1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
77 /* high byte of address is stored in this port for i-th dma channel */
81  * Setup a DMA channel's bounce buffer.
90 		panic("isa_dma_init: channel out of range");  in isa_dma_init()
104 			   1ul, chan & 4 ? 0x20000ul : 0x10000ul);  in isa_dma_init()
112 	 * If a DMA channel is shared, both drivers have to call isa_dma_init  in isa_dma_init()
134  * Register a DMA channel's usage.  Usually called from a device driver
142 		panic("isa_dma_acquire: channel out of range");  in isa_dma_acquire()
147 		printf("isa_dma_acquire: channel %d already in use\n", chan);  in isa_dma_acquire()
159  * Unregister a DMA channel's usage.  Usually called from a device driver
167 		panic("isa_dma_release: channel out of range");  in isa_dma_release()
171 		printf("isa_dma_release: channel %d not in use\n", chan);  in isa_dma_release()
193  * isa_dmacascade(): program 8237 DMA controller channel to accept
201 		panic("isa_dmacascade: channel out of range");  in isa_dmacascade()
205 	/* set dma channel mode, and set dma channel mode */  in isa_dmacascade()
206 	if ((chan & 4) == 0) {  in isa_dmacascade()
217  * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
232 		panic("isa_dmastart: channel out of range");  in isa_dmastart()
234 	if ((chan < 4 && nbytes > (1<<16))  in isa_dmastart()
235 	    || (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1)))  in isa_dmastart()
240 		printf("isa_dmastart: channel %d not acquired\n", chan);  in isa_dmastart()
252 		printf("isa_dmastart: channel %d busy\n", chan);  in isa_dmastart()
279 	if ((chan & 4) == 0) {  in isa_dmastart()
284 		/* set dma channel mode, and reset address ff */  in isa_dmastart()
307 		outb(waport + 1, --nbytes);  in isa_dmastart()
310 		/* unmask channel */  in isa_dmastart()
314 		 * Program one of DMA channels 4..7.  These are  in isa_dmastart()
317 		/* set dma channel mode, and reset address ff */  in isa_dmastart()
334 		waport = DMA2_CHN(chan - 4);  in isa_dmastart()
341 		outb(waport + 2, --nbytes);  in isa_dmastart()
344 		/* unmask channel */  in isa_dmastart()
355 		panic("isa_dmadone: channel out of range");  in isa_dmadone()
358 		printf("isa_dmadone: channel %d not acquired\n", chan);  in isa_dmadone()
364 		printf("isa_dmadone: channel %d not busy\n", chan);  in isa_dmadone()
367 		outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);  in isa_dmadone()
382  * (non-contiguous physical pages, outside of bus address space,
392 	u_int dma_pgmsk = (chan & 4) ?  ~(128*1024-1) : ~(64*1024-1);  in isa_dmarangecheck()
414  * Query the progress of a transfer on a DMA channel.
427  * - read low1
429  * - read high1
431  * - read low2
433  * - read high2
442  * or -1 if the channel requested is not active.
454 	/* channel active? */  in isa_dmastatus_locked()
456 		printf("isa_dmastatus: channel %d not active\n", chan);  in isa_dmastatus_locked()
457 		return(-1);  in isa_dmastatus_locked()
459 	/* channel busy? */  in isa_dmastatus_locked()
464 	    return -2 ;  in isa_dmastatus_locked()
466 	if (chan < 4) {			/* low DMA controller */  in isa_dmastatus_locked()
471 		waport = DMA2_CHN(chan - 4) + 2;  in isa_dmastatus_locked()
494 	if (chan >= 4)			/* high channels move words */  in isa_dmastatus_locked()
518 	if (chan < 4)  in isa_dmatc()
534 		printf("isa_dmastop: channel %d not acquired\n", chan);    in isa_dmastop()
540 		return -2 ;  in isa_dmastop()
543 	if ((chan & 4) == 0) {  in isa_dmastop()
544 		outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);  in isa_dmastop()
546 		outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);  in isa_dmastop()