1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/types.h>
3 #include <linux/kernel.h>
4 #include <linux/export.h>
5 #include <linux/ide.h>
6 #include <linux/scatterlist.h>
7 #include <linux/dma-mapping.h>
8 #include <linux/io.h>
9
10 /**
11 * config_drive_for_dma - attempt to activate IDE DMA
12 * @drive: the drive to place in DMA mode
13 *
14 * If the drive supports at least mode 2 DMA or UDMA of any kind
15 * then attempt to place it into DMA mode. Drives that are known to
16 * support DMA but predate the DMA properties or that are known
17 * to have DMA handling bugs are also set up appropriately based
18 * on the good/bad drive lists.
19 */
20
config_drive_for_dma(ide_drive_t * drive)21 int config_drive_for_dma(ide_drive_t *drive)
22 {
23 ide_hwif_t *hwif = drive->hwif;
24 u16 *id = drive->id;
25
26 if (drive->media != ide_disk) {
27 if (hwif->host_flags & IDE_HFLAG_NO_ATAPI_DMA)
28 return 0;
29 }
30
31 /*
32 * Enable DMA on any drive that has
33 * UltraDMA (mode 0/1/2/3/4/5/6) enabled
34 */
35 if ((id[ATA_ID_FIELD_VALID] & 4) &&
36 ((id[ATA_ID_UDMA_MODES] >> 8) & 0x7f))
37 return 1;
38
39 /*
40 * Enable DMA on any drive that has mode2 DMA
41 * (multi or single) enabled
42 */
43 if ((id[ATA_ID_MWDMA_MODES] & 0x404) == 0x404 ||
44 (id[ATA_ID_SWDMA_MODES] & 0x404) == 0x404)
45 return 1;
46
47 /* Consult the list of known "good" drives */
48 if (ide_dma_good_drive(drive))
49 return 1;
50
51 return 0;
52 }
53
ide_dma_sff_read_status(ide_hwif_t * hwif)54 u8 ide_dma_sff_read_status(ide_hwif_t *hwif)
55 {
56 unsigned long addr = hwif->dma_base + ATA_DMA_STATUS;
57
58 if (hwif->host_flags & IDE_HFLAG_MMIO)
59 return readb((void __iomem *)addr);
60 else
61 return inb(addr);
62 }
63 EXPORT_SYMBOL_GPL(ide_dma_sff_read_status);
64
ide_dma_sff_write_status(ide_hwif_t * hwif,u8 val)65 static void ide_dma_sff_write_status(ide_hwif_t *hwif, u8 val)
66 {
67 unsigned long addr = hwif->dma_base + ATA_DMA_STATUS;
68
69 if (hwif->host_flags & IDE_HFLAG_MMIO)
70 writeb(val, (void __iomem *)addr);
71 else
72 outb(val, addr);
73 }
74
75 /**
76 * ide_dma_host_set - Enable/disable DMA on a host
77 * @drive: drive to control
78 *
79 * Enable/disable DMA on an IDE controller following generic
80 * bus-mastering IDE controller behaviour.
81 */
82
ide_dma_host_set(ide_drive_t * drive,int on)83 void ide_dma_host_set(ide_drive_t *drive, int on)
84 {
85 ide_hwif_t *hwif = drive->hwif;
86 u8 unit = drive->dn & 1;
87 u8 dma_stat = hwif->dma_ops->dma_sff_read_status(hwif);
88
89 if (on)
90 dma_stat |= (1 << (5 + unit));
91 else
92 dma_stat &= ~(1 << (5 + unit));
93
94 ide_dma_sff_write_status(hwif, dma_stat);
95 }
96 EXPORT_SYMBOL_GPL(ide_dma_host_set);
97
98 /**
99 * ide_build_dmatable - build IDE DMA table
100 *
101 * ide_build_dmatable() prepares a dma request. We map the command
102 * to get the pci bus addresses of the buffers and then build up
103 * the PRD table that the IDE layer wants to be fed.
104 *
105 * Most chipsets correctly interpret a length of 0x0000 as 64KB,
106 * but at least one (e.g. CS5530) misinterprets it as zero (!).
107 * So we break the 64KB entry into two 32KB entries instead.
108 *
109 * Returns the number of built PRD entries if all went okay,
110 * returns 0 otherwise.
111 *
112 * May also be invoked from trm290.c
113 */
114
ide_build_dmatable(ide_drive_t * drive,struct ide_cmd * cmd)115 int ide_build_dmatable(ide_drive_t *drive, struct ide_cmd *cmd)
116 {
117 ide_hwif_t *hwif = drive->hwif;
118 __le32 *table = (__le32 *)hwif->dmatable_cpu;
119 unsigned int count = 0;
120 int i;
121 struct scatterlist *sg;
122 u8 is_trm290 = !!(hwif->host_flags & IDE_HFLAG_TRM290);
123
124 for_each_sg(hwif->sg_table, sg, cmd->sg_nents, i) {
125 u32 cur_addr, cur_len, xcount, bcount;
126
127 cur_addr = sg_dma_address(sg);
128 cur_len = sg_dma_len(sg);
129
130 /*
131 * Fill in the dma table, without crossing any 64kB boundaries.
