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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/iommu.h> | |
32 | #include <asm/hvcall.h> | |
33 | #include <linux/dma-mapping.h> | |
34 | #include <linux/interrupt.h> | |
35 | #include "ibmvscsi.h" | |
36 | ||
37 | /* ------------------------------------------------------------ | |
38 | * Routines for managing the command/response queue | |
39 | */ | |
40 | /** | |
41 | * ibmvscsi_handle_event: - Interrupt handler for crq events | |
42 | * @irq: number of irq to handle, not used | |
43 | * @dev_instance: ibmvscsi_host_data of host that received interrupt | |
44 | * @regs: pt_regs with registers | |
45 | * | |
46 | * Disables interrupts and schedules srp_task | |
47 | * Always returns IRQ_HANDLED | |
48 | */ | |
49 | static irqreturn_t ibmvscsi_handle_event(int irq, | |
50 | void *dev_instance, | |
51 | struct pt_regs *regs) | |
52 | { | |
53 | struct ibmvscsi_host_data *hostdata = | |
54 | (struct ibmvscsi_host_data *)dev_instance; | |
55 | vio_disable_interrupts(to_vio_dev(hostdata->dev)); | |
56 | tasklet_schedule(&hostdata->srp_task); | |
57 | return IRQ_HANDLED; | |
58 | } | |
59 | ||
60 | /** | |
61 | * release_crq_queue: - Deallocates data and unregisters CRQ | |
62 | * @queue: crq_queue to initialize and register | |
63 | * @host_data: ibmvscsi_host_data of host | |
64 | * | |
65 | * Frees irq, deallocates a page for messages, unmaps dma, and unregisters | |
66 | * the crq with the hypervisor. | |
67 | */ | |
68 | void ibmvscsi_release_crq_queue(struct crq_queue *queue, | |
69 | struct ibmvscsi_host_data *hostdata, | |
70 | int max_requests) | |
71 | { | |
72 | long rc; | |
73 | struct vio_dev *vdev = to_vio_dev(hostdata->dev); | |
74 | free_irq(vdev->irq, (void *)hostdata); | |
75 | tasklet_kill(&hostdata->srp_task); | |
76 | do { | |
77 | rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address); | |
78 | } while ((rc == H_Busy) || (H_isLongBusy(rc))); | |
79 | dma_unmap_single(hostdata->dev, | |
80 | queue->msg_token, | |
81 | queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL); | |
82 | free_page((unsigned long)queue->msgs); | |
83 | } | |
84 | ||
85 | /** | |
86 | * crq_queue_next_crq: - Returns the next entry in message queue | |
87 | * @queue: crq_queue to use | |
88 | * | |
89 | * Returns pointer to next entry in queue, or NULL if there are no new | |
90 | * entried in the CRQ. | |
91 | */ | |
92 | static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue) | |
93 | { | |
94 | struct viosrp_crq *crq; | |
95 | unsigned long flags; | |
96 | ||
97 | spin_lock_irqsave(&queue->lock, flags); | |
98 | crq = &queue->msgs[queue->cur]; | |
99 | if (crq->valid & 0x80) { | |
100 | if (++queue->cur == queue->size) | |
101 | queue->cur = 0; | |
102 | } else | |
103 | crq = NULL; | |
104 | spin_unlock_irqrestore(&queue->lock, flags); | |
105 | ||
106 | return crq; | |
107 | } | |
108 | ||
109 | /** | |
110 | * ibmvscsi_send_crq: - Send a CRQ | |
111 | * @hostdata: the adapter | |
112 | * @word1: the first 64 bits of the data | |
113 | * @word2: the second 64 bits of the data | |
114 | */ | |
115 | int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2) | |
116 | { | |
117 | struct vio_dev *vdev = to_vio_dev(hostdata->dev); | |
118 | ||
119 | return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2); | |
120 | } | |
121 | ||
122 | /** | |
123 | * ibmvscsi_task: - Process srps asynchronously | |
124 | * @data: ibmvscsi_host_data of host | |
125 | */ | |
126 | static void ibmvscsi_task(void *data) | |
127 | { | |
128 | struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data; | |
129 | struct vio_dev *vdev = to_vio_dev(hostdata->dev); | |
130 | struct viosrp_crq *crq; | |
131 | int done = 0; | |
132 | ||
133 | while (!done) { | |
134 | /* Pull all the valid messages off the CRQ */ | |
135 | while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) { | |
136 | ibmvscsi_handle_crq(crq, hostdata); | |
137 | crq->valid = 0x00; | |
138 | } | |
139 | ||
140 | vio_enable_interrupts(vdev); | |
