1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 User DMA 4 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 14 void 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 25 int 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 63 void 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 */ 80 void 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 92 int 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 unpin_user_pages(dma->map, dma->page_count); 135 dma->page_count = 0; 136 return -ENOMEM; 137 } 138 139 /* Map SG List */ 140 dma->SG_length = dma_map_sg(&itv->pdev->dev, dma->SGlist, 141 dma->page_count, DMA_TO_DEVICE); 142 143 /* Fill SG Array with new values */ 144 ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1); 145 146 /* Tag SG Array with Interrupt Bit */ 147 dma->SGarray[dma->SG_length - 1].size |= cpu_to_le32(0x80000000); 148 149 ivtv_udma_sync_for_device(itv); 150 return dma->page_count; 151 } 152 153 void ivtv_udma_unmap(struct ivtv *itv) 154 { 155 struct ivtv_user_dma *dma = &itv->udma; 156 157 IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n"); 158 159 /* Nothing to free */ 160 if (dma->page_count == 0) 161 return; 162 163 /* Unmap Scatterlist */ 164 if (dma->SG_length) { 165 dma_unmap_sg(&itv->pdev->dev, dma->SGlist, dma->page_count, 166 DMA_TO_DEVICE); 167 dma->SG_length = 0; 168 } 169 /* sync DMA */ 170 ivtv_udma_sync_for_cpu(itv); 171 172 unpin_user_pages(dma->map, dma->page_count); 173 dma->page_count = 0; 174 } 175 176 void ivtv_udma_free(struct ivtv *itv) 177 { 178 int i; 179 180 /* Unmap SG Array */ 181 if (itv->udma.SG_handle) { 182 dma_unmap_single(&itv->pdev->dev, itv->udma.SG_handle, 183 sizeof(itv->udma.SGarray), DMA_TO_DEVICE); 184 } 185 186 /* Unmap Scatterlist */ 187 if (itv->udma.SG_length) { 188 dma_unmap_sg(&itv->pdev->dev, itv->udma.SGlist, 189 itv->udma.page_count, DMA_TO_DEVICE); 190 } 191 192 for (i = 0; i < IVTV_DMA_SG_OSD_ENT; i++) { 193 if (itv->udma.bouncemap[i]) 194 __free_page(itv->udma.bouncemap[i]); 195 } 196 } 197 198 void ivtv_udma_start(struct ivtv *itv) 199 { 200 IVTV_DEBUG_DMA("start UDMA\n"); 201 write_reg(itv->udma.SG_handle, IVTV_REG_DECDMAADDR); 202 write_reg_sync(read_reg(IVTV_REG_DMAXFER) | 0x01, IVTV_REG_DMAXFER); 203 set_bit(IVTV_F_I_DMA, &itv->i_flags); 204 set_bit(IVTV_F_I_UDMA, &itv->i_flags); 205 clear_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags); 206 } 207 208 void ivtv_udma_prepare(struct ivtv *itv) 209 { 210 unsigned long flags; 211 212 spin_lock_irqsave(&itv->dma_reg_lock, flags); 213 if (!test_bit(IVTV_F_I_DMA, &itv->i_flags)) 214 ivtv_udma_start(itv); 215 else 216 set_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags); 217 spin_unlock_irqrestore(&itv->dma_reg_lock, flags); 218 } 219