arm64: arm_generic: prevent reading stale time
[linux-2.6/btrfs-unstable.git] / arch / arm64 / include / asm / io.h
blobd2f05a608274534a08180fc3866658a225bb560c
1 /*
2 * Based on arch/arm/include/asm/io.h
4 * Copyright (C) 1996-2000 Russell King
5 * Copyright (C) 2012 ARM Ltd.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 #ifndef __ASM_IO_H
20 #define __ASM_IO_H
22 #ifdef __KERNEL__
24 #include <linux/types.h>
26 #include <asm/byteorder.h>
27 #include <asm/barrier.h>
28 #include <asm/pgtable.h>
31 * Generic IO read/write. These perform native-endian accesses.
33 static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
35 asm volatile("strb %w0, [%1]" : : "r" (val), "r" (addr));
38 static inline void __raw_writew(u16 val, volatile void __iomem *addr)
40 asm volatile("strh %w0, [%1]" : : "r" (val), "r" (addr));
43 static inline void __raw_writel(u32 val, volatile void __iomem *addr)
45 asm volatile("str %w0, [%1]" : : "r" (val), "r" (addr));
48 static inline void __raw_writeq(u64 val, volatile void __iomem *addr)
50 asm volatile("str %0, [%1]" : : "r" (val), "r" (addr));
53 static inline u8 __raw_readb(const volatile void __iomem *addr)
55 u8 val;
56 asm volatile("ldrb %w0, [%1]" : "=r" (val) : "r" (addr));
57 return val;
60 static inline u16 __raw_readw(const volatile void __iomem *addr)
62 u16 val;
63 asm volatile("ldrh %w0, [%1]" : "=r" (val) : "r" (addr));
64 return val;
67 static inline u32 __raw_readl(const volatile void __iomem *addr)
69 u32 val;
70 asm volatile("ldr %w0, [%1]" : "=r" (val) : "r" (addr));
71 return val;
74 static inline u64 __raw_readq(const volatile void __iomem *addr)
76 u64 val;
77 asm volatile("ldr %0, [%1]" : "=r" (val) : "r" (addr));
78 return val;
81 /* IO barriers */
82 #define __iormb() rmb()
83 #define __iowmb() wmb()
85 #define mmiowb() do { } while (0)
88 * Relaxed I/O memory access primitives. These follow the Device memory
89 * ordering rules but do not guarantee any ordering relative to Normal memory
90 * accesses.
92 #define readb_relaxed(c) ({ u8 __v = __raw_readb(c); __v; })
93 #define readw_relaxed(c) ({ u16 __v = le16_to_cpu((__force __le16)__raw_readw(c)); __v; })
94 #define readl_relaxed(c) ({ u32 __v = le32_to_cpu((__force __le32)__raw_readl(c)); __v; })
96 #define writeb_relaxed(v,c) ((void)__raw_writeb((v),(c)))
97 #define writew_relaxed(v,c) ((void)__raw_writew((__force u16)cpu_to_le16(v),(c)))
98 #define writel_relaxed(v,c) ((void)__raw_writel((__force u32)cpu_to_le32(v),(c)))
101 * I/O memory access primitives. Reads are ordered relative to any
102 * following Normal memory access. Writes are ordered relative to any prior
103 * Normal memory access.
105 #define readb(c) ({ u8 __v = readb_relaxed(c); __iormb(); __v; })
106 #define readw(c) ({ u16 __v = readw_relaxed(c); __iormb(); __v; })
107 #define readl(c) ({ u32 __v = readl_relaxed(c); __iormb(); __v; })
109 #define writeb(v,c) ({ __iowmb(); writeb_relaxed((v),(c)); })
110 #define writew(v,c) ({ __iowmb(); writew_relaxed((v),(c)); })
111 #define writel(v,c) ({ __iowmb(); writel_relaxed((v),(c)); })
114 * I/O port access primitives.
