1 /* SPDX-License-Identifier: GPL-2.0 */ <<
2 #ifndef __ASM_GENERIC_DMA_H <<
3 #define __ASM_GENERIC_DMA_H <<
4 /* 1 /*
5 * This file traditionally describes the i8237 !! 2 * include/asm-alpha/dma.h
6 * Most architectures don't have these any mor <<
7 * implementation from kernel/dma.c by not def <<
8 * 3 *
9 * Some code relies on seeing MAX_DMA_ADDRESS !! 4 * This is essentially the same as the i386 DMA stuff, as the AlphaPCs
>> 5 * use ISA-compatible dma. The only extension is support for high-page
>> 6 * registers that allow to set the top 8 bits of a 32-bit DMA address.
>> 7 * This register should be written last when setting up a DMA address
>> 8 * as this will also enable DMA across 64 KB boundaries.
10 */ 9 */
11 #define MAX_DMA_ADDRESS PAGE_OFFSET <<
12 10
13 extern int request_dma(unsigned int dmanr, con !! 11 /* $Id: dma.h,v 1.7 1992/12/14 00:29:34 root Exp root $
14 extern void free_dma(unsigned int dmanr); !! 12 * linux/include/asm/dma.h: Defines for using and allocating dma channels.
>> 13 * Written by Hennus Bergman, 1992.
>> 14 * High DMA channel support & info by Hannu Savolainen
>> 15 * and John Boyd, Nov. 1992.
>> 16 */
>> 17
>> 18 #ifndef _ASM_DMA_H
>> 19 #define _ASM_DMA_H
>> 20
>> 21 #include <linux/config.h>
>> 22 #include <linux/spinlock.h>
>> 23 #include <asm/io.h>
>> 24
>> 25 #define dma_outb outb
>> 26 #define dma_inb inb
>> 27
>> 28 /*
>> 29 * NOTES about DMA transfers:
>> 30 *
>> 31 * controller 1: channels 0-3, byte operations, ports 00-1F
>> 32 * controller 2: channels 4-7, word operations, ports C0-DF
>> 33 *
>> 34 * - ALL registers are 8 bits only, regardless of transfer size
>> 35 * - channel 4 is not used - cascades 1 into 2.
>> 36 * - channels 0-3 are byte - addresses/counts are for physical bytes
>> 37 * - channels 5-7 are word - addresses/counts are for physical words
>> 38 * - transfers must not cross physical 64K (0-3) or 128K (5-7) boundaries
>> 39 * - transfer count loaded to registers is 1 less than actual count
>> 40 * - controller 2 offsets are all even (2x offsets for controller 1)
>> 41 * - page registers for 5-7 don't use data bit 0, represent 128K pages
>> 42 * - page registers for 0-3 use bit 0, represent 64K pages
>> 43 *
>> 44 * DMA transfers are limited to the lower 16MB of _physical_ memory.
>> 45 * Note that addresses loaded into registers must be _physical_ addresses,
>> 46 * not logical addresses (which may differ if paging is active).
>> 47 *
>> 48 * Address mapping for channels 0-3:
>> 49 *
>> 50 * A23 ... A16 A15 ... A8 A7 ... A0 (Physical addresses)
>> 51 * | ... | | ... | | ... |
>> 52 * | ... | | ... | | ... |
>> 53 * | ... | | ... | | ... |
>> 54 * P7 ... P0 A7 ... A0 A7 ... A0
>> 55 * | Page | Addr MSB | Addr LSB | (DMA registers)
>> 56 *
>> 57 * Address mapping for channels 5-7:
>> 58 *
>> 59 * A23 ... A17 A16 A15 ... A9 A8 A7 ... A1 A0 (Physical addresses)
>> 60 * | ... | \ \ ... \ \ \ ... \ \
>> 61 * | ... | \ \ ... \ \ \ ... \ (not used)
>> 62 * | ... | \ \ ... \ \ \ ... \
>> 63 * P7 ... P1 (0) A7 A6 ... A0 A7 A6 ... A0
>> 64 * | Page | Addr MSB | Addr LSB | (DMA registers)
>> 65 *
>> 66 * Again, channels 5-7 transfer _physical_ words (16 bits), so addresses
>> 67 * and counts _must_ be word-aligned (the lowest address bit is _ignored_ at
>> 68 * the hardware level, so odd-byte transfers aren't possible).
