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