xref: /illumos-gate/usr/src/uts/common/sys/sysmacros.h (revision 03270635d68df6a0392fb8f4b7c04acad764648b)
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 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
22 /*	  All Rights Reserved	*/
23 
24 
25 /*
26  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  *
29  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
30  *
31  * Copyright 2018 Joyent Inc.
32  */
33 
34 #ifndef _SYS_SYSMACROS_H
35 #define	_SYS_SYSMACROS_H
36 
37 #include <sys/param.h>
38 #include <sys/stddef.h>
39 
40 #ifdef	__cplusplus
41 extern "C" {
42 #endif
43 
44 /*
45  * Some macros for units conversion
46  */
47 /*
48  * Disk blocks (sectors) and bytes.
49  */
50 #define	dtob(DD)	((DD) << DEV_BSHIFT)
51 #define	btod(BB)	(((BB) + DEV_BSIZE - 1) >> DEV_BSHIFT)
52 #define	btodt(BB)	((BB) >> DEV_BSHIFT)
53 #define	lbtod(BB)	(((offset_t)(BB) + DEV_BSIZE - 1) >> DEV_BSHIFT)
54 
55 /* common macros */
56 #ifndef MIN
57 #define	MIN(a, b)	((a) < (b) ? (a) : (b))
58 #endif
59 #ifndef MAX
60 #define	MAX(a, b)	((a) < (b) ? (b) : (a))
61 #endif
62 #ifndef ABS
63 #define	ABS(a)		((a) < 0 ? -(a) : (a))
64 #endif
65 #ifndef	SIGNOF
66 #define	SIGNOF(a)	((a) < 0 ? -1 : (a) > 0)
67 #endif
68 
69 #ifdef _KERNEL
70 
71 /*
72  * Convert a single byte to/from binary-coded decimal (BCD).
73  */
74 extern unsigned char byte_to_bcd[256];
75 extern unsigned char bcd_to_byte[256];
76 
77 #define	BYTE_TO_BCD(x)	byte_to_bcd[(x) & 0xff]
78 #define	BCD_TO_BYTE(x)	bcd_to_byte[(x) & 0xff]
79 
80 #endif	/* _KERNEL */
81 
82 /*
83  * WARNING: The device number macros defined here should not be used by device
84  * drivers or user software. Device drivers should use the device functions
85  * defined in the DDI/DKI interface (see also ddi.h). Application software
86  * should make use of the library routines available in makedev(3). A set of
87  * new device macros are provided to operate on the expanded device number
88  * format supported in SVR4. Macro versions of the DDI device functions are
89  * provided for use by kernel proper routines only. Macro routines bmajor(),
90  * major(), minor(), emajor(), eminor(), and makedev() will be removed or
91  * their definitions changed at the next major release following SVR4.
92  */
93 
94 #define	O_BITSMAJOR	7	/* # of SVR3 major device bits */
95 #define	O_BITSMINOR	8	/* # of SVR3 minor device bits */
96 #define	O_MAXMAJ	0x7f	/* SVR3 max major value */
97 #define	O_MAXMIN	0xff	/* SVR3 max minor value */
98 
99 
100 #define	L_BITSMAJOR32	14	/* # of SVR4 major device bits */
101 #define	L_BITSMINOR32	18	/* # of SVR4 minor device bits */
102 #define	L_MAXMAJ32	0x3fff	/* SVR4 max major value */
103 #define	L_MAXMIN32	0x3ffff	/* MAX minor for 3b2 software drivers. */
104 				/* For 3b2 hardware devices the minor is */
105 				/* restricted to 256 (0-255) */
106 
107 #ifdef _LP64
108 #define	L_BITSMAJOR	32	/* # of major device bits in 64-bit Solaris */
109 #define	L_BITSMINOR	32	/* # of minor device bits in 64-bit Solaris */
110 #define	L_MAXMAJ	0xfffffffful	/* max major value */
111 #define	L_MAXMIN	0xfffffffful	/* max minor value */
112 #else
113 #define	L_BITSMAJOR	L_BITSMAJOR32
114 #define	L_BITSMINOR	L_BITSMINOR32
115 #define	L_MAXMAJ	L_MAXMAJ32
116 #define	L_MAXMIN	L_MAXMIN32
117 #endif
118 
119 #ifdef _KERNEL
120 
121 /* major part of a device internal to the kernel */
122 
123 #define	major(x)	(major_t)((((unsigned)(x)) >> O_BITSMINOR) & O_MAXMAJ)
