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 * Author: John Garry <john.garry@huawei.com>
7 */
8
9 #define pr_fmt(fmt) "LOGIC PIO: " fmt
10
11 #include <linux/of.h>
12 #include <linux/io.h>
13 #include <linux/logic_pio.h>
14 #include <linux/mm.h>
15 #include <linux/rculist.h>
16 #include <linux/sizes.h>
17 #include <linux/slab.h>
18
19 /* The unique hardware address list */
20 static LIST_HEAD(io_range_list);
21 static DEFINE_MUTEX(io_range_mutex);
22
23 /* Consider a kernel general helper for this */
24 #define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
25
26 /**
27 * logic_pio_register_range - register logical PIO range for a host
28 * @new_range: pointer to the IO range to be registered.
29 *
30 * Returns 0 on success, the error code in case of failure.
31 *
32 * Register a new IO range node in the IO range list.
33 */
logic_pio_register_range(struct logic_pio_hwaddr * new_range)34 int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
35 {
36 struct logic_pio_hwaddr *range;
37 resource_size_t start;
38 resource_size_t end;
39 resource_size_t mmio_end = 0;
40 resource_size_t iio_sz = MMIO_UPPER_LIMIT;
41 int ret = 0;
42
43 if (!new_range || !new_range->fwnode || !new_range->size ||
44 (new_range->flags == LOGIC_PIO_INDIRECT && !new_range->ops))
45 return -EINVAL;
46
47 start = new_range->hw_start;
48 end = new_range->hw_start + new_range->size;
49
50 mutex_lock(&io_range_mutex);
51 list_for_each_entry(range, &io_range_list, list) {
52 if (range->fwnode == new_range->fwnode) {
53 /* range already there */
54 goto end_register;
55 }
56 if (range->flags == LOGIC_PIO_CPU_MMIO &&
57 new_range->flags == LOGIC_PIO_CPU_MMIO) {
58 /* for MMIO ranges we need to check for overlap */
59 if (start >= range->hw_start + range->size ||
60 end < range->hw_start) {
61 mmio_end = range->io_start + range->size;
62 } else {
63 ret = -EFAULT;
64 goto end_register;
65 }
66 } else if (range->flags == LOGIC_PIO_INDIRECT &&
67 new_range->flags == LOGIC_PIO_INDIRECT) {
68 iio_sz += range->size;
69 }
70 }
71
72 /* range not registered yet, check for available space */
73 if (new_range->flags == LOGIC_PIO_CPU_MMIO) {
74 if (mmio_end + new_range->size - 1 > MMIO_UPPER_LIMIT) {
75 /* if it's too big check if 64K space can be reserved */
76 if (mmio_end + SZ_64K - 1 > MMIO_UPPER_LIMIT) {
77 ret = -E2BIG;
78 goto end_register;
79 }
80 new_range->size = SZ_64K;
81 pr_warn("Requested IO range too big, new size set to 64K\n");
82 }
83 new_range->io_start = mmio_end;
84 } else if (new_range->flags == LOGIC_PIO_INDIRECT) {
85 if (iio_sz + new_range->size - 1 > IO_SPACE_LIMIT) {
86 ret = -E2BIG;
87 goto end_register;
88 }
89 new_range->io_start = iio_sz;
90 } else {
91 /* invalid flag */
92 ret = -EINVAL;
93 goto end_register;
94 }
95
96 list_add_tail_rcu(&new_range->list, &io_range_list);
97
98 end_register:
99 mutex_unlock(&io_range_mutex);
100 return ret;
101 }
102
103 /**
104 * logic_pio_unregister_range - unregister a logical PIO range for a host
105 * @range: pointer to the IO range which has been already registered.
106 *
107 * Unregister a previously-registered IO range node.
108 */
logic_pio_unregister_range(struct logic_pio_hwaddr * range)109 void logic_pio_unregister_range(struct logic_pio_hwaddr *range)
110 {
111 mutex_lock(&io_range_mutex);
112 list_del_rcu(&range->list);
113 mutex_unlock(&io_range_mutex);
114 synchronize_rcu();
115 }
116
117 /**
118 * find_io_range_by_fwnode - find logical PIO range for given FW node
119 * @fwnode: FW node handle associated with logical PIO range
120 *
121 * Returns pointer to node on success, NULL otherwise.
122 *
123 * Traverse the io_range_list to find the registered node for @fwnode.
124 */
find_io_range_by_fwnode(struct fwnode_handle * fwnode)125 struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode)
126 {
127 struct logic_pio_hwaddr *range, *found_range = NULL;
128
129 rcu_read_lock();
130 list_for_each_entry_rcu(range, &io_range_list, list) {
131 if (range->fwnode == fwnode) {
132 found_range = range;
133 break;
134 }
135 }
136 rcu_read_unlock();
137
138 return found_range;
139 }
140
141 /* Return a registered range given an input PIO token */
find_io_range(unsigned long pio)142 static struct logic_pio_hwaddr *find_io_range(unsigned long pio)
143 {
144 struct logic_pio_hwaddr *range, *found_range = NULL;
145
146 rcu_read_lock();
147 list_for_each_entry_rcu(range, &io_range_list, list) {
148 if (in_range(pio, range->io_start, range->size)) {
149 found_range = range;
150 break;
151 }
152 }
153 rcu_read_unlock();
154
155 if (!found_range)
156 pr_err("PIO entry token 0x%lx invalid\n", pio);
157
158 return found_range;
159 }
160
161 /**
162 * logic_pio_to_hwaddr - translate logical PIO to HW address
163 * @pio: logical PIO value
164 *
165 * Returns HW address if valid, ~0 otherwise.
