Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation, version 2. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or |
| 11 | * NON INFRINGEMENT. See the GNU General Public License for |
| 12 | * more details. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/fs.h> |
| 16 | #include <linux/proc_fs.h> |
| 17 | #include <linux/seq_file.h> |
| 18 | #include <linux/rwsem.h> |
| 19 | #include <linux/kprobes.h> |
| 20 | #include <linux/sched.h> |
| 21 | #include <linux/hardirq.h> |
| 22 | #include <linux/uaccess.h> |
| 23 | #include <linux/smp.h> |
| 24 | #include <linux/cdev.h> |
| 25 | #include <linux/compat.h> |
| 26 | #include <asm/hardwall.h> |
| 27 | #include <asm/traps.h> |
| 28 | #include <asm/siginfo.h> |
| 29 | #include <asm/irq_regs.h> |
| 30 | |
| 31 | #include <arch/interrupts.h> |
| 32 | #include <arch/spr_def.h> |
| 33 | |
| 34 | |
| 35 | /* |
| 36 | * This data structure tracks the rectangle data, etc., associated |
| 37 | * one-to-one with a "struct file *" from opening HARDWALL_FILE. |
| 38 | * Note that the file's private data points back to this structure. |
| 39 | */ |
| 40 | struct hardwall_info { |
| 41 | struct list_head list; /* "rectangles" list */ |
| 42 | struct list_head task_head; /* head of tasks in this hardwall */ |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 43 | struct cpumask cpumask; /* cpus in the rectangle */ |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 44 | int ulhc_x; /* upper left hand corner x coord */ |
| 45 | int ulhc_y; /* upper left hand corner y coord */ |
| 46 | int width; /* rectangle width */ |
| 47 | int height; /* rectangle height */ |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 48 | int id; /* integer id for this hardwall */ |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 49 | int teardown_in_progress; /* are we tearing this one down? */ |
| 50 | }; |
| 51 | |
| 52 | /* Currently allocated hardwall rectangles */ |
| 53 | static LIST_HEAD(rectangles); |
| 54 | |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 55 | /* /proc/tile/hardwall */ |
| 56 | static struct proc_dir_entry *hardwall_proc_dir; |
| 57 | |
| 58 | /* Functions to manage files in /proc/tile/hardwall. */ |
| 59 | static void hardwall_add_proc(struct hardwall_info *rect); |
| 60 | static void hardwall_remove_proc(struct hardwall_info *rect); |
| 61 | |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 62 | /* |
| 63 | * Guard changes to the hardwall data structures. |
| 64 | * This could be finer grained (e.g. one lock for the list of hardwall |
| 65 | * rectangles, then separate embedded locks for each one's list of tasks), |
| 66 | * but there are subtle correctness issues when trying to start with |
| 67 | * a task's "hardwall" pointer and lock the correct rectangle's embedded |
| 68 | * lock in the presence of a simultaneous deactivation, so it seems |
| 69 | * easier to have a single lock, given that none of these data |
| 70 | * structures are touched very frequently during normal operation. |
| 71 | */ |
| 72 | static DEFINE_SPINLOCK(hardwall_lock); |
| 73 | |
| 74 | /* Allow disabling UDN access. */ |
| 75 | static int udn_disabled; |
| 76 | static int __init noudn(char *str) |
| 77 | { |
| 78 | pr_info("User-space UDN access is disabled\n"); |
| 79 | udn_disabled = 1; |
| 80 | return 0; |
| 81 | } |
| 82 | early_param("noudn", noudn); |
| 83 | |
| 84 | |
| 85 | /* |
| 86 | * Low-level primitives |
| 87 | */ |
| 88 | |
| 89 | /* Set a CPU bit if the CPU is online. */ |
| 90 | #define cpu_online_set(cpu, dst) do { \ |
| 91 | if (cpu_online(cpu)) \ |
| 92 | cpumask_set_cpu(cpu, dst); \ |
| 93 | } while (0) |
| 94 | |
| 95 | |