124 #define	bmajor(x)	(major_t)((((unsigned)(x)) >> O_BITSMINOR) & O_MAXMAJ)
125 
126 /* get internal major part of expanded device number */
127 
128 #define	getmajor(x)	(major_t)((((dev_t)(x)) >> L_BITSMINOR) & L_MAXMAJ)
129 
130 /* minor part of a device internal to the kernel */
131 
132 #define	minor(x)	(minor_t)((x) & O_MAXMIN)
133 
134 /* get internal minor part of expanded device number */
135 
136 #define	getminor(x)	(minor_t)((x) & L_MAXMIN)
137 
138 #else	/* _KERNEL */
139 
140 /* major part of a device external from the kernel (same as emajor below) */
141 
142 #define	major(x)	(major_t)((((unsigned)(x)) >> O_BITSMINOR) & O_MAXMAJ)
143 
144 /* minor part of a device external from the kernel  (same as eminor below) */
145 
146 #define	minor(x)	(minor_t)((x) & O_MAXMIN)
147 
148 #endif	/* _KERNEL */
149 
150 /* create old device number */
151 
152 #define	makedev(x, y) (unsigned short)(((x) << O_BITSMINOR) | ((y) & O_MAXMIN))
153 
154 /* make an new device number */
155 
156 #define	makedevice(x, y) (dev_t)(((dev_t)(x) << L_BITSMINOR) | ((y) & L_MAXMIN))
157 
158 
159 /*
160  * emajor() allows kernel/driver code to print external major numbers
161  * eminor() allows kernel/driver code to print external minor numbers
162  */
163 
164 #define	emajor(x) \
165 	(major_t)(((unsigned int)(x) >> O_BITSMINOR) > O_MAXMAJ) ? \
166 	    NODEV : (((unsigned int)(x) >> O_BITSMINOR) & O_MAXMAJ)
167 
168 #define	eminor(x) \
169 	(minor_t)((x) & O_MAXMIN)
170 
171 /*
172  * get external major and minor device
173  * components from expanded device number
174  */
175 #define	getemajor(x)	(major_t)((((dev_t)(x) >> L_BITSMINOR) > L_MAXMAJ) ? \
176 			    NODEV : (((dev_t)(x) >> L_BITSMINOR) & L_MAXMAJ))
177 #define	geteminor(x)	(minor_t)((x) & L_MAXMIN)
178 
179 /*
180  * These are versions of the kernel routines for compressing and
181  * expanding long device numbers that don't return errors.
182  */
183 #if (L_BITSMAJOR32 == L_BITSMAJOR) && (L_BITSMINOR32 == L_BITSMINOR)
184 
185 #define	DEVCMPL(x)	(x)
186 #define	DEVEXPL(x)	(x)
187 
188 #else
189 
190 #define	DEVCMPL(x)	\
191 	(dev32_t)((((x) >> L_BITSMINOR) > L_MAXMAJ32 || \
192 	    ((x) & L_MAXMIN) > L_MAXMIN32) ? NODEV32 : \
193 	    ((((x) >> L_BITSMINOR) << L_BITSMINOR32) | ((x) & L_MAXMIN32)))
194 
195 #define	DEVEXPL(x)	\
196 	(((x) == NODEV32) ? NODEV : \
197 	makedevice(((x) >> L_BITSMINOR32) & L_MAXMAJ32, (x) & L_MAXMIN32))
198 
199 #endif /* L_BITSMAJOR32 ... */
200 
201 /* convert to old (SVR3.2) dev format */
202 
203 #define	cmpdev(x) \
204 	(o_dev_t)((((x) >> L_BITSMINOR) > O_MAXMAJ || \
205 	    ((x) & L_MAXMIN) > O_MAXMIN) ? NODEV : \
206 	    ((((x) >> L_BITSMINOR) << O_BITSMINOR) | ((x) & O_MAXMIN)))
207 
208 /* convert to new (SVR4) dev format */
209 
210 #define	expdev(x) \
211 	(dev_t)(((dev_t)(((x) >> O_BITSMINOR) & O_MAXMAJ) << L_BITSMINOR) | \
212 	    ((x) & O_MAXMIN))
213 
214 /*
215  * Macro for checking power of 2 address alignment.
216  */
217 #define	IS_P2ALIGNED(v, a) ((((uintptr_t)(v)) & ((uintptr_t)(a) - 1)) == 0)
218 
219 /*
220  * Macros for counting and rounding.
221  */
222 #define	howmany(x, y)	(((x)+((y)-1))/(y))
223 #define	roundup(x, y)	((((x)+((y)-1))/(y))*(y))
224 
225 /*
226  * Macro to determine if value is a power of 2
227  */
228 #define	ISP2(x)		(((x) & ((x) - 1)) == 0)
229 
230 /*
231  * Macros for various sorts of alignment and rounding.  The "align" must
232  * be a power of 2.  Often times it is a block, sector, or page.
