Merge branch 'for-2.6.22' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus...
[pandora-kernel.git] / drivers / scsi / ibmvscsi / rpa_vscsi.c
1 /* ------------------------------------------------------------
2  * rpa_vscsi.c
3  * (C) Copyright IBM Corporation 1994, 2003
4  * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
5  *          Santiago Leon (santil@us.ibm.com)
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
20  * USA
21  *
22  * ------------------------------------------------------------
23  * RPA-specific functions of the SCSI host adapter for Virtual I/O devices
24  *
25  * This driver allows the Linux SCSI peripheral drivers to directly
26  * access devices in the hosting partition, either on an iSeries
27  * hypervisor system or a converged hypervisor system.
28  */
29
30 #include <asm/vio.h>
31 #include <asm/prom.h>
32 #include <asm/iommu.h>
33 #include <asm/hvcall.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/interrupt.h>
36 #include "ibmvscsi.h"
37
38 static char partition_name[97] = "UNKNOWN";
39 static unsigned int partition_number = -1;
40
41 /* ------------------------------------------------------------
42  * Routines for managing the command/response queue
43  */
44 /**
45  * ibmvscsi_handle_event: - Interrupt handler for crq events
46  * @irq:        number of irq to handle, not used
47  * @dev_instance: ibmvscsi_host_data of host that received interrupt
48  *
49  * Disables interrupts and schedules srp_task
50  * Always returns IRQ_HANDLED
51  */
52 static irqreturn_t ibmvscsi_handle_event(int irq, void *dev_instance)
53 {
54         struct ibmvscsi_host_data *hostdata =
55             (struct ibmvscsi_host_data *)dev_instance;
56         vio_disable_interrupts(to_vio_dev(hostdata->dev));
57         tasklet_schedule(&hostdata->srp_task);
58         return IRQ_HANDLED;
59 }
60
61 /**
62  * release_crq_queue: - Deallocates data and unregisters CRQ
63  * @queue:      crq_queue to initialize and register
64  * @host_data:  ibmvscsi_host_data of host
65  *
66  * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
67  * the crq with the hypervisor.
68  */
69 void ibmvscsi_release_crq_queue(struct crq_queue *queue,
70                                 struct ibmvscsi_host_data *hostdata,
71                                 int max_requests)
72 {
73         long rc;
74         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
75         free_irq(vdev->irq, (void *)hostdata);
76         tasklet_kill(&hostdata->srp_task);
77         do {
78                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
79         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
80         dma_unmap_single(hostdata->dev,
81                          queue->msg_token,
82                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
83         free_page((unsigned long)queue->msgs);
84 }
85
86 /**
87  * crq_queue_next_crq: - Returns the next entry in message queue
88  * @queue:      crq_queue to use
89  *
90  * Returns pointer to next entry in queue, or NULL if there are no new 
91  * entried in the CRQ.
92  */
93 static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
94 {
95         struct viosrp_crq *crq;
96         unsigned long flags;
97
98         spin_lock_irqsave(&queue->lock, flags);
99         crq = &queue->msgs[queue->cur];
100         if (crq->valid & 0x80) {
101                 if (++queue->cur == queue->size)
102                         queue->cur = 0;
103         } else
104                 crq = NULL;
105         spin_unlock_irqrestore(&queue->lock, flags);
106
107         return crq;
108 }
109
110 /**
111  * ibmvscsi_send_crq: - Send a CRQ
112  * @hostdata:   the adapter
113  * @word1:      the first 64 bits of the data
114  * @word2:      the second 64 bits of the data
115  */
116 int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2)
117 {
118         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
119
120         return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
121 }
122
123 /**
124  * ibmvscsi_task: - Process srps asynchronously
125  * @data:       ibmvscsi_host_data of host
126  */
127 static void ibmvscsi_task(void *data)
128 {
129         struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
130         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
131         struct viosrp_crq *crq;
132         int done = 0;
133
134         while (!done) {
135                 /* Pull all the valid messages off the CRQ */
136                 while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
137                         ibmvscsi_handle_crq(crq, hostdata);
138                         crq->valid = 0x00;
139                 }
140
141                 vio_enable_interrupts(vdev);
142                 if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
143                         vio_disable_interrupts(vdev);
144                         ibmvscsi_handle_crq(crq, hostdata);
145                         crq->valid = 0x00;
146                 } else {
147                         done = 1;
148                 }
149         }
150 }
151
152 static void gather_partition_info(void)
153 {
154         struct device_node *rootdn;
155
156         const char *ppartition_name;
157         const unsigned int *p_number_ptr;
158
159         /* Retrieve information about this partition */
160         rootdn = of_find_node_by_path("/");
161         if (!rootdn) {
162                 return;
163         }
164
165         ppartition_name = get_property(rootdn, "ibm,partition-name", NULL);
166         if (ppartition_name)
167                 strncpy(partition_name, ppartition_name,
168                                 sizeof(partition_name));
169         p_number_ptr = get_property(rootdn, "ibm,partition-no", NULL);
170         if (p_number_ptr)
171                 partition_number = *p_number_ptr;
172         of_node_put(rootdn);
173 }
174
175 static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
176 {
177         memset(&hostdata->madapter_info, 0x00,
178                         sizeof(hostdata->madapter_info));
179
180         printk(KERN_INFO "rpa_vscsi: SPR_VERSION: %s\n", SRP_VERSION);
181         strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
182
183         strncpy(hostdata->madapter_info.partition_name, partition_name,
184                         sizeof(hostdata->madapter_info.partition_name));
185
186         hostdata->madapter_info.partition_number = partition_number;
187
188         hostdata->madapter_info.mad_version = 1;
189         hostdata->madapter_info.os_type = 2;
190 }
191
192 /**
193  * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
194  * @queue:      crq_queue to initialize and register
195  * @hostdata:   ibmvscsi_host_data of host
196  *
197  * Allocates a page for messages, maps it for dma, and registers
198  * the crq with the hypervisor.
