1 /*
2 * Intel IXP4xx Queue Manager driver for Linux
3 *
4 * Copyright (C) 2007 Krzysztof Halasa <khc@pm.waw.pl>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of version 2 of the GNU General Public License
8 * as published by the Free Software Foundation.
9 */
10
11 #include <linux/ioport.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <mach/qmgr.h>
16
17 struct qmgr_regs __iomem *qmgr_regs;
18 static struct resource *mem_res;
19 static spinlock_t qmgr_lock;
20 static u32 used_sram_bitmap[4]; /* 128 16-dword pages */
21 static void (*irq_handlers[QUEUES])(void *pdev);
22 static void *irq_pdevs[QUEUES];
23
24 #if DEBUG_QMGR
25 char qmgr_queue_descs[QUEUES][32];
26 #endif
27
qmgr_set_irq(unsigned int queue,int src,void (* handler)(void * pdev),void * pdev)28 void qmgr_set_irq(unsigned int queue, int src,
29 void (*handler)(void *pdev), void *pdev)
30 {
31 unsigned long flags;
32
33 spin_lock_irqsave(&qmgr_lock, flags);
34 if (queue < HALF_QUEUES) {
35 u32 __iomem *reg;
36 int bit;
37 BUG_ON(src > QUEUE_IRQ_SRC_NOT_FULL);
38 reg = &qmgr_regs->irqsrc[queue >> 3]; /* 8 queues per u32 */
39 bit = (queue % 8) * 4; /* 3 bits + 1 reserved bit per queue */
40 __raw_writel((__raw_readl(reg) & ~(7 << bit)) | (src << bit),
41 reg);
42 } else
43 /* IRQ source for queues 32-63 is fixed */
44 BUG_ON(src != QUEUE_IRQ_SRC_NOT_NEARLY_EMPTY);
45
46 irq_handlers[queue] = handler;
47 irq_pdevs[queue] = pdev;
48 spin_unlock_irqrestore(&qmgr_lock, flags);
49 }
50
51
qmgr_irq1_a0(int irq,void * pdev)52 static irqreturn_t qmgr_irq1_a0(int irq, void *pdev)
53 {
54 int i, ret = 0;
55 u32 en_bitmap, src, stat;
56
57 /* ACK - it may clear any bits so don't rely on it */
58 __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[0]);
59
60 en_bitmap = qmgr_regs->irqen[0];
61 while (en_bitmap) {
62 i = __fls(en_bitmap); /* number of the last "low" queue */
63 en_bitmap &= ~BIT(i);
64 src = qmgr_regs->irqsrc[i >> 3];
65 stat = qmgr_regs->stat1[i >> 3];
66 if (src & 4) /* the IRQ condition is inverted */
67 stat = ~stat;
68 if (stat & BIT(src & 3)) {
69 irq_handlers[i](irq_pdevs[i]);
70 ret = IRQ_HANDLED;
71 }
72 }
73 return ret;
74 }
75
76
qmgr_irq2_a0(int irq,void * pdev)77 static irqreturn_t qmgr_irq2_a0(int irq, void *pdev)
78 {
79 int i, ret = 0;
80 u32 req_bitmap;
81
82 /* ACK - it may clear any bits so don't rely on it */
83 __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[1]);
84
85 req_bitmap = qmgr_regs->irqen[1] & qmgr_regs->statne_h;
86 while (req_bitmap) {
87 i = __fls(req_bitmap); /* number of the last "high" queue */
88 req_bitmap &= ~BIT(i);
89 irq_handlers[HALF_QUEUES + i](irq_pdevs[HALF_QUEUES + i]);
90 ret = IRQ_HANDLED;
91 }
92 return ret;
93 }
94
95
qmgr_irq(int irq,void * pdev)96 static irqreturn_t qmgr_irq(int irq, void *pdev)
97 {
98 int i, half = (irq == IRQ_IXP4XX_QM1 ? 0 : 1);
99 u32 req_bitmap = __raw_readl(&qmgr_regs->irqstat[half]);
100
101 if (!req_bitmap)
102 return 0;
103 __raw_writel(req_bitmap, &qmgr_regs->irqstat[half]); /* ACK */
104
105 while (req_bitmap) {
106 i = __fls(req_bitmap); /* number of the last queue */
107 req_bitmap &= ~BIT(i);
108 i += half * HALF_QUEUES;
109 irq_handlers[i](irq_pdevs[i]);
110 }
111 return IRQ_HANDLED;
112 }
113
114
qmgr_enable_irq(unsigned int queue)115 void qmgr_enable_irq(unsigned int queue)
116 {
117 unsigned long flags;
118 int half = queue / 32;
119 u32 mask = 1 << (queue & (HALF_QUEUES - 1));
120
121 spin_lock_irqsave(&qmgr_lock, flags);
122 __raw_writel(__raw_readl(&qmgr_regs->irqen[half]) | mask,
123 &qmgr_regs->irqen[half]);
