xref: /openbmc/linux/arch/riscv/include/asm/io.h (revision 680ef72a)
1 /*
2  * {read,write}{b,w,l,q} based on arch/arm64/include/asm/io.h
3  *   which was based on arch/arm/include/io.h
4  *
5  * Copyright (C) 1996-2000 Russell King
6  * Copyright (C) 2012 ARM Ltd.
7  * Copyright (C) 2014 Regents of the University of California
8  *
9  *   This program is free software; you can redistribute it and/or
10  *   modify it under the terms of the GNU General Public License
11  *   as published by the Free Software Foundation, version 2.
12  *
13  *   This program is distributed in the hope that it will be useful,
14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *   GNU General Public License for more details.
17  */
18 
19 #ifndef _ASM_RISCV_IO_H
20 #define _ASM_RISCV_IO_H
21 
22 #ifdef CONFIG_MMU
23 
24 extern void __iomem *ioremap(phys_addr_t offset, unsigned long size);
25 
26 /*
27  * The RISC-V ISA doesn't yet specify how to query or modify PMAs, so we can't
28  * change the properties of memory regions.  This should be fixed by the
29  * upcoming platform spec.
30  */
31 #define ioremap_nocache(addr, size) ioremap((addr), (size))
32 #define ioremap_wc(addr, size) ioremap((addr), (size))
33 #define ioremap_wt(addr, size) ioremap((addr), (size))
34 
35 extern void iounmap(void __iomem *addr);
36 
37 #endif /* CONFIG_MMU */
38 
39 /* Generic IO read/write.  These perform native-endian accesses. */
40 #define __raw_writeb __raw_writeb
41 static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
42 {
43 	asm volatile("sb %0, 0(%1)" : : "r" (val), "r" (addr));
44 }
45 
46 #define __raw_writew __raw_writew
47 static inline void __raw_writew(u16 val, volatile void __iomem *addr)
48 {
49 	asm volatile("sh %0, 0(%1)" : : "r" (val), "r" (addr));
50 }
51 
52 #define __raw_writel __raw_writel
53 static inline void __raw_writel(u32 val, volatile void __iomem *addr)
54 {
55 	asm volatile("sw %0, 0(%1)" : : "r" (val), "r" (addr));
56 }
57 
58 #ifdef CONFIG_64BIT
59 #define __raw_writeq __raw_writeq
60 static inline void __raw_writeq(u64 val, volatile void __iomem *addr)
61 {
62 	asm volatile("sd %0, 0(%1)" : : "r" (val), "r" (addr));
63 }
64 #endif
65 
66 #define __raw_readb __raw_readb
67 static inline u8 __raw_readb(const volatile void __iomem *addr)
68 {
69 	u8 val;
70 
71 	asm volatile("lb %0, 0(%1)" : "=r" (val) : "r" (addr));
72 	return val;
73 }
74 
75 #define __raw_readw __raw_readw
76 static inline u16 __raw_readw(const volatile void __iomem *addr)
77 {
78 	u16 val;
79 
80 	asm volatile("lh %0, 0(%1)" : "=r" (val) : "r" (addr));
81 	return val;
82 }
83 
84 #define __raw_readl __raw_readl
85 static inline u32 __raw_readl(const volatile void __iomem *addr)
86 {
87 	u32 val;
88 
89 	asm volatile("lw %0, 0(%1)" : "=r" (val) : "r" (addr));
90 	return val;
91 }
92 
93 #ifdef CONFIG_64BIT
94 #define __raw_readq __raw_readq
95 static inline u64 __raw_readq(const volatile void __iomem *addr)
96 {
97 	u64 val;
98 
99 	asm volatile("ld %0, 0(%1)" : "=r" (val) : "r" (addr));
100 	return val;
101 }
102 #endif
103 
104 /*
105  * FIXME: I'm flip-flopping on whether or not we should keep this or enforce
106  * the ordering with I/O on spinlocks like PowerPC does.  The worry is that
107  * drivers won't get this correct, but I also don't want to introduce a fence
108  * into the lock code that otherwise only uses AMOs (and is essentially defined
109  * by the ISA to be correct).   For now I'm leaving this here: "o,w" is
110  * sufficient to ensure that all writes to the device have completed before the
111  * write to the spinlock is allowed to commit.  I surmised this from reading
112  * "ACQUIRES VS I/O ACCESSES" in memory-barriers.txt.
113  */
114 #define mmiowb()	__asm__ __volatile__ ("fence o,w" : : : "memory");
115 
116 /*
117  * Unordered I/O memory access primitives.  These are even more relaxed than
118  * the relaxed versions, as they don't even order accesses between successive
119  * operations to the I/O regions.
