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/vmalloc.h> 19 20 #include <asm/sun3x.h> 21 #include <asm/dvma.h> 22 #include <asm/io.h> 23 #include <asm/page.h> 24 #include <asm/pgtable.h> 25 #include <asm/pgalloc.h> 26 27 /* IOMMU support */ 28 29 #define IOMMU_ADDR_MASK 0x03ffe000 30 #define IOMMU_CACHE_INHIBIT 0x00000040 31 #define IOMMU_FULL_BLOCK 0x00000020 32 #define IOMMU_MODIFIED 0x00000010 33 #define IOMMU_USED 0x00000008 34 #define IOMMU_WRITE_PROTECT 0x00000004 35 #define IOMMU_DT_MASK 0x00000003 36 #define IOMMU_DT_INVALID 0x00000000 37 #define IOMMU_DT_VALID 0x00000001 38 #define IOMMU_DT_BAD 0x00000002 39 40 41 static volatile unsigned long *iommu_pte = (unsigned long *)SUN3X_IOMMU; 42 43 44 #define dvma_entry_paddr(index) (iommu_pte[index] & IOMMU_ADDR_MASK) 45 #define dvma_entry_vaddr(index,paddr) ((index << DVMA_PAGE_SHIFT) | \ 46 (paddr & (DVMA_PAGE_SIZE-1))) 47 #if 0 48 #define dvma_entry_set(index,addr) (iommu_pte[index] = \ 49 (addr & IOMMU_ADDR_MASK) | \ 50 IOMMU_DT_VALID | IOMMU_CACHE_INHIBIT) 51 #else 52 #define dvma_entry_set(index,addr) (iommu_pte[index] = \ 53 (addr & IOMMU_ADDR_MASK) | \ 54 IOMMU_DT_VALID) 55 #endif 56 #define dvma_entry_clr(index) (iommu_pte[index] = IOMMU_DT_INVALID) 57 #define dvma_entry_hash(addr) ((addr >> DVMA_PAGE_SHIFT) ^ \ 58 ((addr & 0x03c00000) >> \ 59 (DVMA_PAGE_SHIFT+4))) 60 61 #undef DEBUG 62 63 #ifdef DEBUG 64 /* code to print out a dvma mapping for debugging purposes */ 65 void dvma_print (unsigned long dvma_addr) 66 { 67 68 unsigned long index; 69 70 index = dvma_addr >> DVMA_PAGE_SHIFT; 71 72 printk("idx %lx dvma_addr %08lx paddr %08lx\n", index, dvma_addr, 73 dvma_entry_paddr(index)); 74 75 76 } 77 #endif 78 79 80 /* create a virtual mapping for a page assigned within the IOMMU 81 so that the cpu can reach it easily */ 82 inline int dvma_map_cpu(unsigned long kaddr, 83 unsigned long vaddr, int len) 84 { 85 pgd_t *pgd; 86 unsigned long end; 87 int ret = 0; 88 89 kaddr &= PAGE_MASK; 90 vaddr &= PAGE_MASK; 91 92 end = PAGE_ALIGN(vaddr + len); 93 94 #ifdef DEBUG 95 printk("dvma: mapping kern %08lx to virt %08lx\n", 96 kaddr, vaddr); 97 #endif 98 pgd = pgd_offset_k(vaddr); 99 100 do { 101 pmd_t *pmd; 102 unsigned long end2; 103 104 if((pmd = pmd_alloc(&init_mm, pgd, vaddr)) == NULL) { 105 ret = -ENOMEM; 106 goto out; 107 } 108 109 if((end & PGDIR_MASK) > (vaddr & PGDIR_MASK)) 110 end2 = (vaddr + (PGDIR_SIZE-1)) & PGDIR_MASK; 111 else 112 end2 = end; 113 114 do { 115 pte_t *pte; 116 unsigned long end3; 117 118 if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) { 119 ret = -ENOMEM; 120 goto out; 121 } 122 123 if((end2 & PMD_MASK) > (vaddr & PMD_MASK)) 124 end3 = (vaddr + (PMD_SIZE-1)) & PMD_MASK; 125 else 126 end3 = end2; 127 128 do { 129 #ifdef DEBUG 130 printk("mapping %08lx phys to %08lx\n", 131 __pa(kaddr), vaddr); 132 #endif 133 set_pte(pte, pfn_pte(virt_to_pfn(kaddr), 134 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 } 149 150 151 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 } 182 183 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