>> 69 *
>> 70 * Transfer count (_not # bytes_) is limited to 64K, represented as actual
>> 71 * count - 1 : 64K => 0xFFFF, 1 => 0x0000. Thus, count is always 1 or more,
>> 72 * and up to 128K bytes may be transferred on channels 5-7 in one operation.
>> 73 *
>> 74 */
>> 75
>> 76 #define MAX_DMA_CHANNELS 8
>> 77
>> 78 /*
>> 79 ISA DMA limitations on Alpha platforms,
>> 80
>> 81 These may be due to SIO (PCI<->ISA bridge) chipset limitation, or
>> 82 just a wiring limit.
>> 83 */
>> 84
>> 85 /* The maximum address for ISA DMA transfer on Alpha XL, due to an
>> 86 hardware SIO limitation, is 64MB.
>> 87 */
>> 88 #define ALPHA_XL_MAX_DMA_ADDRESS (IDENT_ADDR+0x04000000UL)
>> 89
>> 90 /* The maximum address for ISA DMA transfer on RUFFIAN and NAUTILUS,
>> 91 due to an hardware SIO limitation, is 16MB.
>> 92 */
>> 93 #define ALPHA_RUFFIAN_MAX_DMA_ADDRESS (IDENT_ADDR+0x01000000UL)
>> 94 #define ALPHA_NAUTILUS_MAX_DMA_ADDRESS (IDENT_ADDR+0x01000000UL)
>> 95
>> 96 /* The maximum address for ISA DMA transfer on SABLE, and some ALCORs,
>> 97 due to an hardware SIO chip limitation, is 2GB.
>> 98 */
>> 99 #define ALPHA_SABLE_MAX_DMA_ADDRESS (IDENT_ADDR+0x80000000UL)
>> 100 #define ALPHA_ALCOR_MAX_DMA_ADDRESS (IDENT_ADDR+0x80000000UL)
>> 101
>> 102 /*
>> 103 Maximum address for all the others is the complete 32-bit bus
>> 104 address space.
>> 105 */
>> 106 #define ALPHA_MAX_DMA_ADDRESS (IDENT_ADDR+0x100000000UL)
>> 107
>> 108 #ifdef CONFIG_ALPHA_GENERIC
>> 109 # define MAX_DMA_ADDRESS (alpha_mv.max_dma_address)
>> 110 #else
>> 111 # if defined(CONFIG_ALPHA_XL)
>> 112 # define MAX_DMA_ADDRESS ALPHA_XL_MAX_DMA_ADDRESS
>> 113 # elif defined(CONFIG_ALPHA_RUFFIAN)
>> 114 # define MAX_DMA_ADDRESS ALPHA_RUFFIAN_MAX_DMA_ADDRESS
>> 115 # elif defined(CONFIG_ALPHA_NAUTILUS)
>> 116 # define MAX_DMA_ADDRESS ALPHA_NAUTILUS_MAX_DMA_ADDRESS
>> 117 # elif defined(CONFIG_ALPHA_SABLE)
>> 118 # define MAX_DMA_ADDRESS ALPHA_SABLE_MAX_DMA_ADDRESS
>> 119 # elif defined(CONFIG_ALPHA_ALCOR)
>> 120 # define MAX_DMA_ADDRESS ALPHA_ALCOR_MAX_DMA_ADDRESS
>> 121 # else
>> 122 # define MAX_DMA_ADDRESS ALPHA_MAX_DMA_ADDRESS
>> 123 # endif
>> 124 #endif
>> 125
>> 126 /* 8237 DMA controllers */
>> 127 #define IO_DMA1_BASE 0x00 /* 8 bit slave DMA, channels 0..3 */
>> 128 #define IO_DMA2_BASE 0xC0 /* 16 bit master DMA, ch 4(=slave input)..7 */
>> 129
>> 130 /* DMA controller registers */
>> 131 #define DMA1_CMD_REG 0x08 /* command register (w) */
>> 132 #define DMA1_STAT_REG 0x08 /* status register (r) */
>> 133 #define DMA1_REQ_REG 0x09 /* request register (w) */
>> 134 #define DMA1_MASK_REG 0x0A /* single-channel mask (w) */
>> 135 #define DMA1_MODE_REG 0x0B /* mode register (w) */
>> 136 #define DMA1_CLEAR_FF_REG 0x0C /* clear pointer flip-flop (w) */
>> 137 #define DMA1_TEMP_REG 0x0D /* Temporary Register (r) */
