xref: /netbsd-src/sys/external/bsd/drm2/linux/linux_sgt.c (revision f6111af65ebda457f064704b6011d7209da06998)
1*f6111af6Sriastradh /*	$NetBSD: linux_sgt.c,v 1.4 2021/12/24 15:08:31 riastradh Exp $	*/
20be6acb1Sriastradh 
30be6acb1Sriastradh /*-
40be6acb1Sriastradh  * Copyright (c) 2021 The NetBSD Foundation, Inc.
50be6acb1Sriastradh  * All rights reserved.
60be6acb1Sriastradh  *
70be6acb1Sriastradh  * Redistribution and use in source and binary forms, with or without
80be6acb1Sriastradh  * modification, are permitted provided that the following conditions
90be6acb1Sriastradh  * are met:
100be6acb1Sriastradh  * 1. Redistributions of source code must retain the above copyright
110be6acb1Sriastradh  *    notice, this list of conditions and the following disclaimer.
120be6acb1Sriastradh  * 2. Redistributions in binary form must reproduce the above copyright
130be6acb1Sriastradh  *    notice, this list of conditions and the following disclaimer in the
140be6acb1Sriastradh  *    documentation and/or other materials provided with the distribution.
150be6acb1Sriastradh  *
160be6acb1Sriastradh  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
170be6acb1Sriastradh  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
180be6acb1Sriastradh  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
190be6acb1Sriastradh  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
200be6acb1Sriastradh  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
210be6acb1Sriastradh  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
220be6acb1Sriastradh  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
230be6acb1Sriastradh  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
240be6acb1Sriastradh  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
250be6acb1Sriastradh  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
260be6acb1Sriastradh  * POSSIBILITY OF SUCH DAMAGE.
270be6acb1Sriastradh  */
280be6acb1Sriastradh 
290be6acb1Sriastradh #include <sys/cdefs.h>
30*f6111af6Sriastradh __KERNEL_RCSID(0, "$NetBSD: linux_sgt.c,v 1.4 2021/12/24 15:08:31 riastradh Exp $");
310be6acb1Sriastradh 
320be6acb1Sriastradh #include <sys/bus.h>
330be6acb1Sriastradh #include <sys/errno.h>
340be6acb1Sriastradh 
350be6acb1Sriastradh #include <drm/bus_dma_hacks.h>
360be6acb1Sriastradh 
370be6acb1Sriastradh #include <linux/dma-mapping.h>
380be6acb1Sriastradh #include <linux/gfp.h>
390be6acb1Sriastradh #include <linux/mm_types.h>
400be6acb1Sriastradh #include <linux/scatterlist.h>
410be6acb1Sriastradh #include <linux/slab.h>
420be6acb1Sriastradh 
430be6acb1Sriastradh int
sg_alloc_table(struct sg_table * sgt,unsigned npgs,gfp_t gfp)440be6acb1Sriastradh sg_alloc_table(struct sg_table *sgt, unsigned npgs, gfp_t gfp)
450be6acb1Sriastradh {
460be6acb1Sriastradh 
470be6acb1Sriastradh 	sgt->sgl->sg_pgs = kcalloc(npgs, sizeof(sgt->sgl->sg_pgs[0]), gfp);
480be6acb1Sriastradh 	if (sgt->sgl->sg_pgs == NULL)