116 #define IO_SPACE_LIMIT 0xffff
117 #define PCI_IOBASE ((void __iomem *)(MODULES_VADDR - SZ_2M))
119 static inline u8 inb(unsigned long addr)
121 return readb(addr + PCI_IOBASE);
124 static inline u16 inw(unsigned long addr)
126 return readw(addr + PCI_IOBASE);
129 static inline u32 inl(unsigned long addr)
131 return readl(addr + PCI_IOBASE);
134 static inline void outb(u8 b, unsigned long addr)
136 writeb(b, addr + PCI_IOBASE);
139 static inline void outw(u16 b, unsigned long addr)
141 writew(b, addr + PCI_IOBASE);
144 static inline void outl(u32 b, unsigned long addr)
146 writel(b, addr + PCI_IOBASE);
149 #define inb_p(addr) inb(addr)
150 #define inw_p(addr) inw(addr)
151 #define inl_p(addr) inl(addr)
153 #define outb_p(x, addr) outb((x), (addr))
154 #define outw_p(x, addr) outw((x), (addr))
155 #define outl_p(x, addr) outl((x), (addr))
157 static inline void insb(unsigned long addr, void *buffer, int count)
159 u8 *buf = buffer;
160 while (count--)
161 *buf++ = __raw_readb(addr + PCI_IOBASE);
164 static inline void insw(unsigned long addr, void *buffer, int count)
166 u16 *buf = buffer;
167 while (count--)
168 *buf++ = __raw_readw(addr + PCI_IOBASE);
171 static inline void insl(unsigned long addr, void *buffer, int count)
173 u32 *buf = buffer;
174 while (count--)
175 *buf++ = __raw_readl(addr + PCI_IOBASE);
178 static inline void outsb(unsigned long addr, const void *buffer, int count)
180 const u8 *buf = buffer;
181 while (count--)
182 __raw_writeb(*buf++, addr + PCI_IOBASE);
185 static inline void outsw(unsigned long addr, const void *buffer, int count)
187 const u16 *buf = buffer;
188 while (count--)
189 __raw_writew(*buf++, addr + PCI_IOBASE);
192 static inline void outsl(unsigned long addr, const void *buffer, int count)
194 const u32 *buf = buffer;
195 while (count--)
196 __raw_writel(*buf++, addr + PCI_IOBASE);
199 #define insb_p(port,to,len) insb(port,to,len)
200 #define insw_p(port,to,len) insw(port,to,len)
201 #define insl_p(port,to,len) insl(port,to,len)
203 #define outsb_p(port,from,len) outsb(port,from,len)
204 #define outsw_p(port,from,len) outsw(port,from,len)
205 #define outsl_p(port,from,len) outsl(port,from,len)
208 * String version of I/O memory access operations.
210 extern void __memcpy_fromio(void *, const volatile void __iomem *, size_t);
211 extern void __memcpy_toio(volatile void __iomem *, const void *, size_t);
212 extern void __memset_io(volatile void __iomem *, int, size_t);
214 #define memset_io(c,v,l) __memset_io((c),(v),(l))
215 #define memcpy_fromio(a,c,l) __memcpy_fromio((a),(c),(l))
216 #define memcpy_toio(c,a,l) __memcpy_toio((c),(a),(l))
219 * I/O memory mapping functions.
221 extern void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot);
222 extern void __iounmap(volatile void __iomem *addr);
224 #define PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_DIRTY)
225 #define PROT_DEVICE_nGnRE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
226 #define PROT_NORMAL_NC (PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL_NC))
228 #define ioremap(addr, size) __ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
229 #define ioremap_nocache(addr, size) __ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
230 #define ioremap_wc(addr, size) __ioremap((addr), (size), __pgprot(PROT_NORMAL_NC))
231 #define iounmap __iounmap
233 #define ARCH_HAS_IOREMAP_WC
234 #include <asm-generic/iomap.h>
237 * More restrictive address range checking than the default implementation
238 * (PHYS_OFFSET and PHYS_MASK taken into account).
240 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
241 extern int valid_phys_addr_range(unsigned long addr, size_t size);
242 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
244 extern int devmem_is_allowed(unsigned long pfn);
247 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
248 * access
250 #define xlate_dev_mem_ptr(p) __va(p)
253 * Convert a virtual cached pointer to an uncached pointer
255 #define xlate_dev_kmem_ptr(p) p
257 #endif /* __KERNEL__ */
258 #endif /* __ASM_IO_H */