1 /*
2 * Virtual DMA allocation
3 *
4 * (C) 1999 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
5 *
6 * 11/26/2000 -- disabled the existing code because it didn't work for
7 * me in 2.4. Replaced with a significantly more primitive version
8 * similar to the sun3 code. the old functionality was probably more
9 * desirable, but.... -- Sam Creasey (sammy@oh.verio.com)
10 *
11 */
12
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/bitops.h>
16 #include <linux/mm.h>
17 #include <linux/bootmem.h>
18 #include <linux/slab.h>
19 #include <linux/vmalloc.h>
20
21 #include <asm/sun3x.h>
22 #include <asm/dvma.h>
23 #include <asm/io.h>
24 #include <asm/page.h>
25 #include <asm/pgtable.h>
26 #include <asm/pgalloc.h>
27
28 /* IOMMU support */
29
30 #define IOMMU_ADDR_MASK 0x03ffe000
31 #define IOMMU_CACHE_INHIBIT 0x00000040
32 #define IOMMU_FULL_BLOCK 0x00000020
33 #define IOMMU_MODIFIED 0x00000010
34 #define IOMMU_USED 0x00000008
35 #define IOMMU_WRITE_PROTECT 0x00000004
36 #define IOMMU_DT_MASK 0x00000003
37 #define IOMMU_DT_INVALID 0x00000000
38 #define IOMMU_DT_VALID 0x00000001
39 #define IOMMU_DT_BAD 0x00000002
40
41
42 static volatile unsigned long *iommu_pte = (unsigned long *)SUN3X_IOMMU;
43
44
45 #define dvma_entry_paddr(index) (iommu_pte[index] & IOMMU_ADDR_MASK)
46 #define dvma_entry_vaddr(index,paddr) ((index << DVMA_PAGE_SHIFT) | \
47 (paddr & (DVMA_PAGE_SIZE-1)))
48 #if 0
49 #define dvma_entry_set(index,addr) (iommu_pte[index] = \
50 (addr & IOMMU_ADDR_MASK) | \
51 IOMMU_DT_VALID | IOMMU_CACHE_INHIBIT)
52 #else
53 #define dvma_entry_set(index,addr) (iommu_pte[index] = \
54 (addr & IOMMU_ADDR_MASK) | \
55 IOMMU_DT_VALID)
56 #endif
57 #define dvma_entry_clr(index) (iommu_pte[index] = IOMMU_DT_INVALID)
58 #define dvma_entry_hash(addr) ((addr >> DVMA_PAGE_SHIFT) ^ \
59 ((addr & 0x03c00000) >> \
60 (DVMA_PAGE_SHIFT+4)))
61
62 #undef DEBUG
63
64 #ifdef DEBUG
65 /* code to print out a dvma mapping for debugging purposes */
dvma_print(unsigned long dvma_addr)66 void dvma_print (unsigned long dvma_addr)
67 {
68
69 unsigned long index;
70
71 index = dvma_addr >> DVMA_PAGE_SHIFT;
72
73 printk("idx %lx dvma_addr %08lx paddr %08lx\n", index, dvma_addr,
74 dvma_entry_paddr(index));
75
76
77 }
78 #endif
79
80
81 /* create a virtual mapping for a page assigned within the IOMMU
82 so that the cpu can reach it easily */
dvma_map_cpu(unsigned long kaddr,unsigned long vaddr,int len)83 inline int dvma_map_cpu(unsigned long kaddr,
84 unsigned long vaddr, int len)
85 {
86 pgd_t *pgd;
87 unsigned long end;
88 int ret = 0;
89
90 kaddr &= PAGE_MASK;
91 vaddr &= PAGE_MASK;
92
93 end = PAGE_ALIGN(vaddr + len);
94
95 #ifdef DEBUG
96 printk("dvma: mapping kern %08lx to virt %08lx\n",
97 kaddr, vaddr);
98 #endif
99 pgd = pgd_offset_k(vaddr);
100
101 do {
102 pmd_t *pmd;
103 unsigned long end2;
104
105 if((pmd = pmd_alloc_kernel(pgd, vaddr)) == NULL) {
106 ret = -ENOMEM;
107 goto out;
108 }
109
110 if((end & PGDIR_MASK) > (vaddr & PGDIR_MASK))
111 end2 = (vaddr + (PGDIR_SIZE-1)) & PGDIR_MASK;
112 else
113 end2 = end;
114
115 do {
116 pte_t *pte;
117 unsigned long end3;
118
119 if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) {
120 ret = -ENOMEM;
121 goto out;
122 }
123
124 if((end2 & PMD_MASK) > (vaddr & PMD_MASK))
125 end3 = (vaddr + (PMD_SIZE-1)) & PMD_MASK;
126 else
127 end3 = end2;
128
129 do {
130 #ifdef DEBUG
131 printk("mapping %08lx phys to %08lx\n",
132 __pa(kaddr), vaddr);
133 #endif
134 set_pte(pte, __mk_pte(kaddr, PAGE_KERNEL));
135 pte++;
136 kaddr += PAGE_SIZE;
137 vaddr += PAGE_SIZE;
138 } while(vaddr < end3);
139
140 } while(vaddr < end2);
141
142 } while(vaddr < end);
143
144 flush_tlb_all();
145
146 out:
147 return ret;
148 }
149
150
dvma_map_iommu(unsigned long kaddr,unsigned long baddr,int len)151 inline int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
152 int len)
153 {
154 unsigned long end, index;
155
156 index = baddr >> DVMA_PAGE_SHIFT;
157 end = ((baddr+len) >> DVMA_PAGE_SHIFT);
158
159 if(len & ~DVMA_PAGE_MASK)
160 end++;
161
162 for(; index < end ; index++) {
163 // if(dvma_entry_use(index))
164 // BUG();
165 // printk("mapping pa %lx to ba %lx\n", __pa(kaddr), index << DVMA_PAGE_SHIFT);
166
167 dvma_entry_set(index, __pa(kaddr));
168
169 iommu_pte[index] |= IOMMU_FULL_BLOCK;
170 // dvma_entry_inc(index);
171
172 kaddr += DVMA_PAGE_SIZE;
173 }
174
175 #ifdef DEBUG
176 for(index = (baddr >> DVMA_PAGE_SHIFT); index < end; index++)
177 dvma_print(index << DVMA_PAGE_SHIFT);
178 #endif
179 return 0;
180
181 }
182
dvma_unmap_iommu(unsigned long baddr,int len)183 void dvma_unmap_iommu(unsigned long baddr, int len)
184 {
185
186 int index, end;
187
188
189 index = baddr >> DVMA_PAGE_SHIFT;
190 end = (DVMA_PAGE_ALIGN(baddr+len) >> DVMA_PAGE_SHIFT);
191
192 for(; index < end ; index++) {
193 #ifdef DEBUG
194 printk("freeing bus mapping %08x\n", index << DVMA_PAGE_SHIFT);
195 #endif
196 #if 0
197 if(!dvma_entry_use(index))
198 printk("dvma_unmap freeing unused entry %04x\n",
199 index);
200 else
201 dvma_entry_dec(index);
202 #endif
203 dvma_entry_clr(index);
204 }
205
206 }
207
208