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 <asm/mmiowb.h>
  16 #include <asm/pgtable.h>
  17
  18 /*
  19  * MMIO access functions are separated out to break dependency cycles
  20  * when using {read,write}* fns in low-level headers
  21  */
  22 #include <asm/mmio.h>
  23
  24 /*
  25  *  I/O port access constants.
  26  */
  27 #ifdef CONFIG_MMU
  28 #define IO_SPACE_LIMIT          (PCI_IO_SIZE - 1)
  29 #define PCI_IOBASE              ((void __iomem *)PCI_IO_START)
  30 #endif /* CONFIG_MMU */
  31
  32 /*
  33  * Emulation routines for the port-mapped IO space used by some PCI drivers.
  34  * These are defined as being "fully synchronous", but also "not guaranteed to
  35  * be fully ordered with respect to other memory and I/O operations".  We're
  36  * going to be on the safe side here and just make them:
  37  *  - Fully ordered WRT each other, by bracketing them with two fences.  The
  38  *    outer set contains both I/O so inX is ordered with outX, while the inner just
  39  *    needs the type of the access (I for inX and O for outX).
  40  *  - Ordered in the same manner as readX/writeX WRT memory by subsuming their
  41  *    fences.
  42  *  - Ordered WRT timer reads, so udelay and friends don't get elided by the
  43  *    implementation.
  44  * Note that there is no way to actually enforce that outX is a non-posted
  45  * operation on RISC-V, but hopefully the timer ordering constraint is
  46  * sufficient to ensure this works sanely on controllers that support I/O
  47  * writes.
  48  */
  49 #define __io_pbr()      __asm__ __volatile__ ("fence io,i"  : : : "memory");
  50 #define __io_par(v)     __asm__ __volatile__ ("fence i,ior" : : : "memory");
  51 #define __io_pbw()      __asm__ __volatile__ ("fence iow,o" : : : "memory");
  52 #define __io_paw()      __asm__ __volatile__ ("fence o,io"  : : : "memory");
  53
  54 #define inb(c)          ({ u8  __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
  55 #define inw(c)          ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
  56 #define inl(c)          ({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
  57
  58 #define outb(v,c)       ({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
  59 #define outw(v,c)       ({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
  60 #define outl(v,c)       ({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
  61
  62 #ifdef CONFIG_64BIT
  63 #define inq(c)          ({ u64 __v; __io_pbr(); __v = readq_cpu((void*)(c)); __io_par(__v); __v; })
  64 #define outq(v,c)       ({ __io_pbw(); writeq_cpu((v),(void*)(c)); __io_paw(); })
  65 #endif
  66
  67 /*
  68  * Accesses from a single hart to a single I/O address must be ordered.  This
  69  * allows us to use the raw read macros, but we still need to fence before and
  70  * after the block to ensure ordering WRT other macros.  These are defined to
  71  * perform host-endian accesses so we use __raw instead of __cpu.
  72  */
  73 #define __io_reads_ins(port, ctype, len, bfence, afence)                        \
  74         static inline void __ ## port ## len(const volatile void __iomem *addr, \
  75                                              void *buffer,                      \
  76                                              unsigned int count)                \
  77         {                                                                       \
  78                 bfence;                                                         \
  79                 if (count) {                                                    \
  80                         ctype *buf = buffer;                                    \
  81                                                                                 \
  82                         do {                                                    \
  83                                 ctype x = __raw_read ## len(addr);              \
  84                                 *buf++ = x;                                     \
  85                         } while (--count);                                      \
  86                 }                                                               \
  87                 afence;                                                         \
  88         }
  89
  90 #define __io_writes_outs(port, ctype, len, bfence, afence)                      \
  91         static inline void __ ## port ## len(volatile void __iomem *addr,       \
  92                                              const void *buffer,                \
  93                                              unsigned int count)                \
  94         {                                                                       \
  95                 bfence;                                                         \
  96                 if (count) {                                                    \
  97                         const ctype *buf = buffer;                              \
  98                                                                                 \
  99                         do {                                                    \
 100                                 __raw_write ## len(*buf++, addr);               \
 101                         } while (--count);                                      \
 102                 }                                                               \
 103                 afence;                                                         \
 104         }
 105
 106 __io_reads_ins(reads,  u8, b, __io_br(), __io_ar(addr))
 107 __io_reads_ins(reads, u16, w, __io_br(), __io_ar(addr))
 108 __io_reads_ins(reads, u32, l, __io_br(), __io_ar(addr))
 109 #define readsb(addr, buffer, count) __readsb(addr, buffer, count)
 110 #define readsw(addr, buffer, count) __readsw(addr, buffer, count)
 111 #define readsl(addr, buffer, count) __readsl(addr, buffer, count)
 112
 113 __io_reads_ins(ins,  u8, b, __io_pbr(), __io_par(addr))
 114 __io_reads_ins(ins, u16, w, __io_pbr(), __io_par(addr))
 115 __io_reads_ins(ins, u32, l, __io_pbr(), __io_par(addr))
 116 #define insb(addr, buffer, count) __insb((void __iomem *)(long)addr, buffer, count)
 117 #define insw(addr, buffer, count) __insw((void __iomem *)(long)addr, buffer, count)
 118 #define insl(addr, buffer, count) __insl((void __iomem *)(long)addr, buffer, count)
 119
 120 __io_writes_outs(writes,  u8, b, __io_bw(), __io_aw())
 121 __io_writes_outs(writes, u16, w, __io_bw(), __io_aw())
 122 __io_writes_outs(writes, u32, l, __io_bw(), __io_aw())
 123 #define writesb(addr, buffer, count) __writesb(addr, buffer, count)
 124 #define writesw(addr, buffer, count) __writesw(addr, buffer, count)
 125 #define writesl(addr, buffer, count) __writesl(addr, buffer, count)
 126
 127 __io_writes_outs(outs,  u8, b, __io_pbw(), __io_paw())
 128 __io_writes_outs(outs, u16, w, __io_pbw(), __io_paw())
 129 __io_writes_outs(outs, u32, l, __io_pbw(), __io_paw())
 130 #define outsb(addr, buffer, count) __outsb((void __iomem *)(long)addr, buffer, count)
 131 #define outsw(addr, buffer, count) __outsw((void __iomem *)(long)addr, buffer, count)
 132 #define outsl(addr, buffer, count) __outsl((void __iomem *)(long)addr, buffer, count)
 133
 134 #ifdef CONFIG_64BIT
 135 __io_reads_ins(reads, u64, q, __io_br(), __io_ar(addr))
 136 #define readsq(addr, buffer, count) __readsq(addr, buffer, count)
 137
 138 __io_reads_ins(ins, u64, q, __io_pbr(), __io_par(addr))
 139 #define insq(addr, buffer, count) __insq((void __iomem *)addr, buffer, count)
 140
 141 __io_writes_outs(writes, u64, q, __io_bw(), __io_aw())
 142 #define writesq(addr, buffer, count) __writesq(addr, buffer, count)
 143
 144 __io_writes_outs(outs, u64, q, __io_pbr(), __io_paw())
 145 #define outsq(addr, buffer, count) __outsq((void __iomem *)addr, buffer, count)
 146 #endif
 147
 148 #include <asm-generic/io.h>
 149
 150 #endif /* _ASM_RISCV_IO_H */