132 * Most hardware requires 16-bit alignment of all blocks,
133 * but the trm290 requires 32-bit alignment.
134 */
135
136 while (cur_len) {
137 if (count++ >= PRD_ENTRIES)
138 goto use_pio_instead;
139
140 bcount = 0x10000 - (cur_addr & 0xffff);
141 if (bcount > cur_len)
142 bcount = cur_len;
143 *table++ = cpu_to_le32(cur_addr);
144 xcount = bcount & 0xffff;
145 if (is_trm290)
146 xcount = ((xcount >> 2) - 1) << 16;
147 else if (xcount == 0x0000) {
148 if (count++ >= PRD_ENTRIES)
149 goto use_pio_instead;
150 *table++ = cpu_to_le32(0x8000);
151 *table++ = cpu_to_le32(cur_addr + 0x8000);
152 xcount = 0x8000;
153 }
154 *table++ = cpu_to_le32(xcount);
155 cur_addr += bcount;
156 cur_len -= bcount;
157 }
158 }
159
160 if (count) {
161 if (!is_trm290)
162 *--table |= cpu_to_le32(0x80000000);
163 return count;
164 }
165
166 use_pio_instead:
167 printk(KERN_ERR "%s: %s\n", drive->name,
168 count ? "DMA table too small" : "empty DMA table?");
169
170 return 0; /* revert to PIO for this request */
171 }
172 EXPORT_SYMBOL_GPL(ide_build_dmatable);
173
174 /**
175 * ide_dma_setup - begin a DMA phase
176 * @drive: target device
177 * @cmd: command
178 *
179 * Build an IDE DMA PRD (IDE speak for scatter gather table)
180 * and then set up the DMA transfer registers for a device
181 * that follows generic IDE PCI DMA behaviour. Controllers can
182 * override this function if they need to
183 *
184 * Returns 0 on success. If a PIO fallback is required then 1
185 * is returned.
186 */
187
ide_dma_setup(ide_drive_t * drive,struct ide_cmd * cmd)188 int ide_dma_setup(ide_drive_t *drive, struct ide_cmd *cmd)
189 {
190 ide_hwif_t *hwif = drive->hwif;
191 u8 mmio = (hwif->host_flags & IDE_HFLAG_MMIO) ? 1 : 0;
192 u8 rw = (cmd->tf_flags & IDE_TFLAG_WRITE) ? 0 : ATA_DMA_WR;
193 u8 dma_stat;
194
195 /* fall back to pio! */
196 if (ide_build_dmatable(drive, cmd) == 0) {
197 ide_map_sg(drive, cmd);
198 return 1;
199 }
200
201 /* PRD table */
202 if (mmio)
203 writel(hwif->dmatable_dma,
204 (void __iomem *)(hwif->dma_base + ATA_DMA_TABLE_OFS));
205 else
206 outl(hwif->dmatable_dma, hwif->dma_base + ATA_DMA_TABLE_OFS);
207
208 /* specify r/w */
209 if (mmio)
210 writeb(rw, (void __iomem *)(hwif->dma_base + ATA_DMA_CMD));
211 else
212 outb(rw, hwif->dma_base + ATA_DMA_CMD);
213
214 /* read DMA status for INTR & ERROR flags */
215 dma_stat = hwif->dma_ops->dma_sff_read_status(hwif);
216
217 /* clear INTR & ERROR flags */
218 ide_dma_sff_write_status(hwif, dma_stat | ATA_DMA_ERR | ATA_DMA_INTR);
219
220 return 0;
221 }
222 EXPORT_SYMBOL_GPL(ide_dma_setup);
223
224 /**
225 * ide_dma_sff_timer_expiry - handle a DMA timeout
226 * @drive: Drive that timed out
227 *
228 * An IDE DMA transfer timed out. In the event of an error we ask
229 * the driver to resolve the problem, if a DMA transfer is still
230 * in progress we continue to wait (arguably we need to add a
231 * secondary 'I don't care what the drive thinks' timeout here)
232 * Finally if we have an interrupt we let it complete the I/O.
233 * But only one time - we clear expiry and if it's still not
234 * completed after WAIT_CMD, we error and retry in PIO.
235 * This can occur if an interrupt is lost or due to hang or bugs.
