avoid endless loops in lib/swiotlb.c
[wrt350n-kernel.git] / arch / cris / arch-v10 / kernel / dma.c
blobeb1fa0d2b49f92f89c80030c6d81552eb02d3a27
1 /* Wrapper for DMA channel allocator that updates DMA client muxing.
2 * Copyright 2004-2007, Axis Communications AB
3 */
5 #include <linux/kernel.h>
6 #include <linux/module.h>
7 #include <linux/errno.h>
9 #include <asm/dma.h>
10 #include <asm/arch/svinto.h>
12 /* Macro to access ETRAX 100 registers */
13 #define SETS(var, reg, field, val) var = (var & ~IO_MASK_(reg##_, field##_)) | \
14 IO_STATE_(reg##_, field##_, _##val)
17 static char used_dma_channels[MAX_DMA_CHANNELS];
18 static const char * used_dma_channels_users[MAX_DMA_CHANNELS];
20 int cris_request_dma(unsigned int dmanr, const char * device_id,
21 unsigned options, enum dma_owner owner)
23 unsigned long flags;
24 unsigned long int gens;
25 int fail = -EINVAL;
27 if ((dmanr < 0) || (dmanr >= MAX_DMA_CHANNELS)) {
28 printk(KERN_CRIT "cris_request_dma: invalid DMA channel %u\n", dmanr);
29 return -EINVAL;
32 local_irq_save(flags);
33 if (used_dma_channels[dmanr]) {
34 local_irq_restore(flags);
35 if (options & DMA_VERBOSE_ON_ERROR) {
36 printk(KERN_CRIT "Failed to request DMA %i for %s, already allocated by %s\n", dmanr, device_id, used_dma_channels_users[dmanr]);
38 if (options & DMA_PANIC_ON_ERROR) {
39 panic("request_dma error!");
41 return -EBUSY;
44 gens = genconfig_shadow;
46 switch(owner)
48 case dma_eth:
49 if ((dmanr != NETWORK_TX_DMA_NBR) &&
50 (dmanr != NETWORK_RX_DMA_NBR)) {
51 printk(KERN_CRIT "Invalid DMA channel for eth\n");
52 goto bail;
54 break;
55 case dma_ser0:
56 if (dmanr == SER0_TX_DMA_NBR) {
57 SETS(gens, R_GEN_CONFIG, dma6, serial0);
58 } else if (dmanr == SER0_RX_DMA_NBR) {
59 SETS(gens, R_GEN_CONFIG, dma7, serial0);
60 } else {
61 printk(KERN_CRIT "Invalid DMA channel for ser0\n");
62 goto bail;
64 break;
65 case dma_ser1:
66 if (dmanr == SER1_TX_DMA_NBR) {
67 SETS(gens, R_GEN_CONFIG, dma8, serial1);
68 } else if (dmanr == SER1_RX_DMA_NBR) {
69 SETS(gens, R_GEN_CONFIG, dma9, serial1);
70 } else {
71 printk(KERN_CRIT "Invalid DMA channel for ser1\n");
72 goto bail;
74 break;
75 case dma_ser2:
76 if (dmanr == SER2_TX_DMA_NBR) {
77 SETS(gens, R_GEN_CONFIG, dma2, serial2);
78 } else if (dmanr == SER2_RX_DMA_NBR) {
79 SETS(gens, R_GEN_CONFIG, dma3, serial2);
80 } else {
81 printk(KERN_CRIT "Invalid DMA channel for ser2\n");
82 goto bail;
84 break;
85 case dma_ser3:
86 if (dmanr == SER3_TX_DMA_NBR) {
87 SETS(gens, R_GEN_CONFIG, dma4, serial3);
88 } else if (dmanr == SER3_RX_DMA_NBR) {
89 SETS(gens, R_GEN_CONFIG, dma5, serial3);
90 } else {
91 printk(KERN_CRIT "Invalid DMA channel for ser3\n");
92 goto bail;
94 break;
95 case dma_ata:
96 if (dmanr == ATA_TX_DMA_NBR) {
97 SETS(gens, R_GEN_CONFIG, dma2, ata);
