xref: /linux/arch/arm64/include/asm/io.h (revision 364eeb79a213fcf9164208b53764223ad522d6b3)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Based on arch/arm/include/asm/io.h
4  *
5  * Copyright (C) 1996-2000 Russell King
6  * Copyright (C) 2012 ARM Ltd.
7  */
8 #ifndef __ASM_IO_H
9 #define __ASM_IO_H
10 
11 #include <linux/types.h>
12 #include <linux/pgtable.h>
13 
14 #include <asm/byteorder.h>
15 #include <asm/barrier.h>
16 #include <asm/memory.h>
17 #include <asm/early_ioremap.h>
18 #include <asm/alternative.h>
19 #include <asm/cpufeature.h>
20 #include <asm/rsi.h>
21 
22 /*
23  * Generic IO read/write.  These perform native-endian accesses.
24  */
25 #define __raw_writeb __raw_writeb
26 static __always_inline void __raw_writeb(u8 val, volatile void __iomem *addr)
27 {
28 	volatile u8 __iomem *ptr = addr;
29 	asm volatile("strb %w0, %1" : : "rZ" (val), "Qo" (*ptr));
30 }
31 
32 #define __raw_writew __raw_writew
33 static __always_inline void __raw_writew(u16 val, volatile void __iomem *addr)
34 {
35 	volatile u16 __iomem *ptr = addr;
36 	asm volatile("strh %w0, %1" : : "rZ" (val), "Qo" (*ptr));
37 }
38 
39 #define __raw_writel __raw_writel
40 static __always_inline void __raw_writel(u32 val, volatile void __iomem *addr)
41 {
42 	volatile u32 __iomem *ptr = addr;
43 	asm volatile("str %w0, %1" : : "rZ" (val), "Qo" (*ptr));
44 }
45 
46 #define __raw_writeq __raw_writeq
47 static __always_inline void __raw_writeq(u64 val, volatile void __iomem *addr)
48 {
49 	volatile u64 __iomem *ptr = addr;
50 	asm volatile("str %x0, %1" : : "rZ" (val), "Qo" (*ptr));
51 }
52 
53 #define __raw_readb __raw_readb
54 static __always_inline u8 __raw_readb(const volatile void __iomem *addr)
55 {
56 	u8 val;
57 	asm volatile(ALTERNATIVE("ldrb %w0, [%1]",
58 				 "ldarb %w0, [%1]",
59 				 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
60 		     : "=r" (val) : "r" (addr));
61 	return val;
62 }
63 
64 #define __raw_readw __raw_readw
65 static __always_inline u16 __raw_readw(const volatile void __iomem *addr)
66 {
67 	u16 val;
68 
69 	asm volatile(ALTERNATIVE("ldrh %w0, [%1]",
70 				 "ldarh %w0, [%1]",
71 				 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
72 		     : "=r" (val) : "r" (addr));
73 	return val;
74 }
75 
76 #define __raw_readl __raw_readl
77 static __always_inline u32 __raw_readl(const volatile void __iomem *addr)
78 {
79 	u32 val;
80 	asm volatile(ALTERNATIVE("ldr %w0, [%1]",
81 				 "ldar %w0, [%1]",
82 				 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
83 		     : "=r" (val) : "r" (addr));
84 	return val;
85 }
86 
87 #define __raw_readq __raw_readq
88 static __always_inline u64 __raw_readq(const volatile void __iomem *addr)
89 {
90 	u64 val;
91 	asm volatile(ALTERNATIVE("ldr %0, [%1]",
92 				 "ldar %0, [%1]",
93 				 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
94 		     : "=r" (val) : "r" (addr));
95 	return val;
96 }
97 
98 /* IO barriers */
99 #define __io_ar(v)							\
100 ({									\
101 	unsigned long tmp;						\
102 									\
103 	dma_rmb();								\
104 									\
105 	/*								\
106 	 * Create a dummy control dependency from the IO read to any	\
107 	 * later instructions. This ensures that a subsequent call to	\
108 	 * udelay() will be ordered due to the ISB in get_cycles().	\
109 	 */								\
110 	asm volatile("eor	%0, %1, %1\n"				\
111 		     "cbnz	%0, ."					\
112 		     : "=r" (tmp) : "r" ((unsigned long)(v))		\
113 		     : "memory");					\
114 })
115 
116 #define __io_bw()		dma_wmb()
117 #define __io_br(v)
118 #define __io_aw(v)
119 
120 /* arm64-specific, don't use in portable drivers */
121 #define __iormb(v)		__io_ar(v)
122 #define __iowmb()		__io_bw()
123 #define __iomb()		dma_mb()
124 
125 /*
126  *  I/O port access primitives.
