linux/lib/logic_pio.c
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   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 */
  19static LIST_HEAD(io_range_list);
  20static 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 */
  33int 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
  96end_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 */
 107void 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 */
 123struct 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 */
 140static 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 */
 168resource_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 */
 187unsigned 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
 205unsigned 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)                                        \
 231type 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                                                                        \
 249void 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                                                                        \
 264void 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                                                                        \
 281void 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
 297BUILD_LOGIC_IO(b, u8)
 298EXPORT_SYMBOL(logic_inb);
 299EXPORT_SYMBOL(logic_insb);
 300EXPORT_SYMBOL(logic_outb);
 301EXPORT_SYMBOL(logic_outsb);
 302
 303BUILD_LOGIC_IO(w, u16)
 304EXPORT_SYMBOL(logic_inw);
 305EXPORT_SYMBOL(logic_insw);
 306EXPORT_SYMBOL(logic_outw);
 307EXPORT_SYMBOL(logic_outsw);
 308
 309BUILD_LOGIC_IO(l, u32)
 310EXPORT_SYMBOL(logic_inl);
 311EXPORT_SYMBOL(logic_insl);
 312EXPORT_SYMBOL(logic_outl);
 313EXPORT_SYMBOL(logic_outsl);
 314
 315#endif /* CONFIG_INDIRECT_PIO && PCI_IOBASE */
 316
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