[NET]: Relax the reference counting of init_net_ns
[linux-2.6] / include / asm-mips / io.h
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994, 1995 Waldorf GmbH
7  * Copyright (C) 1994 - 2000, 06 Ralf Baechle
8  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9  * Copyright (C) 2004, 2005  MIPS Technologies, Inc.  All rights reserved.
10  *      Author: Maciej W. Rozycki <macro@mips.com>
11  */
12 #ifndef _ASM_IO_H
13 #define _ASM_IO_H
14
15 #include <linux/compiler.h>
16 #include <linux/kernel.h>
17 #include <linux/types.h>
18
19 #include <asm/addrspace.h>
20 #include <asm/byteorder.h>
21 #include <asm/cpu.h>
22 #include <asm/cpu-features.h>
23 #include <asm-generic/iomap.h>
24 #include <asm/page.h>
25 #include <asm/pgtable-bits.h>
26 #include <asm/processor.h>
27 #include <asm/string.h>
28
29 #include <ioremap.h>
30 #include <mangle-port.h>
31
32 /*
33  * Slowdown I/O port space accesses for antique hardware.
34  */
35 #undef CONF_SLOWDOWN_IO
36
37 /*
38  * Raw operations are never swapped in software.  OTOH values that raw
39  * operations are working on may or may not have been swapped by the bus
40  * hardware.  An example use would be for flash memory that's used for
41  * execute in place.
42  */
43 # define __raw_ioswabb(a, x)    (x)
44 # define __raw_ioswabw(a, x)    (x)
45 # define __raw_ioswabl(a, x)    (x)
46 # define __raw_ioswabq(a, x)    (x)
47 # define ____raw_ioswabq(a, x)  (x)
48
49 /* ioswab[bwlq], __mem_ioswab[bwlq] are defined in mangle-port.h */
50
51 #define IO_SPACE_LIMIT 0xffff
52
53 /*
54  * On MIPS I/O ports are memory mapped, so we access them using normal
55  * load/store instructions. mips_io_port_base is the virtual address to
56  * which all ports are being mapped.  For sake of efficiency some code
57  * assumes that this is an address that can be loaded with a single lui
58  * instruction, so the lower 16 bits must be zero.  Should be true on
59  * on any sane architecture; generic code does not use this assumption.
60  */
61 extern const unsigned long mips_io_port_base;
62
63 /*
64  * Gcc will generate code to load the value of mips_io_port_base after each
65  * function call which may be fairly wasteful in some cases.  So we don't
66  * play quite by the book.  We tell gcc mips_io_port_base is a long variable
67  * which solves the code generation issue.  Now we need to violate the
68  * aliasing rules a little to make initialization possible and finally we
69  * will need the barrier() to fight side effects of the aliasing chat.
70  * This trickery will eventually collapse under gcc's optimizer.  Oh well.
71  */
72 static inline void set_io_port_base(unsigned long base)
73 {
74         * (unsigned long *) &mips_io_port_base = base;
75         barrier();
76 }
77
78 /*
79  * Thanks to James van Artsdalen for a better timing-fix than
80  * the two short jumps: using outb's to a nonexistent port seems
81  * to guarantee better timings even on fast machines.
82  *
83  * On the other hand, I'd like to be sure of a non-existent port:
84  * I feel a bit unsafe about using 0x80 (should be safe, though)
85  *
86  *              Linus
87  *
88  */
89
90 #define __SLOW_DOWN_IO \
91         __asm__ __volatile__( \
92                 "sb\t$0,0x80(%0)" \
93                 : : "r" (mips_io_port_base));
94
95 #ifdef CONF_SLOWDOWN_IO
96 #ifdef REALLY_SLOW_IO
97 #define SLOW_DOWN_IO { __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; __SLOW_DOWN_IO; }
98 #else
99 #define SLOW_DOWN_IO __SLOW_DOWN_IO
100 #endif
101 #else
102 #define SLOW_DOWN_IO
103 #endif
104
105 /*
106  *     virt_to_phys    -       map virtual addresses to physical
107  *     @address: address to remap
108  *
109  *     The returned physical address is the physical (CPU) mapping for
110  *     the memory address given. It is only valid to use this function on
111  *     addresses directly mapped or allocated via kmalloc.
