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alistair23-linux/arch/arm/include/asm/io.h
Russell King 1bd46782d0 ARM: avoid unwanted GCC memset()/memcpy() optimisations for IO variants 
We don't want GCC optimising our memset_io(), memcpy_fromio() or
memcpy_toio() variants, so we must not call one of the standard
functions.  Provide a separate name for our assembly memcpy() and
memset() functions, and use that instead, thereby bypassing GCC's
ability to optimise these operations.

GCCs optimisation may introduce unaligned accesses which are invalid
for device mappings.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-07-03 20:46:15 +01:00

471 lines
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/*
* arch/arm/include/asm/io.h
*
* Copyright (C) 1996-2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Modifications:
* 16-Sep-1996 RMK Inlined the inx/outx functions & optimised for both
* constant addresses and variable addresses.
* 04-Dec-1997 RMK Moved a lot of this stuff to the new architecture
* specific IO header files.
* 27-Mar-1999 PJB Second parameter of memcpy_toio is const..
* 04-Apr-1999 PJB Added check_signature.
* 12-Dec-1999 RMK More cleanups
* 18-Jun-2000 RMK Removed virt_to_* and friends definitions
* 05-Oct-2004 BJD Moved memory string functions to use void __iomem
*/
#ifndef __ASM_ARM_IO_H
#define __ASM_ARM_IO_H
#ifdef __KERNEL__
#include <linux/string.h>
#include <linux/types.h>
#include <linux/blk_types.h>
#include <asm/byteorder.h>
#include <asm/memory.h>
#include <asm-generic/pci_iomap.h>
#include <xen/xen.h>
/*
* ISA I/O bus memory addresses are 1:1 with the physical address.
*/
#define isa_virt_to_bus virt_to_phys
#define isa_page_to_bus page_to_phys
#define isa_bus_to_virt phys_to_virt
/*
* Atomic MMIO-wide IO modify
*/
extern void atomic_io_modify(void __iomem *reg, u32 mask, u32 set);
extern void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set);
/*
* Generic IO read/write. These perform native-endian accesses. Note
* that some architectures will want to re-define __raw_{read,write}w.
*/
void __raw_writesb(volatile void __iomem *addr, const void *data, int bytelen);
void __raw_writesw(volatile void __iomem *addr, const void *data, int wordlen);
void __raw_writesl(volatile void __iomem *addr, const void *data, int longlen);
void __raw_readsb(const volatile void __iomem *addr, void *data, int bytelen);
void __raw_readsw(const volatile void __iomem *addr, void *data, int wordlen);
void __raw_readsl(const volatile void __iomem *addr, void *data, int longlen);
#if __LINUX_ARM_ARCH__ < 6
/*
* Half-word accesses are problematic with RiscPC due to limitations of
* the bus. Rather than special-case the machine, just let the compiler
* generate the access for CPUs prior to ARMv6.
*/
#define __raw_readw(a) (__chk_io_ptr(a), *(volatile unsigned short __force *)(a))
#define __raw_writew(v,a) ((void)(__chk_io_ptr(a), *(volatile unsigned short __force *)(a) = (v)))
#else
/*
* When running under a hypervisor, we want to avoid I/O accesses with
* writeback addressing modes as these incur a significant performance
* overhead (the address generation must be emulated in software).
*/
#define __raw_writew __raw_writew
static inline void __raw_writew(u16 val, volatile void __iomem *addr)
{
asm volatile("strh %1, %0"
: : "Q" (*(volatile u16 __force *)addr), "r" (val));
}
#define __raw_readw __raw_readw
static inline u16 __raw_readw(const volatile void __iomem *addr)
{
u16 val;
asm volatile("ldrh %0, %1"
: "=r" (val)
: "Q" (*(volatile u16 __force *)addr));
return val;
}
#endif
#define __raw_writeb __raw_writeb
static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
{
asm volatile("strb %1, %0"
: : "Qo" (*(volatile u8 __force *)addr), "r" (val));
}
#define __raw_writel __raw_writel
static inline void __raw_writel(u32 val, volatile void __iomem *addr)
{
asm volatile("str %1, %0"
: : "Qo" (*(volatile u32 __force *)addr), "r" (val));
}
#define __raw_readb __raw_readb
static inline u8 __raw_readb(const volatile void __iomem *addr)
{
u8 val;
asm volatile("ldrb %0, %1"
: "=r" (val)
: "Qo" (*(volatile u8 __force *)addr));
return val;
}
#define __raw_readl __raw_readl
static inline u32 __raw_readl(const volatile void __iomem *addr)
{
u32 val;
asm volatile("ldr %0, %1"
: "=r" (val)
: "Qo" (*(volatile u32 __force *)addr));
return val;
}
/*
* Architecture ioremap implementation.
