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