| 96 | /* Does the given rectangle contain the given x,y coordinate? */ |
| 97 | static int contains(struct hardwall_info *r, int x, int y) |
| 98 | { |
| 99 | return (x >= r->ulhc_x && x < r->ulhc_x + r->width) && |
| 100 | (y >= r->ulhc_y && y < r->ulhc_y + r->height); |
| 101 | } |
| 102 | |
| 103 | /* Compute the rectangle parameters and validate the cpumask. */ |
| 104 | static int setup_rectangle(struct hardwall_info *r, struct cpumask *mask) |
| 105 | { |
| 106 | int x, y, cpu, ulhc, lrhc; |
| 107 | |
| 108 | /* The first cpu is the ULHC, the last the LRHC. */ |
| 109 | ulhc = find_first_bit(cpumask_bits(mask), nr_cpumask_bits); |
| 110 | lrhc = find_last_bit(cpumask_bits(mask), nr_cpumask_bits); |
| 111 | |
| 112 | /* Compute the rectangle attributes from the cpus. */ |
| 113 | r->ulhc_x = cpu_x(ulhc); |
| 114 | r->ulhc_y = cpu_y(ulhc); |
| 115 | r->width = cpu_x(lrhc) - r->ulhc_x + 1; |
| 116 | r->height = cpu_y(lrhc) - r->ulhc_y + 1; |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 117 | cpumask_copy(&r->cpumask, mask); |
| 118 | r->id = ulhc; /* The ulhc cpu id can be the hardwall id. */ |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 119 | |
| 120 | /* Width and height must be positive */ |
| 121 | if (r->width <= 0 || r->height <= 0) |
| 122 | return -EINVAL; |
| 123 | |
| 124 | /* Confirm that the cpumask is exactly the rectangle. */ |
| 125 | for (y = 0, cpu = 0; y < smp_height; ++y) |
| 126 | for (x = 0; x < smp_width; ++x, ++cpu) |
| 127 | if (cpumask_test_cpu(cpu, mask) != contains(r, x, y)) |
| 128 | return -EINVAL; |
| 129 | |
| 130 | /* |
| 131 | * Note that offline cpus can't be drained when this UDN |
| 132 | * rectangle eventually closes. We used to detect this |
| 133 | * situation and print a warning, but it annoyed users and |
| 134 | * they ignored it anyway, so now we just return without a |
| 135 | * warning. |
| 136 | */ |
| 137 | return 0; |
| 138 | } |
| 139 | |
| 140 | /* Do the two given rectangles overlap on any cpu? */ |
| 141 | static int overlaps(struct hardwall_info *a, struct hardwall_info *b) |
| 142 | { |
| 143 | return a->ulhc_x + a->width > b->ulhc_x && /* A not to the left */ |
| 144 | b->ulhc_x + b->width > a->ulhc_x && /* B not to the left */ |
| 145 | a->ulhc_y + a->height > b->ulhc_y && /* A not above */ |
| 146 | b->ulhc_y + b->height > a->ulhc_y; /* B not above */ |
| 147 | } |
| 148 | |
| 149 | |
| 150 | /* |
| 151 | * Hardware management of hardwall setup, teardown, trapping, |
| 152 | * and enabling/disabling PL0 access to the networks. |
| 153 | */ |
| 154 | |
| 155 | /* Bit field values to mask together for writes to SPR_XDN_DIRECTION_PROTECT */ |
| 156 | enum direction_protect { |
| 157 | N_PROTECT = (1 << 0), |
| 158 | E_PROTECT = (1 << 1), |
| 159 | S_PROTECT = (1 << 2), |
| 160 | W_PROTECT = (1 << 3) |
| 161 | }; |
| 162 | |
| 163 | static void enable_firewall_interrupts(void) |
| 164 | { |
Chris Metcalf | 5d96611 | 2010-11-01 15:24:29 -0400 | [diff] [blame] | 165 | arch_local_irq_unmask_now(INT_UDN_FIREWALL); |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 166 | } |
| 167 | |
| 168 | static void disable_firewall_interrupts(void) |
| 169 | { |
Chris Metcalf | 5d96611 | 2010-11-01 15:24:29 -0400 | [diff] [blame] | 170 | arch_local_irq_mask_now(INT_UDN_FIREWALL); |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 171 | } |
| 172 | |
| 173 | /* Set up hardwall on this cpu based on the passed hardwall_info. */ |
| 174 | static void hardwall_setup_ipi_func(void *info) |
| 175 | { |
| 176 | struct hardwall_info *r = info; |
| 177 | int cpu = smp_processor_id(); |
| 178 | int x = cpu % smp_width; |
| 179 | int y = cpu / smp_width; |