233  */
234 
235 /*
236  * return x rounded down to an align boundary
237  * eg, P2ALIGN(1200, 1024) == 1024 (1*align)
238  * eg, P2ALIGN(1024, 1024) == 1024 (1*align)
239  * eg, P2ALIGN(0x1234, 0x100) == 0x1200 (0x12*align)
240  * eg, P2ALIGN(0x5600, 0x100) == 0x5600 (0x56*align)
241  */
242 #define	P2ALIGN(x, align)		((x) & -(align))
243 
244 /*
245  * return x % (mod) align
246  * eg, P2PHASE(0x1234, 0x100) == 0x34 (x-0x12*align)
247  * eg, P2PHASE(0x5600, 0x100) == 0x00 (x-0x56*align)
248  */
249 #define	P2PHASE(x, align)		((x) & ((align) - 1))
250 
251 /*
252  * return how much space is left in this block (but if it's perfectly
253  * aligned, return 0).
254  * eg, P2NPHASE(0x1234, 0x100) == 0xcc (0x13*align-x)
255  * eg, P2NPHASE(0x5600, 0x100) == 0x00 (0x56*align-x)
256  */
257 #define	P2NPHASE(x, align)		(-(x) & ((align) - 1))
258 
259 /*
260  * return x rounded up to an align boundary
261  * eg, P2ROUNDUP(0x1234, 0x100) == 0x1300 (0x13*align)
262  * eg, P2ROUNDUP(0x5600, 0x100) == 0x5600 (0x56*align)
263  */
264 #define	P2ROUNDUP(x, align)		(-(-(x) & -(align)))
265 
266 /*
267  * return the ending address of the block that x is in
268  * eg, P2END(0x1234, 0x100) == 0x12ff (0x13*align - 1)
269  * eg, P2END(0x5600, 0x100) == 0x56ff (0x57*align - 1)
270  */
271 #define	P2END(x, align)			(-(~(x) & -(align)))
272 
273 /*
274  * return x rounded up to the next phase (offset) within align.
275  * phase should be < align.
276  * eg, P2PHASEUP(0x1234, 0x100, 0x10) == 0x1310 (0x13*align + phase)
277  * eg, P2PHASEUP(0x5600, 0x100, 0x10) == 0x5610 (0x56*align + phase)
278  */
279 #define	P2PHASEUP(x, align, phase)	((phase) - (((phase) - (x)) & -(align)))
280 
281 /*
282  * return TRUE if adding len to off would cause it to cross an align
283  * boundary.
284  * eg, P2BOUNDARY(0x1234, 0xe0, 0x100) == TRUE (0x1234 + 0xe0 == 0x1314)
285  * eg, P2BOUNDARY(0x1234, 0x50, 0x100) == FALSE (0x1234 + 0x50 == 0x1284)
286  */
287 #define	P2BOUNDARY(off, len, align) \
288 	(((off) ^ ((off) + (len) - 1)) > (align) - 1)
289 
290 /*
291  * Return TRUE if they have the same highest bit set.
292  * eg, P2SAMEHIGHBIT(0x1234, 0x1001) == TRUE (the high bit is 0x1000)
293  * eg, P2SAMEHIGHBIT(0x1234, 0x3010) == FALSE (high bit of 0x3010 is 0x2000)
294  */
295 #define	P2SAMEHIGHBIT(x, y)		(((x) ^ (y)) < ((x) & (y)))
296 
297 /*
298  * Typed version of the P2* macros.  These macros should be used to ensure
299  * that the result is correctly calculated based on the data type of (x),
300  * which is passed in as the last argument, regardless of the data
301  * type of the alignment.  For example, if (x) is of type uint64_t,
302  * and we want to round it up to a page boundary using "PAGESIZE" as
303  * the alignment, we can do either
304  *	P2ROUNDUP(x, (uint64_t)PAGESIZE)
305  * or
306  *	P2ROUNDUP_TYPED(x, PAGESIZE, uint64_t)
307  */
308 #define	P2ALIGN_TYPED(x, align, type)	\
309 	((type)(x) & -(type)(align))
310 #define	P2PHASE_TYPED(x, align, type)	\
311 	((type)(x) & ((type)(align) - 1))
312 #define	P2NPHASE_TYPED(x, align, type)	\
313 	(-(type)(x) & ((type)(align) - 1))
314 #define	P2ROUNDUP_TYPED(x, align, type)	\
315 	(-(-(type)(x) & -(type)(align)))
316 #define	P2END_TYPED(x, align, type)	\
317 	(-(~(type)(x) & -(type)(align)))
318 #define	P2PHASEUP_TYPED(x, align, phase, type)	\
319 	((type)(phase) - (((type)(phase) - (type)(x)) & -(type)(align)))
320 #define	P2CROSS_TYPED(x, y, align, type)	\
321 	(((type)(x) ^ (type)(y)) > (type)(align) - 1)
322 #define	P2SAMEHIGHBIT_TYPED(x, y, type) \
323 	(((type)(x) ^ (type)(y)) < ((type)(x) & (type)(y)))
324 
325 /*
326  * Macros to atomically increment/decrement a variable.  mutex and var
327  * must be pointers.
