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| 1 | +// SPDX-License-Identifier: GPL-2.0+ |
| 2 | +/* |
| 3 | + * TCE helpers for IODA PCI/PCIe on PowerNV platforms |
| 4 | + * |
| 5 | + * Copyright 2018 IBM Corp. |
| 6 | + * |
| 7 | + * This program is free software; you can redistribute it and/or |
| 8 | + * modify it under the terms of the GNU General Public License |
| 9 | + * as published by the Free Software Foundation; either version |
| 10 | + * 2 of the License, or (at your option) any later version. |
| 11 | + */ |
| 12 | + |
| 13 | +#include <linux/kernel.h> |
| 14 | +#include <linux/iommu.h> |
| 15 | + |
| 16 | +#include <asm/iommu.h> |
| 17 | +#include <asm/tce.h> |
| 18 | +#include "pci.h" |
| 19 | + |
| 20 | +void pnv_pci_setup_iommu_table(struct iommu_table *tbl, |
| 21 | + void *tce_mem, u64 tce_size, |
| 22 | + u64 dma_offset, unsigned int page_shift) |
| 23 | +{ |
| 24 | + tbl->it_blocksize = 16; |
| 25 | + tbl->it_base = (unsigned long)tce_mem; |
| 26 | + tbl->it_page_shift = page_shift; |
| 27 | + tbl->it_offset = dma_offset >> tbl->it_page_shift; |
| 28 | + tbl->it_index = 0; |
| 29 | + tbl->it_size = tce_size >> 3; |
| 30 | + tbl->it_busno = 0; |
| 31 | + tbl->it_type = TCE_PCI; |
| 32 | +} |
| 33 | + |
| 34 | +static __be64 *pnv_tce(struct iommu_table *tbl, long idx) |
| 35 | +{ |
| 36 | + __be64 *tmp = ((__be64 *)tbl->it_base); |
| 37 | + int level = tbl->it_indirect_levels; |
| 38 | + const long shift = ilog2(tbl->it_level_size); |
| 39 | + unsigned long mask = (tbl->it_level_size - 1) << (level * shift); |
| 40 | + |
| 41 | + while (level) { |
| 42 | + int n = (idx & mask) >> (level * shift); |
| 43 | + unsigned long tce = be64_to_cpu(tmp[n]); |
| 44 | + |
| 45 | + tmp = __va(tce & ~(TCE_PCI_READ | TCE_PCI_WRITE)); |
| 46 | + idx &= ~mask; |
| 47 | + mask >>= shift; |
| 48 | + --level; |
| 49 | + } |
| 50 | + |
| 51 | + return tmp + idx; |
| 52 | +} |
| 53 | + |
| 54 | +int pnv_tce_build(struct iommu_table *tbl, long index, long npages, |
| 55 | + unsigned long uaddr, enum dma_data_direction direction, |
| 56 | + unsigned long attrs) |
| 57 | +{ |
| 58 | + u64 proto_tce = iommu_direction_to_tce_perm(direction); |
| 59 | + u64 rpn = __pa(uaddr) >> tbl->it_page_shift; |
| 60 | + long i; |
| 61 | + |
| 62 | + if (proto_tce & TCE_PCI_WRITE) |
| 63 | + proto_tce |= TCE_PCI_READ; |
| 64 | + |
| 65 | + for (i = 0; i < npages; i++) { |
| 66 | + unsigned long newtce = proto_tce | |
| 67 | + ((rpn + i) << tbl->it_page_shift); |
| 68 | + unsigned long idx = index - tbl->it_offset + i; |
| 69 | + |
| 70 | + *(pnv_tce(tbl, idx)) = cpu_to_be64(newtce); |
| 71 | + } |
| 72 | + |
| 73 | + return 0; |
| 74 | +} |
| 75 | + |
| 76 | +#ifdef CONFIG_IOMMU_API |
| 77 | +int pnv_tce_xchg(struct iommu_table *tbl, long index, |
| 78 | + unsigned long *hpa, enum dma_data_direction *direction) |
| 79 | +{ |
| 80 | + u64 proto_tce = iommu_direction_to_tce_perm(*direction); |
| 81 | + unsigned long newtce = *hpa | proto_tce, oldtce; |
| 82 | + unsigned long idx = index - tbl->it_offset; |
| 83 | + |
| 84 | + BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl)); |
| 85 | + |
| 86 | + if (newtce & TCE_PCI_WRITE) |
| 87 | + newtce |= TCE_PCI_READ; |
| 88 | + |
| 89 | + oldtce = be64_to_cpu(xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce))); |
| 90 | + *hpa = oldtce & ~(TCE_PCI_READ | TCE_PCI_WRITE); |
| 91 | + *direction = iommu_tce_direction(oldtce); |
| 92 | + |
| 93 | + return 0; |
| 94 | +} |
| 95 | +#endif |
| 96 | + |
| 97 | +void pnv_tce_free(struct iommu_table *tbl, long index, long npages) |
| 98 | +{ |
| 99 | + long i; |
| 100 | + |
| 101 | + for (i = 0; i < npages; i++) { |
| 102 | + unsigned long idx = index - tbl->it_offset + i; |
| 103 | + |
