xref: /linux/arch/arm64/include/asm/io.h (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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  * The ARM64 iowrite implementation is intended to support drivers that want to
134  * use write combining. For instance PCI drivers using write combining with a 64
135  * byte __iowrite64_copy() expect to get a 64 byte MemWr TLP on the PCIe bus.
136  *
137  * Newer ARM core have sensitive write combining buffers, it is important that
138  * the stores be contiguous blocks of store instructions. Normal memcpy
139  * approaches have a very low chance to generate write combining.
140  *
141  * Since this is the only API on ARM64 that should be used with write combining
142  * it also integrates the DGH hint which is supposed to lower the latency to
143  * emit the large TLP from the CPU.
144  */
145 
146 static __always_inline void
147 __const_memcpy_toio_aligned32(volatile u32 __iomem *to, const u32 *from,
148 			      size_t count)
149 {
150 	switch (count) {
151 	case 8:
152 		asm volatile("str %w0, [%8, #4 * 0]\n"
153 			     "str %w1, [%8, #4 * 1]\n"
154 			     "str %w2, [%8, #4 * 2]\n"
155 			     "str %w3, [%8, #4 * 3]\n"
156 			     "str %w4, [%8, #4 * 4]\n"
157 			     "str %w5, [%8, #4 * 5]\n"
158 			     "str %w6, [%8, #4 * 6]\n"
159 			     "str %w7, [%8, #4 * 7]\n"
160 			     :
161 			     : "rZ"(from[0]), "rZ"(from[1]), "rZ"(from[2]),
162 			       "rZ"(from[3]), "rZ"(from[4]), "rZ"(from[5]),
163 			       "rZ"(from[6]), "rZ"(from[7]), "r"(to));
164 		break;
165 	case 4:
166 		asm volatile("str %w0, [%4, #4 * 0]\n"
167 			     "str %w1, [%4, #4 * 1]\n"
168 			     "str %w2, [%4, #4 * 2]\n"
169 			     "str %w3, [%4, #4 * 3]\n"
170 			     :
171 			     : "rZ"(from[0]), "rZ"(from[1]), "rZ"(from[2]),
172 			       "rZ"(from[3]), "r"(to));
173 		break;
174 	case 2:
175 		asm volatile("str %w0, [%2, #4 * 0]\n"
176 			     "str %w1, [%2, #4 * 1]\n"
177 			     :
178 			     : "rZ"(from[0]), "rZ"(from[1]), "r"(to));
179 		break;
180 	case 1:
181 		__raw_writel(*from, to);
182 		break;
183 	default:
184 		BUILD_BUG();
185 	}
186 }
187 
188 void __iowrite32_copy_full(void __iomem *to, const void *from, size_t count);
189 
190 static __always_inline void
191 __iowrite32_copy(void __iomem *to, const void *from, size_t count)
192 {
193 	if (__builtin_constant_p(count) &&
194 	    (count == 8 || count == 4 || count == 2 || count == 1)) {
195 		__const_memcpy_toio_aligned32(to, from, count);
196 		dgh();
197 	} else {
198 		__iowrite32_copy_full(to, from, count);
199 	}
200 }
201 #define __iowrite32_copy __iowrite32_copy
202 
203 static __always_inline void
204 __const_memcpy_toio_aligned64(volatile u64 __iomem *to, const u64 *from,
205 			      size_t count)
206 {
207 	switch (count) {
208 	case 8:
209 		asm volatile("str %x0, [%8, #8 * 0]\n"
210 			     "str %x1, [%8, #8 * 1]\n"
211 			     "str %x2, [%8, #8 * 2]\n"
212 			     "str %x3, [%8, #8 * 3]\n"
213 			     "str %x4, [%8, #8 * 4]\n"
214 			     "str %x5, [%8, #8 * 5]\n"
215 			     "str %x6, [%8, #8 * 6]\n"
216 			     "str %x7, [%8, #8 * 7]\n"
217 			     :
218 			     : "rZ"(from[0]), "rZ"(from[1]), "rZ"(from[2]),
219 			       "rZ"(from[3]), "rZ"(from[4]), "rZ"(from[5]),
220 			       "rZ"(from[6]), "rZ"(from[7]), "r"(to));
221 		break;
222 	case 4:
223 		asm volatile("str %x0, [%4, #8 * 0]\n"
224 			     "str %x1, [%4, #8 * 1]\n"
225 			     "str %x2, [%4, #8 * 2]\n"
226 			     "str %x3, [%4, #8 * 3]\n"
227 			     :
228 			     : "rZ"(from[0]), "rZ"(from[1]), "rZ"(from[2]),
229 			       "rZ"(from[3]), "r"(to));
230 		break;
231 	case 2:
232 		asm volatile("str %x0, [%2, #8 * 0]\n"
233 			     "str %x1, [%2, #8 * 1]\n"
234 			     :
235 			     : "rZ"(from[0]), "rZ"(from[1]), "r"(to));
236 		break;
237 	case 1:
238 		__raw_writeq(*from, to);
239 		break;
240 	default:
241 		BUILD_BUG();
242 	}
243 }
244 
245 void __iowrite64_copy_full(void __iomem *to, const void *from, size_t count);
246 
247 static __always_inline void
248 __iowrite64_copy(void __iomem *to, const void *from, size_t count)
249 {
250 	if (__builtin_constant_p(count) &&
251 	    (count == 8 || count == 4 || count == 2 || count == 1)) {
252 		__const_memcpy_toio_aligned64(to, from, count);
253 		dgh();
254 	} else {
255 		__iowrite64_copy_full(to, from, count);
256 	}
257 }
258 #define __iowrite64_copy __iowrite64_copy
259 
260 /*
261  * I/O memory mapping functions.
262  */
263 
264 typedef int (*ioremap_prot_hook_t)(phys_addr_t phys_addr, size_t size,
265 				   pgprot_t *prot);
266 int arm64_ioremap_prot_hook_register(const ioremap_prot_hook_t hook);
267 
268 #define ioremap_prot ioremap_prot
269 
270 #define _PAGE_IOREMAP PROT_DEVICE_nGnRE
271 
272 #define ioremap_wc(addr, size)	\
273 	ioremap_prot((addr), (size), PROT_NORMAL_NC)
274 #define ioremap_np(addr, size)	\
275 	ioremap_prot((addr), (size), PROT_DEVICE_nGnRnE)
276 
277 /*
278  * io{read,write}{16,32,64}be() macros
279  */
280 #define ioread16be(p)		({ __u16 __v = be16_to_cpu((__force __be16)__raw_readw(p)); __iormb(__v); __v; })
281 #define ioread32be(p)		({ __u32 __v = be32_to_cpu((__force __be32)__raw_readl(p)); __iormb(__v); __v; })
282 #define ioread64be(p)		({ __u64 __v = be64_to_cpu((__force __be64)__raw_readq(p)); __iormb(__v); __v; })
283 
284 #define iowrite16be(v,p)	({ __iowmb(); __raw_writew((__force __u16)cpu_to_be16(v), p); })
285 #define iowrite32be(v,p)	({ __iowmb(); __raw_writel((__force __u32)cpu_to_be32(v), p); })
286 #define iowrite64be(v,p)	({ __iowmb(); __raw_writeq((__force __u64)cpu_to_be64(v), p); })
287 
288 #include <asm-generic/io.h>
289 
290 #define ioremap_cache ioremap_cache
291 static inline void __iomem *ioremap_cache(phys_addr_t addr, size_t size)
292 {
293 	if (pfn_is_map_memory(__phys_to_pfn(addr)))
294 		return (void __iomem *)__phys_to_virt(addr);
295 
296 	return ioremap_prot(addr, size, PROT_NORMAL);
297 }
298 
299 /*
300  * More restrictive address range checking than the default implementation
301  * (PHYS_OFFSET and PHYS_MASK taken into account).
302  */
303 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
304 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
305 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
306 
307 extern bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
308 					unsigned long flags);
309 #define arch_memremap_can_ram_remap arch_memremap_can_ram_remap
310 
311 static inline bool arm64_is_protected_mmio(phys_addr_t phys_addr, size_t size)
312 {
313 	if (unlikely(is_realm_world()))
314 		return __arm64_is_protected_mmio(phys_addr, size);
315 	return false;
316 }
317 
318 #endif	/* __ASM_IO_H */
319