112  *
113  *     This function does not give bus mappings for DMA transfers. In
114  *     almost all conceivable cases a device driver should not be using
115  *     this function
116  */
117 static inline unsigned long virt_to_phys(volatile const void *address)
118 {
119         return (unsigned long)address - PAGE_OFFSET + PHYS_OFFSET;
120 }
121
122 /*
123  *     phys_to_virt    -       map physical address to virtual
124  *     @address: address to remap
125  *
126  *     The returned virtual address is a current CPU mapping for
127  *     the memory address given. It is only valid to use this function on
128  *     addresses that have a kernel mapping
129  *
130  *     This function does not handle bus mappings for DMA transfers. In
131  *     almost all conceivable cases a device driver should not be using
132  *     this function
133  */
134 static inline void * phys_to_virt(unsigned long address)
135 {
136         return (void *)(address + PAGE_OFFSET - PHYS_OFFSET);
137 }
138
139 /*
140  * ISA I/O bus memory addresses are 1:1 with the physical address.
141  */
142 static inline unsigned long isa_virt_to_bus(volatile void * address)
143 {
144         return (unsigned long)address - PAGE_OFFSET;
145 }
146
147 static inline void * isa_bus_to_virt(unsigned long address)
148 {
149         return (void *)(address + PAGE_OFFSET);
150 }
151
152 #define isa_page_to_bus page_to_phys
153
154 /*
155  * However PCI ones are not necessarily 1:1 and therefore these interfaces
156  * are forbidden in portable PCI drivers.
157  *
158  * Allow them for x86 for legacy drivers, though.
159  */
160 #define virt_to_bus virt_to_phys
161 #define bus_to_virt phys_to_virt
162
163 /*
164  * isa_slot_offset is the address where E(ISA) busaddress 0 is mapped
165  * for the processor.  This implies the assumption that there is only
166  * one of these busses.
167  */
168 extern unsigned long isa_slot_offset;
169
170 /*
171  * Change "struct page" to physical address.
172  */
173 #define page_to_phys(page)      ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
174
175 extern void __iomem * __ioremap(phys_t offset, phys_t size, unsigned long flags);
176 extern void __iounmap(const volatile void __iomem *addr);
177
178 static inline void __iomem * __ioremap_mode(phys_t offset, unsigned long size,
179         unsigned long flags)
180 {
181         void __iomem *addr = plat_ioremap(offset, size, flags);
182
183         if (addr)
184                 return addr;
185
186 #define __IS_LOW512(addr) (!((phys_t)(addr) & (phys_t) ~0x1fffffffULL))
187
188         if (cpu_has_64bit_addresses) {
189                 u64 base = UNCAC_BASE;
190
191                 /*
192                  * R10000 supports a 2 bit uncached attribute therefore
193                  * UNCAC_BASE may not equal IO_BASE.
194                  */
195                 if (flags == _CACHE_UNCACHED)
196                         base = (u64) IO_BASE;
197                 return (void __iomem *) (unsigned long) (base + offset);
198         } else if (__builtin_constant_p(offset) &&
199                    __builtin_constant_p(size) && __builtin_constant_p(flags)) {
200                 phys_t phys_addr, last_addr;
201
202                 phys_addr = fixup_bigphys_addr(offset, size);
203
204                 /* Don't allow wraparound or zero size. */
205                 last_addr = phys_addr + size - 1;
206                 if (!size || last_addr < phys_addr)
207                         return NULL;
208
209                 /*
210                  * Map uncached objects in the low 512MB of address
211                  * space using KSEG1.
