1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Bit operations for the Hexagon architecture
  4 *
  5 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
  6 */
  7
  8#ifndef _ASM_BITOPS_H
  9#define _ASM_BITOPS_H
 10
 11#include <linux/compiler.h>
 12#include <asm/byteorder.h>
 13#include <asm/atomic.h>
 14#include <asm/barrier.h>
 15
 16#ifdef __KERNEL__
 17
 18/*
 19 * The offset calculations for these are based on BITS_PER_LONG == 32
 20 * (i.e. I get to shift by #5-2 (32 bits per long, 4 bytes per access),
 21 * mask by 0x0000001F)
 22 *
 23 * Typically, R10 is clobbered for address, R11 bit nr, and R12 is temp
 24 */
 25
 26/**
 27 * test_and_clear_bit - clear a bit and return its old value
 28 * @nr:  bit number to clear
 29 * @addr:  pointer to memory
 30 */
 31static inline int test_and_clear_bit(int nr, volatile void *addr)
 32{
 33	int oldval;
 34
 35	__asm__ __volatile__ (
 36	"	{R10 = %1; R11 = asr(%2,#5); }\n"
 37	"	{R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n"
 38	"1:	R12 = memw_locked(R10);\n"
 39	"	{ P0 = tstbit(R12,R11); R12 = clrbit(R12,R11); }\n"
 40	"	memw_locked(R10,P1) = R12;\n"
 41	"	{if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n"
 42	: "=&r" (oldval)
 43	: "r" (addr), "r" (nr)
 44	: "r10", "r11", "r12", "p0", "p1", "memory"
 45	);
 46
 47	return oldval;
 48}
 49
 50/**
 51 * test_and_set_bit - set a bit and return its old value
 52 * @nr:  bit number to set
 53 * @addr:  pointer to memory
 54 */
 55static inline int test_and_set_bit(int nr, volatile void *addr)
 56{
 57	int oldval;
 58
 59	__asm__ __volatile__ (
 60	"	{R10 = %1; R11 = asr(%2,#5); }\n"
 61	"	{R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n"
 62	"1:	R12 = memw_locked(R10);\n"
 63	"	{ P0 = tstbit(R12,R11); R12 = setbit(R12,R11); }\n"
 64	"	memw_locked(R10,P1) = R12;\n"
 65	"	{if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n"
 66	: "=&r" (oldval)
 67	: "r" (addr), "r" (nr)
 68	: "r10", "r11", "r12", "p0", "p1", "memory"
 69	);
 70
 71
 72	return oldval;
 73
 74}
 75
 76/**
 77 * test_and_change_bit - toggle a bit and return its old value
 78 * @nr:  bit number to set
 79 * @addr:  pointer to memory
 80 */
 81static inline int test_and_change_bit(int nr, volatile void *addr)
 82{
 83	int oldval;
 84
 85	__asm__ __volatile__ (
 86	"	{R10 = %1; R11 = asr(%2,#5); }\n"
 87	"	{R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n"
 88	"1:	R12 = memw_locked(R10);\n"
 89	"	{ P0 = tstbit(R12,R11); R12 = togglebit(R12,R11); }\n"
 90	"	memw_locked(R10,P1) = R12;\n"
 91	"	{if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n"
 92	: "=&r" (oldval)
 93	: "r" (addr), "r" (nr)
 94	: "r10", "r11", "r12", "p0", "p1", "memory"
 95	);
 96
 97	return oldval;
 98
 99}
100
101/*
102 * Atomic, but doesn't care about the return value.
103 * Rewrite later to save a cycle or two.
104 */
105
106static inline void clear_bit(int nr, volatile void *addr)
107{
108	test_and_clear_bit(nr, addr);
109}
110
111static inline void set_bit(int nr, volatile void *addr)
112{
113	test_and_set_bit(nr, addr);
114}
115
116static inline void change_bit(int nr, volatile void *addr)
117{
118	test_and_change_bit(nr, addr);
119}
120
121
122/*
123 * These are allowed to be non-atomic.  In fact the generic flavors are
124 * in non-atomic.h.  Would it be better to use intrinsics for this?
125 *
126 * OK, writes in our architecture do not invalidate LL/SC, so this has to
127 * be atomic, particularly for things like slab_lock and slab_unlock.