127  */
128 #define arch_has_dev_port()	(1)
129 #define IO_SPACE_LIMIT		(PCI_IO_SIZE - 1)
130 #define PCI_IOBASE		((void __iomem *)PCI_IO_START)
131 
132 /*
133  * String version of I/O memory access operations.
134  */
135 extern void __memcpy_fromio(void *, const volatile void __iomem *, size_t);
136 extern void __memcpy_toio(volatile void __iomem *, const void *, size_t);
137 extern void __memset_io(volatile void __iomem *, int, size_t);
138 
139 #define memset_io(c,v,l)	__memset_io((c),(v),(l))
140 #define memcpy_fromio(a,c,l)	__memcpy_fromio((a),(c),(l))
141 #define memcpy_toio(c,a,l)	__memcpy_toio((c),(a),(l))
142 
143 /*
144  * The ARM64 iowrite implementation is intended to support drivers that want to
145  * use write combining. For instance PCI drivers using write combining with a 64
146  * byte __iowrite64_copy() expect to get a 64 byte MemWr TLP on the PCIe bus.
147  *
148  * Newer ARM core have sensitive write combining buffers, it is important that
149  * the stores be contiguous blocks of store instructions. Normal memcpy
150  * approaches have a very low chance to generate write combining.
151  *
152  * Since this is the only API on ARM64 that should be used with write combining
153  * it also integrates the DGH hint which is supposed to lower the latency to
154  * emit the large TLP from the CPU.
155  */
156 
157 static __always_inline void
158 __const_memcpy_toio_aligned32(volatile u32 __iomem *to, const u32 *from,
159 			      size_t count)
160 {
161 	switch (count) {
162 	case 8:
163 		asm volatile("str %w0, [%8, #4 * 0]\n"
164 			     "str %w1, [%8, #4 * 1]\n"
165 			     "str %w2, [%8, #4 * 2]\n"
166 			     "str %w3, [%8, #4 * 3]\n"
167 			     "str %w4, [%8, #4 * 4]\n"
168 			     "str %w5, [%8, #4 * 5]\n"
169 			     "str %w6, [%8, #4 * 6]\n"
170 			     "str %w7, [%8, #4 * 7]\n"
171 			     :
172 			     : "rZ"(from[0]), "rZ"(from[1]), "rZ"(from[2]),
173 			       "rZ"(from[3]), "rZ"(from[4]), "rZ"(from[5]),
174 			       "rZ"(from[6]), "rZ"(from[7]), "r"(to));
175 		break;
176 	case 4:
177 		asm volatile("str %w0, [%4, #4 * 0]\n"
178 			     "str %w1, [%4, #4 * 1]\n"
179 			     "str %w2, [%4, #4 * 2]\n"
180 			     "str %w3, [%4, #4 * 3]\n"
181 			     :
182 			     : "rZ"(from[0]), "rZ"(from[1]), "rZ"(from[2]),
183 			       "rZ"(from[3]), "r"(to));
184 		break;
185 	case 2:
186 		asm volatile("str %w0, [%2, #4 * 0]\n"
187 			     "str %w1, [%2, #4 * 1]\n"
188 			     :
189 			     : "rZ"(from[0]), "rZ"(from[1]), "r"(to));
190 		break;
191 	case 1:
192 		__raw_writel(*from, to);
193 		break;
194 	default:
195 		BUILD_BUG();
196 	}
197 }
198 
199 void __iowrite32_copy_full(void __iomem *to, const void *from, size_t count);
200 
201 static __always_inline void
202 __iowrite32_copy(void __iomem *to, const void *from, size_t count)
203 {
204 	if (__builtin_constant_p(count) &&
205 	    (count == 8 || count == 4 || count == 2 || count == 1)) {
206 		__const_memcpy_toio_aligned32(to, from, count);
207 		dgh();
208 	} else {
209 		__iowrite32_copy_full(to, from, count);
210 	}
211 }
212 #define __iowrite32_copy __iowrite32_copy
213 
214 static __always_inline void
215 __const_memcpy_toio_aligned64(volatile u64 __iomem *to, const u64 *from,
216 			      size_t count)
217 {
218 	switch (count) {
219 	case 8:
220 		asm volatile("str %x0, [%8, #8 * 0]\n"
221 			     "str %x1, [%8, #8 * 1]\n"
222 			     "str %x2, [%8, #8 * 2]\n"
223 			     "str %x3, [%8, #8 * 3]\n"
224 			     "str %x4, [%8, #8 * 4]\n"
225 			     "str %x5, [%8, #8 * 5]\n"
226 			     "str %x6, [%8, #8 * 6]\n"