212                  */
213                 if (__IS_LOW512(phys_addr) && __IS_LOW512(last_addr) &&
214                     flags == _CACHE_UNCACHED)
215                         return (void __iomem *)
216                                 (unsigned long)CKSEG1ADDR(phys_addr);
217         }
218
219         return __ioremap(offset, size, flags);
220
221 #undef __IS_LOW512
222 }
223
224 /*
225  * ioremap     -   map bus memory into CPU space
226  * @offset:    bus address of the memory
227  * @size:      size of the resource to map
228  *
229  * ioremap performs a platform specific sequence of operations to
230  * make bus memory CPU accessible via the readb/readw/readl/writeb/
231  * writew/writel functions and the other mmio helpers. The returned
232  * address is not guaranteed to be usable directly as a virtual
233  * address.
234  */
235 #define ioremap(offset, size)                                           \
236         __ioremap_mode((offset), (size), _CACHE_UNCACHED)
237
238 /*
239  * ioremap_nocache     -   map bus memory into CPU space
240  * @offset:    bus address of the memory
241  * @size:      size of the resource to map
242  *
243  * ioremap_nocache performs a platform specific sequence of operations to
244  * make bus memory CPU accessible via the readb/readw/readl/writeb/
245  * writew/writel functions and the other mmio helpers. The returned
246  * address is not guaranteed to be usable directly as a virtual
247  * address.
248  *
249  * This version of ioremap ensures that the memory is marked uncachable
250  * on the CPU as well as honouring existing caching rules from things like
251  * the PCI bus. Note that there are other caches and buffers on many
252  * busses. In paticular driver authors should read up on PCI writes
253  *
254  * It's useful if some control registers are in such an area and
255  * write combining or read caching is not desirable:
256  */
257 #define ioremap_nocache(offset, size)                                   \
258         __ioremap_mode((offset), (size), _CACHE_UNCACHED)
259
260 /*
261  * ioremap_cachable -   map bus memory into CPU space
262  * @offset:         bus address of the memory
263  * @size:           size of the resource to map
264  *
265  * ioremap_nocache performs a platform specific sequence of operations to
266  * make bus memory CPU accessible via the readb/readw/readl/writeb/
267  * writew/writel functions and the other mmio helpers. The returned
268  * address is not guaranteed to be usable directly as a virtual
269  * address.
270  *
271  * This version of ioremap ensures that the memory is marked cachable by
272  * the CPU.  Also enables full write-combining.  Useful for some
273  * memory-like regions on I/O busses.
274  */
275 #define ioremap_cachable(offset, size)                                  \
276         __ioremap_mode((offset), (size), PAGE_CACHABLE_DEFAULT)
277
278 /*
279  * These two are MIPS specific ioremap variant.  ioremap_cacheable_cow
280  * requests a cachable mapping, ioremap_uncached_accelerated requests a
281  * mapping using the uncached accelerated mode which isn't supported on
282  * all processors.
