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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 User DMA4 5 Copyright (C) 2003-2004 Kevin Thayer <nufan_wfk at yahoo.com>6 Copyright (C) 2004 Chris Kennedy <c@groovy.org>7 Copyright (C) 2005-2007 Hans Verkuil <hverkuil@xs4all.nl>8 9 */10 11#include "ivtv-driver.h"12#include "ivtv-udma.h"13 14void ivtv_udma_get_page_info(struct ivtv_dma_page_info *dma_page, unsigned long first, unsigned long size)15{16 dma_page->uaddr = first & PAGE_MASK;17 dma_page->offset = first & ~PAGE_MASK;18 dma_page->tail = 1 + ((first+size-1) & ~PAGE_MASK);19 dma_page->first = (first & PAGE_MASK) >> PAGE_SHIFT;20 dma_page->last = ((first+size-1) & PAGE_MASK) >> PAGE_SHIFT;21 dma_page->page_count = dma_page->last - dma_page->first + 1;22 if (dma_page->page_count == 1) dma_page->tail -= dma_page->offset;23}24 25int ivtv_udma_fill_sg_list (struct ivtv_user_dma *dma, struct ivtv_dma_page_info *dma_page, int map_offset)26{27 int i, offset;28 unsigned long flags;29 30 if (map_offset < 0)31 return map_offset;32 33 offset = dma_page->offset;34 35 /* Fill SG Array with new values */36 for (i = 0; i < dma_page->page_count; i++) {37 unsigned int len = (i == dma_page->page_count - 1) ?38 dma_page->tail : PAGE_SIZE - offset;39 40 if (PageHighMem(dma->map[map_offset])) {41 void *src;42 43 if (dma->bouncemap[map_offset] == NULL)44 dma->bouncemap[map_offset] = alloc_page(GFP_KERNEL);45 if (dma->bouncemap[map_offset] == NULL)46 return -1;47 local_irq_save(flags);48 src = kmap_atomic(dma->map[map_offset]) + offset;49 memcpy(page_address(dma->bouncemap[map_offset]) + offset, src, len);50 kunmap_atomic(src);51 local_irq_restore(flags);52 sg_set_page(&dma->SGlist[map_offset], dma->bouncemap[map_offset], len, offset);53 }54 else {55 sg_set_page(&dma->SGlist[map_offset], dma->map[map_offset], len, offset);56 }57 offset = 0;58 map_offset++;59 }60 return map_offset;61}62 63void ivtv_udma_fill_sg_array (struct ivtv_user_dma *dma, u32 buffer_offset, u32 buffer_offset_2, u32 split) {64 int i;65 struct scatterlist *sg;66 67 for_each_sg(dma->SGlist, sg, dma->SG_length, i) {68 dma->SGarray[i].size = cpu_to_le32(sg_dma_len(sg));69 dma->SGarray[i].src = cpu_to_le32(sg_dma_address(sg));70 dma->SGarray[i].dst = cpu_to_le32(buffer_offset);71 buffer_offset += sg_dma_len(sg);72 73 split -= sg_dma_len(sg);74 if (split == 0)75 buffer_offset = buffer_offset_2;76 }77}78 79/* User DMA Buffers */80void ivtv_udma_alloc(struct ivtv *itv)81{82 if (itv->udma.SG_handle == 0) {83 /* Map DMA Page Array Buffer */84 itv->udma.SG_handle = dma_map_single(&itv->pdev->dev,85 itv->udma.SGarray,86 sizeof(itv->udma.SGarray),87 DMA_TO_DEVICE);88 ivtv_udma_sync_for_cpu(itv);89 }90}91 92int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,93 void __user *userbuf, int size_in_bytes)94{95 struct ivtv_dma_page_info user_dma;96 struct ivtv_user_dma *dma = &itv->udma;97 int err;98 99 IVTV_DEBUG_DMA("ivtv_udma_setup, dst: 0x%08x\n", (unsigned int)ivtv_dest_addr);100 101 /* Still in USE */102 if (dma->SG_length || dma->page_count) {103 IVTV_DEBUG_WARN("ivtv_udma_setup: SG_length %d page_count %d still full?