xref: /titanic_50/usr/src/uts/sun4v/os/ppage.c (revision bdfc6d18da790deeec2e0eb09c625902defe2498)
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/systm.h>
31 #include <sys/archsystm.h>
32 #include <sys/machsystm.h>
33 #include <sys/t_lock.h>
34 #include <sys/vmem.h>
35 #include <sys/mman.h>
36 #include <sys/vm.h>
37 #include <sys/cpu.h>
38 #include <sys/cmn_err.h>
39 #include <sys/cpuvar.h>
40 #include <sys/atomic.h>
41 #include <vm/as.h>
42 #include <vm/hat.h>
43 #include <vm/as.h>
44 #include <vm/page.h>
45 #include <vm/seg.h>
46 #include <vm/seg_kmem.h>
47 #include <vm/hat_sfmmu.h>
48 #include <sys/debug.h>
49 #include <sys/cpu_module.h>
50 
51 /*
52  * A quick way to generate a cache consistent address to map in a page.
53  * users: ppcopy, pagezero, /proc, dev/mem
54  *
55  * The ppmapin/ppmapout routines provide a quick way of generating a cache
56  * consistent address by reserving a given amount of kernel address space.
57  * The base is PPMAPBASE and its size is PPMAPSIZE.  This memory is divided
58  * into x number of sets, where x is the number of colors for the virtual
59  * cache. The number of colors is how many times a page can be mapped
60  * simulatenously in the cache.  For direct map caches this translates to
61  * the number of pages in the cache.
62  * Each set will be assigned a group of virtual pages from the reserved memory
63  * depending on its virtual color.
64  * When trying to assign a virtual address we will find out the color for the
65  * physical page in question (if applicable).  Then we will try to find an
66  * available virtual page from the set of the appropiate color.
67  */
68 
69 #define	clsettoarray(color, set) ((color * nsets) + set)
70 
71 int pp_slots = 4;		/* small default, tuned by cpu module */
72 
73 /* tuned by cpu module, default is "safe" */
74 int pp_consistent_coloring = PPAGE_STORES_POLLUTE | PPAGE_LOADS_POLLUTE;
75 
76 static caddr_t	ppmap_vaddrs[PPMAPSIZE / MMU_PAGESIZE];
77 static int	nsets;			/* number of sets */
78 static int	ppmap_pages;		/* generate align mask */
79 static int	ppmap_shift;		/* set selector */
80 
81 #ifdef PPDEBUG
82 #define		MAXCOLORS	16	/* for debug only */
83 static int	ppalloc_noslot = 0;	/* # of allocations from kernelmap */
84 static int	align_hits[MAXCOLORS];
85 static int	pp_allocs;		/* # of ppmapin requests */
86 #endif /* PPDEBUG */
87 
88 /*
89  * There are only 64 TLB entries on spitfire, 16 on cheetah
90  * (fully-associative TLB) so we allow the cpu module to tune the
91  * number to use here via pp_slots.
92  */
93 static struct ppmap_va {
94 	caddr_t	ppmap_slots[MAXPP_SLOTS];
95 } ppmap_va[NCPU];
96 
97 void
98 ppmapinit(void)
99 {
100 	int color, nset, setsize;
101 	caddr_t va;
102 
103 	ASSERT(pp_slots <= MAXPP_SLOTS);
104 
105 	va = (caddr_t)PPMAPBASE;
106 	if (cache & CACHE_VAC) {
107 		int a;
108 
109 		ppmap_pages = mmu_btop(shm_alignment);
110 		nsets = PPMAPSIZE / shm_alignment;
111 		setsize = shm_alignment;
112 		ppmap_shift = MMU_PAGESHIFT;
113 		a = ppmap_pages;
114 		while (a >>= 1)
115 			ppmap_shift++;
116 	} else {
117 		/*
118 		 * If we do not have a virtual indexed cache we simply
119 		 * have only one set containing all pages.
