[PATCH] I2O: remove Markus from MAINTAINERS
[linux-2.6] / arch / m68k / sun3x / dvma.c
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 */
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 */
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(&init_mm, 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, pfn_pte(virt_to_pfn(kaddr),
135                                                      PAGE_KERNEL));
136                                 pte++;
137                                 kaddr += PAGE_SIZE;
138                                 vaddr += PAGE_SIZE;
139                         } while(vaddr < end3);
140
141                 } while(vaddr < end2);
142
143         } while(vaddr < end);
144
145         flush_tlb_all();
146
147  out:
148         return ret;
149 }
150
151
152 inline int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
153                                  int len)
154 {
155         unsigned long end, index;
156
157         index = baddr >> DVMA_PAGE_SHIFT;
158         end = ((baddr+len) >> DVMA_PAGE_SHIFT);
159
160         if(len & ~DVMA_PAGE_MASK)
161                 end++;
162
163         for(; index < end ; index++) {
164 //              if(dvma_entry_use(index))
165 //                      BUG();
166 //              printk("mapping pa %lx to ba %lx\n", __pa(kaddr), index << DVMA_PAGE_SHIFT);
167
168                 dvma_entry_set(index, __pa(kaddr));
169
170                 iommu_pte[index] |= IOMMU_FULL_BLOCK;
171 //              dvma_entry_inc(index);
172
173                 kaddr += DVMA_PAGE_SIZE;
174         }
175
176 #ifdef DEBUG
177         for(index = (baddr >> DVMA_PAGE_SHIFT); index < end; index++)
178                 dvma_print(index << DVMA_PAGE_SHIFT);
179 #endif
180         return 0;
181
182 }
183
184 void dvma_unmap_iommu(unsigned long baddr, int len)
185 {
186
187         int index, end;
188
189
190         index = baddr >> DVMA_PAGE_SHIFT;
191         end = (DVMA_PAGE_ALIGN(baddr+len) >> DVMA_PAGE_SHIFT);
192
193         for(; index < end ; index++) {
194 #ifdef DEBUG
195                 printk("freeing bus mapping %08x\n", index << DVMA_PAGE_SHIFT);
196 #endif
197 #if 0
198                 if(!dvma_entry_use(index))
199                         printk("dvma_unmap freeing unused entry %04x\n",
200                                index);
201                 else
202                         dvma_entry_dec(index);
203 #endif
204                 dvma_entry_clr(index);
205         }
206
207 }
208