xref: /titanic_41/usr/src/uts/sun4u/io/iocache.c (revision f808c858fa61e7769218966759510a8b1190dfcf)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/conf.h>
31 #include <sys/ddi.h>
32 #include <sys/sunddi.h>
33 #include <sys/ddi_impldefs.h>
34 #include <sys/cmn_err.h>
35 #include <vm/hat_sfmmu.h>
36 
37 #include <sys/iommu.h>
38 #include <sys/iocache.h>
39 #include <sys/sysiosbus.h>
40 
41 #include <sys/nexusdebug.h>
42 #include <sys/debug.h>
43 
44 #define	IOCACHE_REGISTERS_DEBUG		0x1
45 #define	IOCACHE_SYNC_DEBUG		0x2
46 #define	IOCACHE_DIAG_REG_DEBUG		0x4
47 #define	IOCACHE_SYNC_FAIL_DEBUG		0x8
48 
49 #define	MAX_RETRY			10
50 
51 /* Flag which enables the streaming buffer */
52 int stream_buf_on = 1;
53 /*
54  * This is the number of pages that a mapping request needs before we force
55  * the streaming buffer sync code to use diagnostic registers.  This value
56  * was determined through a series of test runs measuring dma mapping
57  * setup performance.
58  */
59 int stream_buf_sync_using_diag = 36;
60 
61 int
62 stream_buf_init(struct sbus_soft_state *softsp, caddr_t address)
63 {
64 	uchar_t version;
65 #ifdef DEBUG
66 	debug_info = 1;
67 	debug_print_level = 0;
68 #endif
69 	version = (uchar_t)(*softsp->sysio_ctrl_reg >> SYSIO_VER_SHIFT);
70 	version &= 0xf;
71 
72 	if (stream_buf_on == 0 || version == 0) {
73 		softsp->stream_buf_off = STREAM_BUF_OFF;
74 		if (version == 0)
75 			cmn_err(CE_CONT, "Disabling streaming buffer due to "
76 			    "SYSIO Rev %d.\n", version);
77 		return (DDI_SUCCESS);
78 	}
79 
80 	/*
81 	 * Simply add each registers offset to the base address
82 	 * to calculate the already mapped virtual address of
83 	 * the device register...
84 	 *
85 	 * define a macro for the pointer arithmetic; all registers
86 	 * are 64 bits wide and are defined as uint64_t's.
87 	 */
88 
89 #define	REG_ADDR(b, o)	(uint64_t *)((caddr_t)(b) + (o))
90 
91 	softsp->str_buf_ctrl_reg = REG_ADDR(address, OFF_STR_BUF_CTRL_REG);
92 	softsp->str_buf_flush_reg = REG_ADDR(address, OFF_STR_BUF_FLUSH_REG);
93 	softsp->str_buf_sync_reg = REG_ADDR(address, OFF_STR_BUF_SYNC_REG);
94 	softsp->str_buf_pg_tag_diag = REG_ADDR(address, STR_BUF_PAGE_TAG_DIAG);
95 
96 #undef	REG_ADDR
97 
98 	DPRINTF(IOCACHE_REGISTERS_DEBUG, ("Streaming buffer control reg: 0x%p, "
99 	    "Streaming buffer flush reg: 0x%p, Streaming buffer sync reg: 0x%p",
100 	    softsp->str_buf_ctrl_reg, softsp->str_buf_flush_reg,
101 	    softsp->str_buf_sync_reg));
102 
103 	/* Initialize stream buffer sync reg mutex */
104 	mutex_init(&softsp->sync_reg_lock, NULL, MUTEX_DEFAULT, NULL);
105 
106 	/* Turn on per instance streaming buffer flag */
107 	softsp->stream_buf_off = 0;
108 
109 	/* Set the hardware registers */
110 	(void) stream_buf_resume_init(softsp);
111 
112 	return (DDI_SUCCESS);
113 }
114 
115 int
116 stream_buf_uninit(struct sbus_soft_state *softsp)
117 {
118 	/* Turn off per instance streaming buffer flag */
119 	softsp->stream_buf_off = 1;
120 
121 	/* Turn off the streaming buffer */
122 	*softsp->str_buf_ctrl_reg = STREAM_BUF_DISABLE;
123 
124 	return (DDI_SUCCESS);
125 }
126 /*
127  * Initialize stream buf hardware when the system is being resumed.
128  * (Subset of stream_buf_init())
129  */
130 int
131 stream_buf_resume_init(struct sbus_soft_state *softsp)
132 {
133 	uchar_t version;
134 
135 	version = (uchar_t)(*softsp->sysio_ctrl_reg >> SYSIO_VER_SHIFT);
136 	version &= 0xf;
137 
138 	if (stream_buf_on == 0 || version == 0) {
139 		softsp->stream_buf_off = STREAM_BUF_OFF;
140 		return (DDI_SUCCESS);
141 	}
142 
143 	/* Turn on the streaming buffer */
144 	*softsp->str_buf_ctrl_reg = STREAM_BUF_ENABLE;
145 
146 	return (DDI_SUCCESS);
147 }
148 
149 /*
150  * The SYSIO spec says that it will get back to us within 0.5 seconds,
151  * but loaded systems have seen response times over 1.5 seconds.  We
152  * err on the side of caution and set the timeout to be 10 seconds.
