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  * 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  */
 109 struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode)
 110 {
 111         struct logic_pio_hwaddr *range, *found_range = NULL;
 112
 113         rcu_read_lock();
 114         list_for_each_entry_rcu(range, &io_range_list, list) {
 115                 if (range->fwnode == fwnode) {
 116                         found_range = range;
 117                         break;
 118                 }
 119         }
 120         rcu_read_unlock();
 121
 122         return found_range;
 123 }
 124
 125 /* Return a registered range given an input PIO token */
 126 static struct logic_pio_hwaddr *find_io_range(unsigned long pio)
 127 {
 128         struct logic_pio_hwaddr *range, *found_range = NULL;
 129
 130         rcu_read_lock();
 131         list_for_each_entry_rcu(range, &io_range_list, list) {
 132                 if (in_range(pio, range->io_start, range->size)) {
 133                         found_range = range;
 134                         break;
 135                 }
 136         }
 137         rcu_read_unlock();
 138
 139         if (!found_range)
 140                 pr_err("PIO entry token 0x%lx invalid\n", pio);
 141
 142         return found_range;
 143 }
 144
 145 /**
 146  * logic_pio_to_hwaddr - translate logical PIO to HW address
 147  * @pio: logical PIO value
 148  *
 149  * Returns HW address if valid, ~0 otherwise.
 150  *
 151  * Translate the input logical PIO to the corresponding hardware address.
 152  * The input PIO should be unique in the whole logical PIO space.
 153  */
 154 resource_size_t logic_pio_to_hwaddr(unsigned long pio)
 155 {
 156         struct logic_pio_hwaddr *range;
 157
 158         range = find_io_range(pio);
 159         if (range)
 160                 return range->hw_start + pio - range->io_start;
 161
 162         return (resource_size_t)~0;
 163 }
 164
 165 /**
 166  * logic_pio_trans_hwaddr - translate HW address to logical PIO
 167  * @fwnode: FW node reference for the host
 168  * @addr: Host-relative HW address
 169  * @size: size to translate
 170  *
 171  * Returns Logical PIO value if successful, ~0UL otherwise
 172  */
 173 unsigned long logic_pio_trans_hwaddr(struct fwnode_handle *fwnode,
 174                                      resource_size_t addr, resource_size_t size)
 175 {
 176         struct logic_pio_hwaddr *range;
 177
 178         range = find_io_range_by_fwnode(fwnode);
 179         if (!range || range->flags == LOGIC_PIO_CPU_MMIO) {
 180                 pr_err("IO range not found or invalid\n");
 181                 return ~0UL;
 182         }
 183         if (range->size < size) {
 184                 pr_err("resource size %pa cannot fit in IO range size %pa\n",
 185                        &size, &range->size);
 186                 return ~0UL;
 187         }
 188         return addr - range->hw_start + range->io_start;
 189 }
 190
 191 unsigned long logic_pio_trans_cpuaddr(resource_size_t addr)
 192 {
 193         struct logic_pio_hwaddr *range;
 194
 195         rcu_read_lock();
 196         list_for_each_entry_rcu(range, &io_range_list, list) {
 197                 if (range->flags != LOGIC_PIO_CPU_MMIO)
 198                         continue;
 199                 if (in_range(addr, range->hw_start, range->size)) {
 200                         unsigned long cpuaddr;
 201
 202                         cpuaddr = addr - range->hw_start + range->io_start;
 203
 204                         rcu_read_unlock();
 205                         return cpuaddr;
 206                 }
 207         }
 208         rcu_read_unlock();
 209
 210         pr_err("addr %pa not registered in io_range_list\n", &addr);
 211
 212         return ~0UL;
 213 }
 214
 215 #if defined(CONFIG_INDIRECT_PIO) && defined(PCI_IOBASE)
 216 #define BUILD_LOGIC_IO(bw, type)                                        \
 217 type logic_in##bw(unsigned long addr)                                   \
 218 {                                                                       \
 219         type ret = (type)~0;                                            \
 220                                                                         \
 221         if (addr < MMIO_UPPER_LIMIT) {                                  \
 222                 ret = read##bw(PCI_IOBASE + addr);                      \
 223         } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 224                 struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 225                                                                         \
 226                 if (entry && entry->ops)                                \
 227                         ret = entry->ops->in(entry->hostdata,           \
 228                                         addr, sizeof(type));            \
 229                 else                                                    \
 230                         WARN_ON_ONCE(1);                                \
 231         }                                                               \
 232         return ret;                                                     \
 233 }                                                                       \
 234                                                                         \
 235 void logic_out##bw(type value, unsigned long addr)                      \
 236 {                                                                       \
 237         if (addr < MMIO_UPPER_LIMIT) {                                  \
 238                 write##bw(value, PCI_IOBASE + 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 && entry->ops)                                \
 243                         entry->ops->out(entry->hostdata,                \
 244                                         addr, value, sizeof(type));     \
 245                 else                                                    \
 246                         WARN_ON_ONCE(1);                                \
 247         }                                                               \
 248 }                                                                       \
 249                                                                         \
 250 void logic_ins##bw(unsigned long addr, void *buffer,            \
 251                    unsigned int count)                                  \
 252 {                                                                       \
 253         if (addr < MMIO_UPPER_LIMIT) {                                  \
 254                 reads##bw(PCI_IOBASE + addr, buffer, count);            \
 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 && entry->ops)                                \
 259                         entry->ops->ins(entry->hostdata,                \
 260                                 addr, buffer, sizeof(type), count);     \
 261                 else                                                    \
 262                         WARN_ON_ONCE(1);                                \
 263         }                                                               \
 264                                                                         \
 265 }                                                                       \
 266                                                                         \
 267 void logic_outs##bw(unsigned long addr, const void *buffer,             \
 268                     unsigned int count)                                 \
 269 {                                                                       \
 270         if (addr < MMIO_UPPER_LIMIT) {                                  \
 271                 writes##bw(PCI_IOBASE + addr, buffer, count);           \
 272         } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
 273                 struct logic_pio_hwaddr *entry = find_io_range(addr);   \
 274                                                                         \
 275                 if (entry && entry->ops)                                \
 276                         entry->ops->outs(entry->hostdata,               \
 277                                 addr, buffer, sizeof(type), count);     \
 278                 else                                                    \
 279                         WARN_ON_ONCE(1);                                \
 280         }                                                               \
 281 }
 282
 283 BUILD_LOGIC_IO(b, u8)
 284 EXPORT_SYMBOL(logic_inb);
 285 EXPORT_SYMBOL(logic_insb);
 286 EXPORT_SYMBOL(logic_outb);
 287 EXPORT_SYMBOL(logic_outsb);
 288
 289 BUILD_LOGIC_IO(w, u16)
 290 EXPORT_SYMBOL(logic_inw);
 291 EXPORT_SYMBOL(logic_insw);
 292 EXPORT_SYMBOL(logic_outw);
 293 EXPORT_SYMBOL(logic_outsw);
 294
 295 BUILD_LOGIC_IO(l, u32)
 296 EXPORT_SYMBOL(logic_inl);
 297 EXPORT_SYMBOL(logic_insl);
 298 EXPORT_SYMBOL(logic_outl);
 299 EXPORT_SYMBOL(logic_outsl);
 300
 301 #endif /* CONFIG_INDIRECT_PIO && PCI_IOBASE */