	return 0;

}

void dvma_unmap_iommu(unsigned long baddr, int len)
{

	int index, end;


	index = baddr >> DVMA_PAGE_SHIFT;
	end = (DVMA_PAGE_ALIGN(baddr+len) >> DVMA_PAGE_SHIFT);

	for(; index < end ; index++) {
		pr_debug("freeing bus mapping %08x\n",
			 index << DVMA_PAGE_SHIFT);
#if 0
		if(!dvma_entry_use(index))
			pr_info("dvma_unmap freeing unused entry %04x\n",
				index);
		else
			dvma_entry_dec(index);
#endif
		dvma_entry_clr(index);
	}

}