227 			     "str %x7, [%8, #8 * 7]\n"
228 			     :
229 			     : "rZ"(from[0]), "rZ"(from[1]), "rZ"(from[2]),
230 			       "rZ"(from[3]), "rZ"(from[4]), "rZ"(from[5]),
231 			       "rZ"(from[6]), "rZ"(from[7]), "r"(to));
232 		break;
233 	case 4:
234 		asm volatile("str %x0, [%4, #8 * 0]\n"
235 			     "str %x1, [%4, #8 * 1]\n"
236 			     "str %x2, [%4, #8 * 2]\n"
237 			     "str %x3, [%4, #8 * 3]\n"
238 			     :
239 			     : "rZ"(from[0]), "rZ"(from[1]), "rZ"(from[2]),
240 			       "rZ"(from[3]), "r"(to));
241 		break;
242 	case 2:
243 		asm volatile("str %x0, [%2, #8 * 0]\n"
244 			     "str %x1, [%2, #8 * 1]\n"
245 			     :
246 			     : "rZ"(from[0]), "rZ"(from[1]), "r"(to));
247 		break;
248 	case 1:
249 		__raw_writeq(*from, to);
250 		break;
251 	default:
252 		BUILD_BUG();
253 	}
254 }
255 
256 void __iowrite64_copy_full(void __iomem *to, const void *from, size_t count);
257 
258 static __always_inline void
259 __iowrite64_copy(void __iomem *to, const void *from, size_t count)
260 {
261 	if (__builtin_constant_p(count) &&
262 	    (count == 8 || count == 4 || count == 2 || count == 1)) {
263 		__const_memcpy_toio_aligned64(to, from, count);
264 		dgh();
265 	} else {
266 		__iowrite64_copy_full(to, from, count);
267 	}
268 }
269 #define __iowrite64_copy __iowrite64_copy
270 
271 /*
272  * I/O memory mapping functions.
273  */
274 
275 typedef int (*ioremap_prot_hook_t)(phys_addr_t phys_addr, size_t size,
276 				   pgprot_t *prot);
277 int arm64_ioremap_prot_hook_register(const ioremap_prot_hook_t hook);
278 
279 #define ioremap_prot ioremap_prot
280 
281 #define _PAGE_IOREMAP PROT_DEVICE_nGnRE
282 
283 #define ioremap_wc(addr, size)	\
284 	ioremap_prot((addr), (size), PROT_NORMAL_NC)
285 #define ioremap_np(addr, size)	\
286 	ioremap_prot((addr), (size), PROT_DEVICE_nGnRnE)
287 
288 /*
289  * io{read,write}{16,32,64}be() macros
290  */
291 #define ioread16be(p)		({ __u16 __v = be16_to_cpu((__force __be16)__raw_readw(p)); __iormb(__v); __v; })
292 #define ioread32be(p)		({ __u32 __v = be32_to_cpu((__force __be32)__raw_readl(p)); __iormb(__v); __v; })
293 #define ioread64be(p)		({ __u64 __v = be64_to_cpu((__force __be64)__raw_readq(p)); __iormb(__v); __v; })
294 
295 #define iowrite16be(v,p)	({ __iowmb(); __raw_writew((__force __u16)cpu_to_be16(v), p); })
296 #define iowrite32be(v,p)	({ __iowmb(); __raw_writel((__force __u32)cpu_to_be32(v), p); })
297 #define iowrite64be(v,p)	({ __iowmb(); __raw_writeq((__force __u64)cpu_to_be64(v), p); })
298 
299 #include <asm-generic/io.h>
300 
301 #define ioremap_cache ioremap_cache
302 static inline void __iomem *ioremap_cache(phys_addr_t addr, size_t size)
303 {
304 	if (pfn_is_map_memory(__phys_to_pfn(addr)))
305 		return (void __iomem *)__phys_to_virt(addr);
306 
307 	return ioremap_prot(addr, size, PROT_NORMAL);
308 }
309 
310 /*
311  * More restrictive address range checking than the default implementation
312  * (PHYS_OFFSET and PHYS_MASK taken into account).
313  */
314 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
315 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
316 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
317 
318 extern bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
319 					unsigned long flags);
320 #define arch_memremap_can_ram_remap arch_memremap_can_ram_remap
321 
322 static inline bool arm64_is_protected_mmio(phys_addr_t phys_addr, size_t size)
323 {
324 	if (unlikely(is_realm_world()))
325 		return __arm64_is_protected_mmio(phys_addr, size);
326 	return false;
327 }
328 
329 #endif	/* __ASM_IO_H */
330