lib/logic_pio.c

   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  * If the range already exists, -EEXIST will be returned, which should be
  32  * considered a success.
  33  *
  34  * Register a new IO range node in the IO range list.
  35  */
  36 int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
  37 {
  38         struct logic_pio_hwaddr *range;
  39         resource_size_t start;
  40         resource_size_t end;
  41         resource_size_t mmio_end = 0;
  42         resource_size_t iio_sz = MMIO_UPPER_LIMIT;
  43         int ret = 0;
  44
  45         if (!new_range || !new_range->fwnode || !new_range->size ||
  46             (new_range->flags == LOGIC_PIO_INDIRECT && !new_range->ops))
  47                 return -EINVAL;
  48
  49         start = new_range->hw_start;
  50         end = new_range->hw_start + new_range->size;
  51
  52         mutex_lock(&io_range_mutex);
  53         list_for_each_entry(range, &io_range_list, list) {
  54                 if (range->fwnode == new_range->fwnode) {
  55                         /* range already there */
  56                         ret = -EEXIST;
  57                         goto end_register;
  58                 }
  59                 if (range->flags == LOGIC_PIO_CPU_MMIO &&
  60                     new_range->flags == LOGIC_PIO_CPU_MMIO) {
  61                         /* for MMIO ranges we need to check for overlap */
  62                         if (start >= range->hw_start + range->size ||
  63                             end < range->hw_start) {
  64                                 mmio_end = range->io_start + range->size;
  65                         } else {
  66                                 ret = -EFAULT;
  67                                 goto end_register;
  68                         }
  69                 } else if (range->flags == LOGIC_PIO_INDIRECT &&
  70                            new_range->flags == LOGIC_PIO_INDIRECT) {
  71                         iio_sz += range->size;
  72                 }
  73         }
  74
  75         /* range not registered yet, check for available space */
  76         if (new_range->flags == LOGIC_PIO_CPU_MMIO) {
  77                 if (mmio_end + new_range->size - 1 > MMIO_UPPER_LIMIT) {
  78                         /* if it's too big check if 64K space can be reserved */
  79                         if (mmio_end + SZ_64K - 1 > MMIO_UPPER_LIMIT) {
  80                                 ret = -E2BIG;
  81                                 goto end_register;
  82                         }
  83                         new_range->size = SZ_64K;
  84                         pr_warn("Requested IO range too big, new size set to 64K\n");
  85                 }
  86                 new_range->io_start = mmio_end;
  87         } else if (new_range->flags == LOGIC_PIO_INDIRECT) {
  88                 if (iio_sz + new_range->size - 1 > IO_SPACE_LIMIT) {
  89                         ret = -E2BIG;
  90                         goto end_register;
  91                 }
  92                 new_range->io_start = iio_sz;
  93         } else {
  94                 /* invalid flag */
  95                 ret = -EINVAL;
  96                 goto end_register;
  97         }
  98
  99         list_add_tail_rcu(&new_range->list, &io_range_list);
 100
 101 end_register:
 102         mutex_unlock(&io_range_mutex);
 103         return ret;
 104 }
 105
 106 /**
 107  * logic_pio_unregister_range - unregister a logical PIO range for a host
 108  * @range: pointer to the IO range which has been already registered.
 109  *
 110  * Unregister a previously-registered IO range node.
 111  */
 112 void logic_pio_unregister_range(struct logic_pio_hwaddr *range)
 113 {
 114         mutex_lock(&io_range_mutex);
 115         list_del_rcu(&range->list);
 116         mutex_unlock(&io_range_mutex);
 117         synchronize_rcu();
 118 }
 119
 120 /**
 121  * find_io_range_by_fwnode - find logical PIO range for given FW node
 122  * @fwnode: FW node handle associated with logical PIO range
 123  *
 124  * Returns pointer to node on success, NULL otherwise.
 125  *
 126  * Traverse the io_range_list to find the registered node for @fwnode.
 127  */
 128 struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode)
 129 {
 130         struct logic_pio_hwaddr *range, *found_range = NULL;
 131
 132         rcu_read_lock();
 133         list_for_each_entry_rcu(range, &io_range_list, list) {
 134                 if (range->fwnode == fwnode) {
 135                         found_range = range;
 136                         break;
 137                 }
 138         }
 139         rcu_read_unlock();
 140
 141         return found_range;
 142 }
 143
 144 /* Return a registered range given an input PIO token */
 145 static struct logic_pio_hwaddr *find_io_range(unsigned long pio)
 146 {
 147         struct logic_pio_hwaddr *range, *found_range = NULL;
 148
 149         rcu_read_lock();
 150         list_for_each_entry_rcu(range, &io_range_list, list) {
 151                 if (in_range(pio, range->io_start, range->size)) {
 152                         found_range = range;
 153                         break;
 154                 }
 155         }
 156         rcu_read_unlock();
 157
 158         if (!found_range)
 159                 pr_err("PIO entry token 0x%lx invalid\n", pio);
 160
 161         return found_range;
 162 }
 163
 164 /**
 165  * logic_pio_to_hwaddr - translate logical PIO to HW address
 166  * @pio: logical PIO value
 167  *
 168  * Returns HW address if valid, ~0 otherwise.
 169  *
 170  * Translate the input logical PIO to the corresponding hardware address.
 171  * The input PIO should be unique in the whole logical PIO space.
