xref: /titanic_41/usr/src/uts/sun4u/io/iocache.c (revision fcf3ce441efd61da9bb2884968af01cb7c1452cc)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/conf.h>
28 #include <sys/ddi.h>
29 #include <sys/sunddi.h>
30 #include <sys/ddi_impldefs.h>
31 #include <sys/cmn_err.h>
32 #include <vm/hat_sfmmu.h>
33 
34 #include <sys/iommu.h>
35 #include <sys/iocache.h>
36 #include <sys/sysiosbus.h>
37 
38 #include <sys/nexusdebug.h>
39 #include <sys/debug.h>
40 
41 #define	IOCACHE_REGISTERS_DEBUG		0x1
42 #define	IOCACHE_SYNC_DEBUG		0x2
43 #define	IOCACHE_DIAG_REG_DEBUG		0x4
44 #define	IOCACHE_SYNC_FAIL_DEBUG		0x8
45 
46 #define	MAX_RETRY			10
47 
48 /* Flag which enables the streaming buffer */
49 int stream_buf_on = 1;
50 /*
51  * This is the number of pages that a mapping request needs before we force
52  * the streaming buffer sync code to use diagnostic registers.  This value
53  * was determined through a series of test runs measuring dma mapping
54  * setup performance.
55  */
56 int stream_buf_sync_using_diag = 36;
57 
58 int
59 stream_buf_init(struct sbus_soft_state *softsp, caddr_t address)
60 {
61 	uchar_t version;
62 #ifdef DEBUG
63 	debug_info = 1;
64 	debug_print_level = 0;
65 #endif
66 	version = (uchar_t)(*softsp->sysio_ctrl_reg >> SYSIO_VER_SHIFT);
67 	version &= 0xf;
68 
69 	if (stream_buf_on == 0 || version == 0) {
70 		softsp->stream_buf_off = STREAM_BUF_OFF;
71 		if (version == 0)
72 			cmn_err(CE_CONT, "Disabling streaming buffer due to "
73 			    "SYSIO Rev %d.\n", version);
74 		return (DDI_SUCCESS);
75 	}
76 
77 	/*
78 	 * Simply add each registers offset to the base address
79 	 * to calculate the already mapped virtual address of
80 	 * the device register...
81 	 *
82 	 * define a macro for the pointer arithmetic; all registers
83 	 * are 64 bits wide and are defined as uint64_t's.
84 	 */
85 
86 #define	REG_ADDR(b, o)	(uint64_t *)((caddr_t)(b) + (o))
87 
88 	softsp->str_buf_ctrl_reg = REG_ADDR(address, OFF_STR_BUF_CTRL_REG);
89 	softsp->str_buf_flush_reg = REG_ADDR(address, OFF_STR_BUF_FLUSH_REG);
90 	softsp->str_buf_sync_reg = REG_ADDR(address, OFF_STR_BUF_SYNC_REG);
91 	softsp->str_buf_pg_tag_diag = REG_ADDR(address, STR_BUF_PAGE_TAG_DIAG);
92 
93 #undef	REG_ADDR
94 
95 	DPRINTF(IOCACHE_REGISTERS_DEBUG, ("Streaming buffer control reg: 0x%p, "
96 	    "Streaming buffer flush reg: 0x%p, Streaming buffer sync reg: 0x%p",
97 	    (void *)softsp->str_buf_ctrl_reg, (void *)softsp->str_buf_flush_reg,
98 	    (void *)softsp->str_buf_sync_reg));
99 
100 	/* Initialize stream buffer sync reg mutex */
101 	mutex_init(&softsp->sync_reg_lock, NULL, MUTEX_DEFAULT, NULL);
102 
103 	/* Turn on per instance streaming buffer flag */
104 	softsp->stream_buf_off = 0;
105 
106 	/* Set the hardware registers */
107 	(void) stream_buf_resume_init(softsp);
108 
109 	return (DDI_SUCCESS);
110 }
111 
112 int
113 stream_buf_uninit(struct sbus_soft_state *softsp)
114 {
115 	/* Turn off per instance streaming buffer flag */
116 	softsp->stream_buf_off = 1;
117 
118 	/* Turn off the streaming buffer */
119 	*softsp->str_buf_ctrl_reg = STREAM_BUF_DISABLE;
120 
121 	return (DDI_SUCCESS);
122 }
123 /*
124  * Initialize stream buf hardware when the system is being resumed.
125  * (Subset of stream_buf_init())
126  */
127 int
128 stream_buf_resume_init(struct sbus_soft_state *softsp)
129 {
130 	uchar_t version;
131 
132 	version = (uchar_t)(*softsp->sysio_ctrl_reg >> SYSIO_VER_SHIFT);
133 	version &= 0xf;
134 
135 	if (stream_buf_on == 0 || version == 0) {
136 		softsp->stream_buf_off = STREAM_BUF_OFF;
137 		return (DDI_SUCCESS);
138 	}
139 
140 	/* Turn on the streaming buffer */
141 	*softsp->str_buf_ctrl_reg = STREAM_BUF_ENABLE;
142 
143 	return (DDI_SUCCESS);
144 }
145 
146 /*
147  * The SYSIO spec says that it will get back to us within 0.5 seconds,
148  * but loaded systems have seen response times over 1.5 seconds.  We
149  * err on the side of caution and set the timeout to be 10 seconds.