328  */
329 #define	INCR_COUNT(var, mutex) mutex_enter(mutex), (*(var))++, mutex_exit(mutex)
330 #define	DECR_COUNT(var, mutex) mutex_enter(mutex), (*(var))--, mutex_exit(mutex)
331 
332 /*
333  * Macros to declare bitfields - the order in the parameter list is
334  * Low to High - that is, declare bit 0 first.  We only support 8-bit bitfields
335  * because if a field crosses a byte boundary it's not likely to be meaningful
336  * without reassembly in its nonnative endianness.
337  */
338 #if defined(_BIT_FIELDS_LTOH)
339 #define	DECL_BITFIELD2(_a, _b)				\
340 	uint8_t _a, _b
341 #define	DECL_BITFIELD3(_a, _b, _c)			\
342 	uint8_t _a, _b, _c
343 #define	DECL_BITFIELD4(_a, _b, _c, _d)			\
344 	uint8_t _a, _b, _c, _d
345 #define	DECL_BITFIELD5(_a, _b, _c, _d, _e)		\
346 	uint8_t _a, _b, _c, _d, _e
347 #define	DECL_BITFIELD6(_a, _b, _c, _d, _e, _f)		\
348 	uint8_t _a, _b, _c, _d, _e, _f
349 #define	DECL_BITFIELD7(_a, _b, _c, _d, _e, _f, _g)	\
350 	uint8_t _a, _b, _c, _d, _e, _f, _g
351 #define	DECL_BITFIELD8(_a, _b, _c, _d, _e, _f, _g, _h)	\
352 	uint8_t _a, _b, _c, _d, _e, _f, _g, _h
353 #elif defined(_BIT_FIELDS_HTOL)
354 #define	DECL_BITFIELD2(_a, _b)				\
355 	uint8_t _b, _a
356 #define	DECL_BITFIELD3(_a, _b, _c)			\
357 	uint8_t _c, _b, _a
358 #define	DECL_BITFIELD4(_a, _b, _c, _d)			\
359 	uint8_t _d, _c, _b, _a
360 #define	DECL_BITFIELD5(_a, _b, _c, _d, _e)		\
361 	uint8_t _e, _d, _c, _b, _a
362 #define	DECL_BITFIELD6(_a, _b, _c, _d, _e, _f)		\
363 	uint8_t _f, _e, _d, _c, _b, _a
364 #define	DECL_BITFIELD7(_a, _b, _c, _d, _e, _f, _g)	\
365 	uint8_t _g, _f, _e, _d, _c, _b, _a
366 #define	DECL_BITFIELD8(_a, _b, _c, _d, _e, _f, _g, _h)	\
367 	uint8_t _h, _g, _f, _e, _d, _c, _b, _a
368 #else
369 #error	One of _BIT_FIELDS_LTOH or _BIT_FIELDS_HTOL must be defined
370 #endif  /* _BIT_FIELDS_LTOH */
371 
372 #if !defined(ARRAY_SIZE)
373 #define	ARRAY_SIZE(x)	(sizeof (x) / sizeof (x[0]))
374 #endif
375 
376 /*
377  * Add a value to a uint64_t that saturates at UINT64_MAX instead of wrapping
378  * around.
379  */
380 #define	UINT64_OVERFLOW_ADD(val, add) \
381 	((val) > ((val) + (add)) ? (UINT64_MAX) : ((val) + (add)))
382 
383 /*
384  * Convert to an int64, saturating at INT64_MAX.
385  */
386 #define	UINT64_OVERFLOW_TO_INT64(uval) \
387 	(((uval) > INT64_MAX) ? INT64_MAX : (int64_t)(uval))
388 
389 #ifdef	__cplusplus
390 }
391 #endif
392 
393 #endif	/* _SYS_SYSMACROS_H */
394