*/
#define MT_DEVICE 0
#define MT_DEVICE_NONSHARED 1
#define MT_DEVICE_CACHED 2
#define MT_DEVICE_WC 3
/*
* types 4 onwards can be found in asm/mach/map.h and are undefined
* for ioremap
*/
/*
* __arm_ioremap takes CPU physical address.
* __arm_ioremap_pfn takes a Page Frame Number and an offset into that page
* The _caller variety takes a __builtin_return_address(0) value for
* /proc/vmalloc to use - and should only be used in non-inline functions.
*/
extern void __iomem *__arm_ioremap_caller(phys_addr_t, size_t, unsigned int,
void *);
extern void __iomem *__arm_ioremap_pfn(unsigned long, unsigned long, size_t, unsigned int);
extern void __iomem *__arm_ioremap_exec(phys_addr_t, size_t, bool cached);
extern void __iounmap(volatile void __iomem *addr);
extern void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t,
unsigned int, void *);
extern void (*arch_iounmap)(volatile void __iomem *);
/*
* Bad read/write accesses...
*/
extern void __readwrite_bug(const char *fn);
/*
* A typesafe __io() helper
*/
static inline void __iomem *__typesafe_io(unsigned long addr)
{
return (void __iomem *)addr;
}
#define IOMEM(x) ((void __force __iomem *)(x))
/* IO barriers */
#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
#include <asm/barrier.h>
#define __iormb() rmb()
#define __iowmb() wmb()
#else
#define __iormb() do { } while (0)
#define __iowmb() do { } while (0)
#endif
/* PCI fixed i/o mapping */
#define PCI_IO_VIRT_BASE 0xfee00000
#define PCI_IOBASE ((void __iomem *)PCI_IO_VIRT_BASE)
#if defined(CONFIG_PCI)
void pci_ioremap_set_mem_type(int mem_type);
#else
static inline void pci_ioremap_set_mem_type(int mem_type) {}
#endif
extern int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr);
/*
* Now, pick up the machine-defined IO definitions
*/
#ifdef CONFIG_NEED_MACH_IO_H
#include <mach/io.h>
#elif defined(CONFIG_PCI)
#define IO_SPACE_LIMIT ((resource_size_t)0xfffff)
#define __io(a) __typesafe_io(PCI_IO_VIRT_BASE + ((a) & IO_SPACE_LIMIT))
#else
#define __io(a) __typesafe_io((a) & IO_SPACE_LIMIT)
#endif
/*
* This is the limit of PC card/PCI/ISA IO space, which is by default
* 64K if we have PC card, PCI or ISA support. Otherwise, default to
* zero to prevent ISA/PCI drivers claiming IO space (and potentially
* oopsing.)
*
* Only set this larger if you really need inb() et.al. to operate over
* a larger address space. Note that SOC_COMMON ioremaps each sockets
* IO space area, and so inb() et.al. must be defined to operate as per
* readb() et.al. on such platforms.
*/
#ifndef IO_SPACE_LIMIT
#if defined(CONFIG_PCMCIA_SOC_COMMON) || defined(CONFIG_PCMCIA_SOC_COMMON_MODULE)
#define IO_SPACE_LIMIT ((resource_size_t)0xffffffff)
#elif defined(CONFIG_PCI) || defined(CONFIG_ISA) || defined(CONFIG_PCCARD)
#define IO_SPACE_LIMIT ((resource_size_t)0xffff)
#else
#define IO_SPACE_LIMIT ((resource_size_t)0)
#endif
#endif
/*
* IO port access primitives
* -------------------------
*
* The ARM doesn't have special IO access instructions; all IO is memory
* mapped. Note that these are defined to perform little endian accesses
* only. Their primary purpose is to access PCI and ISA peripherals.
*
* Note that for a big endian machine, this implies that the following
* big endian mode connectivity is in place, as described by numerous
* ARM documents:
*
* PCI: D0-D7 D8-D15 D16-D23 D24-D31
* ARM: D24-D31 D16-D23 D8-D15 D0-D7
*
* The machine specific io.h include defines __io to translate an "IO"
* address to a memory address.