283  */
284 #define ioremap_cacheable_cow(offset, size)                             \
285         __ioremap_mode((offset), (size), _CACHE_CACHABLE_COW)
286 #define ioremap_uncached_accelerated(offset, size)                      \
287         __ioremap_mode((offset), (size), _CACHE_UNCACHED_ACCELERATED)
288
289 static inline void iounmap(const volatile void __iomem *addr)
290 {
291         if (plat_iounmap(addr))
292                 return;
293
294 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
295
296         if (cpu_has_64bit_addresses ||
297             (__builtin_constant_p(addr) && __IS_KSEG1(addr)))
298                 return;
299
300         __iounmap(addr);
301
302 #undef __IS_KSEG1
303 }
304
305 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq)                     \
306                                                                         \
307 static inline void pfx##write##bwlq(type val,                           \
308                                     volatile void __iomem *mem)         \
309 {                                                                       \
310         volatile type *__mem;                                           \
311         type __val;                                                     \
312                                                                         \
313         __mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));    \
314                                                                         \
315         __val = pfx##ioswab##bwlq(__mem, val);                          \
316                                                                         \
317         if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
318                 *__mem = __val;                                         \
319         else if (cpu_has_64bits) {                                      \
320                 unsigned long __flags;                                  \
321                 type __tmp;                                             \
322                                                                         \
323                 if (irq)                                                \
324                         local_irq_save(__flags);                        \
325                 __asm__ __volatile__(                                   \
326                         ".set   mips3"          "\t\t# __writeq""\n\t"  \
327                         "dsll32 %L0, %L0, 0"                    "\n\t"  \
328                         "dsrl32 %L0, %L0, 0"                    "\n\t"  \
329                         "dsll32 %M0, %M0, 0"                    "\n\t"  \
330                         "or     %L0, %L0, %M0"                  "\n\t"  \
331                         "sd     %L0, %2"                        "\n\t"  \
332                         ".set   mips0"                          "\n"    \
333                         : "=r" (__tmp)                                  \
334                         : "0" (__val), "m" (*__mem));                   \
335                 if (irq)                                                \
336                         local_irq_restore(__flags);                     \
337         } else                                                          \
338                 BUG();                                                  \
339 }                                                                       \
340                                                                         \
341 static inline type pfx##read##bwlq(const volatile void __iomem *mem)    \
342 {                                                                       \
343         volatile type *__mem;                                           \
344         type __val;                                                     \
345                                                                         \
346         __mem = (void *)__swizzle_addr_##bwlq((unsigned long)(mem));    \
347                                                                         \
348         if (sizeof(type) != sizeof(u64) || sizeof(u64) == sizeof(long)) \
349                 __val = *__mem;                                         \
350         else if (cpu_has_64bits) {                                      \
351                 unsigned long __flags;                                  \
352                                                                         \
353                 if (irq)                                                \
354                         local_irq_save(__flags);                        \
355                 __asm__ __volatile__(                                   \
356                         ".set   mips3"          "\t\t# __readq" "\n\t"  \
357                         "ld     %L0, %1"                        "\n\t"  \
358                         "dsra32 %M0, %L0, 0"                    "\n\t"  \
359                         "sll    %L0, %L0, 0"                    "\n\t"  \
360                         ".set   mips0"                          "\n"    \
361                         : "=r" (__val)                                  \
362                         : "m" (*__mem));                                \
363                 if (irq)                                                \
364                         local_irq_restore(__flags);                     \
365         } else {                                                        \
366                 __val = 0;                                              \
367                 BUG();                                                  \
368         }                                                               \
369                                                                         \
370         return pfx##ioswab##bwlq(__mem, __val);                         \
371 }
372
373 #define __BUILD_IOPORT_SINGLE(pfx, bwlq, type, p, slow)                 \