| 180 | int bits = 0; |
| 181 | if (x == r->ulhc_x) |
| 182 | bits |= W_PROTECT; |
| 183 | if (x == r->ulhc_x + r->width - 1) |
| 184 | bits |= E_PROTECT; |
| 185 | if (y == r->ulhc_y) |
| 186 | bits |= N_PROTECT; |
| 187 | if (y == r->ulhc_y + r->height - 1) |
| 188 | bits |= S_PROTECT; |
| 189 | BUG_ON(bits == 0); |
| 190 | __insn_mtspr(SPR_UDN_DIRECTION_PROTECT, bits); |
| 191 | enable_firewall_interrupts(); |
| 192 | |
| 193 | } |
| 194 | |
| 195 | /* Set up all cpus on edge of rectangle to enable/disable hardwall SPRs. */ |
| 196 | static void hardwall_setup(struct hardwall_info *r) |
| 197 | { |
| 198 | int x, y, cpu, delta; |
| 199 | struct cpumask rect_cpus; |
| 200 | |
| 201 | cpumask_clear(&rect_cpus); |
| 202 | |
| 203 | /* First include the top and bottom edges */ |
| 204 | cpu = r->ulhc_y * smp_width + r->ulhc_x; |
| 205 | delta = (r->height - 1) * smp_width; |
| 206 | for (x = 0; x < r->width; ++x, ++cpu) { |
| 207 | cpu_online_set(cpu, &rect_cpus); |
| 208 | cpu_online_set(cpu + delta, &rect_cpus); |
| 209 | } |
| 210 | |
| 211 | /* Then the left and right edges */ |
| 212 | cpu -= r->width; |
| 213 | delta = r->width - 1; |
| 214 | for (y = 0; y < r->height; ++y, cpu += smp_width) { |
| 215 | cpu_online_set(cpu, &rect_cpus); |
| 216 | cpu_online_set(cpu + delta, &rect_cpus); |
| 217 | } |
| 218 | |
| 219 | /* Then tell all the cpus to set up their protection SPR */ |
| 220 | on_each_cpu_mask(&rect_cpus, hardwall_setup_ipi_func, r, 1); |
| 221 | } |
| 222 | |
| 223 | void __kprobes do_hardwall_trap(struct pt_regs* regs, int fault_num) |
| 224 | { |
| 225 | struct hardwall_info *rect; |
| 226 | struct task_struct *p; |
| 227 | struct siginfo info; |
| 228 | int x, y; |
| 229 | int cpu = smp_processor_id(); |
| 230 | int found_processes; |
| 231 | unsigned long flags; |
| 232 | |
| 233 | struct pt_regs *old_regs = set_irq_regs(regs); |
| 234 | irq_enter(); |
| 235 | |
| 236 | /* This tile trapped a network access; find the rectangle. */ |
| 237 | x = cpu % smp_width; |
| 238 | y = cpu / smp_width; |
| 239 | spin_lock_irqsave(&hardwall_lock, flags); |
| 240 | list_for_each_entry(rect, &rectangles, list) { |
| 241 | if (contains(rect, x, y)) |
| 242 | break; |
| 243 | } |
| 244 | |
| 245 | /* |
| 246 | * It shouldn't be possible not to find this cpu on the |
| 247 | * rectangle list, since only cpus in rectangles get hardwalled. |
| 248 | * The hardwall is only removed after the UDN is drained. |
| 249 | */ |
| 250 | BUG_ON(&rect->list == &rectangles); |
| 251 | |
| 252 | /* |
| 253 | * If we already started teardown on this hardwall, don't worry; |
| 254 | * the abort signal has been sent and we are just waiting for things |
| 255 | * to quiesce. |
| 256 | */ |
| 257 | if (rect->teardown_in_progress) { |
| 258 | pr_notice("cpu %d: detected hardwall violation %#lx" |
| 259 | " while teardown already in progress\n", |
| 260 | cpu, (long) __insn_mfspr(SPR_UDN_DIRECTION_PROTECT)); |
| 261 | goto done; |
| 262 | } |
| 263 | |
| 264 | /* |
| 265 | * Kill off any process that is activated in this rectangle. |
| 266 | * We bypass security to deliver the signal, since it must be |
| 267 | * one of the activated processes that generated the UDN |
| 268 | * message that caused this trap, and all the activated |
| 269 | * processes shared a single open file so are pretty tightly |
| 270 | * bound together from a security point of view to begin with. |
| 271 | */ |
| 272 | rect->teardown_in_progress = 1; |
| 273 | wmb(); /* Ensure visibility of rectangle before notifying processes. */ |
| 274 | pr_notice("cpu %d: detected hardwall violation %#lx...\n", |
| 275 | cpu, (long) __insn_mfspr(SPR_UDN_DIRECTION_PROTECT)); |