150  */
151 #define	SCACHE_NSEC_WAIT	(10ull * NANOSEC)
152 
153 /*
154  * We want to avoid using gethrtime every time we check sync_flag,
155  * so we take SCACHE_SPIN laps before beginning to use gethrtime.
156  */
157 #define	SCACHE_SPIN		10000000
158 
159 void
160 sync_stream_buf(struct sbus_soft_state *softsp, ioaddr_t addr, uint_t npages,
161 	int *sync_flag, uint64_t phys_sync_flag)
162 {
163 #ifndef lint
164 	volatile uint64_t tmp;
165 #endif
166 
167 	int cntr = 0;
168 
169 	if (softsp->stream_buf_off != 0)
170 		return;
171 
172 	DPRINTF(IOCACHE_SYNC_DEBUG, ("sync_stream_buf: ioaddr 0x%x, page cnt "
173 	    "0x%x, sync flag 0x%p, sync flag pf 0x%lx\n", addr, npages,
174 	    (void *)sync_flag, phys_sync_flag));
175 
176 	ASSERT(npages > (uint_t)0);
177 
178 	/* Acquire the sync lock */
179 	mutex_enter(&softsp->sync_reg_lock);
180 
181 	*sync_flag = 0;
182 
183 	if (npages > stream_buf_sync_using_diag) {
184 		int i;
185 		volatile uint64_t *reg_addr;
186 		uint64_t reg;
187 		uint_t ioaddr;
188 		uint_t hiaddr = addr + (npages * IOMMU_PAGESIZE);
189 		int do_sync = 0;
190 
191 		for (i = 0, reg_addr = softsp->str_buf_pg_tag_diag;
192 		    i < STREAM_CACHE_LINES; i++, reg_addr++) {
193 
194 			/* Read the page tag diag reg */
195 			reg = *reg_addr;
196 #ifdef DEBUG
197 			{
198 				uint_t hi, lo;
199 				hi = (uint_t)(reg >> 32);
200 				lo = (uint_t)(reg & 0xffffffff);
201 				DPRINTF(IOCACHE_DIAG_REG_DEBUG,
202 				    ("IO cache line diag "
203 				    "reg addr 0x%p, hi0x%x lo0x%x\n",
204 				    (void *)reg_addr, hi, lo));
205 			}
206 #endif /* DEBUG */
207 			/* Check for a valid line */
208 			if (reg & STR_PG_VALID) {
209 				ioaddr = (uint_t)reg << STR_PG_SHIFT;
210 
211 				DPRINTF(IOCACHE_DIAG_REG_DEBUG, ("ioaddr 0x%x, "
212 				    "range base 0x%x, range extent 0x%x\n",
213 				    ioaddr, addr,
214 				    addr + (npages * IOMMU_PAGESIZE)));
215 				if (ioaddr >= addr && ioaddr <= hiaddr) {
216 					*softsp->str_buf_flush_reg = (uint64_t)
217 					    ioaddr;
218 					do_sync = 1;
219 				}
220 			}
221 		}
222 
223 		if (!do_sync) {
224 			mutex_exit(&softsp->sync_reg_lock);
225 			return;
226 		}
227 	} else {
228 		do {
229 			*softsp->str_buf_flush_reg = (uint64_t)addr;
230 			addr += IOMMU_PAGESIZE;
231 			npages--;
232 		} while (npages > (uint_t)0);
233 	}
234 
235 	/* Ask the hardware to flag when the flush is complete */
236 	*softsp->str_buf_sync_reg = phys_sync_flag;
237 
238 #ifndef lint
239 	/*
240 	 * Due to the sun4u memory models, this noncached load will sync the
241 	 * order of all prior loads and stores regardless of cacheability.
242 	 * No membar_stst() is needed after zeroing the flush sync flag.
243 	 */
244 	tmp = *softsp->sbus_ctrl_reg;
245 #endif
246 
247 	/*
248 	 * Begin spinning on the hardware sync register.  We'll spin for
249 	 * a while (SCACHE_SPIN) before using gethrtime, but once that time
250 	 * is up we'll drop into an inner loop where we use gethrtime on
251 	 * every iteration.  Once SCACHE_NSEC_WAIT nanoseconds have
252 	 * elapsed, we'll assume a Bad Thing has happened and toss.
253 	 */
254 	while (!*((volatile int *)sync_flag)) {
255 		if (cntr++ == SCACHE_SPIN) {
256 			/*
257 			 * If we're here, then we've spun long enough
258 			 * to justify use of gethrtime each iteration.
259 			 */
260 			hrtime_t nsec_start, nsectowait, nsec_current;
261 			nsectowait = SCACHE_NSEC_WAIT;
262 			nsec_current = nsec_start = gethrtime();
263 
264 			while (!*((volatile int *)sync_flag)) {
265 				/*
266 				 * Double check the sync flag again before
267 				 * we panic in case we get preempted.
268 				 * See bugid 4126896
269 				 */
270 				nsec_current = gethrtime();
271 				if ((nsec_current - nsec_start) > nsectowait &&
272 				    !*((volatile int *)sync_flag)) {
273 					/*
274 					 * Trouble.  The SYSIO chip has
275 					 * seemingly gone AWOL.  Vomit.
276 					 */
277 					panic("streaming buffer timed out");
278 				}
279 			}
280 		}
281 	}
282 
283 	/* Finally, drop the sync lock */
284 	mutex_exit(&softsp->sync_reg_lock);
285 }
286