141 | if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) { | |
142 | vio_disable_interrupts(vdev); | |
143 | ibmvscsi_handle_crq(crq, hostdata); | |
144 | crq->valid = 0x00; | |
145 | } else { | |
146 | done = 1; | |
147 | } | |
148 | } | |
149 | } | |
150 | ||
151 | /** | |
152 | * initialize_crq_queue: - Initializes and registers CRQ with hypervisor | |
153 | * @queue: crq_queue to initialize and register | |
154 | * @hostdata: ibmvscsi_host_data of host | |
155 | * | |
156 | * Allocates a page for messages, maps it for dma, and registers | |
157 | * the crq with the hypervisor. | |
158 | * Returns zero on success. | |
159 | */ | |
160 | int ibmvscsi_init_crq_queue(struct crq_queue *queue, | |
161 | struct ibmvscsi_host_data *hostdata, | |
162 | int max_requests) | |
163 | { | |
164 | int rc; | |
165 | struct vio_dev *vdev = to_vio_dev(hostdata->dev); | |
166 | ||
167 | queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL); | |
168 | ||
169 | if (!queue->msgs) | |
170 | goto malloc_failed; | |
171 | queue->size = PAGE_SIZE / sizeof(*queue->msgs); | |
172 | ||
173 | queue->msg_token = dma_map_single(hostdata->dev, queue->msgs, | |
174 | queue->size * sizeof(*queue->msgs), | |
175 | DMA_BIDIRECTIONAL); | |
176 | ||
177 | if (dma_mapping_error(queue->msg_token)) | |
178 | goto map_failed; | |
179 | ||
180 | rc = plpar_hcall_norets(H_REG_CRQ, | |
181 | vdev->unit_address, | |
182 | queue->msg_token, PAGE_SIZE); | |
183 | if (rc == 2) { | |
184 | /* Adapter is good, but other end is not ready */ | |
185 | printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n"); | |
186 | } else if (rc != 0) { | |
187 | printk(KERN_WARNING "ibmvscsi: Error %d opening adapter\n", rc); | |
188 | goto reg_crq_failed; | |
189 | } | |
190 | ||
191 | if (request_irq(vdev->irq, | |
192 | ibmvscsi_handle_event, | |
193 | 0, "ibmvscsi", (void *)hostdata) != 0) { | |
194 | printk(KERN_ERR "ibmvscsi: couldn't register irq 0x%x\n", | |
195 | vdev->irq); | |
196 | goto req_irq_failed; | |
197 | } | |
198 | ||
199 | rc = vio_enable_interrupts(vdev); | |
200 | if (rc != 0) { | |
201 | printk(KERN_ERR "ibmvscsi: Error %d enabling interrupts!!!\n", | |
202 | rc); | |
203 | goto req_irq_failed; | |
204 | } | |
205 | ||
206 | queue->cur = 0; | |
207 | spin_lock_init(&queue->lock); | |
208 | ||
209 | tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task, | |
210 | (unsigned long)hostdata); | |
211 | ||
212 | return 0; | |
213 | ||
214 | req_irq_failed: | |
215 | do { | |
216 | rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address); | |
217 | } while ((rc == H_Busy) || (H_isLongBusy(rc))); | |
218 | reg_crq_failed: | |
219 | dma_unmap_single(hostdata->dev, | |
220 | queue->msg_token, | |
221 | queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL); | |
222 | map_failed: | |
223 | free_page((unsigned long)queue->msgs); | |
224 | malloc_failed: | |
225 | return -1; | |
226 | } | |
227 | ||
228 | /** | |
229 | * reset_crq_queue: - resets a crq after a failure | |
230 | * @queue: crq_queue to initialize and register | |
231 | * @hostdata: ibmvscsi_host_data of host | |
232 | * | |
233 | */ | |
234 | void ibmvscsi_reset_crq_queue(struct crq_queue *queue, | |
235 | struct ibmvscsi_host_data *hostdata) | |
236 | { | |
237 | int rc; | |
238 | struct vio_dev *vdev = to_vio_dev(hostdata->dev); | |
239 | ||
240 | /* Close the CRQ */ | |
241 | do { | |
242 | rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address); | |
243 | } while ((rc == H_Busy) || (H_isLongBusy(rc))); | |
244 | ||
245 | /* Clean out the queue */ | |
246 | memset(queue->msgs, 0x00, PAGE_SIZE); | |
247 | queue->cur = 0; | |
248 | ||
249 | /* And re-open it again */ | |
250 | rc = plpar_hcall_norets(H_REG_CRQ, | |
251 | vdev->unit_address, | |
252 | queue->msg_token, PAGE_SIZE); | |
253 | if (rc == 2) { | |
254 | /* Adapter is good, but other end is not ready */ | |
255 | printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n"); | |
256 | } else if (rc != 0) { | |
257 | printk(KERN_WARNING | |
258 | "ibmvscsi: couldn't register crq--rc 0x%x\n", rc); | |
259 | } | |
260 | } |