| 276 | info.si_signo = SIGILL; |
| 277 | info.si_errno = 0; |
| 278 | info.si_code = ILL_HARDWALL; |
| 279 | found_processes = 0; |
| 280 | list_for_each_entry(p, &rect->task_head, thread.hardwall_list) { |
| 281 | BUG_ON(p->thread.hardwall != rect); |
Oleg Nesterov | ceca3c1 | 2011-04-26 22:37:11 +0200 | [diff] [blame] | 282 | if (!(p->flags & PF_EXITING)) { |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 283 | found_processes = 1; |
| 284 | pr_notice("hardwall: killing %d\n", p->pid); |
Oleg Nesterov | ceca3c1 | 2011-04-26 22:37:11 +0200 | [diff] [blame] | 285 | do_send_sig_info(info.si_signo, &info, p, false); |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 286 | } |
| 287 | } |
| 288 | if (!found_processes) |
| 289 | pr_notice("hardwall: no associated processes!\n"); |
| 290 | |
| 291 | done: |
| 292 | spin_unlock_irqrestore(&hardwall_lock, flags); |
| 293 | |
| 294 | /* |
| 295 | * We have to disable firewall interrupts now, or else when we |
| 296 | * return from this handler, we will simply re-interrupt back to |
| 297 | * it. However, we can't clear the protection bits, since we |
| 298 | * haven't yet drained the network, and that would allow packets |
| 299 | * to cross out of the hardwall region. |
| 300 | */ |
| 301 | disable_firewall_interrupts(); |
| 302 | |
| 303 | irq_exit(); |
| 304 | set_irq_regs(old_regs); |
| 305 | } |
| 306 | |
| 307 | /* Allow access from user space to the UDN. */ |
| 308 | void grant_network_mpls(void) |
| 309 | { |
| 310 | __insn_mtspr(SPR_MPL_UDN_ACCESS_SET_0, 1); |
| 311 | __insn_mtspr(SPR_MPL_UDN_AVAIL_SET_0, 1); |
| 312 | __insn_mtspr(SPR_MPL_UDN_COMPLETE_SET_0, 1); |
| 313 | __insn_mtspr(SPR_MPL_UDN_TIMER_SET_0, 1); |
| 314 | #if !CHIP_HAS_REV1_XDN() |
| 315 | __insn_mtspr(SPR_MPL_UDN_REFILL_SET_0, 1); |
| 316 | __insn_mtspr(SPR_MPL_UDN_CA_SET_0, 1); |
| 317 | #endif |
| 318 | } |
| 319 | |
| 320 | /* Deny access from user space to the UDN. */ |
| 321 | void restrict_network_mpls(void) |
| 322 | { |
| 323 | __insn_mtspr(SPR_MPL_UDN_ACCESS_SET_1, 1); |
| 324 | __insn_mtspr(SPR_MPL_UDN_AVAIL_SET_1, 1); |
| 325 | __insn_mtspr(SPR_MPL_UDN_COMPLETE_SET_1, 1); |
| 326 | __insn_mtspr(SPR_MPL_UDN_TIMER_SET_1, 1); |
| 327 | #if !CHIP_HAS_REV1_XDN() |
| 328 | __insn_mtspr(SPR_MPL_UDN_REFILL_SET_1, 1); |
| 329 | __insn_mtspr(SPR_MPL_UDN_CA_SET_1, 1); |
| 330 | #endif |
| 331 | } |
| 332 | |
| 333 | |
| 334 | /* |
| 335 | * Code to create, activate, deactivate, and destroy hardwall rectangles. |
| 336 | */ |
| 337 | |
| 338 | /* Create a hardwall for the given rectangle */ |
| 339 | static struct hardwall_info *hardwall_create( |
| 340 | size_t size, const unsigned char __user *bits) |
| 341 | { |
| 342 | struct hardwall_info *iter, *rect; |
| 343 | struct cpumask mask; |
| 344 | unsigned long flags; |
| 345 | int rc; |
| 346 | |
| 347 | /* Reject crazy sizes out of hand, a la sys_mbind(). */ |
| 348 | if (size > PAGE_SIZE) |
| 349 | return ERR_PTR(-EINVAL); |
| 350 | |
| 351 | /* Copy whatever fits into a cpumask. */ |
| 352 | if (copy_from_user(&mask, bits, min(sizeof(struct cpumask), size))) |
| 353 | return ERR_PTR(-EFAULT); |
| 354 | |
| 355 | /* |
| 356 | * If the size was short, clear the rest of the mask; |
| 357 | * otherwise validate that the rest of the user mask was zero |
| 358 | * (we don't try hard to be efficient when validating huge masks). |
| 359 | */ |
| 360 | if (size < sizeof(struct cpumask)) { |
| 361 | memset((char *)&mask + size, 0, sizeof(struct cpumask) - size); |
| 362 | } else if (size > sizeof(struct cpumask)) { |
| 363 | size_t i; |
| 364 | for (i = sizeof(struct cpumask); i < size; ++i) { |
| 365 | char c; |