120 		 */
121 		ppmap_pages = 1;
122 		nsets = mmu_btop(PPMAPSIZE);
123 		setsize = MMU_PAGESIZE;
124 		ppmap_shift = MMU_PAGESHIFT;
125 	}
126 	for (color = 0; color < ppmap_pages; color++) {
127 		for (nset = 0; nset < nsets; nset++) {
128 			ppmap_vaddrs[clsettoarray(color, nset)] =
129 			    (caddr_t)((uintptr_t)va + (nset * setsize));
130 		}
131 		va += MMU_PAGESIZE;
132 	}
133 }
134 
135 /*
136  * Allocate a cache consistent virtual address to map a page, pp,
137  * with protection, vprot; and map it in the MMU, using the most
138  * efficient means possible.  The argument avoid is a virtual address
139  * hint which when masked yields an offset into a virtual cache
140  * that should be avoided when allocating an address to map in a
141  * page.  An avoid arg of -1 means you don't care, for instance pagezero.
142  *
143  * machine dependent, depends on virtual address space layout,
144  * understands that all kernel addresses have bit 31 set.
145  *
146  * NOTE: For sun4 platforms the meaning of the hint argument is opposite from
147  * that found in other architectures.  In other architectures the hint
148  * (called avoid) was used to ask ppmapin to NOT use the specified cache color.
149  * This was used to avoid virtual cache trashing in the bcopy.  Unfortunately
150  * in the case of a COW,  this later on caused a cache aliasing conflict.  In
151  * sun4, the bcopy routine uses the block ld/st instructions so we don't have
152  * to worry about virtual cache trashing.  Actually, by using the hint to choose
153  * the right color we can almost guarantee a cache conflict will not occur.
154  */
155 
156 caddr_t
157 ppmapin(page_t *pp, uint_t vprot, caddr_t hint)
158 {
159 	int color, nset, index, start;
160 	caddr_t va;
161 
162 #ifdef PPDEBUG
163 	pp_allocs++;
164 #endif /* PPDEBUG */
165 	if (cache & CACHE_VAC) {
166 		color = sfmmu_get_ppvcolor(pp);
167 		if (color == -1) {
168 			if ((intptr_t)hint != -1L) {
169 				color = addr_to_vcolor(hint);
170 			} else {
171 				color = addr_to_vcolor(mmu_ptob(pp->p_pagenum));
172 			}
173 		}
174 
175 	} else {
176 		/*
177 		 * For physical caches, we can pick any address we want.
178 		 */
179 		color = 0;
180 	}
181 
182 	start = color;
183 	do {
184 		for (nset = 0; nset < nsets; nset++) {
185 			index = clsettoarray(color, nset);
186 			va = ppmap_vaddrs[index];
187 			if (va != NULL) {
188 #ifdef PPDEBUG
189 				align_hits[color]++;
190 #endif /* PPDEBUG */
191 				if (casptr(&ppmap_vaddrs[index],
192 				    va, NULL) == va) {
193 					hat_memload(kas.a_hat, va, pp,
194 						vprot | HAT_NOSYNC,
195 						HAT_LOAD_LOCK);
196 					return (va);
197 				}
198 			}
199 		}
200 		/*
201 		 * first pick didn't succeed, try another
202 		 */
203 		if (++color == ppmap_pages)
204 			color = 0;
205 	} while (color != start);
206 
207 #ifdef PPDEBUG
208 	ppalloc_noslot++;
209 #endif /* PPDEBUG */
210 
211 	/*
212 	 * No free slots; get a random one from the kernel heap area.
213 	 */
214 	va = vmem_alloc(heap_arena, PAGESIZE, VM_SLEEP);
215 
216 	hat_memload(kas.a_hat, va, pp, vprot | HAT_NOSYNC, HAT_LOAD_LOCK);
217 
218 	return (va);
219 
220 }
221 
222 void
223 ppmapout(caddr_t va)
224 {
225 	int color, nset, index;
226 
227 	if (va >= kernelheap && va < ekernelheap) {
228 		/*
229 		 * Space came from kernelmap, flush the page and
230 		 * return the space.
231 		 */
232 		hat_unload(kas.a_hat, va, PAGESIZE,
233 		    (HAT_UNLOAD_NOSYNC | HAT_UNLOAD_UNLOCK));
234 		vmem_free(heap_arena, va, PAGESIZE);
235 	} else {
236 		/*
237 		 * Space came from ppmap_vaddrs[], give it back.
