arch/riscv/include/asm/io.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * {read,write}{b,w,l,q} based on arch/arm64/include/asm/io.h
   4  *   which was based on arch/arm/include/io.h
   5  *
   6  * Copyright (C) 1996-2000 Russell King
   7  * Copyright (C) 2012 ARM Ltd.
   8  * Copyright (C) 2014 Regents of the University of California
   9  */
  10
  11 #ifndef _ASM_RISCV_IO_H
  12 #define _ASM_RISCV_IO_H
  13
  14 #include <linux/types.h>
  15 #include <linux/pgtable.h>
  16 #include <asm/mmiowb.h>
  17 #include <asm/early_ioremap.h>
  18
  19 /*
  20  * MMIO access functions are separated out to break dependency cycles
  21  * when using {read,write}* fns in low-level headers
  22  */
  23 #include <asm/mmio.h>
  24
  25 /*
  26  *  I/O port access constants.
  27  */
  28 #ifdef CONFIG_MMU
  29 #define IO_SPACE_LIMIT          (PCI_IO_SIZE - 1)
  30 #define PCI_IOBASE              ((void __iomem *)PCI_IO_START)
  31 #endif /* CONFIG_MMU */
  32
  33 /*
  34  * Emulation routines for the port-mapped IO space used by some PCI drivers.
  35  * These are defined as being "fully synchronous", but also "not guaranteed to
  36  * be fully ordered with respect to other memory and I/O operations".  We're
  37  * going to be on the safe side here and just make them:
  38  *  - Fully ordered WRT each other, by bracketing them with two fences.  The
  39  *    outer set contains both I/O so inX is ordered with outX, while the inner just
  40  *    needs the type of the access (I for inX and O for outX).
  41  *  - Ordered in the same manner as readX/writeX WRT memory by subsuming their
  42  *    fences.
  43  *  - Ordered WRT timer reads, so udelay and friends don't get elided by the
  44  *    implementation.
  45  * Note that there is no way to actually enforce that outX is a non-posted
  46  * operation on RISC-V, but hopefully the timer ordering constraint is
  47  * sufficient to ensure this works sanely on controllers that support I/O
  48  * writes.
  49  */
  50 #define __io_pbr()      __asm__ __volatile__ ("fence io,i"  : : : "memory");
  51 #define __io_par(v)     __asm__ __volatile__ ("fence i,ior" : : : "memory");
  52 #define __io_pbw()      __asm__ __volatile__ ("fence iow,o" : : : "memory");
  53 #define __io_paw()      __asm__ __volatile__ ("fence o,io"  : : : "memory");
  54
  55 /*
  56  * Accesses from a single hart to a single I/O address must be ordered.  This
  57  * allows us to use the raw read macros, but we still need to fence before and
  58  * after the block to ensure ordering WRT other macros.  These are defined to
  59  * perform host-endian accesses so we use __raw instead of __cpu.
  60  */
  61 #define __io_reads_ins(port, ctype, len, bfence, afence)                        \
  62         static inline void __ ## port ## len(const volatile void __iomem *addr, \
  63                                              void *buffer,                      \
  64                                              unsigned int count)                \
  65         {                                                                       \
  66                 bfence;                                                         \
  67                 if (count) {                                                    \
  68                         ctype *buf = buffer;                                    \
  69                                                                                 \
  70                         do {                                                    \
  71                                 ctype x = __raw_read ## len(addr);              \
  72                                 *buf++ = x;                                     \
  73                         } while (--count);                                      \
  74                 }                                                               \
  75                 afence;                                                         \
  76         }
  77
  78 #define __io_writes_outs(port, ctype, len, bfence, afence)                      \
  79         static inline void __ ## port ## len(volatile void __iomem *addr,       \
  80                                              const void *buffer,                \
  81                                              unsigned int count)                \
  82         {                                                                       \
  83                 bfence;                                                         \
  84                 if (count) {                                                    \
  85                         const ctype *buf = buffer;                              \
  86                                                                                 \
  87                         do {                                                    \
  88                                 __raw_write ## len(*buf++, addr);               \
  89                         } while (--count);                                      \
  90                 }                                                               \
  91                 afence;                                                         \
  92         }
  93
  94 __io_reads_ins(reads,  u8, b, __io_br(), __io_ar(addr))
  95 __io_reads_ins(reads, u16, w, __io_br(), __io_ar(addr))
  96 __io_reads_ins(reads, u32, l, __io_br(), __io_ar(addr))
  97 #define readsb(addr, buffer, count) __readsb(addr, buffer, count)
  98 #define readsw(addr, buffer, count) __readsw(addr, buffer, count)
  99 #define readsl(addr, buffer, count) __readsl(addr, buffer, count)
 100
 101 __io_reads_ins(ins,  u8, b, __io_pbr(), __io_par(addr))
 102 __io_reads_ins(ins, u16, w, __io_pbr(), __io_par(addr))
 103 __io_reads_ins(ins, u32, l, __io_pbr(), __io_par(addr))
 104 #define insb(addr, buffer, count) __insb((void __iomem *)(long)addr, buffer, count)
 105 #define insw(addr, buffer, count) __insw((void __iomem *)(long)addr, buffer, count)
 106 #define insl(addr, buffer, count) __insl((void __iomem *)(long)addr, buffer, count)
 107
 108 __io_writes_outs(writes,  u8, b, __io_bw(), __io_aw())
 109 __io_writes_outs(writes, u16, w, __io_bw(), __io_aw())
 110 __io_writes_outs(writes, u32, l, __io_bw(), __io_aw())
 111 #define writesb(addr, buffer, count) __writesb(addr, buffer, count)
 112 #define writesw(addr, buffer, count) __writesw(addr, buffer, count)
 113 #define writesl(addr, buffer, count) __writesl(addr, buffer, count)
 114
 115 __io_writes_outs(outs,  u8, b, __io_pbw(), __io_paw())
 116 __io_writes_outs(outs, u16, w, __io_pbw(), __io_paw())
 117 __io_writes_outs(outs, u32, l, __io_pbw(), __io_paw())
 118 #define outsb(addr, buffer, count) __outsb((void __iomem *)(long)addr, buffer, count)
 119 #define outsw(addr, buffer, count) __outsw((void __iomem *)(long)addr, buffer, count)
 120 #define outsl(addr, buffer, count) __outsl((void __iomem *)(long)addr, buffer, count)
 121
 122 #ifdef CONFIG_64BIT
 123 __io_reads_ins(reads, u64, q, __io_br(), __io_ar(addr))
 124 #define readsq(addr, buffer, count) __readsq(addr, buffer, count)
 125
 126 __io_reads_ins(ins, u64, q, __io_pbr(), __io_par(addr))
 127 #define insq(addr, buffer, count) __insq((void __iomem *)addr, buffer, count)
 128
 129 __io_writes_outs(writes, u64, q, __io_bw(), __io_aw())
 130 #define writesq(addr, buffer, count) __writesq(addr, buffer, count)
 131
 132 __io_writes_outs(outs, u64, q, __io_pbr(), __io_paw())
 133 #define outsq(addr, buffer, count) __outsq((void __iomem *)addr, buffer, count)
 134 #endif
 135
 136 #include <asm-generic/io.h>
 137
 138 #endif /* _ASM_RISCV_IO_H */