| 366 | if (get_user(c, &bits[i])) |
| 367 | return ERR_PTR(-EFAULT); |
| 368 | if (c) |
| 369 | return ERR_PTR(-EINVAL); |
| 370 | } |
| 371 | } |
| 372 | |
| 373 | /* Allocate a new rectangle optimistically. */ |
| 374 | rect = kmalloc(sizeof(struct hardwall_info), |
| 375 | GFP_KERNEL | __GFP_ZERO); |
Kulikov Vasiliy | 1c689cb | 2010-07-16 20:13:02 +0400 | [diff] [blame] | 376 | if (rect == NULL) |
| 377 | return ERR_PTR(-ENOMEM); |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 378 | INIT_LIST_HEAD(&rect->task_head); |
| 379 | |
| 380 | /* Compute the rectangle size and validate that it's plausible. */ |
| 381 | rc = setup_rectangle(rect, &mask); |
| 382 | if (rc != 0) { |
| 383 | kfree(rect); |
| 384 | return ERR_PTR(rc); |
| 385 | } |
| 386 | |
| 387 | /* Confirm it doesn't overlap and add it to the list. */ |
| 388 | spin_lock_irqsave(&hardwall_lock, flags); |
| 389 | list_for_each_entry(iter, &rectangles, list) { |
| 390 | if (overlaps(iter, rect)) { |
| 391 | spin_unlock_irqrestore(&hardwall_lock, flags); |
| 392 | kfree(rect); |
| 393 | return ERR_PTR(-EBUSY); |
| 394 | } |
| 395 | } |
| 396 | list_add_tail(&rect->list, &rectangles); |
| 397 | spin_unlock_irqrestore(&hardwall_lock, flags); |
| 398 | |
| 399 | /* Set up appropriate hardwalling on all affected cpus. */ |
| 400 | hardwall_setup(rect); |
| 401 | |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 402 | /* Create a /proc/tile/hardwall entry. */ |
| 403 | hardwall_add_proc(rect); |
| 404 | |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 405 | return rect; |
| 406 | } |
| 407 | |
| 408 | /* Activate a given hardwall on this cpu for this process. */ |
| 409 | static int hardwall_activate(struct hardwall_info *rect) |
| 410 | { |
| 411 | int cpu, x, y; |
| 412 | unsigned long flags; |
| 413 | struct task_struct *p = current; |
| 414 | struct thread_struct *ts = &p->thread; |
| 415 | |
| 416 | /* Require a rectangle. */ |
| 417 | if (rect == NULL) |
| 418 | return -ENODATA; |
| 419 | |
| 420 | /* Not allowed to activate a rectangle that is being torn down. */ |
| 421 | if (rect->teardown_in_progress) |
| 422 | return -EINVAL; |
| 423 | |
| 424 | /* |
| 425 | * Get our affinity; if we're not bound to this tile uniquely, |
| 426 | * we can't access the network registers. |
| 427 | */ |
| 428 | if (cpumask_weight(&p->cpus_allowed) != 1) |
| 429 | return -EPERM; |
| 430 | |
| 431 | /* Make sure we are bound to a cpu in this rectangle. */ |
| 432 | cpu = smp_processor_id(); |
| 433 | BUG_ON(cpumask_first(&p->cpus_allowed) != cpu); |
| 434 | x = cpu_x(cpu); |
| 435 | y = cpu_y(cpu); |
| 436 | if (!contains(rect, x, y)) |
| 437 | return -EINVAL; |
| 438 | |
| 439 | /* If we are already bound to this hardwall, it's a no-op. */ |
| 440 | if (ts->hardwall) { |
| 441 | BUG_ON(ts->hardwall != rect); |
| 442 | return 0; |
| 443 | } |
| 444 | |
| 445 | /* Success! This process gets to use the user networks on this cpu. */ |
| 446 | ts->hardwall = rect; |
| 447 | spin_lock_irqsave(&hardwall_lock, flags); |
| 448 | list_add(&ts->hardwall_list, &rect->task_head); |
| 449 | spin_unlock_irqrestore(&hardwall_lock, flags); |
| 450 | grant_network_mpls(); |
| 451 | printk(KERN_DEBUG "Pid %d (%s) activated for hardwall: cpu %d\n", |
| 452 | p->pid, p->comm, cpu); |
| 453 | return 0; |
| 454 | } |
| 455 | |
| 456 | /* |
| 457 | * Deactivate a task's hardwall. Must hold hardwall_lock. |
| 458 | * This method may be called from free_task(), so we don't want to |
| 459 | * rely on too many fields of struct task_struct still being valid. |
| 460 | * We assume the cpus_allowed, pid, and comm fields are still valid. |
| 461 | */ |
