summaryrefslogtreecommitdiffstats
path: root/drivers/soc/ixp4xx/ixp4xx-qmgr.c
blob: 133914e99aeb9eda01b26fe1ccee904164c15a88 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
/*
 * Intel IXP4xx Queue Manager driver for Linux
 *
 * Copyright (C) 2007 Krzysztof Halasa <khc@pm.waw.pl>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 */

#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/soc/ixp4xx/qmgr.h>

/* FIXME: get rid of these static assigments */
#define IRQ_IXP4XX_BASE		16
#define IRQ_IXP4XX_QM1		(IRQ_IXP4XX_BASE + 3)
#define IRQ_IXP4XX_QM2		(IRQ_IXP4XX_BASE + 4)

static struct qmgr_regs __iomem *qmgr_regs = IXP4XX_QMGR_BASE_VIRT;
static struct resource *mem_res;
static spinlock_t qmgr_lock;
static u32 used_sram_bitmap[4]; /* 128 16-dword pages */
static void (*irq_handlers[QUEUES])(void *pdev);
static void *irq_pdevs[QUEUES];

#if DEBUG_QMGR
char qmgr_queue_descs[QUEUES][32];
#endif

void qmgr_set_irq(unsigned int queue, int src,
		  void (*handler)(void *pdev), void *pdev)
{
	unsigned long flags;

	spin_lock_irqsave(&qmgr_lock, flags);
	if (queue < HALF_QUEUES) {
		u32 __iomem *reg;
		int bit;
		BUG_ON(src > QUEUE_IRQ_SRC_NOT_FULL);
		reg = &qmgr_regs->irqsrc[queue >> 3]; /* 8 queues per u32 */
		bit = (queue % 8) * 4; /* 3 bits + 1 reserved bit per queue */
		__raw_writel((__raw_readl(reg) & ~(7 << bit)) | (src << bit),
			     reg);
	} else
		/* IRQ source for queues 32-63 is fixed */
		BUG_ON(src != QUEUE_IRQ_SRC_NOT_NEARLY_EMPTY);

	irq_handlers[queue] = handler;
	irq_pdevs[queue] = pdev;
	spin_unlock_irqrestore(&qmgr_lock, flags);
}


static irqreturn_t qmgr_irq1_a0(int irq, void *pdev)
{
	int i, ret = 0;
	u32 en_bitmap, src, stat;

	/* ACK - it may clear any bits so don't rely on it */
	__raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[0]);

	en_bitmap = qmgr_regs->irqen[0];
	while (en_bitmap) {
		i = __fls(en_bitmap); /* number of the last "low" queue */
		en_bitmap &= ~BIT(i);
		src = qmgr_regs->irqsrc[i >> 3];
		stat = qmgr_regs->stat1[i >> 3];
		if (src & 4) /* the IRQ condition is inverted */
			stat = ~stat;
		if (stat & BIT(src & 3)) {
			irq_handlers[i](irq_pdevs[i]);
			ret = IRQ_HANDLED;
		}
	}
	return ret;
}


static irqreturn_t qmgr_irq2_a0(int irq, void *pdev)
{
	int i, ret = 0;
	u32 req_bitmap;

	/* ACK - it may clear any bits so don't rely on it */
	__raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[1]);

	req_bitmap = qmgr_regs->irqen[1] & qmgr_regs->statne_h;
	while (req_bitmap) {
		i = __fls(req_bitmap); /* number of the last "high" queue */
		req_bitmap &= ~BIT(i);
		irq_handlers[HALF_QUEUES + i](irq_pdevs[HALF_QUEUES + i]);
		ret = IRQ_HANDLED;
	}
	return ret;
}


static irqreturn_t qmgr_irq(int irq, void *pdev)
{
	int i, half = (irq == IRQ_IXP4XX_QM1 ? 0 : 1);
	u32 req_bitmap = __raw_readl(&qmgr_regs->irqstat[half]);

	if (!req_bitmap)
		return 0;
	__raw_writel(req_bitmap, &qmgr_regs->irqstat[half]); /* ACK */

	while (req_bitmap) {
		i = __fls(req_bitmap); /* number of the last queue */
		req_bitmap &= ~BIT(i);
		i += half * HALF_QUEUES;
		irq_handlers[i](irq_pdevs[i]);
	}
	return IRQ_HANDLED;
}


void qmgr_enable_irq(unsigned int queue)
{
	unsigned long flags;
	int half = queue / 32;
	u32 mask = 1 << (queue & (HALF_QUEUES - 1));