| 104 | + *(pnv_tce(tbl, idx)) = cpu_to_be64(0); |
| 105 | + } |
| 106 | +} |
| 107 | + |
| 108 | +unsigned long pnv_tce_get(struct iommu_table *tbl, long index) |
| 109 | +{ |
| 110 | + return be64_to_cpu(*(pnv_tce(tbl, index - tbl->it_offset))); |
| 111 | +} |
| 112 | + |
| 113 | +static void pnv_pci_ioda2_table_do_free_pages(__be64 *addr, |
| 114 | + unsigned long size, unsigned int levels) |
| 115 | +{ |
| 116 | + const unsigned long addr_ul = (unsigned long) addr & |
| 117 | + ~(TCE_PCI_READ | TCE_PCI_WRITE); |
| 118 | + |
| 119 | + if (levels) { |
| 120 | + long i; |
| 121 | + u64 *tmp = (u64 *) addr_ul; |
| 122 | + |
| 123 | + for (i = 0; i < size; ++i) { |
| 124 | + unsigned long hpa = be64_to_cpu(tmp[i]); |
| 125 | + |
| 126 | + if (!(hpa & (TCE_PCI_READ | TCE_PCI_WRITE))) |
| 127 | + continue; |
| 128 | + |
| 129 | + pnv_pci_ioda2_table_do_free_pages(__va(hpa), size, |
| 130 | + levels - 1); |
| 131 | + } |
| 132 | + } |
| 133 | + |
| 134 | + free_pages(addr_ul, get_order(size << 3)); |
| 135 | +} |
| 136 | + |
| 137 | +void pnv_pci_ioda2_table_free_pages(struct iommu_table *tbl) |
| 138 | +{ |
| 139 | + const unsigned long size = tbl->it_indirect_levels ? |
| 140 | + tbl->it_level_size : tbl->it_size; |
| 141 | + |
| 142 | + if (!tbl->it_size) |
| 143 | + return; |
| 144 | + |
| 145 | + pnv_pci_ioda2_table_do_free_pages((__be64 *)tbl->it_base, size, |
| 146 | + tbl->it_indirect_levels); |
| 147 | +} |
| 148 | + |
| 149 | +static __be64 *pnv_pci_ioda2_table_do_alloc_pages(int nid, unsigned int shift, |
| 150 | + unsigned int levels, unsigned long limit, |
| 151 | + unsigned long *current_offset, unsigned long *total_allocated) |
| 152 | +{ |
| 153 | + struct page *tce_mem = NULL; |
| 154 | + __be64 *addr, *tmp; |
| 155 | + unsigned int order = max_t(unsigned int, shift, PAGE_SHIFT) - |
| 156 | + PAGE_SHIFT; |
| 157 | + unsigned long allocated = 1UL << (order + PAGE_SHIFT); |
| 158 | + unsigned int entries = 1UL << (shift - 3); |
| 159 | + long i; |
| 160 | + |
| 161 | + tce_mem = alloc_pages_node(nid, GFP_KERNEL, order); |
| 162 | + if (!tce_mem) { |
| 163 | + pr_err("Failed to allocate a TCE memory, order=%d\n", order); |
| 164 | + return NULL; |
| 165 | + } |
| 166 | + addr = page_address(tce_mem); |
| 167 | + memset(addr, 0, allocated); |
| 168 | + *total_allocated += allocated; |
| 169 | + |
| 170 | + --levels; |
| 171 | + if (!levels) { |
| 172 | + *current_offset += allocated; |
| 173 | + return addr; |
| 174 | + } |
| 175 | + |
| 176 | + for (i = 0; i < entries; ++i) { |
| 177 | + tmp = pnv_pci_ioda2_table_do_alloc_pages(nid, shift, |
| 178 | + levels, limit, current_offset, total_allocated); |
| 179 | + if (!tmp) |
| 180 | + break; |
| 181 | + |
| 182 | + addr[i] = cpu_to_be64(__pa(tmp) | |
| 183 | + TCE_PCI_READ | TCE_PCI_WRITE); |
| 184 | + |
| 185 | + if (*current_offset >= limit) |
| 186 | + break; |
| 187 | + } |
| 188 | + |
| 189 | + return addr; |
| 190 | +} |
| 191 | + |
| 192 | +long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset, |
| 193 | + __u32 page_shift, __u64 window_size, __u32 levels, |
| 194 | + struct iommu_table *tbl) |
| 195 | +{ |
| 196 | + void *addr; |
| 197 | + unsigned long offset = 0, level_shift, total_allocated = 0; |
| 198 | + const unsigned int window_shift = ilog2(window_size); |
| 199 | + unsigned int entries_shift = window_shift - page_shift; |
| 200 | + unsigned int table_shift = max_t(unsigned int, entries_shift + 3, |
| 201 | + PAGE_SHIFT); |
| 202 | + const unsigned long tce_table_size = 1UL << table_shift; |
| 203 | + |
| 204 | + if (!levels || (levels > POWERNV_IOMMU_MAX_LEVELS)) |
| 205 | + return -EINVAL; |
| 206 | + |
| 207 | + if (!is_power_of_2(window_size)) |
| 208 | + return -EINVAL; |
| 209 | + |