490be6acb1Sriastradh 		return -ENOMEM;
500be6acb1Sriastradh 	sgt->sgl->sg_npgs = sgt->nents = npgs;
510be6acb1Sriastradh 	sgt->sgl->sg_dmamap = NULL;
520be6acb1Sriastradh 
530be6acb1Sriastradh 	return 0;
540be6acb1Sriastradh }
550be6acb1Sriastradh 
560be6acb1Sriastradh int
__sg_alloc_table_from_pages(struct sg_table * sgt,struct page ** pgs,unsigned npgs,bus_size_t offset,bus_size_t size,unsigned maxseg,gfp_t gfp)570be6acb1Sriastradh __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pgs,
580be6acb1Sriastradh     unsigned npgs, bus_size_t offset, bus_size_t size, unsigned maxseg,
590be6acb1Sriastradh     gfp_t gfp)
600be6acb1Sriastradh {
610be6acb1Sriastradh 	unsigned i;
620be6acb1Sriastradh 	int ret;
630be6acb1Sriastradh 
640be6acb1Sriastradh 	KASSERT(offset == 0);
650be6acb1Sriastradh 	KASSERT(size == (bus_size_t)npgs << PAGE_SHIFT);
660be6acb1Sriastradh 
670be6acb1Sriastradh 	ret = sg_alloc_table(sgt, npgs, gfp);
680be6acb1Sriastradh 	if (ret)
690be6acb1Sriastradh 		return ret;
700be6acb1Sriastradh 
710be6acb1Sriastradh 	for (i = 0; i < npgs; i++)
720be6acb1Sriastradh 		sgt->sgl->sg_pgs[i] = pgs[i];
730be6acb1Sriastradh 
740be6acb1Sriastradh 	return 0;
750be6acb1Sriastradh }
760be6acb1Sriastradh 
770be6acb1Sriastradh int
sg_alloc_table_from_pages(struct sg_table * sgt,struct page ** pgs,unsigned npgs,bus_size_t offset,bus_size_t size,gfp_t gfp)780be6acb1Sriastradh sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pgs,
790be6acb1Sriastradh     unsigned npgs, bus_size_t offset, bus_size_t size, gfp_t gfp)
800be6acb1Sriastradh {
810be6acb1Sriastradh 
820be6acb1Sriastradh 	return __sg_alloc_table_from_pages(sgt, pgs, npgs, offset, size,
830be6acb1Sriastradh 	    -1, gfp);
840be6acb1Sriastradh }
850be6acb1Sriastradh 
860be6acb1Sriastradh int
sg_alloc_table_from_bus_dmamem(struct sg_table * sgt,bus_dma_tag_t dmat,const bus_dma_segment_t * seg,int nseg,gfp_t gfp)870be6acb1Sriastradh sg_alloc_table_from_bus_dmamem(struct sg_table *sgt, bus_dma_tag_t dmat,
880be6acb1Sriastradh     const bus_dma_segment_t *seg, int nseg, gfp_t gfp)
890be6acb1Sriastradh {
900be6acb1Sriastradh 	int i, npgs = 0;
910be6acb1Sriastradh 	int ret;
920be6acb1Sriastradh 
930be6acb1Sriastradh 	KASSERT(nseg >= 1);
940be6acb1Sriastradh 
950be6acb1Sriastradh 	/*
960be6acb1Sriastradh 	 * Count the number of pages.  Some segments may span multiple
970be6acb1Sriastradh 	 * contiguous pages.
980be6acb1Sriastradh 	 */
990be6acb1Sriastradh 	for (i = 0; i < nseg; i++) {
1000be6acb1Sriastradh 		bus_size_t len = seg[i].ds_len;
1010be6acb1Sriastradh 		for (; len >= PAGE_SIZE; len -= PAGE_SIZE, npgs++) {
1020be6acb1Sriastradh 			if (npgs == INT_MAX)
1030be6acb1Sriastradh 				return -ENOMEM;
1040be6acb1Sriastradh 		}
1050be6acb1Sriastradh 		KASSERTMSG(len == 0, "misaligned segment length: %ju\n",
1060be6acb1Sriastradh 		    (uintmax_t)seg[i].ds_len);
1070be6acb1Sriastradh 	}
1080be6acb1Sriastradh 
1090be6acb1Sriastradh 	ret = sg_alloc_table(sgt, npgs, gfp);