120  */
121 #define readb_cpu(c)		({ u8  __r = __raw_readb(c); __r; })
122 #define readw_cpu(c)		({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; })
123 #define readl_cpu(c)		({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; })
124 
125 #define writeb_cpu(v,c)		((void)__raw_writeb((v),(c)))
126 #define writew_cpu(v,c)		((void)__raw_writew((__force u16)cpu_to_le16(v),(c)))
127 #define writel_cpu(v,c)		((void)__raw_writel((__force u32)cpu_to_le32(v),(c)))
128 
129 #ifdef CONFIG_64BIT
130 #define readq_cpu(c)		({ u64 __r = le64_to_cpu((__force __le64)__raw_readq(c)); __r; })
131 #define writeq_cpu(v,c)		((void)__raw_writeq((__force u64)cpu_to_le64(v),(c)))
132 #endif
133 
134 /*
135  * Relaxed I/O memory access primitives. These follow the Device memory
136  * ordering rules but do not guarantee any ordering relative to Normal memory
137  * accesses.  These are defined to order the indicated access (either a read or
138  * write) with all other I/O memory accesses. Since the platform specification
139  * defines that all I/O regions are strongly ordered on channel 2, no explicit
140  * fences are required to enforce this ordering.
141  */
142 /* FIXME: These are now the same as asm-generic */
143 #define __io_rbr()		do {} while (0)
144 #define __io_rar()		do {} while (0)
145 #define __io_rbw()		do {} while (0)
146 #define __io_raw()		do {} while (0)
147 
148 #define readb_relaxed(c)	({ u8  __v; __io_rbr(); __v = readb_cpu(c); __io_rar(); __v; })
149 #define readw_relaxed(c)	({ u16 __v; __io_rbr(); __v = readw_cpu(c); __io_rar(); __v; })
150 #define readl_relaxed(c)	({ u32 __v; __io_rbr(); __v = readl_cpu(c); __io_rar(); __v; })
151 
152 #define writeb_relaxed(v,c)	({ __io_rbw(); writeb_cpu((v),(c)); __io_raw(); })
153 #define writew_relaxed(v,c)	({ __io_rbw(); writew_cpu((v),(c)); __io_raw(); })
154 #define writel_relaxed(v,c)	({ __io_rbw(); writel_cpu((v),(c)); __io_raw(); })
155 
156 #ifdef CONFIG_64BIT
157 #define readq_relaxed(c)	({ u64 __v; __io_rbr(); __v = readq_cpu(c); __io_rar(); __v; })
158 #define writeq_relaxed(v,c)	({ __io_rbw(); writeq_cpu((v),(c)); __io_raw(); })
159 #endif
160 
161 /*
162  * I/O memory access primitives. Reads are ordered relative to any
163  * following Normal memory access. Writes are ordered relative to any prior
164  * Normal memory access.  The memory barriers here are necessary as RISC-V
165  * doesn't define any ordering between the memory space and the I/O space.
166  */
167 #define __io_br()	do {} while (0)
168 #define __io_ar()	__asm__ __volatile__ ("fence i,r" : : : "memory");
169 #define __io_bw()	__asm__ __volatile__ ("fence w,o" : : : "memory");
170 #define __io_aw()	do {} while (0)
171 
172 #define readb(c)	({ u8  __v; __io_br(); __v = readb_cpu(c); __io_ar(); __v; })
173 #define readw(c)	({ u16 __v; __io_br(); __v = readw_cpu(c); __io_ar(); __v; })
174 #define readl(c)	({ u32 __v; __io_br(); __v = readl_cpu(c); __io_ar(); __v; })
175 
176 #define writeb(v,c)	({ __io_bw(); writeb_cpu((v),(c)); __io_aw(); })
177 #define writew(v,c)	({ __io_bw(); writew_cpu((v),(c)); __io_aw(); })
178 #define writel(v,c)	({ __io_bw(); writel_cpu((v),(c)); __io_aw(); })
179 
180 #ifdef CONFIG_64BIT
181 #define readq(c)	({ u64 __v; __io_br(); __v = readq_cpu(c); __io_ar(); __v; })
182 #define writeq(v,c)	({ __io_bw(); writeq_cpu((v),(c)); __io_aw(); })
183 #endif
184 
185 /*
186  * Emulation routines for the port-mapped IO space used by some PCI drivers.
187  * These are defined as being "fully synchronous", but also "not guaranteed to
188  * be fully ordered with respect to other memory and I/O operations".  We're
189  * going to be on the safe side here and just make them:
190  *  - Fully ordered WRT each other, by bracketing them with two fences.  The
191  *    outer set contains both I/O so inX is ordered with outX, while the inner just
192  *    needs the type of the access (I for inX and O for outX).
193  *  - Ordered in the same manner as readX/writeX WRT memory by subsuming their
194  *    fences.
195  *  - Ordered WRT timer reads, so udelay and friends don't get elided by the
196  *    implementation.
197  * Note that there is no way to actually enforce that outX is a non-posted
198  * operation on RISC-V, but hopefully the timer ordering constraint is
199  * sufficient to ensure this works sanely on controllers that support I/O
200  * writes.
