xref: /plan9/sys/src/cmd/unix/drawterm/kern/allocb.c (revision ec59a3ddbfceee0efe34584c2c9981a5e5ff1ec4)
1 #include	"u.h"
2 #include	"lib.h"
3 #include	"dat.h"
4 #include	"fns.h"
5 #include	"error.h"
6 
7 enum
8 {
9 	Hdrspc		= 64,		/* leave room for high-level headers */
10 	Bdead		= 0x51494F42,	/* "QIOB" */
11 };
12 
13 struct
14 {
15 	Lock	lk;
16 	ulong	bytes;
17 } ialloc;
18 
19 static Block*
_allocb(int size)20 _allocb(int size)
21 {
22 	Block *b;
23 	uintptr addr;
24 
25 	if((b = mallocz(sizeof(Block)+size+Hdrspc, 0)) == nil)
26 		return nil;
27 
28 	b->next = nil;
29 	b->list = nil;
30 	b->free = 0;
31 	b->flag = 0;
32 
33 	/* align start of data portion by rounding up */
34 	addr = (uintptr)b;
35 	addr = ROUND(addr + sizeof(Block), BLOCKALIGN);
36 	b->base = (uchar*)addr;
37 
38 	/* align end of data portion by rounding down */
39 	b->lim = ((uchar*)b) + sizeof(Block)+size+Hdrspc;
40 	addr = (uintptr)(b->lim);
41 	addr = addr & ~(BLOCKALIGN-1);
42 	b->lim = (uchar*)addr;
43 
44 	/* leave sluff at beginning for added headers */
45 	b->rp = b->lim - ROUND(size, BLOCKALIGN);
46 	if(b->rp < b->base)
47 		panic("_allocb");
48 	b->wp = b->rp;
49 
50 	return b;
51 }
52 
53 Block*
allocb(int size)54 allocb(int size)
55 {
56 	Block *b;
57 
58 	/*
59 	 * Check in a process and wait until successful.
60 	 * Can still error out of here, though.
61 	 */
62 	if(up == nil)
63 		panic("allocb without up: %p\n", getcallerpc(&size));
64 	if((b = _allocb(size)) == nil){
65 		panic("allocb: no memory for %d bytes\n", size);
66 	}
67 	setmalloctag(b, getcallerpc(&size));
68 
69 	return b;
70 }
71 
72 Block*
iallocb(int size)73 iallocb(int size)
74 {
75 	Block *b;
76 	static int m1, m2;
77 
78 	if(ialloc.bytes > conf.ialloc){
79 		if((m1++%10000)==0)
80 			print("iallocb: limited %lud/%lud\n",
81 				ialloc.bytes, conf.ialloc);
82 		return 0;
83 	}
84 
85 	if((b = _allocb(size)) == nil){
86 		if((m2++%10000)==0)
87 			print("iallocb: no memory %lud/%lud\n",
88 				ialloc.bytes, conf.ialloc);
89 		return nil;
90 	}
91 	setmalloctag(b, getcallerpc(&size));
92 	b->flag = BINTR;
93 
94 	ilock(&ialloc.lk);
95 	ialloc.bytes += b->lim - b->base;
96 	iunlock(&ialloc.lk);
97 
98 	return b;
99 }
100 
101 void
freeb(Block * b)102 freeb(Block *b)
103 {
104 	void *dead = (void*)Bdead;
105 
106 	if(b == nil)
107 		return;
108 
109 	/*
110 	 * drivers which perform non cache coherent DMA manage their own buffer
111 	 * pool of uncached buffers and provide their own free routine.
112 	 */
113 	if(b->free) {
114 		b->free(b);
115 		return;
116 	}
117 	if(b->flag & BINTR) {
118 		ilock(&ialloc.lk);
119 		ialloc.bytes -= b->lim - b->base;
120 		iunlock(&ialloc.lk);
121 	}
122 
123 	/* poison the block in case someone is still holding onto it */
124 	b->next = dead;
125 	b->rp = dead;
126 	b->wp = dead;
127 	b->lim = dead;
128 	b->base = dead;
129 
130 	free(b);
131 }
132 
133 void
checkb(Block * b,char * msg)134 checkb(Block *b, char *msg)
135 {
136 	void *dead = (void*)Bdead;
137 
138 	if(b == dead)
139 		panic("checkb b %s %lux", msg, b);
140 	if(b->base == dead || b->lim == dead || b->next == dead
141 	  || b->rp == dead || b->wp == dead){
142 		print("checkb: base 0x%8.8luX lim 0x%8.8luX next 0x%8.8luX\n",
143 			b->base, b->lim, b->next);
144 		print("checkb: rp 0x%8.8luX wp 0x%8.8luX\n", b->rp, b->wp);
145 		panic("checkb dead: %s\n", msg);
146 	}
147 
148 	if(b->base > b->lim)
149 		panic("checkb 0 %s %lux %lux", msg, b->base, b->lim);
150 	if(b->rp < b->base)
151 		panic("checkb 1 %s %lux %lux", msg, b->base, b->rp);
152 	if(b->wp < b->base)
153 		panic("checkb 2 %s %lux %lux", msg, b->base, b->wp);
154 	if(b->rp > b->lim)
155 		panic("checkb 3 %s %lux %lux", msg, b->rp, b->lim);
156 	if(b->wp > b->lim)
157 		panic("checkb 4 %s %lux %lux", msg, b->wp, b->lim);
158 
159 }
160 
161 void
iallocsummary(void)162 iallocsummary(void)
163 {
164 	print("ialloc %lud/%lud\n", ialloc.bytes, conf.ialloc);
165 }
166