128 *
129 */
130static inline void __clear_bit(int nr, volatile unsigned long *addr)
131{
132	test_and_clear_bit(nr, addr);
133}
134
135static inline void __set_bit(int nr, volatile unsigned long *addr)
136{
137	test_and_set_bit(nr, addr);
138}
139
140static inline void __change_bit(int nr, volatile unsigned long *addr)
141{
142	test_and_change_bit(nr, addr);
143}
144
145/*  Apparently, at least some of these are allowed to be non-atomic  */
146static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
147{
148	return test_and_clear_bit(nr, addr);
149}
150
151static inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
152{
153	return test_and_set_bit(nr, addr);
154}
155
156static inline int __test_and_change_bit(int nr, volatile unsigned long *addr)
157{
158	return test_and_change_bit(nr, addr);
159}
160
161static inline int __test_bit(int nr, const volatile unsigned long *addr)
162{
163	int retval;
164
165	asm volatile(
166	"{P0 = tstbit(%1,%2); if (P0.new) %0 = #1; if (!P0.new) %0 = #0;}\n"
167	: "=&r" (retval)
168	: "r" (addr[BIT_WORD(nr)]), "r" (nr % BITS_PER_LONG)
169	: "p0"
170	);
171
172	return retval;
173}
174
175#define test_bit(nr, addr) __test_bit(nr, addr)
176
177/*
178 * ffz - find first zero in word.
179 * @word: The word to search
180 *
181 * Undefined if no zero exists, so code should check against ~0UL first.
182 */
183static inline long ffz(int x)
184{
185	int r;
186
187	asm("%0 = ct1(%1);\n"
188		: "=&r" (r)
189		: "r" (x));
190	return r;
191}
192
193/*
194 * fls - find last (most-significant) bit set
195 * @x: the word to search
196 *
197 * This is defined the same way as ffs.
198 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
199 */
200static inline int fls(unsigned int x)
201{
202	int r;
203
204	asm("{ %0 = cl0(%1);}\n"
205		"%0 = sub(#32,%0);\n"
206		: "=&r" (r)
207		: "r" (x)
208		: "p0");
209
210	return r;
211}
212
213/*
214 * ffs - find first bit set
215 * @x: the word to search
216 *
217 * This is defined the same way as
218 * the libc and compiler builtin ffs routines, therefore
219 * differs in spirit from the above ffz (man ffs).
220 */
221static inline int ffs(int x)
222{
223	int r;
224
225	asm("{ P0 = cmp.eq(%1,#0); %0 = ct0(%1);}\n"
226		"{ if P0 %0 = #0; if !P0 %0 = add(%0,#1);}\n"
227		: "=&r" (r)
228		: "r" (x)
229		: "p0");
230
231	return r;
232}
233
234/*
235 * __ffs - find first bit in word.
236 * @word: The word to search
237 *
238 * Undefined if no bit exists, so code should check against 0 first.
239 *
240 * bits_per_long assumed to be 32
241 * numbering starts at 0 I think (instead of 1 like ffs)
242 */
243static inline unsigned long __ffs(unsigned long word)
244{
245	int num;
246
247	asm("%0 = ct0(%1);\n"
248		: "=&r" (num)
249		: "r" (word));
250
251	return num;
252}
253
254/*
255 * __fls - find last (most-significant) set bit in a long word
256 * @word: the word to search
257 *
258 * Undefined if no set bit exists, so code should check against 0 first.
259 * bits_per_long assumed to be 32
260 */
261static inline unsigned long __fls(unsigned long word)
262{
263	int num;
264
265	asm("%0 = cl0(%1);\n"
266		"%0 = sub(#31,%0);\n"
267		: "=&r" (num)
268		: "r" (word));
269
270	return num;
271}
272
273#include <asm-generic/bitops/lock.h>
274#include <asm-generic/bitops/find.h>
275
276#include <asm-generic/bitops/fls64.h>
277#include <asm-generic/bitops/sched.h>
278#include <asm-generic/bitops/hweight.h>
279
280#include <asm-generic/bitops/le.h>
281#include <asm-generic/bitops/ext2-atomic.h>
282
283#endif /* __KERNEL__ */
284#endif