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-rw-r--r--arch/riscv/include/asm/io.h143
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diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h
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+++ b/arch/riscv/include/asm/io.h
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * {read,write}{b,w,l,q} based on arch/arm64/include/asm/io.h
+ * which was based on arch/arm/include/io.h
+ *
+ * Copyright (C) 1996-2000 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2014 Regents of the University of California
+ */
+
+#ifndef _ASM_RISCV_IO_H
+#define _ASM_RISCV_IO_H
+
+#include <linux/types.h>
+#include <linux/pgtable.h>
+#include <asm/mmiowb.h>
+#include <asm/early_ioremap.h>
+
+/*
+ * MMIO access functions are separated out to break dependency cycles
+ * when using {read,write}* fns in low-level headers
+ */
+#include <asm/mmio.h>
+
+/*
+ * I/O port access constants.
+ */
+#ifdef CONFIG_MMU
+#define IO_SPACE_LIMIT (PCI_IO_SIZE - 1)
+#define PCI_IOBASE ((void __iomem *)PCI_IO_START)
+#endif /* CONFIG_MMU */
+
+/*
+ * Emulation routines for the port-mapped IO space used by some PCI drivers.
+ * These are defined as being "fully synchronous", but also "not guaranteed to
+ * be fully ordered with respect to other memory and I/O operations". We're
+ * going to be on the safe side here and just make them:
+ * - Fully ordered WRT each other, by bracketing them with two fences. The
+ * outer set contains both I/O so inX is ordered with outX, while the inner just
+ * needs the type of the access (I for inX and O for outX).
+ * - Ordered in the same manner as readX/writeX WRT memory by subsuming their
+ * fences.
+ * - Ordered WRT timer reads, so udelay and friends don't get elided by the
+ * implementation.
+ * Note that there is no way to actually enforce that outX is a non-posted
+ * operation on RISC-V, but hopefully the timer ordering constraint is
+ * sufficient to ensure this works sanely on controllers that support I/O
+ * writes.
+ */
+#define __io_pbr() __asm__ __volatile__ ("fence io,i" : : : "memory");
+#define __io_par(v) __asm__ __volatile__ ("fence i,ior" : : : "memory");
+#define __io_pbw() __asm__ __volatile__ ("fence iow,o" : : : "memory");
+#define __io_paw() __asm__ __volatile__ ("fence o,io" : : : "memory");
+
+/*
+ * Accesses from a single hart to a single I/O address must be ordered. This
+ * allows us to use the raw read macros, but we still need to fence before and
+ * after the block to ensure ordering WRT other macros. These are defined to
+ * perform host-endian accesses so we use __raw instead of __cpu.
+ */
+#define __io_reads_ins(port, ctype, len, bfence, afence) \
+ static inline void __ ## port ## len(const volatile void __iomem *addr, \
+ void *buffer, \
+ unsigned int count) \
+ { \
+ bfence; \
+ if (count) { \
+ ctype *buf = buffer; \
+ \
+ do { \
+ ctype x = __raw_read ## len(addr); \
+ *buf++ = x; \
+ } while (--count); \
+ } \
+ afence; \
+ }
+
+#define __io_writes_outs(port, ctype, len, bfence, afence) \
+ static inline void __ ## port ## len(volatile void __iomem *addr, \
+ const void *buffer, \
+ unsigned int count) \
+ { \
+ bfence; \
+ if (count) { \
+ const ctype *buf = buffer; \
+ \
+ do { \
+ __raw_write ## len(*buf++, addr); \
+ } while (--count); \
+ } \
+ afence; \
+ }
+
+__io_reads_ins(reads, u8, b, __io_br(), __io_ar(addr))
+__io_reads_ins(reads, u16, w, __io_br(), __io_ar(addr))
+__io_reads_ins(reads, u32, l, __io_br(), __io_ar(addr))
+#define readsb(addr, buffer, count) __readsb(addr, buffer, count)
+#define readsw(addr, buffer, count) __readsw(addr, buffer, count)
+#define readsl(addr, buffer, count) __readsl(addr, buffer, count)
+
+__io_reads_ins(ins, u8, b, __io_pbr(), __io_par(addr))
+__io_reads_ins(ins, u16, w, __io_pbr(), __io_par(addr))
+__io_reads_ins(ins, u32, l, __io_pbr(), __io_par(addr))
+#define insb(addr, buffer, count) __insb(PCI_IOBASE + (addr), buffer, count)
+#define insw(addr, buffer, count) __insw(PCI_IOBASE + (addr), buffer, count)
+#define insl(addr, buffer, count) __insl(PCI_IOBASE + (addr), buffer, count)
+
+__io_writes_outs(writes, u8, b, __io_bw(), __io_aw())
+__io_writes_outs(writes, u16, w, __io_bw(), __io_aw())
+__io_writes_outs(writes, u32, l, __io_bw(), __io_aw())
+#define writesb(addr, buffer, count) __writesb(addr, buffer, count)
+#define writesw(addr, buffer, count) __writesw(addr, buffer, count)
+#define writesl(addr, buffer, count) __writesl(addr, buffer, count)
+
+__io_writes_outs(outs, u8, b, __io_pbw(), __io_paw())
+__io_writes_outs(outs, u16, w, __io_pbw(), __io_paw())
+__io_writes_outs(outs, u32, l, __io_pbw(), __io_paw())
+#define outsb(addr, buffer, count) __outsb(PCI_IOBASE + (addr), buffer, count)
+#define outsw(addr, buffer, count) __outsw(PCI_IOBASE + (addr), buffer, count)
+#define outsl(addr, buffer, count) __outsl(PCI_IOBASE + (addr), buffer, count)
+
+#ifdef CONFIG_64BIT
+__io_reads_ins(reads, u64, q, __io_br(), __io_ar(addr))
+#define readsq(addr, buffer, count) __readsq(addr, buffer, count)
+
+__io_reads_ins(ins, u64, q, __io_pbr(), __io_par(addr))
+#define insq(addr, buffer, count) __insq(PCI_IOBASE + (addr), buffer, count)
+
+__io_writes_outs(writes, u64, q, __io_bw(), __io_aw())
+#define writesq(addr, buffer, count) __writesq(addr, buffer, count)
+
+__io_writes_outs(outs, u64, q, __io_pbr(), __io_paw())
+#define outsq(addr, buffer, count) __outsq(PCI_IOBASE + (addr), buffer, count)
+#endif
+
+#include <asm-generic/io.h>
+
+#ifdef CONFIG_MMU
+#define arch_memremap_wb(addr, size) \
+ ((__force void *)ioremap_prot((addr), (size), _PAGE_KERNEL))
+#endif
+
+#endif /* _ASM_RISCV_IO_H */