>> 138 #define DMA1_RESET_REG 0x0D /* Master Clear (w) */
>> 139 #define DMA1_CLR_MASK_REG 0x0E /* Clear Mask */
>> 140 #define DMA1_MASK_ALL_REG 0x0F /* all-channels mask (w) */
>> 141 #define DMA1_EXT_MODE_REG (0x400 | DMA1_MODE_REG)
>> 142
>> 143 #define DMA2_CMD_REG 0xD0 /* command register (w) */
>> 144 #define DMA2_STAT_REG 0xD0 /* status register (r) */
>> 145 #define DMA2_REQ_REG 0xD2 /* request register (w) */
>> 146 #define DMA2_MASK_REG 0xD4 /* single-channel mask (w) */
>> 147 #define DMA2_MODE_REG 0xD6 /* mode register (w) */
>> 148 #define DMA2_CLEAR_FF_REG 0xD8 /* clear pointer flip-flop (w) */
>> 149 #define DMA2_TEMP_REG 0xDA /* Temporary Register (r) */
>> 150 #define DMA2_RESET_REG 0xDA /* Master Clear (w) */
>> 151 #define DMA2_CLR_MASK_REG 0xDC /* Clear Mask */
>> 152 #define DMA2_MASK_ALL_REG 0xDE /* all-channels mask (w) */
>> 153 #define DMA2_EXT_MODE_REG (0x400 | DMA2_MODE_REG)
>> 154
>> 155 #define DMA_ADDR_0 0x00 /* DMA address registers */
>> 156 #define DMA_ADDR_1 0x02
>> 157 #define DMA_ADDR_2 0x04
>> 158 #define DMA_ADDR_3 0x06
>> 159 #define DMA_ADDR_4 0xC0
>> 160 #define DMA_ADDR_5 0xC4
>> 161 #define DMA_ADDR_6 0xC8
>> 162 #define DMA_ADDR_7 0xCC
>> 163
>> 164 #define DMA_CNT_0 0x01 /* DMA count registers */
>> 165 #define DMA_CNT_1 0x03
>> 166 #define DMA_CNT_2 0x05
>> 167 #define DMA_CNT_3 0x07
>> 168 #define DMA_CNT_4 0xC2
>> 169 #define DMA_CNT_5 0xC6
>> 170 #define DMA_CNT_6 0xCA
>> 171 #define DMA_CNT_7 0xCE
>> 172
>> 173 #define DMA_PAGE_0 0x87 /* DMA page registers */
>> 174 #define DMA_PAGE_1 0x83
>> 175 #define DMA_PAGE_2 0x81
>> 176 #define DMA_PAGE_3 0x82
>> 177 #define DMA_PAGE_5 0x8B
>> 178 #define DMA_PAGE_6 0x89
>> 179 #define DMA_PAGE_7 0x8A
>> 180
>> 181 #define DMA_HIPAGE_0 (0x400 | DMA_PAGE_0)
>> 182 #define DMA_HIPAGE_1 (0x400 | DMA_PAGE_1)
>> 183 #define DMA_HIPAGE_2 (0x400 | DMA_PAGE_2)
>> 184 #define DMA_HIPAGE_3 (0x400 | DMA_PAGE_3)
>> 185 #define DMA_HIPAGE_4 (0x400 | DMA_PAGE_4)
>> 186 #define DMA_HIPAGE_5 (0x400 | DMA_PAGE_5)
>> 187 #define DMA_HIPAGE_6 (0x400 | DMA_PAGE_6)
>> 188 #define DMA_HIPAGE_7 (0x400 | DMA_PAGE_7)
>> 189
>> 190 #define DMA_MODE_READ 0x44 /* I/O to memory, no autoinit, increment, single mode */
>> 191 #define DMA_MODE_WRITE 0x48 /* memory to I/O, no autoinit, increment, single mode */
>> 192 #define DMA_MODE_CASCADE 0xC0 /* pass thru DREQ->HRQ, DACK<-HLDA only */
>> 193
>> 194 #define DMA_AUTOINIT 0x10
>> 195
>> 196 extern spinlock_t dma_spin_lock;
>> 197
>> 198 static __inline__ unsigned long claim_dma_lock(void)
>> 199 {
>> 200 unsigned long flags;
>> 201 spin_lock_irqsave(&dma_spin_lock, flags);
>> 202 return flags;
>> 203 }
>> 204
>> 205 static __inline__ void release_dma_lock(unsigned long flags)
>> 206 {
>> 207 spin_unlock_irqrestore(&dma_spin_lock, flags);
>> 208 }
>> 209
