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  *
  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(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 */