xref: /openbmc/linux/arch/x86/include/asm/io.h (revision 95298d63)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_IO_H
3 #define _ASM_X86_IO_H
4 
5 /*
6  * This file contains the definitions for the x86 IO instructions
7  * inb/inw/inl/outb/outw/outl and the "string versions" of the same
8  * (insb/insw/insl/outsb/outsw/outsl). You can also use "pausing"
9  * versions of the single-IO instructions (inb_p/inw_p/..).
10  *
11  * This file is not meant to be obfuscating: it's just complicated
12  * to (a) handle it all in a way that makes gcc able to optimize it
13  * as well as possible and (b) trying to avoid writing the same thing
14  * over and over again with slight variations and possibly making a
15  * mistake somewhere.
16  */
17 
18 /*
19  * Thanks to James van Artsdalen for a better timing-fix than
20  * the two short jumps: using outb's to a nonexistent port seems
21  * to guarantee better timings even on fast machines.
22  *
23  * On the other hand, I'd like to be sure of a non-existent port:
24  * I feel a bit unsafe about using 0x80 (should be safe, though)
25  *
26  *		Linus
27  */
28 
29  /*
30   *  Bit simplified and optimized by Jan Hubicka
31   *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999.
32   *
33   *  isa_memset_io, isa_memcpy_fromio, isa_memcpy_toio added,
34   *  isa_read[wl] and isa_write[wl] fixed
35   *  - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
36   */
37 
38 #define ARCH_HAS_IOREMAP_WC
39 #define ARCH_HAS_IOREMAP_WT
40 
41 #include <linux/string.h>
42 #include <linux/compiler.h>
43 #include <asm/page.h>
44 #include <asm/early_ioremap.h>
45 #include <asm/pgtable_types.h>
46 
47 #define build_mmio_read(name, size, type, reg, barrier) \
48 static inline type name(const volatile void __iomem *addr) \
49 { type ret; asm volatile("mov" size " %1,%0":reg (ret) \
50 :"m" (*(volatile type __force *)addr) barrier); return ret; }
51 
52 #define build_mmio_write(name, size, type, reg, barrier) \
53 static inline void name(type val, volatile void __iomem *addr) \
54 { asm volatile("mov" size " %0,%1": :reg (val), \
55 "m" (*(volatile type __force *)addr) barrier); }
56 
57 build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
58 build_mmio_read(readw, "w", unsigned short, "=r", :"memory")
59 build_mmio_read(readl, "l", unsigned int, "=r", :"memory")
60 
61 build_mmio_read(__readb, "b", unsigned char, "=q", )
62 build_mmio_read(__readw, "w", unsigned short, "=r", )
63 build_mmio_read(__readl, "l", unsigned int, "=r", )
64 
65 build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
66 build_mmio_write(writew, "w", unsigned short, "r", :"memory")
67 build_mmio_write(writel, "l", unsigned int, "r", :"memory")
68 
69 build_mmio_write(__writeb, "b", unsigned char, "q", )
70 build_mmio_write(__writew, "w", unsigned short, "r", )
71 build_mmio_write(__writel, "l", unsigned int, "r", )
72 
73 #define readb readb
74 #define readw readw
75 #define readl readl
76 #define readb_relaxed(a) __readb(a)
77 #define readw_relaxed(a) __readw(a)
78 #define readl_relaxed(a) __readl(a)
79 #define __raw_readb __readb
80 #define __raw_readw __readw
81 #define __raw_readl __readl
82 
83 #define writeb writeb
84 #define writew writew
85 #define writel writel
86 #define writeb_relaxed(v, a) __writeb(v, a)
87 #define writew_relaxed(v, a) __writew(v, a)
88 #define writel_relaxed(v, a) __writel(v, a)
89 #define __raw_writeb __writeb
90 #define __raw_writew __writew
91 #define __raw_writel __writel
92 
93 #ifdef CONFIG_X86_64
94 
95 build_mmio_read(readq, "q", u64, "=r", :"memory")
96 build_mmio_read(__readq, "q", u64, "=r", )
97 build_mmio_write(writeq, "q", u64, "r", :"memory")
98 build_mmio_write(__writeq, "q", u64, "r", )
99 
100 #define readq_relaxed(a)	__readq(a)
101 #define writeq_relaxed(v, a)	__writeq(v, a)
102 
103 #define __raw_readq		__readq
104 #define __raw_writeq		__writeq
105 
106 /* Let people know that we have them */
107 #define readq			readq
108 #define writeq			writeq
109 
110 #endif
111 
112 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
113 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
114 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
115 
116 /**
117  *	virt_to_phys	-	map virtual addresses to physical
118  *	@address: address to remap
119  *
120  *	The returned physical address is the physical (CPU) mapping for
121  *	the memory address given. It is only valid to use this function on
122  *	addresses directly mapped or allocated via kmalloc.