*
* Note that we prevent GCC re-ordering or caching values in expressions
* by introducing sequence points into the in*() definitions. Note that
* __raw_* do not guarantee this behaviour.
*
* The {in,out}[bwl] macros are for emulating x86-style PCI/ISA IO space.
*/
#ifdef __io
#define outb(v,p) ({ __iowmb(); __raw_writeb(v,__io(p)); })
#define outw(v,p) ({ __iowmb(); __raw_writew((__force __u16) \
cpu_to_le16(v),__io(p)); })
#define outl(v,p) ({ __iowmb(); __raw_writel((__force __u32) \
cpu_to_le32(v),__io(p)); })
#define inb(p) ({ __u8 __v = __raw_readb(__io(p)); __iormb(); __v; })
#define inw(p) ({ __u16 __v = le16_to_cpu((__force __le16) \
__raw_readw(__io(p))); __iormb(); __v; })
#define inl(p) ({ __u32 __v = le32_to_cpu((__force __le32) \
__raw_readl(__io(p))); __iormb(); __v; })
#define outsb(p,d,l) __raw_writesb(__io(p),d,l)
#define outsw(p,d,l) __raw_writesw(__io(p),d,l)
#define outsl(p,d,l) __raw_writesl(__io(p),d,l)
#define insb(p,d,l) __raw_readsb(__io(p),d,l)
#define insw(p,d,l) __raw_readsw(__io(p),d,l)
#define insl(p,d,l) __raw_readsl(__io(p),d,l)
#endif
/*
* String version of IO memory access ops:
*/
extern void _memcpy_fromio(void *, const volatile void __iomem *, size_t);
extern void _memcpy_toio(volatile void __iomem *, const void *, size_t);
extern void _memset_io(volatile void __iomem *, int, size_t);
#define mmiowb()
/*
* Memory access primitives
* ------------------------
*
* These perform PCI memory accesses via an ioremap region. They don't
* take an address as such, but a cookie.
*
* Again, this are defined to perform little endian accesses. See the
* IO port primitives for more information.
*/
#ifndef readl
#define readb_relaxed(c) ({ u8 __r = __raw_readb(c); __r; })
#define readw_relaxed(c) ({ u16 __r = le16_to_cpu((__force __le16) \
__raw_readw(c)); __r; })
#define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32) \
__raw_readl(c)); __r; })
#define writeb_relaxed(v,c) __raw_writeb(v,c)
#define writew_relaxed(v,c) __raw_writew((__force u16) cpu_to_le16(v),c)
#define writel_relaxed(v,c) __raw_writel((__force u32) cpu_to_le32(v),c)
#define readb(c) ({ u8 __v = readb_relaxed(c); __iormb(); __v; })
#define readw(c) ({ u16 __v = readw_relaxed(c); __iormb(); __v; })
#define readl(c) ({ u32 __v = readl_relaxed(c); __iormb(); __v; })
#define writeb(v,c) ({ __iowmb(); writeb_relaxed(v,c); })
#define writew(v,c) ({ __iowmb(); writew_relaxed(v,c); })
#define writel(v,c) ({ __iowmb(); writel_relaxed(v,c); })
#define readsb(p,d,l) __raw_readsb(p,d,l)
#define readsw(p,d,l) __raw_readsw(p,d,l)
#define readsl(p,d,l) __raw_readsl(p,d,l)
#define writesb(p,d,l) __raw_writesb(p,d,l)
#define writesw(p,d,l) __raw_writesw(p,d,l)
#define writesl(p,d,l) __raw_writesl(p,d,l)
#ifndef __ARMBE__
static inline void memset_io(volatile void __iomem *dst, unsigned c,
size_t count)
{
extern void mmioset(void *, unsigned int, size_t);
mmioset((void __force *)dst, c, count);
}
#define memset_io(dst,c,count) memset_io(dst,c,count)
static inline void memcpy_fromio(void *to, const volatile void __iomem *from,
size_t count)
{
extern void mmiocpy(void *, const void *, size_t);
mmiocpy(to, (const void __force *)from, count);
}
#define memcpy_fromio(to,from,count) memcpy_fromio(to,from,count)
static inline void memcpy_toio(volatile void __iomem *to, const void *from,
size_t count)
{
extern void mmiocpy(void *, const void *, size_t);
mmiocpy((void __force *)to, from, count);
}
#define memcpy_toio(to,from,count) memcpy_toio(to,from,count)
#else
#define memset_io(c,v,l) _memset_io(c,(v),(l))
#define memcpy_fromio(a,c,l) _memcpy_fromio((a),c,(l))
#define memcpy_toio(c,a,l) _memcpy_toio(c,(a),(l))
#endif
#endif /* readl */
/*
* ioremap() and friends.