153  */
154 #define	SCACHE_NSEC_WAIT	(10ull * NANOSEC)
155 
156 /*
157  * We want to avoid using gethrtime every time we check sync_flag,
158  * so we take SCACHE_SPIN laps before beginning to use gethrtime.
159  */
160 #define	SCACHE_SPIN		10000000
161 
162 void
163 sync_stream_buf(struct sbus_soft_state *softsp, ioaddr_t addr, uint_t npages,
164 	int *sync_flag, uint64_t phys_sync_flag)
165 {
166 #ifndef lint
167 	volatile uint64_t tmp;
168 #endif
169 
170 	int cntr = 0;
171 
172 	if (softsp->stream_buf_off != 0)
173 		return;
174 
175 	DPRINTF(IOCACHE_SYNC_DEBUG, ("sync_stream_buf: ioaddr 0x%x, page cnt "
176 	    "0x%x, sync flag 0x%p, sync flag pf 0x%lx\n", addr, npages,
177 	    sync_flag, phys_sync_flag));
178 
179 	ASSERT(npages > (uint_t)0);
180 
181 	/* Acquire the sync lock */
182 	mutex_enter(&softsp->sync_reg_lock);
183 
184 	*sync_flag = 0;
185 
186 	if (npages > stream_buf_sync_using_diag) {
187 		int i;
188 		volatile uint64_t *reg_addr;
189 		uint64_t reg;
190 		uint_t ioaddr;
191 		uint_t hiaddr = addr + (npages * IOMMU_PAGESIZE);
192 		int do_sync = 0;
193 
194 		for (i = 0, reg_addr = softsp->str_buf_pg_tag_diag;
195 		    i < STREAM_CACHE_LINES; i++, reg_addr++) {
196 
197 			/* Read the page tag diag reg */
198 			reg = *reg_addr;
199 #ifdef DEBUG
200 			{
201 				uint_t hi, lo;
202 				hi = (uint_t)(reg >> 32);
203 				lo = (uint_t)(reg & 0xffffffff);
204 				DPRINTF(IOCACHE_DIAG_REG_DEBUG,
205 				    ("IO cache line diag "
206 				    "reg addr 0x%p, hi0x%x lo0x%x\n",
207 				    reg_addr, hi, lo));
208 			}
209 #endif /* DEBUG */
210 			/* Check for a valid line */
211 			if (reg & STR_PG_VALID) {
212 				ioaddr = (uint_t)reg << STR_PG_SHIFT;
213 
214 				DPRINTF(IOCACHE_DIAG_REG_DEBUG, ("ioaddr 0x%x, "
215 				    "range base 0x%x, range extent 0x%x\n",
216 				    ioaddr, addr,
217 				    addr + (npages * IOMMU_PAGESIZE)));
218 				if (ioaddr >= addr && ioaddr <= hiaddr) {
219 					*softsp->str_buf_flush_reg = (uint64_t)
220 					    ioaddr;
221 					do_sync = 1;
222 				}
223 			}
224 		}
225 
226 		if (!do_sync) {
227 			mutex_exit(&softsp->sync_reg_lock);
228 			return;
229 		}
230 	} else {
231 		do {
232 			*softsp->str_buf_flush_reg = (uint64_t)addr;
233 			addr += IOMMU_PAGESIZE;
234 			npages--;
235 		} while (npages > (uint_t)0);
236 	}
237 
238 	/* Ask the hardware to flag when the flush is complete */
239 	*softsp->str_buf_sync_reg = phys_sync_flag;
240 
241 #ifndef lint
242 	/*
243 	 * Due to the sun4u memory models, this noncached load will sync the
244 	 * order of all prior loads and stores regardless of cacheability.
245 	 * No membar_stst() is needed after zeroing the flush sync flag.
246 	 */
247 	tmp = *softsp->sbus_ctrl_reg;
248 #endif
249 
250 	/*
251 	 * Begin spinning on the hardware sync register.  We'll spin for
252 	 * a while (SCACHE_SPIN) before using gethrtime, but once that time
253 	 * is up we'll drop into an inner loop where we use gethrtime on
254 	 * every iteration.  Once SCACHE_NSEC_WAIT nanoseconds have
255 	 * elapsed, we'll assume a Bad Thing has happened and toss.
256 	 */
257 	while (!*((volatile int *)sync_flag)) {
258 		if (cntr++ == SCACHE_SPIN) {
259 			/*
260 			 * If we're here, then we've spun long enough
261 			 * to justify use of gethrtime each iteration.
262 			 */
263 			hrtime_t nsec_start, nsectowait, nsec_current;
264 			nsectowait = SCACHE_NSEC_WAIT;
265 			nsec_current = nsec_start = gethrtime();
266 
267 			while (!*((volatile int *)sync_flag)) {
268 				/*
269 				 * Double check the sync flag again before
270 				 * we panic in case we get preempted.
271 				 * See bugid 4126896
272 				 */
273 				nsec_current = gethrtime();
274 				if ((nsec_current - nsec_start) > nsectowait &&
275 				!*((volatile int *)sync_flag)) {
276 					/*
277 					 * Trouble.  The SYSIO chip has
278 					 * seemingly gone AWOL.  Vomit.
279 					 */
280 					panic("streaming buffer timed out");
281 				}
282 			}
283 		}
284 	}
285 
286 	/* Finally, drop the sync lock */
287 	mutex_exit(&softsp->sync_reg_lock);
288 }
289