123  *
124  *	This function does not give bus mappings for DMA transfers. In
125  *	almost all conceivable cases a device driver should not be using
126  *	this function
127  */
128 
129 static inline phys_addr_t virt_to_phys(volatile void *address)
130 {
131 	return __pa(address);
132 }
133 #define virt_to_phys virt_to_phys
134 
135 /**
136  *	phys_to_virt	-	map physical address to virtual
137  *	@address: address to remap
138  *
139  *	The returned virtual address is a current CPU mapping for
140  *	the memory address given. It is only valid to use this function on
141  *	addresses that have a kernel mapping
142  *
143  *	This function does not handle bus mappings for DMA transfers. In
144  *	almost all conceivable cases a device driver should not be using
145  *	this function
146  */
147 
148 static inline void *phys_to_virt(phys_addr_t address)
149 {
150 	return __va(address);
151 }
152 #define phys_to_virt phys_to_virt
153 
154 /*
155  * Change "struct page" to physical address.
156  */
157 #define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
158 
159 /*
160  * ISA I/O bus memory addresses are 1:1 with the physical address.
161  * However, we truncate the address to unsigned int to avoid undesirable
162  * promitions in legacy drivers.
163  */
164 static inline unsigned int isa_virt_to_bus(volatile void *address)
165 {
166 	return (unsigned int)virt_to_phys(address);
167 }
168 #define isa_bus_to_virt		phys_to_virt
169 
170 /*
171  * However PCI ones are not necessarily 1:1 and therefore these interfaces
172  * are forbidden in portable PCI drivers.
173  *
174  * Allow them on x86 for legacy drivers, though.
175  */
176 #define virt_to_bus virt_to_phys
177 #define bus_to_virt phys_to_virt
178 
179 /*
180  * The default ioremap() behavior is non-cached; if you need something
181  * else, you probably want one of the following.
182  */
183 extern void __iomem *ioremap_uc(resource_size_t offset, unsigned long size);
184 #define ioremap_uc ioremap_uc
185 extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
186 #define ioremap_cache ioremap_cache
187 extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size, unsigned long prot_val);
188 #define ioremap_prot ioremap_prot
189 extern void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned long size);
190 #define ioremap_encrypted ioremap_encrypted
191 
192 /**
193  * ioremap     -   map bus memory into CPU space
194  * @offset:    bus address of the memory
195  * @size:      size of the resource to map
196  *
197  * ioremap performs a platform specific sequence of operations to
198  * make bus memory CPU accessible via the readb/readw/readl/writeb/
199  * writew/writel functions and the other mmio helpers. The returned
200  * address is not guaranteed to be usable directly as a virtual
201  * address.
202  *
203  * If the area you are trying to map is a PCI BAR you should have a
204  * look at pci_iomap().