98 } else if (dmanr == ATA_RX_DMA_NBR) {
99 SETS(gens, R_GEN_CONFIG, dma3, ata);
100 } else {
101 printk(KERN_CRIT "Invalid DMA channel for ata\n");
102 goto bail;
104 break;
105 case dma_ext0:
106 if (dmanr == EXTDMA0_TX_DMA_NBR) {
107 SETS(gens, R_GEN_CONFIG, dma4, extdma0);
108 } else if (dmanr == EXTDMA0_RX_DMA_NBR) {
109 SETS(gens, R_GEN_CONFIG, dma5, extdma0);
110 } else {
111 printk(KERN_CRIT "Invalid DMA channel for ext0\n");
112 goto bail;
114 break;
115 case dma_ext1:
116 if (dmanr == EXTDMA1_TX_DMA_NBR) {
117 SETS(gens, R_GEN_CONFIG, dma6, extdma1);
118 } else if (dmanr == EXTDMA1_RX_DMA_NBR) {
119 SETS(gens, R_GEN_CONFIG, dma7, extdma1);
120 } else {
121 printk(KERN_CRIT "Invalid DMA channel for ext1\n");
122 goto bail;
124 break;
125 case dma_int6:
126 if (dmanr == MEM2MEM_RX_DMA_NBR) {
127 SETS(gens, R_GEN_CONFIG, dma7, intdma6);
128 } else {
129 printk(KERN_CRIT "Invalid DMA channel for int6\n");
130 goto bail;
132 break;
133 case dma_int7:
134 if (dmanr == MEM2MEM_TX_DMA_NBR) {
135 SETS(gens, R_GEN_CONFIG, dma6, intdma7);
136 } else {
137 printk(KERN_CRIT "Invalid DMA channel for int7\n");
138 goto bail;
140 break;
141 case dma_usb:
142 if (dmanr == USB_TX_DMA_NBR) {
143 SETS(gens, R_GEN_CONFIG, dma8, usb);
144 } else if (dmanr == USB_RX_DMA_NBR) {
145 SETS(gens, R_GEN_CONFIG, dma9, usb);
146 } else {
147 printk(KERN_CRIT "Invalid DMA channel for usb\n");
148 goto bail;
150 break;
151 case dma_scsi0:
152 if (dmanr == SCSI0_TX_DMA_NBR) {
153 SETS(gens, R_GEN_CONFIG, dma2, scsi0);
154 } else if (dmanr == SCSI0_RX_DMA_NBR) {
155 SETS(gens, R_GEN_CONFIG, dma3, scsi0);
156 } else {
157 printk(KERN_CRIT "Invalid DMA channel for scsi0\n");
158 goto bail;
160 break;
161 case dma_scsi1:
162 if (dmanr == SCSI1_TX_DMA_NBR) {
163 SETS(gens, R_GEN_CONFIG, dma4, scsi1);
164 } else if (dmanr == SCSI1_RX_DMA_NBR) {
165 SETS(gens, R_GEN_CONFIG, dma5, scsi1);
166 } else {
167 printk(KERN_CRIT "Invalid DMA channel for scsi1\n");
168 goto bail;
170 break;
171 case dma_par0:
172 if (dmanr == PAR0_TX_DMA_NBR) {
173 SETS(gens, R_GEN_CONFIG, dma2, par0);
174 } else if (dmanr == PAR0_RX_DMA_NBR) {
175 SETS(gens, R_GEN_CONFIG, dma3, par0);
176 } else {
177 printk(KERN_CRIT "Invalid DMA channel for par0\n");
178 goto bail;
180 break;
181 case dma_par1:
182 if (dmanr == PAR1_TX_DMA_NBR) {
183 SETS(gens, R_GEN_CONFIG, dma4, par1);
184 } else if (dmanr == PAR1_RX_DMA_NBR) {
185 SETS(gens, R_GEN_CONFIG, dma5, par1);
186 } else {
187 printk(KERN_CRIT "Invalid DMA channel for par1\n");
188 goto bail;
190 break;
191 default:
192 printk(KERN_CRIT "Invalid DMA owner.\n");
193 goto bail;
196 used_dma_channels[dmanr] = 1;
197 used_dma_channels_users[dmanr] = device_id;
200 volatile int i;
201 genconfig_shadow = gens;
