1/*
2 * Copyright 2002/03, Thomas Kurschel. All rights reserved.
3 * Distributed under the terms of the MIT License.
4 */
5
6/*
7	Part of Open SCSI bus manager
8
9	Bus node layer.
10
11	Whenever a controller driver publishes a new controller, a new SCSI bus
12	for public and internal use is registered in turn. After that, this
13	bus is told to rescan for devices. For each device, there is a
14	device registered for peripheral drivers. (see devices.c)
15*/
16
17#include "scsi_internal.h"
18
19#include <string.h>
20#include <malloc.h>
21
22
23// bus service should hurry up a bit - good controllers don't take much time
24// but are very happy to be busy; don't make it realtime though as we
25// don't really need that but would risk to steel processing power of
26// realtime-demanding threads
27#define BUS_SERVICE_PRIORITY B_URGENT_DISPLAY_PRIORITY
28
29
30/**	implementation of service thread:
31 *	it handles DPC and pending requests
32 */
33
34static void
35scsi_do_service(scsi_bus_info *bus)
36{
37	while (true) {
38		SHOW_FLOW0( 3, "" );
39
40		// handle DPCs first as they are more urgent
41		if (scsi_check_exec_dpc(bus))
42			continue;
43
44		if (scsi_check_exec_service(bus))
45			continue;
46
47		break;
48	}
49}
50
51
52/** main loop of service thread */
53
54static int32
55scsi_service_threadproc(void *arg)
56{
57	scsi_bus_info *bus = (scsi_bus_info *)arg;
58	int32 processed_notifications = 0;
59
60	SHOW_FLOW(3, "bus = %p", bus);
61
62	while (true) {
63		// we handle multiple requests in scsi_do_service at once;
64		// to save time, we will acquire all notifications that are sent
65		// up to now at once.
66		// (Sadly, there is no "set semaphore to zero" function, so this
67		//  is a poor-man emulation)
68		acquire_sem_etc(bus->start_service, processed_notifications + 1, 0, 0);
69
70		SHOW_FLOW0( 3, "1" );
71
72		if (bus->shutting_down)
73			break;
74
75		// get number of notifications _before_ servicing to make sure no new
76		// notifications are sent after do_service()
77		get_sem_count(bus->start_service, &processed_notifications);
78
79		scsi_do_service(bus);
80	}
81
82	return 0;
83}
84
85
86static scsi_bus_info *
87scsi_create_bus(device_node *node, uint8 path_id)
88{
89	scsi_bus_info *bus;
90	int res;
91
92	SHOW_FLOW0(3, "");
93
94	bus = (scsi_bus_info *)malloc(sizeof(*bus));
95	if (bus == NULL)
96		return NULL;
97
98	memset(bus, 0, sizeof(*bus));
99
100	bus->path_id = path_id;
101
102	if (pnp->get_attr_uint32(node, SCSI_DEVICE_MAX_TARGET_COUNT, &bus->max_target_count, true) != B_OK)
103		bus->max_target_count = MAX_TARGET_ID + 1;
104
105	bus->node = node;
106	bus->lock_count = bus->blocked[0] = bus->blocked[1] = 0;
107	bus->sim_overflow = 0;
108	bus->shutting_down = false;
109
110	bus->waiting_devices = NULL;
111	//bus->resubmitted_req = NULL;
112
113	bus->dpc_list = NULL;
114
115	if ((bus->scan_lun_lock = create_sem(1, "scsi_scan_lun_lock")) < 0) {
116		res = bus->scan_lun_lock;
117		goto err6;
118	}
119
120	bus->start_service = create_sem(0, "scsi_start_service");
121	if (bus->start_service < 0) {
122		res = bus->start_service;
123		goto err4;
124	}
125
126	res = INIT_BEN(&bus->mutex, "scsi_bus_mutex");
127	if (res < B_OK)
128		goto err3;
129
130	spinlock_irq_init(&bus->dpc_lock);
131
132	res = scsi_init_ccb_alloc(bus);
133	if (res < B_OK)
134		goto err2;
135
136	bus->service_thread = spawn_kernel_thread(scsi_service_threadproc,
137		"scsi_bus_service", BUS_SERVICE_PRIORITY, bus);
138
139	if (bus->service_thread < 0) {
140		res = bus->service_thread;
141		goto err1;
142	}
143
144	resume_thread(bus->service_thread);
145
146	return bus;
147
148err1:
149	scsi_uninit_ccb_alloc(bus);
150err2:
151	DELETE_BEN(&bus->mutex);
152err3:
153	delete_sem(bus->start_service);
154err4:
155	delete_sem(bus->scan_lun_lock);
156err6:
157	free(bus);
158	return NULL;
159}
160
161
162static status_t
163scsi_destroy_bus(scsi_bus_info *bus)
164{
165	int32 retcode;
166
167	// noone is using this bus now, time to clean it up
168	bus->shutting_down = true;
169	release_sem(bus->start_service);
170
171	wait_for_thread(bus->service_thread, &retcode);
172
173	delete_sem(bus->start_service);
174	DELETE_BEN(&bus->mutex);
175	delete_sem(bus->scan_lun_lock);
176