205  */
206 void __iomem *ioremap(resource_size_t offset, unsigned long size);
207 #define ioremap ioremap
208 
209 extern void iounmap(volatile void __iomem *addr);
210 #define iounmap iounmap
211 
212 extern void set_iounmap_nonlazy(void);
213 
214 #ifdef __KERNEL__
215 
216 void memcpy_fromio(void *, const volatile void __iomem *, size_t);
217 void memcpy_toio(volatile void __iomem *, const void *, size_t);
218 void memset_io(volatile void __iomem *, int, size_t);
219 
220 #define memcpy_fromio memcpy_fromio
221 #define memcpy_toio memcpy_toio
222 #define memset_io memset_io
223 
224 #include <asm-generic/iomap.h>
225 
226 /*
227  * ISA space is 'always mapped' on a typical x86 system, no need to
228  * explicitly ioremap() it. The fact that the ISA IO space is mapped
229  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values
230  * are physical addresses. The following constant pointer can be
231  * used as the IO-area pointer (it can be iounmapped as well, so the
232  * analogy with PCI is quite large):
233  */
234 #define __ISA_IO_base ((char __iomem *)(PAGE_OFFSET))
235 
236 #endif /* __KERNEL__ */
237 
238 extern void native_io_delay(void);
239 
240 extern int io_delay_type;
241 extern void io_delay_init(void);
242 
243 #if defined(CONFIG_PARAVIRT)
244 #include <asm/paravirt.h>
245 #else
246 
247 static inline void slow_down_io(void)
248 {
249 	native_io_delay();
250 #ifdef REALLY_SLOW_IO
251 	native_io_delay();
252 	native_io_delay();
253 	native_io_delay();
254 #endif
255 }
256 
257 #endif
258 
259 #ifdef CONFIG_AMD_MEM_ENCRYPT
260 #include <linux/jump_label.h>
261 
262 extern struct static_key_false sev_enable_key;
263 static inline bool sev_key_active(void)
264 {
265 	return static_branch_unlikely(&sev_enable_key);
266 }
267 
268 #else /* !CONFIG_AMD_MEM_ENCRYPT */
269 
270 static inline bool sev_key_active(void) { return false; }
271 
272 #endif /* CONFIG_AMD_MEM_ENCRYPT */
273 
274 #define BUILDIO(bwl, bw, type)						\
275 static inline void out##bwl(unsigned type value, int port)		\
276 {									\
277 	asm volatile("out" #bwl " %" #bw "0, %w1"			\
278 		     : : "a"(value), "Nd"(port));			\
279 }									\
280 									\
281 static inline unsigned type in##bwl(int port)				\
282 {									\
283 	unsigned type value;						\
284 	asm volatile("in" #bwl " %w1, %" #bw "0"			\
285 		     : "=a"(value) : "Nd"(port));			\
286 	return value;							\
287 }									\
288 									\
289 static inline void out##bwl##_p(unsigned type value, int port)		\
290 {									\
291 	out##bwl(value, port);						\
292 	slow_down_io();							\
293 }									\
294 									\
295 static inline unsigned type in##bwl##_p(int port)			\
296 {									\
297 	unsigned type value = in##bwl(port);				\
298 	slow_down_io();							\
299 	return value;							\
300 }									\
301 									\
302 static inline void outs##bwl(int port, const void *addr, unsigned long count) \
303 {									\
304 	if (sev_key_active()) {						\
305 		unsigned type *value = (unsigned type *)addr;		\
306 		while (count) {						\
307 			out##bwl(*value, port);				\
308 			value++;					\
309 			count--;					\
310 		}							\
311 	} else {							\
312 		asm volatile("rep; outs" #bwl				\
313 			     : "+S"(addr), "+c"(count)			\
314 			     : "d"(port) : "memory");			\
315 	}								\
316 }									\
317 									\
318 static inline void ins##bwl(int port, void *addr, unsigned long count)	\
319 {									\
320 	if (sev_key_active()) {						\
321 		unsigned type *value = (unsigned type *)addr;		\
322 		while (count) {						\
323 			*value = in##bwl(port);				\
324 			value++;					\
325 			count--;					\
326 		}							\
327 	} else {							\