166 *
167 * Translate the input logical PIO to the corresponding hardware address.
168 * The input PIO should be unique in the whole logical PIO space.
169 */
logic_pio_to_hwaddr(unsigned long pio)170 resource_size_t logic_pio_to_hwaddr(unsigned long pio)
171 {
172 struct logic_pio_hwaddr *range;
173
174 range = find_io_range(pio);
175 if (range)
176 return range->hw_start + pio - range->io_start;
177
178 return (resource_size_t)~0;
179 }
180
181 /**
182 * logic_pio_trans_hwaddr - translate HW address to logical PIO
183 * @fwnode: FW node reference for the host
184 * @addr: Host-relative HW address
185 * @size: size to translate
186 *
187 * Returns Logical PIO value if successful, ~0UL otherwise
188 */
logic_pio_trans_hwaddr(struct fwnode_handle * fwnode,resource_size_t addr,resource_size_t size)189 unsigned long logic_pio_trans_hwaddr(struct fwnode_handle *fwnode,
190 resource_size_t addr, resource_size_t size)
191 {
192 struct logic_pio_hwaddr *range;
193
194 range = find_io_range_by_fwnode(fwnode);
195 if (!range || range->flags == LOGIC_PIO_CPU_MMIO) {
196 pr_err("IO range not found or invalid\n");
197 return ~0UL;
198 }
199 if (range->size < size) {
200 pr_err("resource size %pa cannot fit in IO range size %pa\n",
201 &size, &range->size);
202 return ~0UL;
203 }
204 return addr - range->hw_start + range->io_start;
205 }
206
logic_pio_trans_cpuaddr(resource_size_t addr)207 unsigned long logic_pio_trans_cpuaddr(resource_size_t addr)
208 {
209 struct logic_pio_hwaddr *range;
210
211 rcu_read_lock();
212 list_for_each_entry_rcu(range, &io_range_list, list) {
213 if (range->flags != LOGIC_PIO_CPU_MMIO)
214 continue;
215 if (in_range(addr, range->hw_start, range->size)) {
216 unsigned long cpuaddr;
217
218 cpuaddr = addr - range->hw_start + range->io_start;
219
220 rcu_read_unlock();
221 return cpuaddr;
222 }
223 }
224 rcu_read_unlock();
225
226 pr_err("addr %pa not registered in io_range_list\n", &addr);
227
228 return ~0UL;
229 }
230
231 #if defined(CONFIG_INDIRECT_PIO) && defined(PCI_IOBASE)
232 #define BUILD_LOGIC_IO(bwl, type) \
233 type logic_in##bwl(unsigned long addr) \
234 { \
235 type ret = (type)~0; \
236 \
237 if (addr < MMIO_UPPER_LIMIT) { \
238 ret = _in##bwl(addr); \
239 } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
240 struct logic_pio_hwaddr *entry = find_io_range(addr); \
241 \
242 if (entry) \
243 ret = entry->ops->in(entry->hostdata, \
244 addr, sizeof(type)); \
245 else \
246 WARN_ON_ONCE(1); \
247 } \
248 return ret; \
249 } \
250 \
251 void logic_out##bwl(type value, unsigned long addr) \
252 { \
253 if (addr < MMIO_UPPER_LIMIT) { \
254 _out##bwl(value, addr); \
255 } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
256 struct logic_pio_hwaddr *entry = find_io_range(addr); \
257 \
258 if (entry) \
259 entry->ops->out(entry->hostdata, \
260 addr, value, sizeof(type)); \
261 else \
262 WARN_ON_ONCE(1); \
263 } \
264 } \
265 \
266 void logic_ins##bwl(unsigned long addr, void *buffer, \
267 unsigned int count) \
268 { \
269 if (addr < MMIO_UPPER_LIMIT) { \
270 reads##bwl(PCI_IOBASE + addr, buffer, count); \
271 } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
272 struct logic_pio_hwaddr *entry = find_io_range(addr); \
273 \
274 if (entry) \
275 entry->ops->ins(entry->hostdata, \
276 addr, buffer, sizeof(type), count); \
277 else \
278 WARN_ON_ONCE(1); \
279 } \
280 \
281 } \
282 \
283 void logic_outs##bwl(unsigned long addr, const void *buffer, \
284 unsigned int count) \
285 { \
286 if (addr < MMIO_UPPER_LIMIT) { \
287 writes##bwl(PCI_IOBASE + addr, buffer, count); \
288 } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
289 struct logic_pio_hwaddr *entry = find_io_range(addr); \
290 \
291 if (entry) \
292 entry->ops->outs(entry->hostdata, \
293 addr, buffer, sizeof(type), count); \
294 else \
295 WARN_ON_ONCE(1); \
296 } \
297 }
298
299 BUILD_LOGIC_IO(b, u8)
300 EXPORT_SYMBOL(logic_inb);
301 EXPORT_SYMBOL(logic_insb);
302 EXPORT_SYMBOL(logic_outb);
303 EXPORT_SYMBOL(logic_outsb);
304
305 BUILD_LOGIC_IO(w, u16)
306 EXPORT_SYMBOL(logic_inw);
307 EXPORT_SYMBOL(logic_insw);
308 EXPORT_SYMBOL(logic_outw);
309 EXPORT_SYMBOL(logic_outsw);
310
311 BUILD_LOGIC_IO(l, u32)
312 EXPORT_SYMBOL(logic_inl);
313 EXPORT_SYMBOL(logic_insl);
314 EXPORT_SYMBOL(logic_outl);
315 EXPORT_SYMBOL(logic_outsl);
316
317 #endif /* CONFIG_INDIRECT_PIO && PCI_IOBASE */
318
