summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/iwlwifi/iwl-agn-ict.c
blob: f1b40ec1c873d083c97bdd5c2e25db907af1ba33 (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
/******************************************************************************
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
 * USA
 *
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * Contact Information:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *****************************************************************************/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/etherdevice.h>
#include <linux/sched.h>
#include <linux/gfp.h>
#include <net/mac80211.h>

#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-agn.h"
#include "iwl-helpers.h"

#define ICT_COUNT (PAGE_SIZE/sizeof(u32))

/* Free dram table */
void iwl_free_isr_ict(struct iwl_priv *priv)
{
	if (priv->_agn.ict_tbl_vir) {
		dma_free_coherent(priv->bus.dev,
				  (sizeof(u32) * ICT_COUNT) + PAGE_SIZE,
				  priv->_agn.ict_tbl_vir,
				  priv->_agn.ict_tbl_dma);
		priv->_agn.ict_tbl_vir = NULL;
	}
}


/* allocate dram shared table it is a PAGE_SIZE aligned
 * also reset all data related to ICT table interrupt.
 */
int iwl_alloc_isr_ict(struct iwl_priv *priv)
{

	/* allocate shrared data table */
	priv->_agn.ict_tbl_vir =
		dma_alloc_coherent(priv->bus.dev,
				   (sizeof(u32) * ICT_COUNT) + PAGE_SIZE,
				   &priv->_agn.ict_tbl_dma, GFP_KERNEL);
	if (!priv->_agn.ict_tbl_vir)
		return -ENOMEM;

	/* align table to PAGE_SIZE boundary */
	priv->_agn.aligned_ict_tbl_dma = ALIGN(priv->_agn.ict_tbl_dma, PAGE_SIZE);

	IWL_DEBUG_ISR(priv, "ict dma addr %Lx dma aligned %Lx diff %d\n",
			     (unsigned long long)priv->_agn.ict_tbl_dma,
			     (unsigned long long)priv->_agn.aligned_ict_tbl_dma,
			(int)(priv->_agn.aligned_ict_tbl_dma - priv->_agn.ict_tbl_dma));

	priv->_agn.ict_tbl =  priv->_agn.ict_tbl_vir +
			  (priv->_agn.aligned_ict_tbl_dma - priv->_agn.ict_tbl_dma);

	IWL_DEBUG_ISR(priv, "ict vir addr %p vir aligned %p diff %d\n",
			     priv->_agn.ict_tbl, priv->_agn.ict_tbl_vir,
			(int)(priv->_agn.aligned_ict_tbl_dma - priv->_agn.ict_tbl_dma));

	/* reset table and index to all 0 */
	memset(priv->_agn.ict_tbl_vir,0, (sizeof(u32) * ICT_COUNT) + PAGE_SIZE);
	priv->_agn.ict_index = 0;

	/* add periodic RX interrupt */
	priv->inta_mask |= CSR_INT_BIT_RX_PERIODIC;
	return 0;
}

/* Device is going up inform it about using ICT interrupt table,
 * also we need to tell the driver to start using ICT interrupt.
 */
int iwl_reset_ict(struct iwl_priv *priv)
{
	u32 val;
	unsigned long flags;

	if (!priv->_agn.ict_tbl_vir)
		return 0;

	spin_lock_irqsave(&priv->lock, flags);
	iwl_disable_interrupts(priv);

	memset(&priv->_agn.ict_tbl[0], 0, sizeof(u32) * ICT_COUNT);

	val = priv->_agn.aligned_ict_tbl_dma >> PAGE_SHIFT;

	val |= CSR_DRAM_INT_TBL_ENABLE;
	val |= CSR_DRAM_INIT_TBL_WRAP_CHECK;

	IWL_DEBUG_ISR(priv, "CSR_DRAM_INT_TBL_REG =0x%X "
			"aligned dma address %Lx\n",
			val, (unsigned long long)priv->_agn.aligned_ict_tbl_dma);

	iwl_write32(priv, CSR_DRAM_INT_TBL_REG, val);
	priv->_agn.use_ict = true;
	priv->_agn.ict_index = 0;
	iwl_write32(priv, CSR_INT, priv->inta_mask);
	iwl_enable_interrupts(priv);
	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

/* Device is going down disable ict interrupt usage */
void iwl_disable_ict(struct iwl_priv *priv)
{
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	priv->_agn.use_ict = false;
	spin_unlock_irqrestore(&priv->lock, flags);
}

static irqreturn_t iwl_isr(int irq, void *data)
{
	struct iwl_priv *priv = data;
	u32 inta, inta_mask;
	unsigned long flags;
#ifdef CONFIG_IWLWIFI_DEBUG
	u32 inta_fh;
#endif
	if (!priv)
		return IRQ_NONE;

	spin_lock_irqsave(&priv->lock, flags);

	/* Disable (but don't clear!) interrupts here to avoid
	 *    back-to-back ISRs and sporadic interrupts from our NIC.
	 * If we have something to service, the tasklet will re-enable ints.
	 * If we *don't* have something, we'll re-enable before leaving here. */
	inta_mask = iwl_read32(priv, CSR_INT_MASK);  /* just for debug */
	iwl_write32(priv, CSR_INT_MASK, 0x00000000);

	/* Discover which interrupts are active/pending */
	inta = iwl_read32(priv, CSR_INT);

	/* Ignore interrupt if there's nothing in NIC to service.
	 * This may be due to IRQ shared with another device,
	 * or due to sporadic interrupts thrown from our NIC. */
	if (!inta) {
		IWL_DEBUG_ISR(priv, "Ignore interrupt, inta == 0\n");
		goto none;
	}

	if ((inta == 0xFFFFFFFF) || ((inta & 0xFFFFFFF0) == 0xa5a5a5a0)) {
		/* Hardware disappeared. It might have already raised
		 * an interrupt */
		IWL_WARN(priv, "HARDWARE GONE?? INTA == 0x%08x\n", inta);
		goto unplugged;
	}