	spin_lock_irqsave(&qmgr_lock, flags);
	__raw_writel(__raw_readl(&qmgr_regs->irqen[half]) | mask,
		     &qmgr_regs->irqen[half]);
	spin_unlock_irqrestore(&qmgr_lock, flags);
}

void qmgr_disable_irq(unsigned int queue)
{
	unsigned long flags;
	int half = queue / 32;
	u32 mask = 1 << (queue & (HALF_QUEUES - 1));

	spin_lock_irqsave(&qmgr_lock, flags);
	__raw_writel(__raw_readl(&qmgr_regs->irqen[half]) & ~mask,
		     &qmgr_regs->irqen[half]);
	__raw_writel(mask, &qmgr_regs->irqstat[half]); /* clear */
	spin_unlock_irqrestore(&qmgr_lock, flags);
}

static inline void shift_mask(u32 *mask)
{
	mask[3] = mask[3] << 1 | mask[2] >> 31;
	mask[2] = mask[2] << 1 | mask[1] >> 31;
	mask[1] = mask[1] << 1 | mask[0] >> 31;
	mask[0] <<= 1;
}

#if DEBUG_QMGR
int qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
		       unsigned int nearly_empty_watermark,
		       unsigned int nearly_full_watermark,
		       const char *desc_format, const char* name)
#else
int __qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
			 unsigned int nearly_empty_watermark,
			 unsigned int nearly_full_watermark)
#endif
{
	u32 cfg, addr = 0, mask[4]; /* in 16-dwords */
	int err;

	BUG_ON(queue >= QUEUES);

	if ((nearly_empty_watermark | nearly_full_watermark) & ~7)
		return -EINVAL;

	switch (len) {
	case  16:
		cfg = 0 << 24;
		mask[0] = 0x1;
		break;
	case  32:
		cfg = 1 << 24;
		mask[0] = 0x3;
		break;
	case  64:
		cfg = 2 << 24;
		mask[0] = 0xF;
		break;
	case 128:
		cfg = 3 << 24;
		mask[0] = 0xFF;
		break;
	default:
		return -EINVAL;
	}

	cfg |= nearly_empty_watermark << 26;
	cfg |= nearly_full_watermark << 29;
	len /= 16;		/* in 16-dwords: 1, 2, 4 or 8 */
	mask[1] = mask[2] = mask[3] = 0;

	if (!try_module_get(THIS_MODULE))
		return -ENODEV;

	spin_lock_irq(&qmgr_lock);
	if (__raw_readl(&qmgr_regs->sram[queue])) {
		err = -EBUSY;
		goto err;
	}

	while (1) {
		if (!(used_sram_bitmap[0] & mask[0]) &&
		    !(used_sram_bitmap[1] & mask[1]) &&
		    !(used_sram_bitmap[2] & mask[2]) &&
		    !(used_sram_bitmap[3] & mask[3]))
			break; /* found free space */

		addr++;
		shift_mask(mask);
		if (addr + len > ARRAY_SIZE(qmgr_regs->sram)) {
			printk(KERN_ERR "qmgr: no free SRAM space for"
			       " queue %i\n", queue);
			err = -ENOMEM;
			goto err;
		}
	}

	used_sram_bitmap[0] |= mask[0];
	used_sram_bitmap[1] |= mask[1];
	used_sram_bitmap[2] |= mask[2];
	used_sram_bitmap[3] |= mask[3];
	__raw_writel(cfg | (addr << 14), &qmgr_regs->sram[queue]);
#if DEBUG_QMGR
	snprintf(qmgr_queue_descs[queue], sizeof(qmgr_queue_descs[0]),
		 desc_format, name);
	printk(KERN_DEBUG "qmgr: requested queue %s(%i) addr = 0x%02X\n",
	       qmgr_queue_descs[queue], queue, addr);
#endif
	spin_unlock_irq(&qmgr_lock);
	return 0;

err:
	spin_unlock_irq(&qmgr_lock);
	module_put(THIS_MODULE);
	return err;
}

void qmgr_release_queue(unsigned int queue)
{
	u32 cfg, addr, mask[4];

	BUG_ON(queue >= QUEUES); /* not in valid range */

	spin_lock_irq(&qmgr_lock);
	cfg = __raw_readl(&qmgr_regs->sram[queue]);
	addr = (cfg >> 14) & 0xFF;

	BUG_ON(!addr);		/* not requested */

	switch ((cfg >> 24) & 3) {
	case 0: mask[0] = 0x1; break;
	case 1: mask[0] = 0x3; break;
	case 2: mask[0] = 0xF; break;
	case 3: mask[0] = 0xFF; break;
	}

	mask[1] = mask[2] = mask[3] = 0;

	while (addr--)
		shift_mask(mask);

