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 42static 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#define dvma_entry_set(index,addr) (iommu_pte[index] = \ 49 (addr & IOMMU_ADDR_MASK) | \ 50 IOMMU_DT_VALID) 51#define dvma_entry_clr(index) (iommu_pte[index] = IOMMU_DT_INVALID) 52#define dvma_entry_hash(addr) ((addr >> DVMA_PAGE_SHIFT) ^ \ 53 ((addr & 0x03c00000) >> \ 54 (DVMA_PAGE_SHIFT+4))) 55 56#undef DEBUG 57 58#ifdef DEBUG 59/* code to print out a dvma mapping for debugging purposes */ 60void dvma_print (unsigned long dvma_addr) 61{ 62 63 unsigned long index; 64 65 index = dvma_addr >> DVMA_PAGE_SHIFT; 66 67 printk("idx %lx dvma_addr %08lx paddr %08lx\n", index, dvma_addr, 68 dvma_entry_paddr(index)); 69 70 71} 72#endif 73 74 75/* create a virtual mapping for a page assigned within the IOMMU 76 so that the cpu can reach it easily */ 77inline int dvma_map_cpu(unsigned long kaddr, 78 unsigned long vaddr, int len) 79{ 80 pgd_t *pgd; 81 unsigned long end; 82 int ret = 0; 83 84 kaddr &= PAGE_MASK; 85 vaddr &= PAGE_MASK; 86 87 end = PAGE_ALIGN(vaddr + len); 88 89#ifdef DEBUG 90 printk("dvma: mapping kern %08lx to virt %08lx\n", 91 kaddr, vaddr); 92#endif 93 pgd = pgd_offset_k(vaddr); 94 95 do { 96 pmd_t *pmd; 97 unsigned long end2; 98 99 if((pmd = pmd_alloc(&init_mm, pgd, vaddr)) == NULL) { 100 ret = -ENOMEM; 101 goto out; 102 } 103 104 if((end & PGDIR_MASK) > (vaddr & PGDIR_MASK)) 105 end2 = (vaddr + (PGDIR_SIZE-1)) & PGDIR_MASK; 106 else 107 end2 = end; 108 109 do { 110 pte_t *pte; 111 unsigned long end3; 112 113 if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) { 114 ret = -ENOMEM; 115 goto out; 116 } 117 118 if((end2 & PMD_MASK) > (vaddr & PMD_MASK)) 119 end3 = (vaddr + (PMD_SIZE-1)) & PMD_MASK; 120 else 121 end3 = end2; 122 123 do { 124#ifdef DEBUG 125 printk("mapping %08lx phys to %08lx\n", 126 __pa(kaddr), vaddr); 127#endif 128 set_pte(pte, pfn_pte(virt_to_pfn(kaddr), 129 PAGE_KERNEL)); 130 pte++; 131 kaddr += PAGE_SIZE; 132 vaddr += PAGE_SIZE; 133 } while(vaddr < end3); 134 135 } while(vaddr < end2); 136 137 } while(vaddr < end); 138 139 flush_tlb_all(); 140 141 out: 142 return ret; 143} 144 145 146inline int dvma_map_iommu(unsigned long kaddr, unsigned long baddr, 147 int len) 148{ 149 unsigned long end, index; 150 151 index = baddr >> DVMA_PAGE_SHIFT; 152 end = ((baddr+len) >> DVMA_PAGE_SHIFT); 153 154 if(len & ~DVMA_PAGE_MASK) 155 end++; 156 157 for(; index < end ; index++) { 158// if(dvma_entry_use(index)) 159// BUG(); 160// printk("mapping pa %lx to ba %lx\n", __pa(kaddr), index << DVMA_PAGE_SHIFT); 161 162 dvma_entry_set(index, __pa(kaddr)); 163 164 iommu_pte[index] |= IOMMU_FULL_BLOCK; 165// dvma_entry_inc(index); 166 167 kaddr += DVMA_PAGE_SIZE; 168 } 169 170#ifdef DEBUG 171 for(index = (baddr >> DVMA_PAGE_SHIFT); index < end; index++) 172 dvma_print(index << DVMA_PAGE_SHIFT); 173#endif 174 return 0; 175 176} 177 178void dvma_unmap_iommu(unsigned long baddr, int len) 179{ 180 181 int index, end; 182 183 184 index = baddr >> DVMA_PAGE_SHIFT; 185 end = (DVMA_PAGE_ALIGN(baddr+len) >> DVMA_PAGE_SHIFT); 186 187 for(; index < end ; index++) { 188#ifdef DEBUG 189 printk("freeing bus mapping %08x\n", index << DVMA_PAGE_SHIFT); 190#endif 191 dvma_entry_clr(index); 192 } 193 194} 195