| 462 | static void _hardwall_deactivate(struct task_struct *task) |
| 463 | { |
| 464 | struct thread_struct *ts = &task->thread; |
| 465 | |
| 466 | if (cpumask_weight(&task->cpus_allowed) != 1) { |
| 467 | pr_err("pid %d (%s) releasing networks with" |
| 468 | " an affinity mask containing %d cpus!\n", |
| 469 | task->pid, task->comm, |
| 470 | cpumask_weight(&task->cpus_allowed)); |
| 471 | BUG(); |
| 472 | } |
| 473 | |
| 474 | BUG_ON(ts->hardwall == NULL); |
| 475 | ts->hardwall = NULL; |
| 476 | list_del(&ts->hardwall_list); |
| 477 | if (task == current) |
| 478 | restrict_network_mpls(); |
| 479 | } |
| 480 | |
| 481 | /* Deactivate a task's hardwall. */ |
| 482 | int hardwall_deactivate(struct task_struct *task) |
| 483 | { |
| 484 | unsigned long flags; |
| 485 | int activated; |
| 486 | |
| 487 | spin_lock_irqsave(&hardwall_lock, flags); |
| 488 | activated = (task->thread.hardwall != NULL); |
| 489 | if (activated) |
| 490 | _hardwall_deactivate(task); |
| 491 | spin_unlock_irqrestore(&hardwall_lock, flags); |
| 492 | |
| 493 | if (!activated) |
| 494 | return -EINVAL; |
| 495 | |
| 496 | printk(KERN_DEBUG "Pid %d (%s) deactivated for hardwall: cpu %d\n", |
| 497 | task->pid, task->comm, smp_processor_id()); |
| 498 | return 0; |
| 499 | } |
| 500 | |
| 501 | /* Stop a UDN switch before draining the network. */ |
| 502 | static void stop_udn_switch(void *ignored) |
| 503 | { |
| 504 | #if !CHIP_HAS_REV1_XDN() |
| 505 | /* Freeze the switch and the demux. */ |
| 506 | __insn_mtspr(SPR_UDN_SP_FREEZE, |
| 507 | SPR_UDN_SP_FREEZE__SP_FRZ_MASK | |
| 508 | SPR_UDN_SP_FREEZE__DEMUX_FRZ_MASK | |
| 509 | SPR_UDN_SP_FREEZE__NON_DEST_EXT_MASK); |
| 510 | #endif |
| 511 | } |
| 512 | |
| 513 | /* Drain all the state from a stopped switch. */ |
| 514 | static void drain_udn_switch(void *ignored) |
| 515 | { |
| 516 | #if !CHIP_HAS_REV1_XDN() |
| 517 | int i; |
| 518 | int from_tile_words, ca_count; |
| 519 | |
| 520 | /* Empty out the 5 switch point fifos. */ |
| 521 | for (i = 0; i < 5; i++) { |
| 522 | int words, j; |
| 523 | __insn_mtspr(SPR_UDN_SP_FIFO_SEL, i); |
| 524 | words = __insn_mfspr(SPR_UDN_SP_STATE) & 0xF; |
| 525 | for (j = 0; j < words; j++) |
| 526 | (void) __insn_mfspr(SPR_UDN_SP_FIFO_DATA); |
| 527 | BUG_ON((__insn_mfspr(SPR_UDN_SP_STATE) & 0xF) != 0); |
| 528 | } |
| 529 | |
| 530 | /* Dump out the 3 word fifo at top. */ |
| 531 | from_tile_words = (__insn_mfspr(SPR_UDN_DEMUX_STATUS) >> 10) & 0x3; |
| 532 | for (i = 0; i < from_tile_words; i++) |
| 533 | (void) __insn_mfspr(SPR_UDN_DEMUX_WRITE_FIFO); |
| 534 | |
| 535 | /* Empty out demuxes. */ |
| 536 | while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 0)) |
| 537 | (void) __tile_udn0_receive(); |
| 538 | while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 1)) |
| 539 | (void) __tile_udn1_receive(); |
| 540 | while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 2)) |
| 541 | (void) __tile_udn2_receive(); |
| 542 | while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 3)) |
| 543 | (void) __tile_udn3_receive(); |
| 544 | BUG_ON((__insn_mfspr(SPR_UDN_DATA_AVAIL) & 0xF) != 0); |
| 545 | |
| 546 | /* Empty out catch all. */ |
| 547 | ca_count = __insn_mfspr(SPR_UDN_DEMUX_CA_COUNT); |
| 548 | for (i = 0; i < ca_count; i++) |
| 549 | (void) __insn_mfspr(SPR_UDN_CA_DATA); |
| 550 | BUG_ON(__insn_mfspr(SPR_UDN_DEMUX_CA_COUNT) != 0); |
| 551 | |
| 552 | /* Clear demux logic. */ |
| 553 | __insn_mtspr(SPR_UDN_DEMUX_CTL, 1); |
| 554 | |
| 555 | /* |
| 556 | * Write switch state; experimentation indicates that 0xc3000 |
| 557 | * is an idle switch point. |
| 558 | */ |
| 559 | for (i = 0; i < 5; i++) { |