238 		 */
239 		color = addr_to_vcolor(va);
240 		ASSERT((cache & CACHE_VAC)? (color < ppmap_pages) : 1);
241 
242 		nset = ((uintptr_t)va >> ppmap_shift) & (nsets - 1);
243 		index = clsettoarray(color, nset);
244 		hat_unload(kas.a_hat, va, PAGESIZE,
245 		    (HAT_UNLOAD_NOSYNC | HAT_UNLOAD_UNLOCK));
246 
247 		ASSERT(ppmap_vaddrs[index] == NULL);
248 		ppmap_vaddrs[index] = va;
249 	}
250 }
251 
252 #ifdef DEBUG
253 #define	PP_STAT_ADD(stat)	(stat)++
254 uint_t pload, ploadfail;
255 uint_t ppzero, ppzero_short;
256 #else
257 #define	PP_STAT_ADD(stat)
258 #endif /* DEBUG */
259 
260 static void
261 pp_unload_tlb(caddr_t *pslot, caddr_t va)
262 {
263 	ASSERT(*pslot == va);
264 
265 	vtag_flushpage(va, KCONTEXT);
266 	*pslot = NULL;				/* release the slot */
267 }
268 
269 /*
270  * Routine to copy kernel pages during relocation.  It will copy one
271  * PAGESIZE page to another PAGESIZE page.  This function may be called
272  * above LOCK_LEVEL so it should not grab any locks.
273  */
274 void
275 ppcopy_kernel__relocatable(page_t *fm_pp, page_t *to_pp)
276 {
277 	uint64_t fm_pa, to_pa;
278 	size_t nbytes;
279 
280 	fm_pa = (uint64_t)(fm_pp->p_pagenum) << MMU_PAGESHIFT;
281 	to_pa = (uint64_t)(to_pp->p_pagenum) << MMU_PAGESHIFT;
282 
283 	nbytes = MMU_PAGESIZE;
284 
285 	for (; nbytes > 0; fm_pa += 32, to_pa += 32, nbytes -= 32)
286 		hw_pa_bcopy32(fm_pa, to_pa);
287 }
288 
289 /*
290  * Copy the data from the physical page represented by "frompp" to
291  * that represented by "topp".
292  *
293  * Try to use per cpu mapping first, if that fails then call pp_mapin
294  * to load it.
295  */
296 void
297 ppcopy(page_t *fm_pp, page_t *to_pp)
298 {
299 	caddr_t fm_va, to_va;
300 
301 	fm_va = ppmapin(fm_pp, PROT_READ, (caddr_t)-1);
302 	to_va = ppmapin(to_pp, PROT_READ | PROT_WRITE, fm_va);
303 	bcopy(fm_va, to_va, PAGESIZE);
304 	ppmapout(fm_va);
305 	ppmapout(to_va);
306 }
307 
308 /*
309  * Zero the physical page from off to off + len given by `pp'
310  * without changing the reference and modified bits of page.
311  *
312  * Again, we'll try per cpu mapping first.
313  */
314 void
315 pagezero(page_t *pp, uint_t off, uint_t len)
316 {
317 	caddr_t va;
318 	extern int hwblkclr(void *, size_t);
319 	extern int use_hw_bzero;
320 
321 	ASSERT((int)len > 0 && (int)off >= 0 && off + len <= PAGESIZE);
322 	ASSERT(PAGE_LOCKED(pp));
323 
324 	PP_STAT_ADD(ppzero);
325 
326 	if (len != MMU_PAGESIZE || !use_hw_bzero) {
327 		PP_STAT_ADD(ppzero_short);
328 	}
329 
330 	kpreempt_disable();
331 
332 	va = ppmapin(pp, PROT_READ | PROT_WRITE, (caddr_t)-1);
333 
334 	if (!use_hw_bzero) {
335 		bzero(va + off, len);
336 		sync_icache(va + off, len);
337 	} else if (hwblkclr(va + off, len)) {
338 		/*
339 		 * We may not have used block commit asi.
340 		 * So flush the I-$ manually
341 		 */
342 		sync_icache(va + off, len);
343 	} else {
344 		/*
345 		 * We have used blk commit, and flushed the I-$. However we
346 		 * still may have an instruction in the pipeline. Only a flush
347 		 * instruction will invalidate that.
348 		 */
349 		doflush(va);
350 	}
351 
352 	ppmapout(va);
353 	kpreempt_enable();
354 }
355