aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/ibmvscsi/rpa_vscsi.c
blob: 01b8ac641eb89d5460cb7383a24c865230e4c45e (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
/* ------------------------------------------------------------
 * rpa_vscsi.c
 * (C) Copyright IBM Corporation 1994, 2003
 * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
 *          Santiago Leon (santil@us.ibm.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 *
 * ------------------------------------------------------------
 * RPA-specific functions of the SCSI host adapter for Virtual I/O devices
 *
 * This driver allows the Linux SCSI peripheral drivers to directly
 * access devices in the hosting partition, either on an iSeries
 * hypervisor system or a converged hypervisor system.
 */

#include <asm/vio.h>
#include <asm/prom.h>
#include <asm/iommu.h>
#include <asm/hvcall.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include "ibmvscsi.h"

static char partition_name[97] = "UNKNOWN";
static unsigned int partition_number = -1;

/* ------------------------------------------------------------
 * Routines for managing the command/response queue
 */
/**
 * ibmvscsi_handle_event: - Interrupt handler for crq events
 * @irq:	number of irq to handle, not used
 * @dev_instance: ibmvscsi_host_data of host that received interrupt
 * @regs:	pt_regs with registers
 *
 * Disables interrupts and schedules srp_task
 * Always returns IRQ_HANDLED
 */
static irqreturn_t ibmvscsi_handle_event(int irq,
					 void *dev_instance,
					 struct pt_regs *regs)
{
	struct ibmvscsi_host_data *hostdata =
	    (struct ibmvscsi_host_data *)dev_instance;
	vio_disable_interrupts(to_vio_dev(hostdata->dev));
	tasklet_schedule(&hostdata->srp_task);
	return IRQ_HANDLED;
}

/**
 * release_crq_queue: - Deallocates data and unregisters CRQ
 * @queue:	crq_queue to initialize and register
 * @host_data:	ibmvscsi_host_data of host
 *
 * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
 * the crq with the hypervisor.
 */
void ibmvscsi_release_crq_queue(struct crq_queue *queue,
				struct ibmvscsi_host_data *hostdata,
				int max_requests)
{
	long rc;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
	free_irq(vdev->irq, (void *)hostdata);
	tasklet_kill(&hostdata->srp_task);
	do {
		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
	dma_unmap_single(hostdata->dev,
			 queue->msg_token,
			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
	free_page((unsigned long)queue->msgs);
}

/**
 * crq_queue_next_crq: - Returns the next entry in message queue
 * @queue:	crq_queue to use
 *
 * Returns pointer to next entry in queue, or NULL if there are no new 
 * entried in the CRQ.
 */
static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
{
	struct viosrp_crq *crq;
	unsigned long flags;

	spin_lock_irqsave(&queue->lock, flags);
	crq = &queue->msgs[queue->cur];
	if (crq->valid & 0x80) {
		if (++queue->cur == queue->size)
			queue->cur = 0;
	} else
		crq = NULL;
	spin_unlock_irqrestore(&queue->lock, flags);

	return crq;
}

/**
 * ibmvscsi_send_crq: - Send a CRQ
 * @hostdata:	the adapter
 * @word1:	the first 64 bits of the data
 * @word2:	the second 64 bits of the data
 */
int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2)
{
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
}

/**
 * ibmvscsi_task: - Process srps asynchronously
 * @data:	ibmvscsi_host_data of host
 */
static void ibmvscsi_task(void *data)
{
	struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
	struct viosrp_crq *crq;
	int done = 0;

	while (!done) {
		/* Pull all the valid messages off the CRQ */
		while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
			ibmvscsi_handle_crq(crq, hostdata);
			crq->valid = 0x00;
		}

		vio_enable_interrupts(vdev);
		if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
			vio_disable_interrupts(vdev);
			ibmvscsi_handle_crq(crq, hostdata);
			crq->valid = 0x00;
		} else {
			done = 1;
		}
	}
}

static void gather_partition_info(void)
{
	struct device_node *rootdn;

	const char *ppartition_name;
	const unsigned int *p_number_ptr;