374                                                                         \
375 static inline void pfx##out##bwlq##p(type val, unsigned long port)      \
376 {                                                                       \
377         volatile type *__addr;                                          \
378         type __val;                                                     \
379                                                                         \
380         __addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
381                                                                         \
382         __val = pfx##ioswab##bwlq(__addr, val);                         \
383                                                                         \
384         /* Really, we want this to be atomic */                         \
385         BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));             \
386                                                                         \
387         *__addr = __val;                                                \
388         slow;                                                           \
389 }                                                                       \
390                                                                         \
391 static inline type pfx##in##bwlq##p(unsigned long port)                 \
392 {                                                                       \
393         volatile type *__addr;                                          \
394         type __val;                                                     \
395                                                                         \
396         __addr = (void *)__swizzle_addr_##bwlq(mips_io_port_base + port); \
397                                                                         \
398         BUILD_BUG_ON(sizeof(type) > sizeof(unsigned long));             \
399                                                                         \
400         __val = *__addr;                                                \
401         slow;                                                           \
402                                                                         \
403         return pfx##ioswab##bwlq(__addr, __val);                        \
404 }
405
406 #define __BUILD_MEMORY_PFX(bus, bwlq, type)                             \
407                                                                         \
408 __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1)
409
410 #define BUILDIO_MEM(bwlq, type)                                         \
411                                                                         \
412 __BUILD_MEMORY_PFX(__raw_, bwlq, type)                                  \
413 __BUILD_MEMORY_PFX(, bwlq, type)                                        \
414 __BUILD_MEMORY_PFX(__mem_, bwlq, type)                                  \
415
416 BUILDIO_MEM(b, u8)
417 BUILDIO_MEM(w, u16)
418 BUILDIO_MEM(l, u32)
419 BUILDIO_MEM(q, u64)
420
421 #define __BUILD_IOPORT_PFX(bus, bwlq, type)                             \
422         __BUILD_IOPORT_SINGLE(bus, bwlq, type, ,)                       \
423         __BUILD_IOPORT_SINGLE(bus, bwlq, type, _p, SLOW_DOWN_IO)
424
425 #define BUILDIO_IOPORT(bwlq, type)                                      \
426         __BUILD_IOPORT_PFX(, bwlq, type)                                \
427         __BUILD_IOPORT_PFX(__mem_, bwlq, type)
428
429 BUILDIO_IOPORT(b, u8)
430 BUILDIO_IOPORT(w, u16)
431 BUILDIO_IOPORT(l, u32)
432 #ifdef CONFIG_64BIT
433 BUILDIO_IOPORT(q, u64)
434 #endif
435
436 #define __BUILDIO(bwlq, type)                                           \
437                                                                         \
438 __BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 0)
439
440 __BUILDIO(q, u64)
441
442 #define readb_relaxed                   readb
443 #define readw_relaxed                   readw
444 #define readl_relaxed                   readl
445 #define readq_relaxed                   readq
446
447 /*
448  * Some code tests for these symbols
449  */
450 #define readq                           readq
451 #define writeq                          writeq
452
453 #define __BUILD_MEMORY_STRING(bwlq, type)                               \
454                                                                         \
455 static inline void writes##bwlq(volatile void __iomem *mem,             \
456                                 const void *addr, unsigned int count)   \
457 {                                                                       \
458         const volatile type *__addr = addr;                             \
459                                                                         \
460         while (count--) {                                               \
461                 __mem_write##bwlq(*__addr, mem);                        \
462                 __addr++;                                               \
463         }                                                               \
464 }                                                                       \
465                                                                         \
466 static inline void reads##bwlq(volatile void __iomem *mem, void *addr,  \
467                                unsigned int count)                      \
468 {                                                                       \
469         volatile type *__addr = addr;                                   \
470                                                                         \
471         while (count--) {                                               \
472                 *__addr = __mem_read##bwlq(mem);                        \
473                 __addr++;                                               \
474         }                                                               \