| 210 | + /* Adjust direct table size from window_size and levels */ |
| 211 | + entries_shift = (entries_shift + levels - 1) / levels; |
| 212 | + level_shift = entries_shift + 3; |
| 213 | + level_shift = max_t(unsigned int, level_shift, PAGE_SHIFT); |
| 214 | + |
| 215 | + if ((level_shift - 3) * levels + page_shift >= 60) |
| 216 | + return -EINVAL; |
| 217 | + |
| 218 | + /* Allocate TCE table */ |
| 219 | + addr = pnv_pci_ioda2_table_do_alloc_pages(nid, level_shift, |
| 220 | + levels, tce_table_size, &offset, &total_allocated); |
| 221 | + |
| 222 | + /* addr==NULL means that the first level allocation failed */ |
| 223 | + if (!addr) |
| 224 | + return -ENOMEM; |
| 225 | + |
| 226 | + /* |
| 227 | + * First level was allocated but some lower level failed as |
| 228 | + * we did not allocate as much as we wanted, |
| 229 | + * release partially allocated table. |
| 230 | + */ |
| 231 | + if (offset < tce_table_size) { |
| 232 | + pnv_pci_ioda2_table_do_free_pages(addr, |
| 233 | + 1ULL << (level_shift - 3), levels - 1); |
| 234 | + return -ENOMEM; |
| 235 | + } |
| 236 | + |
| 237 | + /* Setup linux iommu table */ |
| 238 | + pnv_pci_setup_iommu_table(tbl, addr, tce_table_size, bus_offset, |
| 239 | + page_shift); |
| 240 | + tbl->it_level_size = 1ULL << (level_shift - 3); |
| 241 | + tbl->it_indirect_levels = levels - 1; |
| 242 | + tbl->it_allocated_size = total_allocated; |
| 243 | + |
| 244 | + pr_devel("Created TCE table: ws=%08llx ts=%lx @%08llx\n", |
| 245 | + window_size, tce_table_size, bus_offset); |
| 246 | + |
| 247 | + return 0; |
| 248 | +} |
| 249 | + |
| 250 | +static void pnv_iommu_table_group_link_free(struct rcu_head *head) |
| 251 | +{ |
| 252 | + struct iommu_table_group_link *tgl = container_of(head, |
| 253 | + struct iommu_table_group_link, rcu); |
| 254 | + |
| 255 | + kfree(tgl); |
| 256 | +} |
| 257 | + |
| 258 | +void pnv_pci_unlink_table_and_group(struct iommu_table *tbl, |
| 259 | + struct iommu_table_group *table_group) |
| 260 | +{ |
| 261 | + long i; |
| 262 | + bool found; |
| 263 | + struct iommu_table_group_link *tgl; |
| 264 | + |
| 265 | + if (!tbl || !table_group) |
| 266 | + return; |
| 267 | + |
| 268 | + /* Remove link to a group from table's list of attached groups */ |
| 269 | + found = false; |
| 270 | + list_for_each_entry_rcu(tgl, &tbl->it_group_list, next) { |
| 271 | + if (tgl->table_group == table_group) { |
| 272 | + list_del_rcu(&tgl->next); |
| 273 | + call_rcu(&tgl->rcu, pnv_iommu_table_group_link_free); |
| 274 | + found = true; |
| 275 | + break; |
| 276 | + } |
| 277 | + } |
| 278 | + if (WARN_ON(!found)) |
| 279 | + return; |
| 280 | + |
| 281 | + /* Clean a pointer to iommu_table in iommu_table_group::tables[] */ |
| 282 | + found = false; |
| 283 | + for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { |
| 284 | + if (table_group->tables[i] == tbl) { |
| 285 | + table_group->tables[i] = NULL; |
| 286 | + found = true; |
| 287 | + break; |
| 288 | + } |
| 289 | + } |
| 290 | + WARN_ON(!found); |
| 291 | +} |
| 292 | + |
| 293 | +long pnv_pci_link_table_and_group(int node, int num, |
| 294 | + struct iommu_table *tbl, |
| 295 | + struct iommu_table_group *table_group) |
| 296 | +{ |
| 297 | + struct iommu_table_group_link *tgl = NULL; |
| 298 | + |
| 299 | + if (WARN_ON(!tbl || !table_group)) |
| 300 | + return -EINVAL; |
| 301 | + |
| 302 | + tgl = kzalloc_node(sizeof(struct iommu_table_group_link), GFP_KERNEL, |
| 303 | + node); |
| 304 | + if (!tgl) |
| 305 | + return -ENOMEM; |
| 306 | + |
| 307 | + tgl->table_group = table_group; |
| 308 | + list_add_rcu(&tgl->next, &tbl->it_group_list); |
| 309 | + |
| 310 | + table_group->tables[num] = tbl; |
| 311 | + |
| 312 | + return 0; |
| 313 | +} |
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