#ifdef CONFIG_IWLWIFI_DEBUG
	if (iwl_get_debug_level(priv) & (IWL_DL_ISR)) {
		inta_fh = iwl_read32(priv, CSR_FH_INT_STATUS);
		IWL_DEBUG_ISR(priv, "ISR inta 0x%08x, enabled 0x%08x, "
			      "fh 0x%08x\n", inta, inta_mask, inta_fh);
	}
#endif

	priv->_agn.inta |= inta;
	/* iwl_irq_tasklet() will service interrupts and re-enable them */
	if (likely(inta))
		tasklet_schedule(&priv->irq_tasklet);
	else if (test_bit(STATUS_INT_ENABLED, &priv->status) && !priv->_agn.inta)
		iwl_enable_interrupts(priv);

 unplugged:
	spin_unlock_irqrestore(&priv->lock, flags);
	return IRQ_HANDLED;

 none:
	/* re-enable interrupts here since we don't have anything to service. */
	/* only Re-enable if disabled by irq  and no schedules tasklet. */
	if (test_bit(STATUS_INT_ENABLED, &priv->status) && !priv->_agn.inta)
		iwl_enable_interrupts(priv);

	spin_unlock_irqrestore(&priv->lock, flags);
	return IRQ_NONE;
}

/* interrupt handler using ict table, with this interrupt driver will
 * stop using INTA register to get device's interrupt, reading this register
 * is expensive, device will write interrupts in ICT dram table, increment
 * index then will fire interrupt to driver, driver will OR all ICT table
 * entries from current index up to table entry with 0 value. the result is
 * the interrupt we need to service, driver will set the entries back to 0 and
 * set index.
 */
irqreturn_t iwl_isr_ict(int irq, void *data)
{
	struct iwl_priv *priv = data;
	u32 inta, inta_mask;
	u32 val = 0;
	unsigned long flags;

	if (!priv)
		return IRQ_NONE;

	/* dram interrupt table not set yet,
	 * use legacy interrupt.
	 */
	if (!priv->_agn.use_ict)
		return iwl_isr(irq, data);

	spin_lock_irqsave(&priv->lock, flags);

	/* Disable (but don't clear!) interrupts here to avoid
	 * back-to-back ISRs and sporadic interrupts from our NIC.
	 * If we have something to service, the tasklet will re-enable ints.
	 * If we *don't* have something, we'll re-enable before leaving here.
	 */
	inta_mask = iwl_read32(priv, CSR_INT_MASK);  /* just for debug */
	iwl_write32(priv, CSR_INT_MASK, 0x00000000);


	/* Ignore interrupt if there's nothing in NIC to service.
	 * This may be due to IRQ shared with another device,
	 * or due to sporadic interrupts thrown from our NIC. */
	if (!priv->_agn.ict_tbl[priv->_agn.ict_index]) {
		IWL_DEBUG_ISR(priv, "Ignore interrupt, inta == 0\n");
		goto none;
	}

	/* read all entries that not 0 start with ict_index */
	while (priv->_agn.ict_tbl[priv->_agn.ict_index]) {

		val |= le32_to_cpu(priv->_agn.ict_tbl[priv->_agn.ict_index]);
		IWL_DEBUG_ISR(priv, "ICT index %d value 0x%08X\n",
				priv->_agn.ict_index,
				le32_to_cpu(priv->_agn.ict_tbl[priv->_agn.ict_index]));
		priv->_agn.ict_tbl[priv->_agn.ict_index] = 0;
		priv->_agn.ict_index = iwl_queue_inc_wrap(priv->_agn.ict_index,
						     ICT_COUNT);

	}

	/* We should not get this value, just ignore it. */
	if (val == 0xffffffff)
		val = 0;

	/*
	 * this is a w/a for a h/w bug. the h/w bug may cause the Rx bit
	 * (bit 15 before shifting it to 31) to clear when using interrupt
	 * coalescing. fortunately, bits 18 and 19 stay set when this happens
	 * so we use them to decide on the real state of the Rx bit.
	 * In order words, bit 15 is set if bit 18 or bit 19 are set.
	 */
	if (val & 0xC0000)
		val |= 0x8000;

	inta = (0xff & val) | ((0xff00 & val) << 16);
	IWL_DEBUG_ISR(priv, "ISR inta 0x%08x, enabled 0x%08x ict 0x%08x\n",
			inta, inta_mask, val);

	inta &= priv->inta_mask;
	priv->_agn.inta |= inta;

	/* iwl_irq_tasklet() will service interrupts and re-enable them */
	if (likely(inta))
		tasklet_schedule(&priv->irq_tasklet);
	else if (test_bit(STATUS_INT_ENABLED, &priv->status) && !priv->_agn.inta) {
		/* Allow interrupt if was disabled by this handler and
		 * no tasklet was schedules, We should not enable interrupt,
		 * tasklet will enable it.
		 */
		iwl_enable_interrupts(priv);
	}

	spin_unlock_irqrestore(&priv->lock, flags);
	return IRQ_HANDLED;

 none:
	/* re-enable interrupts here since we don't have anything to service.
	 * only Re-enable if disabled by irq.
	 */
	if (test_bit(STATUS_INT_ENABLED, &priv->status) && !priv->_agn.inta)
		iwl_enable_interrupts(priv);

	spin_unlock_irqrestore(&priv->lock, flags);
	return IRQ_NONE;
}