isadma.c revision 1.18
1 /* $NetBSD: isadma.c,v 1.18 1996/03/31 20:51:43 mycroft Exp $ */ 2 3 #include <sys/param.h> 4 #include <sys/systm.h> 5 #include <sys/file.h> 6 #include <sys/buf.h> 7 #include <sys/syslog.h> 8 #include <sys/malloc.h> 9 #include <sys/uio.h> 10 11 #include <vm/vm.h> 12 13 #include <machine/pio.h> 14 15 #include <dev/isa/isareg.h> 16 #include <dev/isa/isadmavar.h> 17 #include <dev/isa/isadmareg.h> 18 19 /* region of physical memory known to be contiguous */ 20 vm_offset_t isaphysmem; 21 static caddr_t dma_bounce[8]; /* XXX */ 22 static char bounced[8]; /* XXX */ 23 #define MAXDMASZ 512 /* XXX */ 24 static u_int8_t dma_finished; 25 26 /* high byte of address is stored in this port for i-th dma channel */ 27 static int dmapageport[2][4] = { 28 {0x87, 0x83, 0x81, 0x82}, 29 {0x8f, 0x8b, 0x89, 0x8a} 30 }; 31 32 static u_int8_t dmamode[4] = { 33 DMA37MD_READ | DMA37MD_SINGLE, 34 DMA37MD_WRITE | DMA37MD_SINGLE, 35 DMA37MD_READ | DMA37MD_LOOP, 36 DMA37MD_WRITE | DMA37MD_LOOP 37 }; 38 39 /* 40 * isa_dmacascade(): program 8237 DMA controller channel to accept 41 * external dma control by a board. 42 */ 43 void 44 isa_dmacascade(chan) 45 int chan; 46 { 47 48 #ifdef ISADMA_DEBUG 49 if (chan < 0 || chan > 7) 50 panic("isa_dmacascade: impossible request"); 51 #endif 52 53 /* set dma channel mode, and set dma channel mode */ 54 if ((chan & 4) == 0) { 55 outb(DMA1_MODE, chan | DMA37MD_CASCADE); 56 outb(DMA1_SMSK, chan); 57 } else { 58 chan &= 3; 59 60 outb(DMA2_MODE, chan | DMA37MD_CASCADE); 61 outb(DMA2_SMSK, chan); 62 } 63 } 64 65 /* 66 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment 67 * problems by using a bounce buffer. 68 */ 69 void 70 isa_dmastart(flags, addr, nbytes, chan) 71 int flags; 72 caddr_t addr; 73 vm_size_t nbytes; 74 int chan; 75 { 76 vm_offset_t phys; 77 int waport; 78 caddr_t newaddr; 79 80 #ifdef ISADMA_DEBUG 81 if (chan < 0 || chan > 7 || 82 ((chan & 4) ? (nbytes >= (1<<17) || nbytes & 1 || (u_int)addr & 1) : 83 (nbytes >= (1<<16)))) 84 panic("isa_dmastart: impossible request"); 85 #endif 86 87 if (isa_dmarangecheck(addr, nbytes, chan)) { 88 if (dma_bounce[chan] == 0) 89 dma_bounce[chan] = 90 /*(caddr_t)malloc(MAXDMASZ, M_TEMP, M_WAITOK);*/ 91 (caddr_t) isaphysmem + NBPG*chan; 92 bounced[chan] = 1; 93 newaddr = dma_bounce[chan]; 94 *(int *) newaddr = 0; /* XXX */ 95 /* copy bounce buffer on write */ 96 if ((flags & DMAMODE_READ) == 0) 97 bcopy(addr, newaddr, nbytes); 98 addr = newaddr; 99 } 100 101 /* translate to physical */ 102 phys = pmap_extract(pmap_kernel(), (vm_offset_t)addr); 103 104 dma_finished &= ~(1 << chan); 105 106 if ((chan & 4) == 0) { 107 /* 108 * Program one of DMA channels 0..3. These are 109 * byte mode channels. 110 */ 111 /* set dma channel mode, and reset address ff */ 112 outb(DMA1_MODE, chan | dmamode[flags]); 113 outb(DMA1_FFC, 0); 114 115 /* send start address */ 116 waport = DMA1_CHN(chan); 117 outb(dmapageport[0][chan], phys>>16); 118 outb(waport, phys); 119 outb(waport, phys>>8); 120 121 /* send count */ 122 outb(waport + 1, --nbytes); 123 outb(waport + 1, nbytes>>8); 124 125 /* unmask channel */ 126 outb(DMA1_SMSK, chan | DMA37SM_CLEAR); 127 } else { 128 chan &= 3; 129 130 /* 131 * Program one of DMA channels 4..7. These are 132 * word mode channels. 