\n",104 dma->SG_length, dma->page_count);105 return -EBUSY;106 }107 108 ivtv_udma_get_page_info(&user_dma, (unsigned long)userbuf, size_in_bytes);109 110 if (user_dma.page_count <= 0) {111 IVTV_DEBUG_WARN("ivtv_udma_setup: Error %d page_count from %d bytes %d offset\n",112 user_dma.page_count, size_in_bytes, user_dma.offset);113 return -EINVAL;114 }115 116 /* Pin user pages for DMA Xfer */117 err = pin_user_pages_unlocked(user_dma.uaddr, user_dma.page_count,118 dma->map, 0);119 120 if (user_dma.page_count != err) {121 IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",122 err, user_dma.page_count);123 if (err >= 0) {124 unpin_user_pages(dma->map, err);125 return -EINVAL;126 }127 return err;128 }129 130 dma->page_count = user_dma.page_count;131 132 /* Fill SG List with new values */133 if (ivtv_udma_fill_sg_list(dma, &user_dma, 0) < 0) {134 IVTV_DEBUG_WARN("%s: could not allocate bounce buffers for highmem userspace buffers\n",135 __func__);136 unpin_user_pages(dma->map, dma->page_count);137 dma->page_count = 0;138 return -ENOMEM;139 }140 141 /* Map SG List */142 dma->SG_length = dma_map_sg(&itv->pdev->dev, dma->SGlist,143 dma->page_count, DMA_TO_DEVICE);144 if (!dma->SG_length) {145 IVTV_DEBUG_WARN("%s: DMA map error, SG_length is 0\n", __func__);146 unpin_user_pages(dma->map, dma->page_count);147 dma->page_count = 0;148 return -EINVAL;149 }150 151 /* Fill SG Array with new values */152 ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1);153 154 /* Tag SG Array with Interrupt Bit */155 dma->SGarray[dma->SG_length - 1].size |= cpu_to_le32(0x80000000);156 157 ivtv_udma_sync_for_device(itv);158 return dma->page_count;159}160 161void ivtv_udma_unmap(struct ivtv *itv)162{163 struct ivtv_user_dma *dma = &itv->udma;164 165 IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n");166 167 /* Nothing to free */168 if (dma->page_count == 0)169 return;170 171 /* Unmap Scatterlist */172 if (dma->SG_length) {173 dma_unmap_sg(&itv->pdev->dev, dma->SGlist, dma->page_count,174 DMA_TO_DEVICE);175 dma->SG_length = 0;176 }177 /* sync DMA */178 ivtv_udma_sync_for_cpu(itv);179 180 unpin_user_pages(dma->map, dma->page_count);181 dma->page_count = 0;182}183 184void ivtv_udma_free(struct ivtv *itv)185{186 int i;187 188 /* Unmap SG Array */189 if (itv->udma.SG_handle) {190 dma_unmap_single(&itv->pdev->dev, itv->udma.SG_handle,191 sizeof(itv->udma.SGarray), DMA_TO_DEVICE);192 }193 194 /* Unmap Scatterlist */195 if (itv->udma.SG_length) {196 dma_unmap_sg(&itv->pdev->dev, itv->udma.SGlist,197 itv->udma.page_count, DMA_TO_DEVICE);198 }199 200 for (i = 0; i < IVTV_DMA_SG_OSD_ENT; i++) {201 if (itv->udma.bouncemap[i])202 __free_page(itv->udma.bouncemap[i]);203 }204}205 206void ivtv_udma_start(struct ivtv *itv)207{208 IVTV_DEBUG_DMA("start UDMA\n");209 write_reg(itv->udma.SG_handle, IVTV_REG_DECDMAADDR);210 write_reg_sync(read_reg(IVTV_REG_DMAXFER) | 0x01, IVTV_REG_DMAXFER);211 set_bit(IVTV_F_I_DMA, &itv->i_flags);212 set_bit(IVTV_F_I_UDMA, &itv->i_flags);213 clear_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);214}215 216void ivtv_udma_prepare(struct ivtv *itv)217{218 unsigned long flags;219 220 spin_lock_irqsave(&itv->dma_reg_lock, flags);221 if (!test_bit(IVTV_F_I_DMA, &itv->i_flags))222 ivtv_udma_start(itv);223 else224 set_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);225 spin_unlock_irqrestore(&itv->dma_reg_lock, flags);226}227