 172  */
 173 resource_size_t logic_pio_to_hwaddr(unsigned long pio)
 174 {
 175         struct logic_pio_hwaddr *range;
 176
 177         range = find_io_range(pio);
 178         if (range)
 179                 return range->hw_start + pio - range->io_start;
 180
 181         return (resource_size_t)~0;
 182 }
 183
 184 /**
 185  * logic_pio_trans_hwaddr - translate HW address to logical PIO
 186  * @fwnode: FW node reference for the host
 187  * @addr: Host-relative HW address
 188  * @size: size to translate
 189  *
 190  * Returns Logical PIO value if successful, ~0UL otherwise
 191  */
 192 unsigned long logic_pio_trans_hwaddr(struct fwnode_handle *fwnode,
 193                                      resource_size_t addr, resource_size_t size)
 194 {
 195         struct logic_pio_hwaddr *range;
 196
 197         range = find_io_range_by_fwnode(fwnode);
 198         if (!range || range->flags == LOGIC_PIO_CPU_MMIO) {
 199                 pr_err("IO range not found or invalid\n");
 200                 return ~0UL;
 201         }
 202         if (range->size < size) {
 203                 pr_err("resource size %pa cannot fit in IO range size %pa\n",
 204                        &size, &range->size);
 205                 return ~0UL;
 206         }
 207         return addr - range->hw_start + range->io_start;
 208 }
 209
 210 unsigned long logic_pio_trans_cpuaddr(resource_size_t addr)
 211 {
 212         struct logic_pio_hwaddr *range;
 213
 214         rcu_read_lock();
 215         list_for_each_entry_rcu(range, &io_range_list, list) {
 216                 if (range->flags != LOGIC_PIO_CPU_MMIO)
 217                         continue;
 218                 if (in_range(addr, range->hw_start, range->size)) {
 219                         unsigned long cpuaddr;
 220
 221                         cpuaddr = addr - range->hw_start + range->io_start;
 222
 223                         rcu_read_unlock();
 224                         return cpuaddr;
 225                 }
 226         }
 227         rcu_read_unlock();
 228
 229         pr_err("addr %pa not registered in io_range_list\n", &addr);
 230
 231         return ~0UL;
 232 }
 233
 234 #if defined(CONFIG_INDIRECT_PIO) && defined(PCI_IOBASE)
 235 #define BUILD_LOGIC_IO(bwl, type)                                       \
 236 type logic_in##bwl(unsigned long addr)                                  \
 237 {                                                                       \
 238         type ret = (type)~0;                                            \
 239                                                                         \
 240         if (addr < MMIO_UPPER_LIMIT) {                                  \
 241                 ret = _in##bwl(addr);                                   \
 242         } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 243                 struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 244                                                                         \
 245                 if (entry)                                              \
 246                         ret = entry->ops->in(entry->hostdata,           \
 247                                         addr, sizeof(type));            \
 248                 else                                                    \
 249                         WARN_ON_ONCE(1);                                \
 250         }                                                               \
 251         return ret;                                                     \
 252 }                                                                       \
 253                                                                         \
 254 void logic_out##bwl(type value, unsigned long addr)                     \
 255 {                                                                       \
 256         if (addr < MMIO_UPPER_LIMIT) {                                  \
 257                 _out##bwl(value, addr);                         \
 258         } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 259                 struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 260                                                                         \
 261                 if (entry)                                              \
 262                         entry->ops->out(entry->hostdata,                \
 263                                         addr, value, sizeof(type));     \
 264                 else                                                    \
 265                         WARN_ON_ONCE(1);                                \
 266         }                                                               \
 267 }                                                                       \
 268                                                                         \
 269 void logic_ins##bwl(unsigned long addr, void *buffer,                   \
 270                     unsigned int count)                                 \
 271 {                                                                       \
 272         if (addr < MMIO_UPPER_LIMIT) {                                  \
 273                 reads##bwl(PCI_IOBASE + addr, buffer, count);           \
 274         } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 275                 struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 276                                                                         \
 277                 if (entry)                                              \
 278                         entry->ops->ins(entry->hostdata,                \
 279                                 addr, buffer, sizeof(type), count);     \
 280                 else                                                    \
 281                         WARN_ON_ONCE(1);                                \
 282         }                                                               \
 283                                                                         \
 284 }                                                                       \
 285                                                                         \
 286 void logic_outs##bwl(unsigned long addr, const void *buffer,            \
 287                      unsigned int count)                                \
 288 {                                                                       \
 289         if (addr < MMIO_UPPER_LIMIT) {                                  \
 290                 writes##bwl(PCI_IOBASE + addr, buffer, count);          \
 291         } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 292                 struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 293                                                                         \
 294                 if (entry)                                              \
 295                         entry->ops->outs(entry->hostdata,               \
 296                                 addr, buffer, sizeof(type), count);     \
 297                 else                                                    \
 298                         WARN_ON_ONCE(1);                                \
 299         }                                                               \
 300 }
 301
 302 BUILD_LOGIC_IO(b, u8)
 303 EXPORT_SYMBOL(logic_inb);
 304 EXPORT_SYMBOL(logic_insb);
 305 EXPORT_SYMBOL(logic_outb);
 306 EXPORT_SYMBOL(logic_outsb);
 307
 308 BUILD_LOGIC_IO(w, u16)
 309 EXPORT_SYMBOL(logic_inw);
 310 EXPORT_SYMBOL(logic_insw);
 311 EXPORT_SYMBOL(logic_outw);
 312 EXPORT_SYMBOL(logic_outsw);
 313
 314 BUILD_LOGIC_IO(l, u32)
 315 EXPORT_SYMBOL(logic_inl);
 316 EXPORT_SYMBOL(logic_insl);
 317 EXPORT_SYMBOL(logic_outl);
 318 EXPORT_SYMBOL(logic_outsl);
 319
 320 #endif /* CONFIG_INDIRECT_PIO && PCI_IOBASE */