199  * Returns zero on success.
200  */
201 int ibmvscsi_init_crq_queue(struct crq_queue *queue,
202                             struct ibmvscsi_host_data *hostdata,
203                             int max_requests)
204 {
205         int rc;
206         int retrc;
207         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
208
209         queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
210
211         if (!queue->msgs)
212                 goto malloc_failed;
213         queue->size = PAGE_SIZE / sizeof(*queue->msgs);
214
215         queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
216                                           queue->size * sizeof(*queue->msgs),
217                                           DMA_BIDIRECTIONAL);
218
219         if (dma_mapping_error(queue->msg_token))
220                 goto map_failed;
221
222         gather_partition_info();
223         set_adapter_info(hostdata);
224
225         retrc = rc = plpar_hcall_norets(H_REG_CRQ,
226                                 vdev->unit_address,
227                                 queue->msg_token, PAGE_SIZE);
228         if (rc == H_RESOURCE)
229                 /* maybe kexecing and resource is busy. try a reset */
230                 rc = ibmvscsi_reset_crq_queue(queue,
231                                               hostdata);
232
233         if (rc == 2) {
234                 /* Adapter is good, but other end is not ready */
235                 printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
236                 retrc = 0;
237         } else if (rc != 0) {
238                 printk(KERN_WARNING "ibmvscsi: Error %d opening adapter\n", rc);
239                 goto reg_crq_failed;
240         }
241
242         if (request_irq(vdev->irq,
243                         ibmvscsi_handle_event,
244                         0, "ibmvscsi", (void *)hostdata) != 0) {
245                 printk(KERN_ERR "ibmvscsi: couldn't register irq 0x%x\n",
246                        vdev->irq);
247                 goto req_irq_failed;
248         }
249
250         rc = vio_enable_interrupts(vdev);
251         if (rc != 0) {
252                 printk(KERN_ERR "ibmvscsi:  Error %d enabling interrupts!!!\n",
253                        rc);
254                 goto req_irq_failed;
255         }
256
257         queue->cur = 0;
258         spin_lock_init(&queue->lock);
259
260         tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
261                      (unsigned long)hostdata);
262
263         return retrc;
264
265       req_irq_failed:
266         do {
267                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
268         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
269       reg_crq_failed:
270         dma_unmap_single(hostdata->dev,
271                          queue->msg_token,
272                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
273       map_failed:
274         free_page((unsigned long)queue->msgs);
275       malloc_failed:
276         return -1;
277 }
278
279 /**
280  * reenable_crq_queue: - reenables a crq after
281  * @queue:      crq_queue to initialize and register
282  * @hostdata:   ibmvscsi_host_data of host
283  *
284  */
285 int ibmvscsi_reenable_crq_queue(struct crq_queue *queue,
286                                  struct ibmvscsi_host_data *hostdata)
287 {
288         int rc;
289         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
290
291         /* Re-enable the CRQ */
292         do {
293                 rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
294         } while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
295
296         if (rc)
297                 printk(KERN_ERR "ibmvscsi: Error %d enabling adapter\n", rc);
298         return rc;
299 }
300
301 /**
302  * reset_crq_queue: - resets a crq after a failure
303  * @queue:      crq_queue to initialize and register
304  * @hostdata:   ibmvscsi_host_data of host
305  *
306  */
307 int ibmvscsi_reset_crq_queue(struct crq_queue *queue,
308                               struct ibmvscsi_host_data *hostdata)
309 {
310         int rc;
311         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
312
313         /* Close the CRQ */
314         do {
315                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
316         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
317
318         /* Clean out the queue */
319         memset(queue->msgs, 0x00, PAGE_SIZE);
320         queue->cur = 0;
321
322         set_adapter_info(hostdata);
323
324         /* And re-open it again */
325         rc = plpar_hcall_norets(H_REG_CRQ,
326                                 vdev->unit_address,
327                                 queue->msg_token, PAGE_SIZE);
328         if (rc == 2) {
329                 /* Adapter is good, but other end is not ready */
330                 printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
331         } else if (rc != 0) {
332                 printk(KERN_WARNING
333                        "ibmvscsi: couldn't register crq--rc 0x%x\n", rc);
334         }
335         return rc;
336 }