| 560 | __insn_mtspr(SPR_UDN_SP_FIFO_SEL, i); |
| 561 | __insn_mtspr(SPR_UDN_SP_STATE, 0xc3000); |
| 562 | } |
| 563 | #endif |
| 564 | } |
| 565 | |
| 566 | /* Reset random UDN state registers at boot up and during hardwall teardown. */ |
| 567 | void reset_network_state(void) |
| 568 | { |
| 569 | #if !CHIP_HAS_REV1_XDN() |
| 570 | /* Reset UDN coordinates to their standard value */ |
| 571 | unsigned int cpu = smp_processor_id(); |
| 572 | unsigned int x = cpu % smp_width; |
| 573 | unsigned int y = cpu / smp_width; |
| 574 | #endif |
| 575 | |
| 576 | if (udn_disabled) |
| 577 | return; |
| 578 | |
| 579 | #if !CHIP_HAS_REV1_XDN() |
| 580 | __insn_mtspr(SPR_UDN_TILE_COORD, (x << 18) | (y << 7)); |
| 581 | |
| 582 | /* Set demux tags to predefined values and enable them. */ |
| 583 | __insn_mtspr(SPR_UDN_TAG_VALID, 0xf); |
| 584 | __insn_mtspr(SPR_UDN_TAG_0, (1 << 0)); |
| 585 | __insn_mtspr(SPR_UDN_TAG_1, (1 << 1)); |
| 586 | __insn_mtspr(SPR_UDN_TAG_2, (1 << 2)); |
| 587 | __insn_mtspr(SPR_UDN_TAG_3, (1 << 3)); |
| 588 | #endif |
| 589 | |
| 590 | /* Clear out other random registers so we have a clean slate. */ |
| 591 | __insn_mtspr(SPR_UDN_AVAIL_EN, 0); |
| 592 | __insn_mtspr(SPR_UDN_DEADLOCK_TIMEOUT, 0); |
| 593 | #if !CHIP_HAS_REV1_XDN() |
| 594 | __insn_mtspr(SPR_UDN_REFILL_EN, 0); |
| 595 | __insn_mtspr(SPR_UDN_DEMUX_QUEUE_SEL, 0); |
| 596 | __insn_mtspr(SPR_UDN_SP_FIFO_SEL, 0); |
| 597 | #endif |
| 598 | |
| 599 | /* Start the switch and demux. */ |
| 600 | #if !CHIP_HAS_REV1_XDN() |
| 601 | __insn_mtspr(SPR_UDN_SP_FREEZE, 0); |
| 602 | #endif |
| 603 | } |
| 604 | |
| 605 | /* Restart a UDN switch after draining. */ |
| 606 | static void restart_udn_switch(void *ignored) |
| 607 | { |
| 608 | reset_network_state(); |
| 609 | |
| 610 | /* Disable firewall interrupts. */ |
| 611 | __insn_mtspr(SPR_UDN_DIRECTION_PROTECT, 0); |
| 612 | disable_firewall_interrupts(); |
| 613 | } |
| 614 | |
| 615 | /* Build a struct cpumask containing all valid tiles in bounding rectangle. */ |
| 616 | static void fill_mask(struct hardwall_info *r, struct cpumask *result) |
| 617 | { |
| 618 | int x, y, cpu; |
| 619 | |
| 620 | cpumask_clear(result); |
| 621 | |
| 622 | cpu = r->ulhc_y * smp_width + r->ulhc_x; |
| 623 | for (y = 0; y < r->height; ++y, cpu += smp_width - r->width) { |
| 624 | for (x = 0; x < r->width; ++x, ++cpu) |
| 625 | cpu_online_set(cpu, result); |
| 626 | } |
| 627 | } |
| 628 | |
| 629 | /* Last reference to a hardwall is gone, so clear the network. */ |
| 630 | static void hardwall_destroy(struct hardwall_info *rect) |
| 631 | { |
| 632 | struct task_struct *task; |
| 633 | unsigned long flags; |
| 634 | struct cpumask mask; |
| 635 | |
| 636 | /* Make sure this file actually represents a rectangle. */ |
| 637 | if (rect == NULL) |
| 638 | return; |
| 639 | |
| 640 | /* |
| 641 | * Deactivate any remaining tasks. It's possible to race with |
| 642 | * some other thread that is exiting and hasn't yet called |
| 643 | * deactivate (when freeing its thread_info), so we carefully |
| 644 | * deactivate any remaining tasks before freeing the |
| 645 | * hardwall_info object itself. |
| 646 | */ |
| 647 | spin_lock_irqsave(&hardwall_lock, flags); |
| 648 | list_for_each_entry(task, &rect->task_head, thread.hardwall_list) |
| 649 | _hardwall_deactivate(task); |
| 650 | spin_unlock_irqrestore(&hardwall_lock, flags); |
| 651 | |
| 652 | /* Drain the UDN. */ |
| 653 | printk(KERN_DEBUG "Clearing hardwall rectangle %dx%d %d,%d\n", |
| 654 | rect->width, rect->height, rect->ulhc_x, rect->ulhc_y); |
| 655 | fill_mask(rect, &mask); |
| 656 | on_each_cpu_mask(&mask, stop_udn_switch, NULL, 1); |
