xref: /openbmc/linux/lib/logic_pio.c (revision 0c874100)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 HiSilicon Limited, All Rights Reserved.
4  * Author: Gabriele Paoloni <gabriele.paoloni@huawei.com>
5  * Author: Zhichang Yuan <yuanzhichang@hisilicon.com>
6  */
7 
8 #define pr_fmt(fmt)	"LOGIC PIO: " fmt
9 
10 #include <linux/of.h>
11 #include <linux/io.h>
12 #include <linux/logic_pio.h>
13 #include <linux/mm.h>
14 #include <linux/rculist.h>
15 #include <linux/sizes.h>
16 #include <linux/slab.h>
17 
18 /* The unique hardware address list */
19 static LIST_HEAD(io_range_list);
20 static DEFINE_MUTEX(io_range_mutex);
21 
22 /* Consider a kernel general helper for this */
23 #define in_range(b, first, len)        ((b) >= (first) && (b) < (first) + (len))
24 
25 /**
26  * logic_pio_register_range - register logical PIO range for a host
27  * @new_range: pointer to the IO range to be registered.
28  *
29  * Returns 0 on success, the error code in case of failure.
30  *
31  * Register a new IO range node in the IO range list.
32  */
33 int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
34 {
35 	struct logic_pio_hwaddr *range;
36 	resource_size_t start;
37 	resource_size_t end;
38 	resource_size_t mmio_sz = 0;
39 	resource_size_t iio_sz = MMIO_UPPER_LIMIT;
40 	int ret = 0;
41 
42 	if (!new_range || !new_range->fwnode || !new_range->size)
43 		return -EINVAL;
44 
45 	start = new_range->hw_start;
46 	end = new_range->hw_start + new_range->size;
47 
48 	mutex_lock(&io_range_mutex);
49 	list_for_each_entry_rcu(range, &io_range_list, list) {
50 		if (range->fwnode == new_range->fwnode) {
51 			/* range already there */
52 			goto end_register;
53 		}
54 		if (range->flags == LOGIC_PIO_CPU_MMIO &&
55 		    new_range->flags == LOGIC_PIO_CPU_MMIO) {
56 			/* for MMIO ranges we need to check for overlap */
57 			if (start >= range->hw_start + range->size ||
58 			    end < range->hw_start) {
59 				mmio_sz += range->size;
60 			} else {
61 				ret = -EFAULT;
62 				goto end_register;
63 			}
64 		} else if (range->flags == LOGIC_PIO_INDIRECT &&
65 			   new_range->flags == LOGIC_PIO_INDIRECT) {
66 			iio_sz += range->size;
67 		}
68 	}
69 
70 	/* range not registered yet, check for available space */
71 	if (new_range->flags == LOGIC_PIO_CPU_MMIO) {
72 		if (mmio_sz + new_range->size - 1 > MMIO_UPPER_LIMIT) {
73 			/* if it's too big check if 64K space can be reserved */
74 			if (mmio_sz + SZ_64K - 1 > MMIO_UPPER_LIMIT) {
75 				ret = -E2BIG;
76 				goto end_register;
77 			}
78 			new_range->size = SZ_64K;
79 			pr_warn("Requested IO range too big, new size set to 64K\n");
80 		}
81 		new_range->io_start = mmio_sz;
82 	} else if (new_range->flags == LOGIC_PIO_INDIRECT) {
83 		if (iio_sz + new_range->size - 1 > IO_SPACE_LIMIT) {
84 			ret = -E2BIG;
85 			goto end_register;
86 		}
87 		new_range->io_start = iio_sz;
88 	} else {
89 		/* invalid flag */
90 		ret = -EINVAL;
91 		goto end_register;
92 	}
93 
94 	list_add_tail_rcu(&new_range->list, &io_range_list);
95 
96 end_register:
97 	mutex_unlock(&io_range_mutex);
98 	return ret;
99 }
100 
101 /**
102  * find_io_range_by_fwnode - find logical PIO range for given FW node
103  * @fwnode: FW node handle associated with logical PIO range
104  *
105  * Returns pointer to node on success, NULL otherwise.
106  *
107  * Traverse the io_range_list to find the registered node for @fwnode.
108  */
109 struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode)
110 {
111 	struct logic_pio_hwaddr *range;
112 
113 	list_for_each_entry_rcu(range, &io_range_list, list) {
114 		if (range->fwnode == fwnode)
115 			return range;
116 	}
117 	return NULL;
118 }
119 
120 /* Return a registered range given an input PIO token */
121 static struct logic_pio_hwaddr *find_io_range(unsigned long pio)
122 {
123 	struct logic_pio_hwaddr *range;
124 
125 	list_for_each_entry_rcu(range, &io_range_list, list) {
126 		if (in_range(pio, range->io_start, range->size))
127 			return range;
128 	}
129 	pr_err("PIO entry token %lx invalid\n", pio);
130 	return NULL;
131 }
132 
133 /**
134  * logic_pio_to_hwaddr - translate logical PIO to HW address
135  * @pio: logical PIO value
136  *
137  * Returns HW address if valid, ~0 otherwise.
138  *
139  * Translate the input logical PIO to the corresponding hardware address.
140  * The input PIO should be unique in the whole logical PIO space.
