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 41static 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#define dvma_entry_set(index,addr) (iommu_pte[index] = \ 48 (addr & IOMMU_ADDR_MASK) | \ 49 IOMMU_DT_VALID) 50#define dvma_entry_clr(index) (iommu_pte[index] = IOMMU_DT_INVALID) 51#define dvma_entry_hash(addr) ((addr >> DVMA_PAGE_SHIFT) ^ \ 52 ((addr & 0x03c00000) >> \ 53 (DVMA_PAGE_SHIFT+4))) 54 55#undef DEBUG 56 57#ifdef DEBUG 58/* code to print out a dvma mapping for debugging purposes */ 59void dvma_print (unsigned long dvma_addr) 60{ 61 62 unsigned long index; 63 64 index = dvma_addr >> DVMA_PAGE_SHIFT; 65 66 printk("idx %lx dvma_addr %08lx paddr %08lx\n", index, dvma_addr, 67 dvma_entry_paddr(index)); 68 69 70} 71#endif 72 73 74/* create a virtual mapping for a page assigned within the IOMMU 75 so that the cpu can reach it easily */ 76inline int dvma_map_cpu(unsigned long kaddr, 77 unsigned long vaddr, int len) 78{ 79 pgd_t *pgd; 80 unsigned long end; 81 int ret = 0; 82 83 kaddr &= PAGE_MASK; 84 vaddr &= PAGE_MASK; 85 86 end = PAGE_ALIGN(vaddr + len); 87 88#ifdef DEBUG 89 printk("dvma: mapping kern %08lx to virt %08lx\n", 90 kaddr, vaddr); 91#endif 92 pgd = pgd_offset_k(vaddr); 93 94 do { 95 pmd_t *pmd; 96 unsigned long end2; 97 98 if((pmd = pmd_alloc(&init_mm, pgd, vaddr)) == NULL) { 99 ret = -ENOMEM; 100 goto out; 101 } 102 103 if((end & PGDIR_MASK) > (vaddr & PGDIR_MASK)) 104 end2 = (vaddr + (PGDIR_SIZE-1)) & PGDIR_MASK; 105 else 106 end2 = end; 107 108 do { 109 pte_t *pte; 110 unsigned long end3; 111 112 if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) { 113 ret = -ENOMEM; 114 goto out; 115 } 116 117 if((end2 & PMD_MASK) > (vaddr & PMD_MASK)) 118 end3 = (vaddr + (PMD_SIZE-1)) & PMD_MASK; 119 else 120 end3 = end2; 121 122 do { 123#ifdef DEBUG 124 printk("mapping %08lx phys to %08lx\n", 125 __pa(kaddr), vaddr); 126#endif 127 set_pte(pte, pfn_pte(virt_to_pfn(kaddr), 128 PAGE_KERNEL)); 129 pte++; 130 kaddr += PAGE_SIZE; 131 vaddr += PAGE_SIZE; 132 } while(vaddr < end3); 133 134 } while(vaddr < end2); 135 136 } while(vaddr < end); 137 138 flush_tlb_all(); 139 140 out: 141 return ret; 142} 143 144 145inline int dvma_map_iommu(unsigned long kaddr, unsigned long baddr, 146 int len) 147{ 148 unsigned long end, index; 149 150 index = baddr >> DVMA_PAGE_SHIFT; 151 end = ((baddr+len) >> DVMA_PAGE_SHIFT); 152 153 if(len & ~DVMA_PAGE_MASK) 154 end++; 155 156 for(; index < end ; index++) { 157// if(dvma_entry_use(index)) 158// BUG(); 159// printk("mapping pa %lx to ba %lx\n", __pa(kaddr), index << DVMA_PAGE_SHIFT); 160 161 dvma_entry_set(index, __pa(kaddr)); 162 163 iommu_pte[index] |= IOMMU_FULL_BLOCK; 164// dvma_entry_inc(index); 165 166 kaddr += DVMA_PAGE_SIZE; 167 } 168 169#ifdef DEBUG 170 for(index = (baddr >> DVMA_PAGE_SHIFT); index < end; index++) 171 dvma_print(index << DVMA_PAGE_SHIFT); 172#endif 173 return 0; 174 175} 176 177void dvma_unmap_iommu(unsigned long baddr, int len) 178{ 179 180 int index, end; 181 182 183 index = baddr >> DVMA_PAGE_SHIFT; 184 end = (DVMA_PAGE_ALIGN(baddr+len) >> DVMA_PAGE_SHIFT); 185 186 for(; index < end ; index++) { 187#ifdef DEBUG 188 printk("freeing bus mapping %08x\n", index << DVMA_PAGE_SHIFT); 189#endif 190 dvma_entry_clr(index); 191 } 192 193} 194