133 */ 134 /* set dma channel mode, and reset address ff */ 135 outb(DMA2_MODE, chan | dmamode[flags]); 136 outb(DMA2_FFC, 0); 137 138 /* send start address */ 139 waport = DMA2_CHN(chan); 140 outb(dmapageport[1][chan], phys>>16); 141 phys >>= 1; 142 outb(waport, phys); 143 outb(waport, phys>>8); 144 145 /* send count */ 146 nbytes >>= 1; 147 outb(waport + 2, --nbytes); 148 outb(waport + 2, nbytes>>8); 149 150 /* unmask channel */ 151 outb(DMA2_SMSK, chan | DMA37SM_CLEAR); 152 } 153 } 154 155 void 156 isa_dmaabort(chan) 157 int chan; 158 { 159 160 #ifdef ISADMA_DEBUG 161 if (chan < 0 || chan > 7) 162 panic("isa_dmaabort: impossible request"); 163 #endif 164 165 bounced[chan] = 0; 166 167 /* mask channel */ 168 if ((chan & 4) == 0) 169 outb(DMA1_SMSK, DMA37SM_SET | chan); 170 else 171 outb(DMA2_SMSK, DMA37SM_SET | (chan & 3)); 172 } 173 174 int 175 isa_dmafinished(chan) 176 int chan; 177 { 178 179 #ifdef ISADMA_DEBUG 180 if (chan < 0 || chan > 7) 181 panic("isa_dmafinished: impossible request"); 182 #endif 183 184 /* check that the terminal count was reached */ 185 if ((chan & 4) == 0) 186 dma_finished |= inb(DMA1_SR) & 0x0f; 187 else 188 dma_finished |= (inb(DMA2_SR) & 0x0f) << 4; 189 190 return ((dma_finished & (1 << chan)) != 0); 191 } 192 193 void 194 isa_dmadone(flags, addr, nbytes, chan) 195 int flags; 196 caddr_t addr; 197 vm_size_t nbytes; 198 int chan; 199 { 200 201 #ifdef ISADMA_DEBUG 202 if (chan < 0 || chan > 7) 203 panic("isa_dmadone: impossible request"); 204 #endif 205 206 if (!isa_dmafinished(chan)) 207 printf("isa_dmadone: channel %d not finished\n", chan); 208 209 /* mask channel */ 210 if ((chan & 4) == 0) 211 outb(DMA1_SMSK, DMA37SM_SET | chan); 212 else 213 outb(DMA2_SMSK, DMA37SM_SET | (chan & 3)); 214 215 /* copy bounce buffer on read */ 216 if (bounced[chan]) { 217 bcopy(dma_bounce[chan], addr, nbytes); 218 bounced[chan] = 0; 219 } 220 } 221 222 /* 223 * Check for problems with the address range of a DMA transfer 224 * (non-contiguous physical pages, outside of bus address space, 225 * crossing DMA page boundaries). 226 * Return true if special handling needed. 227 */ 228 int 229 isa_dmarangecheck(va, length, chan) 230 vm_offset_t va; 231 u_long length; 232 int chan; 233 { 234 vm_offset_t phys, priorpage = 0, endva; 235 u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1); 236 237 endva = round_page(va + length); 238 for (; va < endva ; va += NBPG) { 239 phys = trunc_page(pmap_extract(pmap_kernel(), va)); 240 if (phys == 0) 241 panic("isa_dmacheck: no physical page present"); 242 if (phys >= (1<<24)) 243 return 1; 244 if (priorpage) { 245 if (priorpage + NBPG != phys) 246 return 1; 247 /* check if crossing a DMA page boundary */ 248 if ((priorpage ^ phys) & dma_pgmsk) 249 return 1; 250 } 251 priorpage = phys; 252 } 253 return 0; 254 } 255 256 /* head of queue waiting for physmem to become available */ 257 struct buf isa_physmemq; 258 259 /* blocked waiting for resource to become free for exclusive use */ 260 static isaphysmemflag; 261 /* if waited for and call requested when free (B_CALL) */ 262 static void (*isaphysmemunblock)(); /* needs to be a list */ 263 264 /* 265 * Allocate contiguous physical memory for transfer, returning 266 * a *virtual* address to region. May block waiting for resource. 267 * (assumed to be called at splbio()) 268 */ 269 caddr_t 270 isa_allocphysmem(caddr_t va, unsigned length, void (*func)()) { 271 272 isaphysmemunblock = func; 273 while (isaphysmemflag & B_BUSY) { 274 isaphysmemflag |= B_WANTED; 275 sleep((caddr_t)&isaphysmemflag, PRIBIO); 276 } 277 isaphysmemflag |= B_BUSY; 278 279 return((caddr_t)isaphysmem); 280 } 281 282 /* 283 * Free contiguous physical memory used for transfer. 284 * (assumed to be called at splbio()) 285 */ 286 void 287 isa_freephysmem(caddr_t va, unsigned length) { 288 289 isaphysmemflag &= ~B_BUSY; 290 if (isaphysmemflag & B_WANTED) { 291 isaphysmemflag &= B_WANTED; 292 wakeup((caddr_t)&isaphysmemflag); 293 if (isaphysmemunblock) 294 (*isaphysmemunblock)(); 295 } 296 } 297
Indexes created Wed Sep 24 02:09:48 GMT 2025