1100be6acb1Sriastradh 	if (ret)
1110be6acb1Sriastradh 		return ret;
1120be6acb1Sriastradh 
1130be6acb1Sriastradh 	/* XXX errno NetBSD->Linux */
1140be6acb1Sriastradh 	ret = -bus_dmamem_export_pages(dmat, seg, nseg, sgt->sgl->sg_pgs,
1150be6acb1Sriastradh 	    sgt->sgl->sg_npgs);
1160be6acb1Sriastradh 	if (ret)
1170be6acb1Sriastradh 		goto out;
1180be6acb1Sriastradh 
1190be6acb1Sriastradh 	/* Success!  */
1200be6acb1Sriastradh 	ret = 0;
1210be6acb1Sriastradh 
1220be6acb1Sriastradh out:	if (ret)
1230be6acb1Sriastradh 		sg_free_table(sgt);
1240be6acb1Sriastradh 	return ret;
1250be6acb1Sriastradh }
1260be6acb1Sriastradh 
1270be6acb1Sriastradh void
sg_free_table(struct sg_table * sgt)1280be6acb1Sriastradh sg_free_table(struct sg_table *sgt)
1290be6acb1Sriastradh {
1300be6acb1Sriastradh 
131dd51f0c2Sriastradh 	if (sgt->sgl->sg_dmamap) {
132dd51f0c2Sriastradh 		KASSERT(sgt->sgl->sg_dmat);
133dd51f0c2Sriastradh 		bus_dmamap_destroy(sgt->sgl->sg_dmat, sgt->sgl->sg_dmamap);
134dd51f0c2Sriastradh 	}
1350be6acb1Sriastradh 	kfree(sgt->sgl->sg_pgs);
1360be6acb1Sriastradh 	sgt->sgl->sg_pgs = NULL;
1370be6acb1Sriastradh 	sgt->sgl->sg_npgs = 0;
1380be6acb1Sriastradh }
1390be6acb1Sriastradh 
1400be6acb1Sriastradh int
dma_map_sg(bus_dma_tag_t dmat,struct scatterlist * sg,int nents,int dir)1410be6acb1Sriastradh dma_map_sg(bus_dma_tag_t dmat, struct scatterlist *sg, int nents, int dir)
1420be6acb1Sriastradh {
1430be6acb1Sriastradh 
1440be6acb1Sriastradh 	return dma_map_sg_attrs(dmat, sg, nents, dir, 0);
1450be6acb1Sriastradh }
1460be6acb1Sriastradh 
1470be6acb1Sriastradh int
dma_map_sg_attrs(bus_dma_tag_t dmat,struct scatterlist * sg,int nents,int dir,int attrs)1480be6acb1Sriastradh dma_map_sg_attrs(bus_dma_tag_t dmat, struct scatterlist *sg, int nents,
1490be6acb1Sriastradh     int dir, int attrs)
1500be6acb1Sriastradh {
1510be6acb1Sriastradh 	int flags = 0;
1520be6acb1Sriastradh 	bool loaded = false;
1530be6acb1Sriastradh 	int ret, error = 0;
1540be6acb1Sriastradh 
1550be6acb1Sriastradh 	KASSERT(sg->sg_dmamap == NULL);
156*f6111af6Sriastradh 	KASSERT(sg->sg_npgs);
1570be6acb1Sriastradh 	KASSERT(nents >= 1);
1580be6acb1Sriastradh 
1590be6acb1Sriastradh 	switch (dir) {
1600be6acb1Sriastradh 	case DMA_TO_DEVICE:
1610be6acb1Sriastradh 		flags |= BUS_DMA_WRITE;
1620be6acb1Sriastradh 		break;
1630be6acb1Sriastradh 	case DMA_FROM_DEVICE:
1640be6acb1Sriastradh 		flags |= BUS_DMA_READ;
1650be6acb1Sriastradh 		break;
1660be6acb1Sriastradh 	case DMA_BIDIRECTIONAL:
167e04c635fSriastradh 		flags |= BUS_DMA_READ|BUS_DMA_WRITE;
1680be6acb1Sriastradh 		break;
1690be6acb1Sriastradh 	case DMA_NONE:
170e04c635fSriastradh 	default:
1710be6acb1Sriastradh 		panic("invalid DMA direction %d", dir);
1720be6acb1Sriastradh 	}
1730be6acb1Sriastradh 
1740be6acb1Sriastradh 	error = bus_dmamap_create(dmat, (bus_size_t)sg->sg_npgs << PAGE_SHIFT,
1750be6acb1Sriastradh 	    nents, PAGE_SIZE, 0, BUS_DMA_WAITOK, &sg->sg_dmamap);