124 spin_unlock_irqrestore(&qmgr_lock, flags);
125 }
126
qmgr_disable_irq(unsigned int queue)127 void qmgr_disable_irq(unsigned int queue)
128 {
129 unsigned long flags;
130 int half = queue / 32;
131 u32 mask = 1 << (queue & (HALF_QUEUES - 1));
132
133 spin_lock_irqsave(&qmgr_lock, flags);
134 __raw_writel(__raw_readl(&qmgr_regs->irqen[half]) & ~mask,
135 &qmgr_regs->irqen[half]);
136 __raw_writel(mask, &qmgr_regs->irqstat[half]); /* clear */
137 spin_unlock_irqrestore(&qmgr_lock, flags);
138 }
139
shift_mask(u32 * mask)140 static inline void shift_mask(u32 *mask)
141 {
142 mask[3] = mask[3] << 1 | mask[2] >> 31;
143 mask[2] = mask[2] << 1 | mask[1] >> 31;
144 mask[1] = mask[1] << 1 | mask[0] >> 31;
145 mask[0] <<= 1;
146 }
147
148 #if DEBUG_QMGR
qmgr_request_queue(unsigned int queue,unsigned int len,unsigned int nearly_empty_watermark,unsigned int nearly_full_watermark,const char * desc_format,const char * name)149 int qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
150 unsigned int nearly_empty_watermark,
151 unsigned int nearly_full_watermark,
152 const char *desc_format, const char* name)
153 #else
154 int __qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
155 unsigned int nearly_empty_watermark,
156 unsigned int nearly_full_watermark)
157 #endif
158 {
159 u32 cfg, addr = 0, mask[4]; /* in 16-dwords */
160 int err;
161
162 BUG_ON(queue >= QUEUES);
163
164 if ((nearly_empty_watermark | nearly_full_watermark) & ~7)
165 return -EINVAL;
166
167 switch (len) {
168 case 16:
169 cfg = 0 << 24;
170 mask[0] = 0x1;
171 break;
172 case 32:
173 cfg = 1 << 24;
174 mask[0] = 0x3;
175 break;
176 case 64:
177 cfg = 2 << 24;
178 mask[0] = 0xF;
179 break;
180 case 128:
181 cfg = 3 << 24;
182 mask[0] = 0xFF;
183 break;
184 default:
185 return -EINVAL;
186 }
187
188 cfg |= nearly_empty_watermark << 26;
189 cfg |= nearly_full_watermark << 29;
190 len /= 16; /* in 16-dwords: 1, 2, 4 or 8 */
191 mask[1] = mask[2] = mask[3] = 0;
192
193 if (!try_module_get(THIS_MODULE))
194 return -ENODEV;
195
196 spin_lock_irq(&qmgr_lock);
197 if (__raw_readl(&qmgr_regs->sram[queue])) {
198 err = -EBUSY;
199 goto err;
200 }
201
202 while (1) {
203 if (!(used_sram_bitmap[0] & mask[0]) &&
204 !(used_sram_bitmap[1] & mask[1]) &&
205 !(used_sram_bitmap[2] & mask[2]) &&
206 !(used_sram_bitmap[3] & mask[3]))
207 break; /* found free space */
208
209 addr++;
210 shift_mask(mask);
211 if (addr + len > ARRAY_SIZE(qmgr_regs->sram)) {
212 printk(KERN_ERR "qmgr: no free SRAM space for"
213 " queue %i\n", queue);
214 err = -ENOMEM;
215 goto err;
216 }
217 }
218
219 used_sram_bitmap[0] |= mask[0];
220 used_sram_bitmap[1] |= mask[1];
221 used_sram_bitmap[2] |= mask[2];
222 used_sram_bitmap[3] |= mask[3];
223 __raw_writel(cfg | (addr << 14), &qmgr_regs->sram[queue]);
224 #if DEBUG_QMGR
225 snprintf(qmgr_queue_descs[queue], sizeof(qmgr_queue_descs[0]),
226 desc_format, name);
227 printk(KERN_DEBUG "qmgr: requested queue %s(%i) addr = 0x%02X\n",
228 qmgr_queue_descs[queue], queue, addr);
229 #endif
230 spin_unlock_irq(&qmgr_lock);
231 return 0;
232
233 err:
234 spin_unlock_irq(&qmgr_lock);
235 module_put(THIS_MODULE);
236 return err;
237 }
238
qmgr_release_queue(unsigned int queue)239 void qmgr_release_queue(unsigned int queue)
240 {
241 u32 cfg, addr, mask[4];
242
243 BUG_ON(queue >= QUEUES); /* not in valid range */
244
245 spin_lock_irq(&qmgr_lock);
246 cfg = __raw_readl(&qmgr_regs->sram[queue]);
247 addr = (cfg >> 14) & 0xFF;
248
249 BUG_ON(!addr); /* not requested */
250
251 switch ((cfg >> 24) & 3) {
