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_sz = 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_rcu(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_sz += 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_sz + new_range->size - 1 > MMIO_UPPER_LIMIT) {
  73                        /* if it's too big check if 64K space can be reserved */
  74                        if (mmio_sz + 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_sz;
  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 * find_io_range_by_fwnode - find logical PIO range for given FW node
 103 * @fwnode: FW node handle associated with logical PIO range
 104 *
 105 * Returns pointer to node on success, NULL otherwise.
 106 *
 107 * Traverse the io_range_list to find the registered node for @fwnode.
 108 */
 109struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode)
 110{
 111        struct logic_pio_hwaddr *range;
 112
 113        list_for_each_entry_rcu(range, &io_range_list, list) {
 114                if (range->fwnode == fwnode)
 115                        return range;
 116        }
 117        return NULL;
 118}
 119
 120/* Return a registered range given an input PIO token */
 121static struct logic_pio_hwaddr *find_io_range(unsigned long pio)
 122{
 123        struct logic_pio_hwaddr *range;
 124
 125        list_for_each_entry_rcu(range, &io_range_list, list) {
 126                if (in_range(pio, range->io_start, range->size))
 127                        return range;
 128        }
 129        pr_err("PIO entry token %lx invalid\n", pio);
 130        return NULL;
 131}
 132
 133/**
 134 * logic_pio_to_hwaddr - translate logical PIO to HW address
 135 * @pio: logical PIO value
 136 *
 137 * Returns HW address if valid, ~0 otherwise.
 138 *
 139 * Translate the input logical PIO to the corresponding hardware address.
 140 * The input PIO should be unique in the whole logical PIO space.
 141 */
 142resource_size_t logic_pio_to_hwaddr(unsigned long pio)
 143{
 144        struct logic_pio_hwaddr *range;
 145
 146        range = find_io_range(pio);
 147        if (range)
 148                return range->hw_start + pio - range->io_start;
 149
 150        return (resource_size_t)~0;
 151}
 152
 153/**
 154 * logic_pio_trans_hwaddr - translate HW address to logical PIO
 155 * @fwnode: FW node reference for the host
 156 * @addr: Host-relative HW address
 157 * @size: size to translate
 158 *
 159 * Returns Logical PIO value if successful, ~0UL otherwise
 160 */
 161unsigned long logic_pio_trans_hwaddr(struct fwnode_handle *fwnode,
 162                                     resource_size_t addr, resource_size_t size)
 163{
 164        struct logic_pio_hwaddr *range;
 165
 166        range = find_io_range_by_fwnode(fwnode);
 167        if (!range || range->flags == LOGIC_PIO_CPU_MMIO) {
 168                pr_err("IO range not found or invalid\n");
 169                return ~0UL;
 170        }
 171        if (range->size < size) {
 172                pr_err("resource size %pa cannot fit in IO range size %pa\n",
 173                       &size, &range->size);
 174                return ~0UL;
 175        }
 176        return addr - range->hw_start + range->io_start;
 177}
 178
 179unsigned long logic_pio_trans_cpuaddr(resource_size_t addr)
 180{
 181        struct logic_pio_hwaddr *range;
 182
 183        list_for_each_entry_rcu(range, &io_range_list, list) {
 184                if (range->flags != LOGIC_PIO_CPU_MMIO)
 185                        continue;
 186                if (in_range(addr, range->hw_start, range->size))
 187                        return addr - range->hw_start + range->io_start;
 188        }
 189        pr_err("addr %llx not registered in io_range_list\n",
 190               (unsigned long long) addr);
 191        return ~0UL;
 192}
 193
 194#if defined(CONFIG_INDIRECT_PIO) && defined(PCI_IOBASE)
 195#define BUILD_LOGIC_IO(bw, type)                                        \
 196type logic_in##bw(unsigned long addr)                                   \
 197{                                                                       \
 198        type ret = (type)~0;                                            \
 199                                                                        \
 200        if (addr < MMIO_UPPER_LIMIT) {                                  \
 201                ret = read##bw(PCI_IOBASE + addr);                      \
 202        } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 203                struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 204                                                                        \
 205                if (entry && entry->ops)                                \
 206                        ret = entry->ops->in(entry->hostdata,           \
 207                                        addr, sizeof(type));            \
 208                else                                                    \
 209                        WARN_ON_ONCE(1);                                \
 210        }                                                               \
 211        return ret;                                                     \
 212}                                                                       \
 213                                                                        \
 214void logic_out##bw(type value, unsigned long addr)                      \
 215{                                                                       \
 216        if (addr < MMIO_UPPER_LIMIT) {                                  \
 217                write##bw(value, PCI_IOBASE + addr);                    \
 218        } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 219                struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 220                                                                        \
 221                if (entry && entry->ops)                                \
 222                        entry->ops->out(entry->hostdata,                \
 223                                        addr, value, sizeof(type));     \
 224                else                                                    \
 225                        WARN_ON_ONCE(1);                                \
 226        }                                                               \
 227}                                                                       \
 228                                                                        \
 229void logic_ins##bw(unsigned long addr, void *buffer,            \
 230                   unsigned int count)                                  \
 231{                                                                       \
 232        if (addr < MMIO_UPPER_LIMIT) {                                  \
 233                reads##bw(PCI_IOBASE + addr, buffer, count);            \
 234        } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 235                struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 236                                                                        \
 237                if (entry && entry->ops)                                \
 238                        entry->ops->ins(entry->hostdata,                \
 239                                addr, buffer, sizeof(type), count);     \
 240                else                                                    \
 241                        WARN_ON_ONCE(1);                                \
 242        }                                                               \
 243                                                                        \
 244}                                                                       \
 245                                                                        \
 246void logic_outs##bw(unsigned long addr, const void *buffer,             \
 247                    unsigned int count)                                 \
 248{                                                                       \
 249        if (addr < MMIO_UPPER_LIMIT) {                                  \
 250                writes##bw(PCI_IOBASE + addr, buffer, count);           \
 251        } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 252                struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 253                                                                        \
 254                if (entry && entry->ops)                                \
 255                        entry->ops->outs(entry->hostdata,               \
 256                                addr, buffer, sizeof(type), count);     \
 257                else                                                    \
 258                        WARN_ON_ONCE(1);                                \
 259        }                                                               \
 260}
 261
 262BUILD_LOGIC_IO(b, u8)
 263EXPORT_SYMBOL(logic_inb);
 264EXPORT_SYMBOL(logic_insb);
 265EXPORT_SYMBOL(logic_outb);
 266EXPORT_SYMBOL(logic_outsb);
 267
 268BUILD_LOGIC_IO(w, u16)
 269EXPORT_SYMBOL(logic_inw);
 270EXPORT_SYMBOL(logic_insw);
 271EXPORT_SYMBOL(logic_outw);
 272EXPORT_SYMBOL(logic_outsw);
 273
 274BUILD_LOGIC_IO(l, u32)
 275EXPORT_SYMBOL(logic_inl);
 276EXPORT_SYMBOL(logic_insl);
 277EXPORT_SYMBOL(logic_outl);
 278EXPORT_SYMBOL(logic_outsl);
 279
 280#endif /* CONFIG_INDIRECT_PIO && PCI_IOBASE */
 281
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