>> 210 /* enable/disable a specific DMA channel */
>> 211 static __inline__ void enable_dma(unsigned int dmanr)
>> 212 {
>> 213 if (dmanr<=3)
>> 214 dma_outb(dmanr, DMA1_MASK_REG);
>> 215 else
>> 216 dma_outb(dmanr & 3, DMA2_MASK_REG);
>> 217 }
>> 218
>> 219 static __inline__ void disable_dma(unsigned int dmanr)
>> 220 {
>> 221 if (dmanr<=3)
>> 222 dma_outb(dmanr | 4, DMA1_MASK_REG);
>> 223 else
>> 224 dma_outb((dmanr & 3) | 4, DMA2_MASK_REG);
>> 225 }
>> 226
>> 227 /* Clear the 'DMA Pointer Flip Flop'.
>> 228 * Write 0 for LSB/MSB, 1 for MSB/LSB access.
>> 229 * Use this once to initialize the FF to a known state.
>> 230 * After that, keep track of it. :-)
>> 231 * --- In order to do that, the DMA routines below should ---
>> 232 * --- only be used while interrupts are disabled! ---
>> 233 */
>> 234 static __inline__ void clear_dma_ff(unsigned int dmanr)
>> 235 {
>> 236 if (dmanr<=3)
>> 237 dma_outb(0, DMA1_CLEAR_FF_REG);
>> 238 else
>> 239 dma_outb(0, DMA2_CLEAR_FF_REG);
>> 240 }
>> 241
>> 242 /* set mode (above) for a specific DMA channel */
>> 243 static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
>> 244 {
>> 245 if (dmanr<=3)
>> 246 dma_outb(mode | dmanr, DMA1_MODE_REG);
>> 247 else
>> 248 dma_outb(mode | (dmanr&3), DMA2_MODE_REG);
>> 249 }
>> 250
>> 251 /* set extended mode for a specific DMA channel */
>> 252 static __inline__ void set_dma_ext_mode(unsigned int dmanr, char ext_mode)
>> 253 {
>> 254 if (dmanr<=3)
>> 255 dma_outb(ext_mode | dmanr, DMA1_EXT_MODE_REG);
>> 256 else
>> 257 dma_outb(ext_mode | (dmanr&3), DMA2_EXT_MODE_REG);
>> 258 }
>> 259
>> 260 /* Set only the page register bits of the transfer address.
>> 261 * This is used for successive transfers when we know the contents of
>> 262 * the lower 16 bits of the DMA current address register.
>> 263 */
>> 264 static __inline__ void set_dma_page(unsigned int dmanr, unsigned int pagenr)
>> 265 {
>> 266 switch(dmanr) {
>> 267 case 0:
>> 268 dma_outb(pagenr, DMA_PAGE_0);
>> 269 dma_outb((pagenr >> 8), DMA_HIPAGE_0);
>> 270 break;
>> 271 case 1:
>> 272 dma_outb(pagenr, DMA_PAGE_1);
>> 273 dma_outb((pagenr >> 8), DMA_HIPAGE_1);
>> 274 break;
>> 275 case 2:
>> 276 dma_outb(pagenr, DMA_PAGE_2);
>> 277 dma_outb((pagenr >> 8), DMA_HIPAGE_2);
>> 278 break;
>> 279 case 3:
>> 280 dma_outb(pagenr, DMA_PAGE_3);
>> 281 dma_outb((pagenr >> 8), DMA_HIPAGE_3);
>> 282 break;
>> 283 case 5:
>> 284 dma_outb(pagenr & 0xfe, DMA_PAGE_5);
>> 285 dma_outb((pagenr >> 8), DMA_HIPAGE_5);
>> 286 break;
>> 287 case 6:
>> 288 dma_outb(pagenr & 0xfe, DMA_PAGE_6);
>> 289 dma_outb((pagenr >> 8), DMA_HIPAGE_6);
>> 290 break;
>> 291 case 7:
>> 292 dma_outb(pagenr & 0xfe, DMA_PAGE_7);
>> 293 dma_outb((pagenr >> 8), DMA_HIPAGE_7);
>> 294 break;
>> 295 }
>> 296 }
>> 297
>> 298
>> 299 /* Set transfer address & page bits for specific DMA channel.