*
* ioremap() takes a resource address, and size. Due to the ARM memory
* types, it is important to use the correct ioremap() function as each
* mapping has specific properties.
*
* Function Memory type Cacheability Cache hint
* ioremap() Device n/a n/a
* ioremap_nocache() Device n/a n/a
* ioremap_cache() Normal Writeback Read allocate
* ioremap_wc() Normal Non-cacheable n/a
* ioremap_wt() Normal Non-cacheable n/a
*
* All device mappings have the following properties:
* - no access speculation
* - no repetition (eg, on return from an exception)
* - number, order and size of accesses are maintained
* - unaligned accesses are "unpredictable"
* - writes may be delayed before they hit the endpoint device
*
* ioremap_nocache() is the same as ioremap() as there are too many device
* drivers using this for device registers, and documentation which tells
* people to use it for such for this to be any different. This is not a
* safe fallback for memory-like mappings, or memory regions where the
* compiler may generate unaligned accesses - eg, via inlining its own
* memcpy.
*
* All normal memory mappings have the following properties:
* - reads can be repeated with no side effects
* - repeated reads return the last value written
* - reads can fetch additional locations without side effects
* - writes can be repeated (in certain cases) with no side effects
* - writes can be merged before accessing the target
* - unaligned accesses can be supported
* - ordering is not guaranteed without explicit dependencies or barrier
* instructions
* - writes may be delayed before they hit the endpoint memory
*
* The cache hint is only a performance hint: CPUs may alias these hints.
* Eg, a CPU not implementing read allocate but implementing write allocate
* will provide a write allocate mapping instead.
*/
void __iomem *ioremap(resource_size_t res_cookie, size_t size);
#define ioremap ioremap
#define ioremap_nocache ioremap
void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size);
#define ioremap_cache ioremap_cache
void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size);
#define ioremap_wc ioremap_wc
#define ioremap_wt ioremap_wc
void iounmap(volatile void __iomem *iomem_cookie);
#define iounmap iounmap
/*
* io{read,write}{16,32}be() macros
*/
#define ioread16be(p) ({ __u16 __v = be16_to_cpu((__force __be16)__raw_readw(p)); __iormb(); __v; })
#define ioread32be(p) ({ __u32 __v = be32_to_cpu((__force __be32)__raw_readl(p)); __iormb(); __v; })
#define iowrite16be(v,p) ({ __iowmb(); __raw_writew((__force __u16)cpu_to_be16(v), p); })
#define iowrite32be(v,p) ({ __iowmb(); __raw_writel((__force __u32)cpu_to_be32(v), p); })
#ifndef ioport_map
#define ioport_map ioport_map
extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
#endif
#ifndef ioport_unmap
#define ioport_unmap ioport_unmap
extern void ioport_unmap(void __iomem *addr);
#endif
struct pci_dev;
#define pci_iounmap pci_iounmap
extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
/*
* Convert a physical pointer to a virtual kernel pointer for /dev/mem
* access
*/
#define xlate_dev_mem_ptr(p) __va(p)
/*
* Convert a virtual cached pointer to an uncached pointer
*/
#define xlate_dev_kmem_ptr(p) p
#include <asm-generic/io.h>
/*
* can the hardware map this into one segment or not, given no other
* constraints.
*/
#define BIOVEC_MERGEABLE(vec1, vec2) \
((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
struct bio_vec;
extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
const struct bio_vec *vec2);
#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
(__BIOVEC_PHYS_MERGEABLE(vec1, vec2) && \
(!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
#ifdef CONFIG_MMU
#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
extern int devmem_is_allowed(unsigned long pfn);
#endif
/*
* Register ISA memory and port locations for glibc iopl/inb/outb
* emulation.
*/
extern void register_isa_ports(unsigned int mmio, unsigned int io,
unsigned int io_shift);
#endif /* __KERNEL__ */
#endif /* __ASM_ARM_IO_H */
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