236 */
237
ide_dma_sff_timer_expiry(ide_drive_t * drive)238 int ide_dma_sff_timer_expiry(ide_drive_t *drive)
239 {
240 ide_hwif_t *hwif = drive->hwif;
241 u8 dma_stat = hwif->dma_ops->dma_sff_read_status(hwif);
242
243 printk(KERN_WARNING "%s: %s: DMA status (0x%02x)\n",
244 drive->name, __func__, dma_stat);
245
246 if ((dma_stat & 0x18) == 0x18) /* BUSY Stupid Early Timer !! */
247 return WAIT_CMD;
248
249 hwif->expiry = NULL; /* one free ride for now */
250
251 if (dma_stat & ATA_DMA_ERR) /* ERROR */
252 return -1;
253
254 if (dma_stat & ATA_DMA_ACTIVE) /* DMAing */
255 return WAIT_CMD;
256
257 if (dma_stat & ATA_DMA_INTR) /* Got an Interrupt */
258 return WAIT_CMD;
259
260 return 0; /* Status is unknown -- reset the bus */
261 }
262 EXPORT_SYMBOL_GPL(ide_dma_sff_timer_expiry);
263
ide_dma_start(ide_drive_t * drive)264 void ide_dma_start(ide_drive_t *drive)
265 {
266 ide_hwif_t *hwif = drive->hwif;
267 u8 dma_cmd;
268
269 /* Note that this is done *after* the cmd has
270 * been issued to the drive, as per the BM-IDE spec.
271 * The Promise Ultra33 doesn't work correctly when
272 * we do this part before issuing the drive cmd.
273 */
274 if (hwif->host_flags & IDE_HFLAG_MMIO) {
275 dma_cmd = readb((void __iomem *)(hwif->dma_base + ATA_DMA_CMD));
276 writeb(dma_cmd | ATA_DMA_START,
277 (void __iomem *)(hwif->dma_base + ATA_DMA_CMD));
278 } else {
279 dma_cmd = inb(hwif->dma_base + ATA_DMA_CMD);
280 outb(dma_cmd | ATA_DMA_START, hwif->dma_base + ATA_DMA_CMD);
281 }
282 }
283 EXPORT_SYMBOL_GPL(ide_dma_start);
284
285 /* returns 1 on error, 0 otherwise */
ide_dma_end(ide_drive_t * drive)286 int ide_dma_end(ide_drive_t *drive)
287 {
288 ide_hwif_t *hwif = drive->hwif;
289 u8 dma_stat = 0, dma_cmd = 0;
290
291 /* stop DMA */
292 if (hwif->host_flags & IDE_HFLAG_MMIO) {
293 dma_cmd = readb((void __iomem *)(hwif->dma_base + ATA_DMA_CMD));
294 writeb(dma_cmd & ~ATA_DMA_START,
295 (void __iomem *)(hwif->dma_base + ATA_DMA_CMD));
296 } else {
297 dma_cmd = inb(hwif->dma_base + ATA_DMA_CMD);
298 outb(dma_cmd & ~ATA_DMA_START, hwif->dma_base + ATA_DMA_CMD);
299 }
300
301 /* get DMA status */
302 dma_stat = hwif->dma_ops->dma_sff_read_status(hwif);
303
304 /* clear INTR & ERROR bits */
305 ide_dma_sff_write_status(hwif, dma_stat | ATA_DMA_ERR | ATA_DMA_INTR);
306
307 #define CHECK_DMA_MASK (ATA_DMA_ACTIVE | ATA_DMA_ERR | ATA_DMA_INTR)
308
309 /* verify good DMA status */
310 if ((dma_stat & CHECK_DMA_MASK) != ATA_DMA_INTR)
311 return 0x10 | dma_stat;
312 return 0;
313 }
314 EXPORT_SYMBOL_GPL(ide_dma_end);
315
316 /* returns 1 if dma irq issued, 0 otherwise */
ide_dma_test_irq(ide_drive_t * drive)317 int ide_dma_test_irq(ide_drive_t *drive)
318 {
319 ide_hwif_t *hwif = drive->hwif;
320 u8 dma_stat = hwif->dma_ops->dma_sff_read_status(hwif);
321
322 return (dma_stat & ATA_DMA_INTR) ? 1 : 0;
323 }
324 EXPORT_SYMBOL_GPL(ide_dma_test_irq);
325
326 const struct ide_dma_ops sff_dma_ops = {
327 .dma_host_set = ide_dma_host_set,
328 .dma_setup = ide_dma_setup,
329 .dma_start = ide_dma_start,
330 .dma_end = ide_dma_end,
331 .dma_test_irq = ide_dma_test_irq,
332 .dma_lost_irq = ide_dma_lost_irq,
333 .dma_timer_expiry = ide_dma_sff_timer_expiry,
334 .dma_sff_read_status = ide_dma_sff_read_status,
335 };
336 EXPORT_SYMBOL_GPL(sff_dma_ops);
337