#if DEBUG_QMGR
	printk(KERN_DEBUG "qmgr: releasing queue %s(%i)\n",
	       qmgr_queue_descs[queue], queue);
	qmgr_queue_descs[queue][0] = '\x0';
#endif

	while ((addr = qmgr_get_entry(queue)))
		printk(KERN_ERR "qmgr: released queue %i not empty: 0x%08X\n",
		       queue, addr);

	__raw_writel(0, &qmgr_regs->sram[queue]);

	used_sram_bitmap[0] &= ~mask[0];
	used_sram_bitmap[1] &= ~mask[1];
	used_sram_bitmap[2] &= ~mask[2];
	used_sram_bitmap[3] &= ~mask[3];
	irq_handlers[queue] = NULL; /* catch IRQ bugs */
	spin_unlock_irq(&qmgr_lock);

	module_put(THIS_MODULE);
}

static int ixp4xx_qmgr_probe(struct platform_device *pdev)
{
	int i, err;
	irq_handler_t handler1, handler2;

	mem_res = request_mem_region(IXP4XX_QMGR_BASE_PHYS,
				     IXP4XX_QMGR_REGION_SIZE,
				     "IXP4xx Queue Manager");
	if (mem_res == NULL)
		return -EBUSY;

	/* reset qmgr registers */
	for (i = 0; i < 4; i++) {
		__raw_writel(0x33333333, &qmgr_regs->stat1[i]);
		__raw_writel(0, &qmgr_regs->irqsrc[i]);
	}
	for (i = 0; i < 2; i++) {
		__raw_writel(0, &qmgr_regs->stat2[i]);
		__raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[i]); /* clear */
		__raw_writel(0, &qmgr_regs->irqen[i]);
	}

	__raw_writel(0xFFFFFFFF, &qmgr_regs->statne_h);
	__raw_writel(0, &qmgr_regs->statf_h);

	for (i = 0; i < QUEUES; i++)
		__raw_writel(0, &qmgr_regs->sram[i]);

	if (cpu_is_ixp42x_rev_a0()) {
		handler1 = qmgr_irq1_a0;
		handler2 = qmgr_irq2_a0;
	} else
		handler1 = handler2 = qmgr_irq;

	err = request_irq(IRQ_IXP4XX_QM1, handler1, 0, "IXP4xx Queue Manager",
			  NULL);
	if (err) {
		printk(KERN_ERR "qmgr: failed to request IRQ%i (%i)\n",
		       IRQ_IXP4XX_QM1, err);
		goto error_irq;
	}

	err = request_irq(IRQ_IXP4XX_QM2, handler2, 0, "IXP4xx Queue Manager",
			  NULL);
	if (err) {
		printk(KERN_ERR "qmgr: failed to request IRQ%i (%i)\n",
		       IRQ_IXP4XX_QM2, err);
		goto error_irq2;
	}

	used_sram_bitmap[0] = 0xF; /* 4 first pages reserved for config */
	spin_lock_init(&qmgr_lock);

	printk(KERN_INFO "IXP4xx Queue Manager initialized.\n");
	return 0;

error_irq2:
	free_irq(IRQ_IXP4XX_QM1, NULL);
error_irq:
	release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
	return err;
}

static int ixp4xx_qmgr_remove(struct platform_device *pdev)
{
	free_irq(IRQ_IXP4XX_QM1, NULL);
	free_irq(IRQ_IXP4XX_QM2, NULL);
	synchronize_irq(IRQ_IXP4XX_QM1);
	synchronize_irq(IRQ_IXP4XX_QM2);
	release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);

	return 0;
}

static struct platform_driver ixp4xx_qmgr_driver = {
	.driver = {
		.name           = "ixp4xx-qmgr",
	},
	.probe = ixp4xx_qmgr_probe,
	.remove = ixp4xx_qmgr_remove,
};
module_platform_driver(ixp4xx_qmgr_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Krzysztof Halasa");

EXPORT_SYMBOL(qmgr_set_irq);
EXPORT_SYMBOL(qmgr_enable_irq);
EXPORT_SYMBOL(qmgr_disable_irq);
#if DEBUG_QMGR
EXPORT_SYMBOL(qmgr_queue_descs);
EXPORT_SYMBOL(qmgr_request_queue);
#else
EXPORT_SYMBOL(__qmgr_request_queue);
#endif
EXPORT_SYMBOL(qmgr_release_queue);