141  */
142 resource_size_t logic_pio_to_hwaddr(unsigned long pio)
143 {
144 	struct logic_pio_hwaddr *range;
145 
146 	range = find_io_range(pio);
147 	if (range)
148 		return range->hw_start + pio - range->io_start;
149 
150 	return (resource_size_t)~0;
151 }
152 
153 /**
154  * logic_pio_trans_hwaddr - translate HW address to logical PIO
155  * @fwnode: FW node reference for the host
156  * @addr: Host-relative HW address
157  * @size: size to translate
158  *
159  * Returns Logical PIO value if successful, ~0UL otherwise
160  */
161 unsigned long logic_pio_trans_hwaddr(struct fwnode_handle *fwnode,
162 				     resource_size_t addr, resource_size_t size)
163 {
164 	struct logic_pio_hwaddr *range;
165 
166 	range = find_io_range_by_fwnode(fwnode);
167 	if (!range || range->flags == LOGIC_PIO_CPU_MMIO) {
168 		pr_err("IO range not found or invalid\n");
169 		return ~0UL;
170 	}
171 	if (range->size < size) {
172 		pr_err("resource size %pa cannot fit in IO range size %pa\n",
173 		       &size, &range->size);
174 		return ~0UL;
175 	}
176 	return addr - range->hw_start + range->io_start;
177 }
178 
179 unsigned long logic_pio_trans_cpuaddr(resource_size_t addr)
180 {
181 	struct logic_pio_hwaddr *range;
182 
183 	list_for_each_entry_rcu(range, &io_range_list, list) {
184 		if (range->flags != LOGIC_PIO_CPU_MMIO)
185 			continue;
186 		if (in_range(addr, range->hw_start, range->size))
187 			return addr - range->hw_start + range->io_start;
188 	}
189 	pr_err("addr %llx not registered in io_range_list\n",
190 	       (unsigned long long) addr);
191 	return ~0UL;
192 }
193 
194 #if defined(CONFIG_INDIRECT_PIO) && defined(PCI_IOBASE)
195 #define BUILD_LOGIC_IO(bw, type)					\
196 type logic_in##bw(unsigned long addr)					\
197 {									\
198 	type ret = (type)~0;						\
199 									\
200 	if (addr < MMIO_UPPER_LIMIT) {					\
201 		ret = read##bw(PCI_IOBASE + addr);			\
202 	} else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
203 		struct logic_pio_hwaddr *entry = find_io_range(addr);	\
204 									\
205 		if (entry && entry->ops)				\
206 			ret = entry->ops->in(entry->hostdata,		\
207 					addr, sizeof(type));		\
208 		else							\
209 			WARN_ON_ONCE(1);				\
210 	}								\
211 	return ret;							\
212 }									\
213 									\
214 void logic_out##bw(type value, unsigned long addr)			\
215 {									\
216 	if (addr < MMIO_UPPER_LIMIT) {					\
217 		write##bw(value, PCI_IOBASE + addr);			\
218 	} else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) {	\
219 		struct logic_pio_hwaddr *entry = find_io_range(addr);	\
220 									\
221 		if (entry && entry->ops)				\
222 			entry->ops->out(entry->hostdata,		\
223 					addr, value, sizeof(type));	\
224 		else							\
225 			WARN_ON_ONCE(1);				\
226 	}								\
227 }									\
228 									\
229 void logic_ins##bw(unsigned long addr, void *buffer,		\
230 		   unsigned int count)					\
231 {									\
232 	if (addr < MMIO_UPPER_LIMIT) {					\
233 		reads##bw(PCI_IOBASE + addr, buffer, count);		\
234 	} else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) {	\
235 		struct logic_pio_hwaddr *entry = find_io_range(addr);	\
236 									\
237 		if (entry && entry->ops)				\
238 			entry->ops->ins(entry->hostdata,		\
239 				addr, buffer, sizeof(type), count);	\
240 		else							\
241 			WARN_ON_ONCE(1);				\
242 	}								\
243 									\
244 }									\
245 									\
246 void logic_outs##bw(unsigned long addr, const void *buffer,		\
247 		    unsigned int count)					\
248 {									\
249 	if (addr < MMIO_UPPER_LIMIT) {					\
250 		writes##bw(PCI_IOBASE + addr, buffer, count);		\
251 	} else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) {	\
252 		struct logic_pio_hwaddr *entry = find_io_range(addr);	\
253 									\
254 		if (entry && entry->ops)				\
255 			entry->ops->outs(entry->hostdata,		\
256 				addr, buffer, sizeof(type), count);	\
257 		else							\
258 			WARN_ON_ONCE(1);				\
259 	}								\
260 }
261 
262 BUILD_LOGIC_IO(b, u8)
263 EXPORT_SYMBOL(logic_inb);
264 EXPORT_SYMBOL(logic_insb);
265 EXPORT_SYMBOL(logic_outb);
266 EXPORT_SYMBOL(logic_outsb);
267 
268 BUILD_LOGIC_IO(w, u16)
269 EXPORT_SYMBOL(logic_inw);
270 EXPORT_SYMBOL(logic_insw);
271 EXPORT_SYMBOL(logic_outw);
272 EXPORT_SYMBOL(logic_outsw);
273 
274 BUILD_LOGIC_IO(l, u32)
275 EXPORT_SYMBOL(logic_inl);
276 EXPORT_SYMBOL(logic_insl);
277 EXPORT_SYMBOL(logic_outl);
278 EXPORT_SYMBOL(logic_outsl);
279 
280 #endif /* CONFIG_INDIRECT_PIO && PCI_IOBASE */
281