xref: /openbmc/linux/lib/logic_pio.c (revision f8e17c17)
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   */
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   */
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   */
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 */
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   */
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   */
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  
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(bw, type)					\
233  type logic_in##bw(unsigned long addr)					\
234  {									\
235  	type ret = (type)~0;						\
236  									\
237  	if (addr < MMIO_UPPER_LIMIT) {					\
238  		ret = read##bw(PCI_IOBASE + 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##bw(type value, unsigned long addr)			\
252  {									\
253  	if (addr < MMIO_UPPER_LIMIT) {					\
254  		write##bw(value, PCI_IOBASE + 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##bw(unsigned long addr, void *buffer,			\
267  		   unsigned int count)					\
268  {									\
269  	if (addr < MMIO_UPPER_LIMIT) {					\
270  		reads##bw(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##bw(unsigned long addr, const void *buffer,		\
284  		    unsigned int count)					\
285  {									\
286  	if (addr < MMIO_UPPER_LIMIT) {					\
287  		writes##bw(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