201  */
202 #define __io_pbr()	__asm__ __volatile__ ("fence io,i"  : : : "memory");
203 #define __io_par()	__asm__ __volatile__ ("fence i,ior" : : : "memory");
204 #define __io_pbw()	__asm__ __volatile__ ("fence iow,o" : : : "memory");
205 #define __io_paw()	__asm__ __volatile__ ("fence o,io"  : : : "memory");
206 
207 #define inb(c)		({ u8  __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE + (c))); __io_par(); __v; })
208 #define inw(c)		({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE + (c))); __io_par(); __v; })
209 #define inl(c)		({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE + (c))); __io_par(); __v; })
210 
211 #define outb(v,c)	({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
212 #define outw(v,c)	({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
213 #define outl(v,c)	({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
214 
215 #ifdef CONFIG_64BIT
216 #define inq(c)		({ u64 __v; __io_pbr(); __v = readq_cpu((void*)(c)); __io_par(); __v; })
217 #define outq(v,c)	({ __io_pbw(); writeq_cpu((v),(void*)(c)); __io_paw(); })
218 #endif
219 
220 /*
221  * Accesses from a single hart to a single I/O address must be ordered.  This
222  * allows us to use the raw read macros, but we still need to fence before and
223  * after the block to ensure ordering WRT other macros.  These are defined to
224  * perform host-endian accesses so we use __raw instead of __cpu.
225  */
226 #define __io_reads_ins(port, ctype, len, bfence, afence)			\
227 	static inline void __ ## port ## len(const volatile void __iomem *addr,	\
228 					     void *buffer,			\
229 					     unsigned int count)		\
230 	{									\
231 		bfence;								\
232 		if (count) {							\
233 			ctype *buf = buffer;					\
234 										\
235 			do {							\
236 				ctype x = __raw_read ## len(addr);		\
237 				*buf++ = x;					\
238 			} while (--count);					\
239 		}								\
240 		afence;								\
241 	}
242 
243 #define __io_writes_outs(port, ctype, len, bfence, afence)			\
244 	static inline void __ ## port ## len(volatile void __iomem *addr,	\
245 					     const void *buffer,		\
246 					     unsigned int count)		\
247 	{									\
248 		bfence;								\
249 		if (count) {							\
250 			const ctype *buf = buffer;				\
251 										\
252 			do {							\
253 				__raw_writeq(*buf++, addr);			\
254 			} while (--count);					\
255 		}								\
256 		afence;								\
257 	}
258 
259 __io_reads_ins(reads,  u8, b, __io_br(), __io_ar())
260 __io_reads_ins(reads, u16, w, __io_br(), __io_ar())
261 __io_reads_ins(reads, u32, l, __io_br(), __io_ar())
262 #define readsb(addr, buffer, count) __readsb(addr, buffer, count)
263 #define readsw(addr, buffer, count) __readsw(addr, buffer, count)
264 #define readsl(addr, buffer, count) __readsl(addr, buffer, count)
265 
266 __io_reads_ins(ins,  u8, b, __io_pbr(), __io_par())
267 __io_reads_ins(ins, u16, w, __io_pbr(), __io_par())
268 __io_reads_ins(ins, u32, l, __io_pbr(), __io_par())
269 #define insb(addr, buffer, count) __insb((void __iomem *)addr, buffer, count)
270 #define insw(addr, buffer, count) __insw((void __iomem *)addr, buffer, count)
271 #define insl(addr, buffer, count) __insl((void __iomem *)addr, buffer, count)
272 
273 __io_writes_outs(writes,  u8, b, __io_bw(), __io_aw())
274 __io_writes_outs(writes, u16, w, __io_bw(), __io_aw())
275 __io_writes_outs(writes, u32, l, __io_bw(), __io_aw())
276 #define writesb(addr, buffer, count) __writesb(addr, buffer, count)
277 #define writesw(addr, buffer, count) __writesw(addr, buffer, count)
278 #define writesl(addr, buffer, count) __writesl(addr, buffer, count)
279 
280 __io_writes_outs(outs,  u8, b, __io_pbw(), __io_paw())
281 __io_writes_outs(outs, u16, w, __io_pbw(), __io_paw())
282 __io_writes_outs(outs, u32, l, __io_pbw(), __io_paw())
283 #define outsb(addr, buffer, count) __outsb((void __iomem *)addr, buffer, count)
284 #define outsw(addr, buffer, count) __outsw((void __iomem *)addr, buffer, count)
285 #define outsl(addr, buffer, count) __outsl((void __iomem *)addr, buffer, count)
286 
287 #ifdef CONFIG_64BIT
288 __io_reads_ins(reads, u64, q, __io_br(), __io_ar())
289 #define readsq(addr, buffer, count) __readsq(addr, buffer, count)
290 
291 __io_reads_ins(ins, u64, q, __io_pbr(), __io_par())
292 #define insq(addr, buffer, count) __insq((void __iomem *)addr, buffer, count)
293 
294 __io_writes_outs(writes, u64, q, __io_bw(), __io_aw())
295 #define writesq(addr, buffer, count) __writesq(addr, buffer, count)
296 
297 __io_writes_outs(outs, u64, q, __io_pbr(), __io_paw())
298 #define outsq(addr, buffer, count) __outsq((void __iomem *)addr, buffer, count)
299 #endif
300 
301 #include <asm-generic/io.h>
302 
303 #endif /* _ASM_RISCV_IO_H */
304