io.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * I/O string operations
  4 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  5 *    Copyright (C) 2006 IBM Corporation
  6 *
  7 * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
  8 * and Paul Mackerras.
  9 *
 10 * Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
 11 * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
 12 *
 13 * Rewritten in C by Stephen Rothwell.
 14 */
 15#include <linux/kernel.h>
 16#include <linux/types.h>
 17#include <linux/compiler.h>
 18#include <linux/export.h>
 19
 20#include <asm/io.h>
 21#include <asm/firmware.h>
 22#include <asm/bug.h>
 23
 24/* See definition in io.h */
 25bool isa_io_special;
 26
 27void _insb(const volatile u8 __iomem *port, void *buf, long count)
 28{
 29	u8 *tbuf = buf;
 30	u8 tmp;
 31
 32	if (unlikely(count <= 0))
 33		return;
 34
 35	mb();
 36	do {
 37		tmp = *(const volatile u8 __force *)port;
 38		eieio();
 39		*tbuf++ = tmp;
 40	} while (--count != 0);
 41	data_barrier(tmp);
 42}
 43EXPORT_SYMBOL(_insb);
 44
 45void _outsb(volatile u8 __iomem *port, const void *buf, long count)
 46{
 47	const u8 *tbuf = buf;
 48
 49	if (unlikely(count <= 0))
 50		return;
 51
 52	mb();
 53	do {
 54		*(volatile u8 __force *)port = *tbuf++;
 55	} while (--count != 0);
 56	mb();
 57}
 58EXPORT_SYMBOL(_outsb);
 59
 60void _insw(const volatile u16 __iomem *port, void *buf, long count)
 61{
 62	u16 *tbuf = buf;
 63	u16 tmp;
 64
 65	if (unlikely(count <= 0))
 66		return;
 67
 68	mb();
 69	do {
 70		tmp = *(const volatile u16 __force *)port;
 71		eieio();
 72		*tbuf++ = tmp;
 73	} while (--count != 0);
 74	data_barrier(tmp);
 75}
 76EXPORT_SYMBOL(_insw);
 77
 78void _outsw(volatile u16 __iomem *port, const void *buf, long count)
 79{
 80	const u16 *tbuf = buf;
 81
 82	if (unlikely(count <= 0))
 83		return;
 84
 85	mb();
 86	do {
 87		*(volatile u16 __force *)port = *tbuf++;
 88	} while (--count != 0);
 89	mb();
 90}
 91EXPORT_SYMBOL(_outsw);
 92
 93void _insl(const volatile u32 __iomem *port, void *buf, long count)
 94{
 95	u32 *tbuf = buf;
 96	u32 tmp;
 97
 98	if (unlikely(count <= 0))
 99		return;
100
101	mb();
102	do {
103		tmp = *(const volatile u32 __force *)port;
104		eieio();
105		*tbuf++ = tmp;
106	} while (--count != 0);
107	data_barrier(tmp);
108}
109EXPORT_SYMBOL(_insl);
110
111void _outsl(volatile u32 __iomem *port, const void *buf, long count)
112{
113	const u32 *tbuf = buf;
114
115	if (unlikely(count <= 0))
116		return;
117
118	mb();
119	do {
120		*(volatile u32 __force *)port = *tbuf++;
121	} while (--count != 0);
122	mb();
123}
124EXPORT_SYMBOL(_outsl);
125
126#define IO_CHECK_ALIGN(v,a) ((((unsigned long)(v)) & ((a) - 1)) == 0)
127
128notrace void
129_memset_io(volatile void __iomem *addr, int c, unsigned long n)
130{
131	void *p = (void __force *)addr;
132	u32 lc = c;
133	lc |= lc << 8;
134	lc |= lc << 16;
135
136	mb();
137	while(n && !IO_CHECK_ALIGN(p, 4)) {
138		*((volatile u8 *)p) = c;
139		p++;
140		n--;
141	}
142	while(n >= 4) {
143		*((volatile u32 *)p) = lc;
144		p += 4;
145		n -= 4;
146	}
147	while(n) {
148		*((volatile u8 *)p) = c;
149		p++;
150		n--;
151	}
152	mb();
153}
154EXPORT_SYMBOL(_memset_io);
155
156void _memcpy_fromio(void *dest, const volatile void __iomem *src,
157		    unsigned long n)
158{
159	void *vsrc = (void __force *) src;
160
161	mb();
162	while(n && (!IO_CHECK_ALIGN(vsrc, 4) || !IO_CHECK_ALIGN(dest, 4))) {
163		*((u8 *)dest) = *((volatile u8 *)vsrc);
164		eieio();
165		vsrc++;
166		dest++;
167		n--;
168	}
169	while(n >= 4) {
170		*((u32 *)dest) = *((volatile u32 *)vsrc);
171		eieio();
172		vsrc += 4;
173		dest += 4;
174		n -= 4;
175	}
176	while(n) {
177		*((u8 *)dest) = *((volatile u8 *)vsrc);
178		eieio();
179		vsrc++;
180		dest++;
181		n--;
182	}
183	mb();
184}
185EXPORT_SYMBOL(_memcpy_fromio);
186
187void _memcpy_toio(volatile void __iomem *dest, const void *src, unsigned long n)
188{
189	void *vdest = (void __force *) dest;
190
191	mb();
192	while(n && (!IO_CHECK_ALIGN(vdest, 4) || !IO_CHECK_ALIGN(src, 4))) {
193		*((volatile u8 *)vdest) = *((u8 *)src);
194		src++;
195		vdest++;
196		n--;
197	}
198	while(n >= 4) {
199		*((volatile u32 *)vdest) = *((volatile u32 *)src);
200		src += 4;
201		vdest += 4;
202		n-=4;
203	}
204	while(n) {
205		*((volatile u8 *)vdest) = *((u8 *)src);
206		src++;
207		vdest++;
208		n--;
209	}
210	mb();
211}
212EXPORT_SYMBOL(_memcpy_toio);