1760be6acb1Sriastradh 	if (error)
1770be6acb1Sriastradh 		goto out;
1780be6acb1Sriastradh 	KASSERT(sg->sg_dmamap);
1790be6acb1Sriastradh 
1800be6acb1Sriastradh 	error = bus_dmamap_load_pages(dmat, sg->sg_dmamap, sg->sg_pgs,
1810be6acb1Sriastradh 	    (bus_size_t)sg->sg_npgs << PAGE_SHIFT, BUS_DMA_WAITOK|flags);
1820be6acb1Sriastradh 	if (error)
1830be6acb1Sriastradh 		goto out;
1840be6acb1Sriastradh 	loaded = true;
1850be6acb1Sriastradh 
1860be6acb1Sriastradh 	/* Success! */
1870be6acb1Sriastradh 	KASSERT(sg->sg_dmamap->dm_nsegs > 0);
1880be6acb1Sriastradh 	KASSERT(sg->sg_dmamap->dm_nsegs <= nents);
189dd51f0c2Sriastradh 	sg->sg_dmat = dmat;
1900be6acb1Sriastradh 	ret = sg->sg_dmamap->dm_nsegs;
191e04c635fSriastradh 	error = 0;
1920be6acb1Sriastradh 
1930be6acb1Sriastradh out:	if (error) {
1940be6acb1Sriastradh 		if (loaded)
1950be6acb1Sriastradh 			bus_dmamap_unload(dmat, sg->sg_dmamap);
1960be6acb1Sriastradh 		loaded = false;
1970be6acb1Sriastradh 		if (sg->sg_dmamap)
1980be6acb1Sriastradh 			bus_dmamap_destroy(dmat, sg->sg_dmamap);
1990be6acb1Sriastradh 		sg->sg_dmamap = NULL;
2000be6acb1Sriastradh 		ret = 0;
2010be6acb1Sriastradh 	}
2020be6acb1Sriastradh 	return ret;
2030be6acb1Sriastradh }
2040be6acb1Sriastradh 
2050be6acb1Sriastradh void
dma_unmap_sg(bus_dma_tag_t dmat,struct scatterlist * sg,int nents,int dir)2060be6acb1Sriastradh dma_unmap_sg(bus_dma_tag_t dmat, struct scatterlist *sg, int nents, int dir)
2070be6acb1Sriastradh {
2080be6acb1Sriastradh 
2090be6acb1Sriastradh 	dma_unmap_sg_attrs(dmat, sg, nents, dir, 0);
2100be6acb1Sriastradh }
2110be6acb1Sriastradh 
2120be6acb1Sriastradh void
dma_unmap_sg_attrs(bus_dma_tag_t dmat,struct scatterlist * sg,int nents,int dir,int attrs)2130be6acb1Sriastradh dma_unmap_sg_attrs(bus_dma_tag_t dmat, struct scatterlist *sg, int nents,
2140be6acb1Sriastradh     int dir, int attrs)
2150be6acb1Sriastradh {
2160be6acb1Sriastradh 
217*f6111af6Sriastradh 	KASSERT(sg->sg_dmat == dmat);
218*f6111af6Sriastradh 
2190be6acb1Sriastradh 	bus_dmamap_unload(dmat, sg->sg_dmamap);
2200be6acb1Sriastradh 	bus_dmamap_destroy(dmat, sg->sg_dmamap);
2210be6acb1Sriastradh 	sg->sg_dmamap = NULL;
2220be6acb1Sriastradh }
2230be6acb1Sriastradh 
2240be6acb1Sriastradh bus_addr_t
sg_dma_address(const struct scatterlist * sg)2250be6acb1Sriastradh sg_dma_address(const struct scatterlist *sg)
2260be6acb1Sriastradh {
2270be6acb1Sriastradh 
2280be6acb1Sriastradh 	KASSERT(sg->sg_dmamap->dm_nsegs == 1);
2290be6acb1Sriastradh 	return sg->sg_dmamap->dm_segs[0].ds_addr;
2300be6acb1Sriastradh }
2310be6acb1Sriastradh 
2320be6acb1Sriastradh bus_size_t
sg_dma_len(const struct scatterlist * sg)2330be6acb1Sriastradh sg_dma_len(const struct scatterlist *sg)
2340be6acb1Sriastradh {
2350be6acb1Sriastradh 
2360be6acb1Sriastradh 	KASSERT(sg->sg_dmamap->dm_nsegs == 1);
2370be6acb1Sriastradh 	return sg->sg_dmamap->dm_segs[0].ds_len;
2380be6acb1Sriastradh }
239