202 *R_GEN_CONFIG = genconfig_shadow;
203 /* Wait 12 cycles before doing any DMA command */
204 for(i = 6; i > 0; i--)
205 nop();
207 fail = 0;
208 bail:
209 local_irq_restore(flags);
210 return fail;
213 void cris_free_dma(unsigned int dmanr, const char * device_id)
215 unsigned long flags;
216 if ((dmanr < 0) || (dmanr >= MAX_DMA_CHANNELS)) {
217 printk(KERN_CRIT "cris_free_dma: invalid DMA channel %u\n", dmanr);
218 return;
221 local_irq_save(flags);
222 if (!used_dma_channels[dmanr]) {
223 printk(KERN_CRIT "cris_free_dma: DMA channel %u not allocated\n", dmanr);
224 } else if (device_id != used_dma_channels_users[dmanr]) {
225 printk(KERN_CRIT "cris_free_dma: DMA channel %u not allocated by device\n", dmanr);
226 } else {
227 switch(dmanr)
229 case 0:
230 *R_DMA_CH0_CMD = IO_STATE(R_DMA_CH0_CMD, cmd, reset);
231 while (IO_EXTRACT(R_DMA_CH0_CMD, cmd, *R_DMA_CH0_CMD) ==
232 IO_STATE_VALUE(R_DMA_CH0_CMD, cmd, reset));
233 break;
234 case 1:
235 *R_DMA_CH1_CMD = IO_STATE(R_DMA_CH1_CMD, cmd, reset);
236 while (IO_EXTRACT(R_DMA_CH1_CMD, cmd, *R_DMA_CH1_CMD) ==
237 IO_STATE_VALUE(R_DMA_CH1_CMD, cmd, reset));
238 break;
239 case 2:
240 *R_DMA_CH2_CMD = IO_STATE(R_DMA_CH2_CMD, cmd, reset);
241 while (IO_EXTRACT(R_DMA_CH2_CMD, cmd, *R_DMA_CH2_CMD) ==
242 IO_STATE_VALUE(R_DMA_CH2_CMD, cmd, reset));
243 break;
244 case 3:
245 *R_DMA_CH3_CMD = IO_STATE(R_DMA_CH3_CMD, cmd, reset);
246 while (IO_EXTRACT(R_DMA_CH3_CMD, cmd, *R_DMA_CH3_CMD) ==
247 IO_STATE_VALUE(R_DMA_CH3_CMD, cmd, reset));
248 break;
249 case 4:
250 *R_DMA_CH4_CMD = IO_STATE(R_DMA_CH4_CMD, cmd, reset);
251 while (IO_EXTRACT(R_DMA_CH4_CMD, cmd, *R_DMA_CH4_CMD) ==
252 IO_STATE_VALUE(R_DMA_CH4_CMD, cmd, reset));
253 break;
254 case 5:
255 *R_DMA_CH5_CMD = IO_STATE(R_DMA_CH5_CMD, cmd, reset);
256 while (IO_EXTRACT(R_DMA_CH5_CMD, cmd, *R_DMA_CH5_CMD) ==
257 IO_STATE_VALUE(R_DMA_CH5_CMD, cmd, reset));
258 break;
259 case 6:
260 *R_DMA_CH6_CMD = IO_STATE(R_DMA_CH6_CMD, cmd, reset);
261 while (IO_EXTRACT(R_DMA_CH6_CMD, cmd, *R_DMA_CH6_CMD) ==
262 IO_STATE_VALUE(R_DMA_CH6_CMD, cmd, reset));
263 break;
264 case 7:
265 *R_DMA_CH7_CMD = IO_STATE(R_DMA_CH7_CMD, cmd, reset);
266 while (IO_EXTRACT(R_DMA_CH7_CMD, cmd, *R_DMA_CH7_CMD) ==
267 IO_STATE_VALUE(R_DMA_CH7_CMD, cmd, reset));
268 break;
269 case 8:
270 *R_DMA_CH8_CMD = IO_STATE(R_DMA_CH8_CMD, cmd, reset);
271 while (IO_EXTRACT(R_DMA_CH8_CMD, cmd, *R_DMA_CH8_CMD) ==
272 IO_STATE_VALUE(R_DMA_CH8_CMD, cmd, reset));
273 break;
274 case 9:
275 *R_DMA_CH9_CMD = IO_STATE(R_DMA_CH9_CMD, cmd, reset);
276 while (IO_EXTRACT(R_DMA_CH9_CMD, cmd, *R_DMA_CH9_CMD) ==
277 IO_STATE_VALUE(R_DMA_CH9_CMD, cmd, reset));
278 break;
280 used_dma_channels[dmanr] = 0;
282 local_irq_restore(flags);
285 EXPORT_SYMBOL(cris_request_dma);
286 EXPORT_SYMBOL(cris_free_dma);