LXR linux/lib/logic

   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 */
  20static LIST_HEAD(io_range_list);
  21static 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 */
  36int 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
 101end_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 */
 112void 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 */
 128struct 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 */
 145static 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 */
 173resource_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 */
 192unsigned 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
 210unsigned 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)                                       \
 236type 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                                                                        \
 254void 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                                                                        \
 269void 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                                                                        \
 286void 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
 302BUILD_LOGIC_IO(b, u8)
 303EXPORT_SYMBOL(logic_inb);
 304EXPORT_SYMBOL(logic_insb);
 305EXPORT_SYMBOL(logic_outb);
 306EXPORT_SYMBOL(logic_outsb);
 307
 308BUILD_LOGIC_IO(w, u16)
 309EXPORT_SYMBOL(logic_inw);
 310EXPORT_SYMBOL(logic_insw);
 311EXPORT_SYMBOL(logic_outw);
 312EXPORT_SYMBOL(logic_outsw);
 313
 314BUILD_LOGIC_IO(l, u32)
 315EXPORT_SYMBOL(logic_inl);
 316EXPORT_SYMBOL(logic_insl);
 317EXPORT_SYMBOL(logic_outl);
 318EXPORT_SYMBOL(logic_outsl);
 319
 320#endif /* CONFIG_INDIRECT_PIO && PCI_IOBASE */
 321