177	scsi_uninit_ccb_alloc(bus);
178
179	return B_OK;
180}
181
182
183static status_t
184scsi_init_bus(device_node *node, void **cookie)
185{
186	uint8 path_id;
187	scsi_bus_info *bus;
188	status_t res;
189
190	SHOW_FLOW0( 3, "" );
191
192	if (pnp->get_attr_uint8(node, SCSI_BUS_PATH_ID_ITEM, &path_id, false) != B_OK)
193		return B_ERROR;
194
195	bus = scsi_create_bus(node, path_id);
196	if (bus == NULL)
197		return B_NO_MEMORY;
198
199	// extract controller/protocoll restrictions from node
200	if (pnp->get_attr_uint32(node, B_DMA_ALIGNMENT, &bus->dma_params.alignment,
201			true) != B_OK)
202		bus->dma_params.alignment = 0;
203	if (pnp->get_attr_uint32(node, B_DMA_MAX_TRANSFER_BLOCKS,
204			&bus->dma_params.max_blocks, true) != B_OK)
205		bus->dma_params.max_blocks = 0xffffffff;
206	if (pnp->get_attr_uint32(node, B_DMA_BOUNDARY,
207			&bus->dma_params.dma_boundary, true) != B_OK)
208		bus->dma_params.dma_boundary = ~0;
209	if (pnp->get_attr_uint32(node, B_DMA_MAX_SEGMENT_BLOCKS,
210			&bus->dma_params.max_sg_block_size, true) != B_OK)
211		bus->dma_params.max_sg_block_size = 0xffffffff;
212	if (pnp->get_attr_uint32(node, B_DMA_MAX_SEGMENT_COUNT,
213			&bus->dma_params.max_sg_blocks, true) != B_OK)
214		bus->dma_params.max_sg_blocks = ~0;
215
216	// do some sanity check:
217	bus->dma_params.max_sg_block_size &= ~bus->dma_params.alignment;
218
219	if (bus->dma_params.alignment > B_PAGE_SIZE) {
220		SHOW_ERROR(0, "Alignment (0x%x) must be less then B_PAGE_SIZE",
221			(int)bus->dma_params.alignment);
222		res = B_ERROR;
223		goto err;
224	}
225
226	if (bus->dma_params.max_sg_block_size < 1) {
227		SHOW_ERROR(0, "Max s/g block size (0x%x) is too small",
228			(int)bus->dma_params.max_sg_block_size);
229		res = B_ERROR;
230		goto err;
231	}
232
233	if (bus->dma_params.dma_boundary < B_PAGE_SIZE - 1) {
234		SHOW_ERROR(0, "DMA boundary (0x%x) must be at least B_PAGE_SIZE",
235			(int)bus->dma_params.dma_boundary);
236		res = B_ERROR;
237		goto err;
238	}
239
240	if (bus->dma_params.max_blocks < 1 || bus->dma_params.max_sg_blocks < 1) {
241		SHOW_ERROR(0, "Max blocks (%d) and max s/g blocks (%d) must be at least 1",
242			(int)bus->dma_params.max_blocks, (int)bus->dma_params.max_sg_blocks);
243		res = B_ERROR;
244		goto err;
245	}
246
247	{
248		device_node *parent = pnp->get_parent_node(node);
249		pnp->get_driver(parent, (driver_module_info **)&bus->interface,
250			(void **)&bus->sim_cookie);
251		pnp->put_node(parent);
252
253		bus->interface->set_scsi_bus(bus->sim_cookie, bus);
254	}
255
256	// cache inquiry data
257	scsi_inquiry_path(bus, &bus->inquiry_data);
258
259	// get max. number of commands on bus
260	bus->left_slots = bus->inquiry_data.hba_queue_size;
261	SHOW_FLOW( 3, "Bus has %d slots", bus->left_slots );
262
263	*cookie = bus;
264
265	return B_OK;
266
267err:
268	scsi_destroy_bus(bus);
269	return res;
270}
271
272
273static void
274scsi_uninit_bus(scsi_bus_info *bus)
275{
276	scsi_destroy_bus(bus);
277}
278
279
280uchar
281scsi_inquiry_path(scsi_bus bus, scsi_path_inquiry *inquiry_data)
282{
283	SHOW_FLOW(4, "path_id=%d", bus->path_id);
284	return bus->interface->path_inquiry(bus->sim_cookie, inquiry_data);
285}
286
287
288static uchar
289scsi_reset_bus(scsi_bus_info *bus)
290{
291	return bus->interface->reset_bus(bus->sim_cookie);
292}
293
294
295static status_t
296scsi_bus_module_init(void)
297{
298	SHOW_FLOW0(4, "");
299	return init_temp_sg();
300}
301
302
303static status_t
304scsi_bus_module_uninit(void)
305{
306	SHOW_INFO0(4, "");
307
308	uninit_temp_sg();
309	return B_OK;
310}
311
312
313static status_t
314std_ops(int32 op, ...)
315{
316	switch (op) {
317		case B_MODULE_INIT:
318			return scsi_bus_module_init();
319		case B_MODULE_UNINIT:
320			return scsi_bus_module_uninit();
321
322		default:
323			return B_ERROR;
324	}
325}
326
327
328scsi_bus_interface scsi_bus_module = {
329	{
330		{
331			SCSI_BUS_MODULE_NAME,
332			0,
333			std_ops
334		},
335
336		NULL,	// supported devices
337		NULL,	// register node
338		scsi_init_bus,
339		(void (*)(void *))scsi_uninit_bus,
340		(status_t (*)(void *))scsi_scan_bus,
341		(status_t (*)(void *))scsi_scan_bus,
342		NULL
343	},
344
345	scsi_inquiry_path,
346	scsi_reset_bus,
347};
348