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e5bc0478ab
While reviewing a different change to asm-generic/io.h Arnd spotted that ARC ioread32 and ioread32be both of which come from asm-generic versions are not symmetrical in terms of calling the io barriers. generic ioread32 -> ARC readl() [ has barriers] generic ioread32be -> __be32_to_cpu(__raw_readl()) [ lacks barriers] While generic ioread32be is being remediated to call readl(), that involves a swab32(), causing double swaps on ioread32be() on Big Endian systems. So provide our versions of big endian IO accessors to ensure io barrier calls while also keeping them optimal Suggested-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: stable@vger.kernel.org [4.2+] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
171 lines
4.4 KiB
C
171 lines
4.4 KiB
C
/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef _ASM_ARC_IO_H
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#define _ASM_ARC_IO_H
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#include <linux/types.h>
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#include <asm/byteorder.h>
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#include <asm/page.h>
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#ifdef CONFIG_ISA_ARCV2
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#include <asm/barrier.h>
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#define __iormb() rmb()
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#define __iowmb() wmb()
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#else
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#define __iormb() do { } while (0)
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#define __iowmb() do { } while (0)
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#endif
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extern void __iomem *ioremap(phys_addr_t paddr, unsigned long size);
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extern void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
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unsigned long flags);
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static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
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{
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return (void __iomem *)port;
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}
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static inline void ioport_unmap(void __iomem *addr)
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{
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}
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extern void iounmap(const void __iomem *addr);
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#define ioremap_nocache(phy, sz) ioremap(phy, sz)
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#define ioremap_wc(phy, sz) ioremap(phy, sz)
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#define ioremap_wt(phy, sz) ioremap(phy, sz)
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/*
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* io{read,write}{16,32}be() macros
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*/
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#define ioread16be(p) ({ u16 __v = be16_to_cpu((__force __be16)__raw_readw(p)); __iormb(); __v; })
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#define ioread32be(p) ({ u32 __v = be32_to_cpu((__force __be32)__raw_readl(p)); __iormb(); __v; })
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#define iowrite16be(v,p) ({ __iowmb(); __raw_writew((__force u16)cpu_to_be16(v), p); })
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#define iowrite32be(v,p) ({ __iowmb(); __raw_writel((__force u32)cpu_to_be32(v), p); })
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/* Change struct page to physical address */
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#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
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#define __raw_readb __raw_readb
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static inline u8 __raw_readb(const volatile void __iomem *addr)
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{
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u8 b;
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__asm__ __volatile__(
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" ldb%U1 %0, %1 \n"
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: "=r" (b)
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: "m" (*(volatile u8 __force *)addr)
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: "memory");
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return b;
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}
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#define __raw_readw __raw_readw
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static inline u16 __raw_readw(const volatile void __iomem *addr)
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{
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u16 s;
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__asm__ __volatile__(
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" ldw%U1 %0, %1 \n"
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: "=r" (s)
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: "m" (*(volatile u16 __force *)addr)
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: "memory");
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return s;
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}
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#define __raw_readl __raw_readl
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static inline u32 __raw_readl(const volatile void __iomem *addr)
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{
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u32 w;
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__asm__ __volatile__(
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" ld%U1 %0, %1 \n"
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: "=r" (w)
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: "m" (*(volatile u32 __force *)addr)
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: "memory");
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return w;
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}
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#define __raw_writeb __raw_writeb
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static inline void __raw_writeb(u8 b, volatile void __iomem *addr)
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{
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__asm__ __volatile__(
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" stb%U1 %0, %1 \n"
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:
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: "r" (b), "m" (*(volatile u8 __force *)addr)
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: "memory");
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}
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#define __raw_writew __raw_writew
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static inline void __raw_writew(u16 s, volatile void __iomem *addr)
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{
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__asm__ __volatile__(
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" stw%U1 %0, %1 \n"
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:
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: "r" (s), "m" (*(volatile u16 __force *)addr)
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: "memory");
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}
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#define __raw_writel __raw_writel
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static inline void __raw_writel(u32 w, volatile void __iomem *addr)
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{
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__asm__ __volatile__(
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" st%U1 %0, %1 \n"
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:
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: "r" (w), "m" (*(volatile u32 __force *)addr)
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: "memory");
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}
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/*
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* MMIO can also get buffered/optimized in micro-arch, so barriers needed
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* Based on ARM model for the typical use case
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*
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* <ST [DMA buffer]>
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* <writel MMIO "go" reg>
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* or:
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* <readl MMIO "status" reg>
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* <LD [DMA buffer]>
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*
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* http://lkml.kernel.org/r/20150622133656.GG1583@arm.com
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*/
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#define readb(c) ({ u8 __v = readb_relaxed(c); __iormb(); __v; })
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#define readw(c) ({ u16 __v = readw_relaxed(c); __iormb(); __v; })
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#define readl(c) ({ u32 __v = readl_relaxed(c); __iormb(); __v; })
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#define writeb(v,c) ({ __iowmb(); writeb_relaxed(v,c); })
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#define writew(v,c) ({ __iowmb(); writew_relaxed(v,c); })
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#define writel(v,c) ({ __iowmb(); writel_relaxed(v,c); })
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/*
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* Relaxed API for drivers which can handle barrier ordering themselves
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*
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* Also these are defined to perform little endian accesses.
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* To provide the typical device register semantics of fixed endian,
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* swap the byte order for Big Endian
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*
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* http://lkml.kernel.org/r/201603100845.30602.arnd@arndb.de
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*/
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#define readb_relaxed(c) __raw_readb(c)
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#define readw_relaxed(c) ({ u16 __r = le16_to_cpu((__force __le16) \
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__raw_readw(c)); __r; })
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#define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32) \
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__raw_readl(c)); __r; })
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#define writeb_relaxed(v,c) __raw_writeb(v,c)
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#define writew_relaxed(v,c) __raw_writew((__force u16) cpu_to_le16(v),c)
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#define writel_relaxed(v,c) __raw_writel((__force u32) cpu_to_le32(v),c)
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#include <asm-generic/io.h>
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#endif /* _ASM_ARC_IO_H */
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