>> 300 * Assumes dma flipflop is clear.
>> 301 */
>> 302 static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a)
>> 303 {
>> 304 if (dmanr <= 3) {
>> 305 dma_outb( a & 0xff, ((dmanr&3)<<1) + IO_DMA1_BASE );
>> 306 dma_outb( (a>>8) & 0xff, ((dmanr&3)<<1) + IO_DMA1_BASE );
>> 307 } else {
>> 308 dma_outb( (a>>1) & 0xff, ((dmanr&3)<<2) + IO_DMA2_BASE );
>> 309 dma_outb( (a>>9) & 0xff, ((dmanr&3)<<2) + IO_DMA2_BASE );
>> 310 }
>> 311 set_dma_page(dmanr, a>>16); /* set hipage last to enable 32-bit mode */
>> 312 }
>> 313
>> 314
>> 315 /* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
>> 316 * a specific DMA channel.
>> 317 * You must ensure the parameters are valid.
>> 318 * NOTE: from a manual: "the number of transfers is one more
>> 319 * than the initial word count"! This is taken into account.
>> 320 * Assumes dma flip-flop is clear.
>> 321 * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
>> 322 */
>> 323 static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
>> 324 {
>> 325 count--;
>> 326 if (dmanr <= 3) {
>> 327 dma_outb( count & 0xff, ((dmanr&3)<<1) + 1 + IO_DMA1_BASE );
>> 328 dma_outb( (count>>8) & 0xff, ((dmanr&3)<<1) + 1 + IO_DMA1_BASE );
>> 329 } else {
>> 330 dma_outb( (count>>1) & 0xff, ((dmanr&3)<<2) + 2 + IO_DMA2_BASE );
>> 331 dma_outb( (count>>9) & 0xff, ((dmanr&3)<<2) + 2 + IO_DMA2_BASE );
>> 332 }
>> 333 }
>> 334
>> 335
>> 336 /* Get DMA residue count. After a DMA transfer, this
>> 337 * should return zero. Reading this while a DMA transfer is
>> 338 * still in progress will return unpredictable results.
>> 339 * If called before the channel has been used, it may return 1.
>> 340 * Otherwise, it returns the number of _bytes_ left to transfer.
>> 341 *
>> 342 * Assumes DMA flip-flop is clear.
>> 343 */
>> 344 static __inline__ int get_dma_residue(unsigned int dmanr)
>> 345 {
>> 346 unsigned int io_port = (dmanr<=3)? ((dmanr&3)<<1) + 1 + IO_DMA1_BASE
>> 347 : ((dmanr&3)<<2) + 2 + IO_DMA2_BASE;
>> 348
>> 349 /* using short to get 16-bit wrap around */
>> 350 unsigned short count;
>> 351
>> 352 count = 1 + dma_inb(io_port);
>> 353 count += dma_inb(io_port) << 8;
>> 354
>> 355 return (dmanr<=3)? count : (count<<1);
>> 356 }
>> 357
>> 358
>> 359 /* These are in kernel/dma.c: */
>> 360 extern int request_dma(unsigned int dmanr, const char * device_id); /* reserve a DMA channel */
>> 361 extern void free_dma(unsigned int dmanr); /* release it again */
>> 362 #define KERNEL_HAVE_CHECK_DMA
>> 363 extern int check_dma(unsigned int dmanr);
>> 364
>> 365 /* From PCI */
>> 366
>> 367 #ifdef CONFIG_PCI
>> 368 extern int isa_dma_bridge_buggy;
>> 369 #else
>> 370 #define isa_dma_bridge_buggy (0)
>> 371 #endif
>> 372
15 373
16 #endif /* __ASM_GENERIC_DMA_H */ !! 374 #endif /* _ASM_DMA_H */
17 375
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