	/* Retrieve information about this partition */
	rootdn = find_path_device("/");
	if (!rootdn) {
		return;
	}

	ppartition_name = get_property(rootdn, "ibm,partition-name", NULL);
	if (ppartition_name)
		strncpy(partition_name, ppartition_name,
				sizeof(partition_name));
	p_number_ptr = get_property(rootdn, "ibm,partition-no", NULL);
	if (p_number_ptr)
		partition_number = *p_number_ptr;
}

static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
{
	memset(&hostdata->madapter_info, 0x00,
			sizeof(hostdata->madapter_info));

	printk(KERN_INFO "rpa_vscsi: SPR_VERSION: %s\n", SRP_VERSION);
	strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);

	strncpy(hostdata->madapter_info.partition_name, partition_name,
			sizeof(hostdata->madapter_info.partition_name));

	hostdata->madapter_info.partition_number = partition_number;

	hostdata->madapter_info.mad_version = 1;
	hostdata->madapter_info.os_type = 2;
}

/**
 * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
 * @queue:	crq_queue to initialize and register
 * @hostdata:	ibmvscsi_host_data of host
 *
 * Allocates a page for messages, maps it for dma, and registers
 * the crq with the hypervisor.
 * Returns zero on success.
 */
int ibmvscsi_init_crq_queue(struct crq_queue *queue,
			    struct ibmvscsi_host_data *hostdata,
			    int max_requests)
{
	int rc;
	int retrc;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

	queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);

	if (!queue->msgs)
		goto malloc_failed;
	queue->size = PAGE_SIZE / sizeof(*queue->msgs);

	queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
					  queue->size * sizeof(*queue->msgs),
					  DMA_BIDIRECTIONAL);

	if (dma_mapping_error(queue->msg_token))
		goto map_failed;

	gather_partition_info();
	set_adapter_info(hostdata);

	retrc = rc = plpar_hcall_norets(H_REG_CRQ,
				vdev->unit_address,
				queue->msg_token, PAGE_SIZE);
	if (rc == H_RESOURCE)
		/* maybe kexecing and resource is busy. try a reset */
		rc = ibmvscsi_reset_crq_queue(queue,
					      hostdata);

	if (rc == 2) {
		/* Adapter is good, but other end is not ready */
		printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
		retrc = 0;
	} else if (rc != 0) {
		printk(KERN_WARNING "ibmvscsi: Error %d opening adapter\n", rc);
		goto reg_crq_failed;
	}

	if (request_irq(vdev->irq,
			ibmvscsi_handle_event,
			0, "ibmvscsi", (void *)hostdata) != 0) {
		printk(KERN_ERR "ibmvscsi: couldn't register irq 0x%x\n",
		       vdev->irq);
		goto req_irq_failed;
	}

	rc = vio_enable_interrupts(vdev);
	if (rc != 0) {
		printk(KERN_ERR "ibmvscsi:  Error %d enabling interrupts!!!\n",
		       rc);
		goto req_irq_failed;
	}

	queue->cur = 0;
	spin_lock_init(&queue->lock);

	tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
		     (unsigned long)hostdata);

	return retrc;

      req_irq_failed:
	do {
		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
      reg_crq_failed:
	dma_unmap_single(hostdata->dev,
			 queue->msg_token,
			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
      map_failed:
	free_page((unsigned long)queue->msgs);
      malloc_failed:
	return -1;
}

/**
 * reenable_crq_queue: - reenables a crq after
 * @queue:	crq_queue to initialize and register
 * @hostdata:	ibmvscsi_host_data of host
 *
 */
int ibmvscsi_reenable_crq_queue(struct crq_queue *queue,
				 struct ibmvscsi_host_data *hostdata)
{
	int rc;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

	/* Re-enable the CRQ */
	do {
		rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
	} while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));

	if (rc)
		printk(KERN_ERR "ibmvscsi: Error %d enabling adapter\n", rc);
	return rc;
}

/**
 * reset_crq_queue: - resets a crq after a failure
 * @queue:	crq_queue to initialize and register
 * @hostdata:	ibmvscsi_host_data of host
 *
 */
int ibmvscsi_reset_crq_queue(struct crq_queue *queue,
			      struct ibmvscsi_host_data *hostdata)
{
	int rc;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

	/* Close the CRQ */
	do {
		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));

	/* Clean out the queue */
	memset(queue->msgs, 0x00, PAGE_SIZE);
	queue->cur = 0;

	set_adapter_info(hostdata);

	/* And re-open it again */
	rc = plpar_hcall_norets(H_REG_CRQ,
				vdev->unit_address,
				queue->msg_token, PAGE_SIZE);
	if (rc == 2) {
		/* Adapter is good, but other end is not ready */
		printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
	} else if (rc != 0) {
		printk(KERN_WARNING
		       "ibmvscsi: couldn't register crq--rc 0x%x\n", rc);
	}
	return rc;
}