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