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 */
20static LIST_HEAD(io_range_list);
21static DEFINE_MUTEX(io_range_mutex);
22
23/**
24 * logic_pio_register_range - register logical PIO range for a host
25 * @new_range: pointer to the IO range to be registered.
26 *
27 * Returns 0 on success, the error code in case of failure.
28 * If the range already exists, -EEXIST will be returned, which should be
29 * considered a success.
30 *
31 * Register a new IO range node in the IO range list.
32 */
33int 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_end = 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	    (new_range->flags == LOGIC_PIO_INDIRECT && !new_range->ops))
44		return -EINVAL;
45
46	start = new_range->hw_start;
47	end = new_range->hw_start + new_range->size;
48
49	mutex_lock(&io_range_mutex);
50	list_for_each_entry(range, &io_range_list, list) {
51		if (range->fwnode == new_range->fwnode) {
52			/* range already there */
53			ret = -EEXIST;
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
98end_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 */
109void 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 */
125struct 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 */
142static 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 */
170resource_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 */
189unsigned 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
207unsigned 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)					\
233type 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									\
251void 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									\
266void 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									\
283void 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
299BUILD_LOGIC_IO(b, u8)
300EXPORT_SYMBOL(logic_inb);
301EXPORT_SYMBOL(logic_insb);
302EXPORT_SYMBOL(logic_outb);
303EXPORT_SYMBOL(logic_outsb);
304
305BUILD_LOGIC_IO(w, u16)
306EXPORT_SYMBOL(logic_inw);
307EXPORT_SYMBOL(logic_insw);
308EXPORT_SYMBOL(logic_outw);
309EXPORT_SYMBOL(logic_outsw);
310
311BUILD_LOGIC_IO(l, u32)
312EXPORT_SYMBOL(logic_inl);
313EXPORT_SYMBOL(logic_insl);
314EXPORT_SYMBOL(logic_outl);
315EXPORT_SYMBOL(logic_outsl);
316
317#endif /* CONFIG_INDIRECT_PIO && PCI_IOBASE */
318