475 }
476
477 #define __BUILD_IOPORT_STRING(bwlq, type)                               \
478                                                                         \
479 static inline void outs##bwlq(unsigned long port, const void *addr,     \
480                               unsigned int count)                       \
481 {                                                                       \
482         const volatile type *__addr = addr;                             \
483                                                                         \
484         while (count--) {                                               \
485                 __mem_out##bwlq(*__addr, port);                         \
486                 __addr++;                                               \
487         }                                                               \
488 }                                                                       \
489                                                                         \
490 static inline void ins##bwlq(unsigned long port, void *addr,            \
491                              unsigned int count)                        \
492 {                                                                       \
493         volatile type *__addr = addr;                                   \
494                                                                         \
495         while (count--) {                                               \
496                 *__addr = __mem_in##bwlq(port);                         \
497                 __addr++;                                               \
498         }                                                               \
499 }
500
501 #define BUILDSTRING(bwlq, type)                                         \
502                                                                         \
503 __BUILD_MEMORY_STRING(bwlq, type)                                       \
504 __BUILD_IOPORT_STRING(bwlq, type)
505
506 BUILDSTRING(b, u8)
507 BUILDSTRING(w, u16)
508 BUILDSTRING(l, u32)
509 #ifdef CONFIG_64BIT
510 BUILDSTRING(q, u64)
511 #endif
512
513
514 /* Depends on MIPS II instruction set */
515 #define mmiowb() asm volatile ("sync" ::: "memory")
516
517 static inline void memset_io(volatile void __iomem *addr, unsigned char val, int count)
518 {
519         memset((void __force *) addr, val, count);
520 }
521 static inline void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
522 {
523         memcpy(dst, (void __force *) src, count);
524 }
525 static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
526 {
527         memcpy((void __force *) dst, src, count);
528 }
529
530 /*
531  * ISA space is 'always mapped' on currently supported MIPS systems, no need
532  * to explicitly ioremap() it. The fact that the ISA IO space is mapped
533  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
534  * are physical addresses. The following constant pointer can be
535  * used as the IO-area pointer (it can be iounmapped as well, so the
536  * analogy with PCI is quite large):
537  */
538 #define __ISA_IO_base ((char *)(isa_slot_offset))
539
540 /*
541  * The caches on some architectures aren't dma-coherent and have need to
542  * handle this in software.  There are three types of operations that
543  * can be applied to dma buffers.
544  *
545  *  - dma_cache_wback_inv(start, size) makes caches and coherent by
546  *    writing the content of the caches back to memory, if necessary.
547  *    The function also invalidates the affected part of the caches as
548  *    necessary before DMA transfers from outside to memory.
549  *  - dma_cache_wback(start, size) makes caches and coherent by
550  *    writing the content of the caches back to memory, if necessary.
551  *    The function also invalidates the affected part of the caches as
552  *    necessary before DMA transfers from outside to memory.
553  *  - dma_cache_inv(start, size) invalidates the affected parts of the
554  *    caches.  Dirty lines of the caches may be written back or simply
555  *    be discarded.  This operation is necessary before dma operations
556  *    to the memory.
557  *
558  * This API used to be exported; it now is for arch code internal use only.
559  */
560 #ifdef CONFIG_DMA_NONCOHERENT
561
562 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
563 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
564 extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
565
566 #define dma_cache_wback_inv(start, size)        _dma_cache_wback_inv(start, size)
567 #define dma_cache_wback(start, size)            _dma_cache_wback(start, size)
568 #define dma_cache_inv(start, size)              _dma_cache_inv(start, size)
569
570 #else /* Sane hardware */
571
572 #define dma_cache_wback_inv(start,size) \
573         do { (void) (start); (void) (size); } while (0)
574 #define dma_cache_wback(start,size)     \
575         do { (void) (start); (void) (size); } while (0)
576 #define dma_cache_inv(start,size)       \
577         do { (void) (start); (void) (size); } while (0)
578
579 #endif /* CONFIG_DMA_NONCOHERENT */
580
581 /*
582  * Read a 32-bit register that requires a 64-bit read cycle on the bus.
583  * Avoid interrupt mucking, just adjust the address for 4-byte access.
584  * Assume the addresses are 8-byte aligned.
585  */
586 #ifdef __MIPSEB__
587 #define __CSR_32_ADJUST 4
588 #else
589 #define __CSR_32_ADJUST 0
590 #endif
591
592 #define csr_out32(v, a) (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST) = (v))
593 #define csr_in32(a)    (*(volatile u32 *)((unsigned long)(a) + __CSR_32_ADJUST))
594
595 /*
596  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
597  * access
598  */
599 #define xlate_dev_mem_ptr(p)    __va(p)
600
601 /*
602  * Convert a virtual cached pointer to an uncached pointer
603  */
604 #define xlate_dev_kmem_ptr(p)   p
605
606 #endif /* _ASM_IO_H */