328 		asm volatile("rep; ins" #bwl				\
329 			     : "+D"(addr), "+c"(count)			\
330 			     : "d"(port) : "memory");			\
331 	}								\
332 }
333 
334 BUILDIO(b, b, char)
335 BUILDIO(w, w, short)
336 BUILDIO(l, , int)
337 
338 #define inb inb
339 #define inw inw
340 #define inl inl
341 #define inb_p inb_p
342 #define inw_p inw_p
343 #define inl_p inl_p
344 #define insb insb
345 #define insw insw
346 #define insl insl
347 
348 #define outb outb
349 #define outw outw
350 #define outl outl
351 #define outb_p outb_p
352 #define outw_p outw_p
353 #define outl_p outl_p
354 #define outsb outsb
355 #define outsw outsw
356 #define outsl outsl
357 
358 extern void *xlate_dev_mem_ptr(phys_addr_t phys);
359 extern void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr);
360 
361 #define xlate_dev_mem_ptr xlate_dev_mem_ptr
362 #define unxlate_dev_mem_ptr unxlate_dev_mem_ptr
363 
364 extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
365 				enum page_cache_mode pcm);
366 extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
367 #define ioremap_wc ioremap_wc
368 extern void __iomem *ioremap_wt(resource_size_t offset, unsigned long size);
369 #define ioremap_wt ioremap_wt
370 
371 extern bool is_early_ioremap_ptep(pte_t *ptep);
372 
373 #define IO_SPACE_LIMIT 0xffff
374 
375 #include <asm-generic/io.h>
376 #undef PCI_IOBASE
377 
378 #ifdef CONFIG_MTRR
379 extern int __must_check arch_phys_wc_index(int handle);
380 #define arch_phys_wc_index arch_phys_wc_index
381 
382 extern int __must_check arch_phys_wc_add(unsigned long base,
383 					 unsigned long size);
384 extern void arch_phys_wc_del(int handle);
385 #define arch_phys_wc_add arch_phys_wc_add
386 #endif
387 
388 #ifdef CONFIG_X86_PAT
389 extern int arch_io_reserve_memtype_wc(resource_size_t start, resource_size_t size);
390 extern void arch_io_free_memtype_wc(resource_size_t start, resource_size_t size);
391 #define arch_io_reserve_memtype_wc arch_io_reserve_memtype_wc
392 #endif
393 
394 extern bool arch_memremap_can_ram_remap(resource_size_t offset,
395 					unsigned long size,
396 					unsigned long flags);
397 #define arch_memremap_can_ram_remap arch_memremap_can_ram_remap
398 
399 extern bool phys_mem_access_encrypted(unsigned long phys_addr,
400 				      unsigned long size);
401 
402 /**
403  * iosubmit_cmds512 - copy data to single MMIO location, in 512-bit units
404  * @__dst: destination, in MMIO space (must be 512-bit aligned)
405  * @src: source
406  * @count: number of 512 bits quantities to submit
407  *
408  * Submit data from kernel space to MMIO space, in units of 512 bits at a
409  * time.  Order of access is not guaranteed, nor is a memory barrier
410  * performed afterwards.
411  *
412  * Warning: Do not use this helper unless your driver has checked that the CPU
413  * instruction is supported on the platform.
414  */
415 static inline void iosubmit_cmds512(void __iomem *__dst, const void *src,
416 				    size_t count)
417 {
418 	/*
419 	 * Note that this isn't an "on-stack copy", just definition of "dst"
420 	 * as a pointer to 64-bytes of stuff that is going to be overwritten.
421 	 * In the MOVDIR64B case that may be needed as you can use the
422 	 * MOVDIR64B instruction to copy arbitrary memory around. This trick
423 	 * lets the compiler know how much gets clobbered.
424 	 */
425 	volatile struct { char _[64]; } *dst = __dst;
426 	const u8 *from = src;
427 	const u8 *end = from + count * 64;
428 
429 	while (from < end) {
430 		/* MOVDIR64B [rdx], rax */
431 		asm volatile(".byte 0x66, 0x0f, 0x38, 0xf8, 0x02"
432 			     : "=m" (dst)
433 			     : "d" (from), "a" (dst));
434 		from += 64;
435 	}
436 }
437 
438 #endif /* _ASM_X86_IO_H */
439