xref: /plan9-contrib/sys/src/9/port/allocb.c (revision 906943f9f6b8411972abb5e3a03ed19f74be7ccc)
1 #include	"u.h"
2 #include	"../port/lib.h"
3 #include	"mem.h"
4 #include	"dat.h"
5 #include	"fns.h"
6 #include	"error.h"
7 
8 enum
9 {
10 	Hdrspc		= 64,		/* leave room for high-level headers */
11 	Bdead		= 0x51494F42,	/* "QIOB" */
12 };
13 
14 struct
15 {
16 	Lock;
17 	ulong	bytes;
18 } ialloc;
19 
20 static Block*
21 _allocb(int size)
22 {
23 	Block *b;
24 	ulong addr;
25 
26 	if((b = mallocz(sizeof(Block)+size+Hdrspc, 0)) == nil)
27 		return nil;
28 
29 	b->next = nil;
30 	b->list = nil;
31 	b->free = 0;
32 	b->flag = 0;
33 	b->ref = 0;
34 	_xinc(&b->ref);
35 
36 	/* align start of data portion by rounding up */
37 	addr = (ulong)b;
38 	addr = ROUND(addr + sizeof(Block), BLOCKALIGN);
39 	b->base = (uchar*)addr;
40 
41 	/* align end of data portion by rounding down */
42 	b->lim = ((uchar*)b) + msize(b);
43 	addr = (ulong)(b->lim);
44 	addr = addr & ~(BLOCKALIGN-1);
45 	b->lim = (uchar*)addr;
46 
47 	/* leave sluff at beginning for added headers */
48 	b->rp = b->lim - ROUND(size, BLOCKALIGN);
49 	if(b->rp < b->base)
50 		panic("_allocb");
51 	b->wp = b->rp;
52 
53 	return b;
54 }
55 
56 Block*
57 allocb(int size)
58 {
59 	Block *b;
60 
61 	/*
62 	 * Check in a process and wait until successful.
63 	 * Can still error out of here, though.
64 	 */
65 	if(up == nil)
66 		panic("allocb without up: %#p", getcallerpc(&size));
67 	if((b = _allocb(size)) == nil){
68 		xsummary();
69 		mallocsummary();
70 		panic("allocb: no memory for %d bytes", size);
71 	}
72 	setmalloctag(b, getcallerpc(&size));
73 
74 	return b;
75 }
76 
77 Block*
78 iallocb(int size)
79 {
80 	Block *b;
81 	static int m1, m2, mp;
82 
83 	if(ialloc.bytes > conf.ialloc){
84 		if((m1++%10000)==0){
85 			if(mp++ > 1000){
86 				active.exiting = 1;
87 				exit(0);
88 			}
89 			iprint("iallocb: limited %lud/%lud\n",
90 				ialloc.bytes, conf.ialloc);
91 		}
92 		return nil;
93 	}
94 
95 	if((b = _allocb(size)) == nil){
96 		if((m2++%10000)==0){
97 			if(mp++ > 1000){
98 				active.exiting = 1;
99 				exit(0);
100 			}
101 			iprint("iallocb: no memory %lud/%lud\n",
102 				ialloc.bytes, conf.ialloc);
103 		}
104 		return nil;
105 	}
106 	setmalloctag(b, getcallerpc(&size));
107 	b->flag = BINTR;
108 
109 	ilock(&ialloc);
110 	ialloc.bytes += b->lim - b->base;
111 	iunlock(&ialloc);
112 
113 	return b;
114 }
115 
116 void
117 freeb(Block *b)
118 {
119 	void *dead = (void*)Bdead;
120 	long ref;
121 
122 	if(b == nil || (ref = _xdec(&b->ref)) > 0)
123 		return;
124 
125 	if(ref < 0){
126 		dumpstack();
127 		panic("ref %ld callerpc %#p", ref, getcallerpc(&b));
128 	}
129 
130 	/*
131 	 * drivers which perform non cache coherent DMA manage their own buffer
132 	 * pool of uncached buffers and provide their own free routine.
133 	 */
134 	if(b->free) {
135 		b->free(b);
136 		return;
137 	}
138 	if(b->flag & BINTR) {
139 		ilock(&ialloc);
140 		ialloc.bytes -= b->lim - b->base;
141 		iunlock(&ialloc);
142 	}
143 
144 	/* poison the block in case someone is still holding onto it */
145 	b->next = dead;
146 	b->rp = dead;
147 	b->wp = dead;
148 	b->lim = dead;
149 	b->base = dead;
150 
151 	free(b);
152 }
153 
154 void
155 checkb(Block *b, char *msg)
156 {
157 	void *dead = (void*)Bdead;
158 
159 	if(b == dead)
160 		panic("checkb b %s %lux", msg, b);
161 	if(b->base == dead || b->lim == dead || b->next == dead
162 	  || b->rp == dead || b->wp == dead){
163 		print("checkb: base %#p lim %#p next %#p\n",
164 			b->base, b->lim, b->next);
165 		print("checkb: rp %#p wp %#p\n", b->rp, b->wp);
166 		panic("checkb dead: %s", msg);
167 	}
168 
169 	if(b->base > b->lim)
170 		panic("checkb 0 %s %#p %#p", msg, b->base, b->lim);
171 	if(b->rp < b->base)
172 		panic("checkb 1 %s %#p %#p", msg, b->base, b->rp);
173 	if(b->wp < b->base)
174 		panic("checkb 2 %s %#p %#p", msg, b->base, b->wp);
175 	if(b->rp > b->lim)
176 		panic("checkb 3 %s %#p %#p", msg, b->rp, b->lim);
177 	if(b->wp > b->lim)
178 		panic("checkb 4 %s %#p %#p", msg, b->wp, b->lim);
179 }
180 
181 void
182 iallocsummary(void)
183 {
184 	print("ialloc %lud/%lud\n", ialloc.bytes, conf.ialloc);
185 }
186