252 case 0: mask[0] = 0x1; break;
253 case 1: mask[0] = 0x3; break;
254 case 2: mask[0] = 0xF; break;
255 case 3: mask[0] = 0xFF; break;
256 }
257
258 mask[1] = mask[2] = mask[3] = 0;
259
260 while (addr--)
261 shift_mask(mask);
262
263 #if DEBUG_QMGR
264 printk(KERN_DEBUG "qmgr: releasing queue %s(%i)\n",
265 qmgr_queue_descs[queue], queue);
266 qmgr_queue_descs[queue][0] = '\x0';
267 #endif
268
269 while ((addr = qmgr_get_entry(queue)))
270 printk(KERN_ERR "qmgr: released queue %i not empty: 0x%08X\n",
271 queue, addr);
272
273 __raw_writel(0, &qmgr_regs->sram[queue]);
274
275 used_sram_bitmap[0] &= ~mask[0];
276 used_sram_bitmap[1] &= ~mask[1];
277 used_sram_bitmap[2] &= ~mask[2];
278 used_sram_bitmap[3] &= ~mask[3];
279 irq_handlers[queue] = NULL; /* catch IRQ bugs */
280 spin_unlock_irq(&qmgr_lock);
281
282 module_put(THIS_MODULE);
283 }
284
qmgr_init(void)285 static int qmgr_init(void)
286 {
287 int i, err;
288 irq_handler_t handler1, handler2;
289
290 mem_res = request_mem_region(IXP4XX_QMGR_BASE_PHYS,
291 IXP4XX_QMGR_REGION_SIZE,
292 "IXP4xx Queue Manager");
293 if (mem_res == NULL)
294 return -EBUSY;
295
296 qmgr_regs = ioremap(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
297 if (qmgr_regs == NULL) {
298 err = -ENOMEM;
299 goto error_map;
300 }
301
302 /* reset qmgr registers */
303 for (i = 0; i < 4; i++) {
304 __raw_writel(0x33333333, &qmgr_regs->stat1[i]);
305 __raw_writel(0, &qmgr_regs->irqsrc[i]);
306 }
307 for (i = 0; i < 2; i++) {
308 __raw_writel(0, &qmgr_regs->stat2[i]);
309 __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[i]); /* clear */
310 __raw_writel(0, &qmgr_regs->irqen[i]);
311 }
312
313 __raw_writel(0xFFFFFFFF, &qmgr_regs->statne_h);
314 __raw_writel(0, &qmgr_regs->statf_h);
315
316 for (i = 0; i < QUEUES; i++)
317 __raw_writel(0, &qmgr_regs->sram[i]);
318
319 if (cpu_is_ixp42x_rev_a0()) {
320 handler1 = qmgr_irq1_a0;
321 handler2 = qmgr_irq2_a0;
322 } else
323 handler1 = handler2 = qmgr_irq;
324
325 err = request_irq(IRQ_IXP4XX_QM1, handler1, 0, "IXP4xx Queue Manager",
326 NULL);
327 if (err) {
328 printk(KERN_ERR "qmgr: failed to request IRQ%i (%i)\n",
329 IRQ_IXP4XX_QM1, err);
330 goto error_irq;
331 }
332
333 err = request_irq(IRQ_IXP4XX_QM2, handler2, 0, "IXP4xx Queue Manager",
334 NULL);
335 if (err) {
336 printk(KERN_ERR "qmgr: failed to request IRQ%i (%i)\n",
337 IRQ_IXP4XX_QM2, err);
338 goto error_irq2;
339 }
340
341 used_sram_bitmap[0] = 0xF; /* 4 first pages reserved for config */
342 spin_lock_init(&qmgr_lock);
343
344 printk(KERN_INFO "IXP4xx Queue Manager initialized.\n");
345 return 0;
346
347 error_irq2:
348 free_irq(IRQ_IXP4XX_QM1, NULL);
349 error_irq:
350 iounmap(qmgr_regs);
351 error_map:
352 release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
353 return err;
354 }
355
qmgr_remove(void)356 static void qmgr_remove(void)
357 {
358 free_irq(IRQ_IXP4XX_QM1, NULL);
359 free_irq(IRQ_IXP4XX_QM2, NULL);
360 synchronize_irq(IRQ_IXP4XX_QM1);
361 synchronize_irq(IRQ_IXP4XX_QM2);
362 iounmap(qmgr_regs);
363 release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
364 }
365
366 module_init(qmgr_init);
367 module_exit(qmgr_remove);
368
369 MODULE_LICENSE("GPL v2");
370 MODULE_AUTHOR("Krzysztof Halasa");
371
372 EXPORT_SYMBOL(qmgr_regs);
373 EXPORT_SYMBOL(qmgr_set_irq);
374 EXPORT_SYMBOL(qmgr_enable_irq);
375 EXPORT_SYMBOL(qmgr_disable_irq);
376 #if DEBUG_QMGR
377 EXPORT_SYMBOL(qmgr_queue_descs);
378 EXPORT_SYMBOL(qmgr_request_queue);
379 #else
380 EXPORT_SYMBOL(__qmgr_request_queue);
381 #endif
382 EXPORT_SYMBOL(qmgr_release_queue);
383