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 #ifdef DEBUG 62 /* code to print out a dvma mapping for debugging purposes */ 63 void dvma_print (unsigned long dvma_addr) 64 { 65 66 unsigned long index; 67 68 index = dvma_addr >> DVMA_PAGE_SHIFT; 69 70 pr_info("idx %lx dvma_addr %08lx paddr %08lx\n", index, dvma_addr, 71 dvma_entry_paddr(index)); 72 } 73 #endif 74 75 76 /* create a virtual mapping for a page assigned within the IOMMU 77 so that the cpu can reach it easily */ 78 inline int dvma_map_cpu(unsigned long kaddr, 79 unsigned long vaddr, int len) 80 { 81 pgd_t *pgd; 82 unsigned long end; 83 int ret = 0; 84 85 kaddr &= PAGE_MASK; 86 vaddr &= PAGE_MASK; 87 88 end = PAGE_ALIGN(vaddr + len); 89 90 pr_debug("dvma: mapping kern %08lx to virt %08lx\n", kaddr, vaddr); 91 pgd = pgd_offset_k(vaddr); 92 93 do { 94 pmd_t *pmd; 95 unsigned long end2; 96 97 if((pmd = pmd_alloc(&init_mm, pgd, vaddr)) == NULL) { 98 ret = -ENOMEM; 99 goto out; 100 } 101 102 if((end & PGDIR_MASK) > (vaddr & PGDIR_MASK)) 103 end2 = (vaddr + (PGDIR_SIZE-1)) & PGDIR_MASK; 104 else 105 end2 = end; 106 107 do { 108 pte_t *pte; 109 unsigned long end3; 110 111 if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) { 112 ret = -ENOMEM; 113 goto out; 114 } 115 116 if((end2 & PMD_MASK) > (vaddr & PMD_MASK)) 117 end3 = (vaddr + (PMD_SIZE-1)) & PMD_MASK; 118 else 119 end3 = end2; 120 121 do { 122 pr_debug("mapping %08lx phys to %08lx\n", 123 __pa(kaddr), vaddr); 124 set_pte(pte, pfn_pte(virt_to_pfn(kaddr), 125 PAGE_KERNEL)); 126 pte++; 127 kaddr += PAGE_SIZE; 128 vaddr += PAGE_SIZE; 129 } while(vaddr < end3); 130 131 } while(vaddr < end2); 132 133 } while(vaddr < end); 134 135 flush_tlb_all(); 136 137 out: 138 return ret; 139 } 140 141 142 inline int dvma_map_iommu(unsigned long kaddr, unsigned long baddr, 143 int len) 144 { 145 unsigned long end, index; 146 147 index = baddr >> DVMA_PAGE_SHIFT; 148 end = ((baddr+len) >> DVMA_PAGE_SHIFT); 149 150 if(len & ~DVMA_PAGE_MASK) 151 end++; 152 153 for(; index < end ; index++) { 154 // if(dvma_entry_use(index)) 155 // BUG(); 156 // pr_info("mapping pa %lx to ba %lx\n", __pa(kaddr), 157 // index << DVMA_PAGE_SHIFT); 158 159 dvma_entry_set(index, __pa(kaddr)); 160 161 iommu_pte[index] |= IOMMU_FULL_BLOCK; 162 // dvma_entry_inc(index); 163 164 kaddr += DVMA_PAGE_SIZE; 165 } 166 167 #ifdef DEBUG 168 for(index = (baddr >> DVMA_PAGE_SHIFT); index < end; index++) 169 dvma_print(index << DVMA_PAGE_SHIFT); 170 #endif 171 return 0; 172 173 } 174 175 void dvma_unmap_iommu(unsigned long baddr, int len) 176 { 177 178 int index, end; 179 180 181 index = baddr >> DVMA_PAGE_SHIFT; 182 end = (DVMA_PAGE_ALIGN(baddr+len) >> DVMA_PAGE_SHIFT); 183 184 for(; index < end ; index++) { 185 pr_debug("freeing bus mapping %08x\n", 186 index << DVMA_PAGE_SHIFT); 187 #if 0 188 if(!dvma_entry_use(index)) 189 pr_info("dvma_unmap freeing unused entry %04x\n", 190 index); 191 else 192 dvma_entry_dec(index); 193 #endif 194 dvma_entry_clr(index); 195 } 196 197 } 198 199