| 657 | on_each_cpu_mask(&mask, drain_udn_switch, NULL, 1); |
| 658 | |
| 659 | /* Restart switch and disable firewall. */ |
| 660 | on_each_cpu_mask(&mask, restart_udn_switch, NULL, 1); |
| 661 | |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 662 | /* Remove the /proc/tile/hardwall entry. */ |
| 663 | hardwall_remove_proc(rect); |
| 664 | |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 665 | /* Now free the rectangle from the list. */ |
| 666 | spin_lock_irqsave(&hardwall_lock, flags); |
| 667 | BUG_ON(!list_empty(&rect->task_head)); |
| 668 | list_del(&rect->list); |
| 669 | spin_unlock_irqrestore(&hardwall_lock, flags); |
| 670 | kfree(rect); |
| 671 | } |
| 672 | |
| 673 | |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 674 | static int hardwall_proc_show(struct seq_file *sf, void *v) |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 675 | { |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 676 | struct hardwall_info *rect = sf->private; |
| 677 | char buf[256]; |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 678 | |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 679 | int rc = cpulist_scnprintf(buf, sizeof(buf), &rect->cpumask); |
| 680 | buf[rc++] = '\n'; |
| 681 | seq_write(sf, buf, rc); |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 682 | return 0; |
| 683 | } |
| 684 | |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 685 | static int hardwall_proc_open(struct inode *inode, |
| 686 | struct file *file) |
| 687 | { |
| 688 | return single_open(file, hardwall_proc_show, PDE(inode)->data); |
| 689 | } |
| 690 | |
| 691 | static const struct file_operations hardwall_proc_fops = { |
| 692 | .open = hardwall_proc_open, |
| 693 | .read = seq_read, |
| 694 | .llseek = seq_lseek, |
| 695 | .release = single_release, |
| 696 | }; |
| 697 | |
| 698 | static void hardwall_add_proc(struct hardwall_info *rect) |
| 699 | { |
| 700 | char buf[64]; |
| 701 | snprintf(buf, sizeof(buf), "%d", rect->id); |
| 702 | proc_create_data(buf, 0444, hardwall_proc_dir, |
| 703 | &hardwall_proc_fops, rect); |
| 704 | } |
| 705 | |
| 706 | static void hardwall_remove_proc(struct hardwall_info *rect) |
| 707 | { |
| 708 | char buf[64]; |
| 709 | snprintf(buf, sizeof(buf), "%d", rect->id); |
| 710 | remove_proc_entry(buf, hardwall_proc_dir); |
| 711 | } |
| 712 | |
| 713 | int proc_pid_hardwall(struct task_struct *task, char *buffer) |
| 714 | { |
| 715 | struct hardwall_info *rect = task->thread.hardwall; |
| 716 | return rect ? sprintf(buffer, "%d\n", rect->id) : 0; |
| 717 | } |
| 718 | |
| 719 | void proc_tile_hardwall_init(struct proc_dir_entry *root) |
| 720 | { |
| 721 | if (!udn_disabled) |
| 722 | hardwall_proc_dir = proc_mkdir("hardwall", root); |
| 723 | } |
| 724 | |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 725 | |
| 726 | /* |
| 727 | * Character device support via ioctl/close. |
| 728 | */ |
| 729 | |
| 730 | static long hardwall_ioctl(struct file *file, unsigned int a, unsigned long b) |
| 731 | { |
| 732 | struct hardwall_info *rect = file->private_data; |
| 733 | |
| 734 | if (_IOC_TYPE(a) != HARDWALL_IOCTL_BASE) |
| 735 | return -EINVAL; |
| 736 | |
| 737 | switch (_IOC_NR(a)) { |
| 738 | case _HARDWALL_CREATE: |
| 739 | if (udn_disabled) |
| 740 | return -ENOSYS; |
| 741 | if (rect != NULL) |
| 742 | return -EALREADY; |
| 743 | rect = hardwall_create(_IOC_SIZE(a), |
| 744 | (const unsigned char __user *)b); |
| 745 | if (IS_ERR(rect)) |
| 746 | return PTR_ERR(rect); |
| 747 | file->private_data = rect; |
| 748 | return 0; |
| 749 | |
| 750 | case _HARDWALL_ACTIVATE: |
| 751 | return hardwall_activate(rect); |
| 752 | |
| 753 | case _HARDWALL_DEACTIVATE: |
| 754 | if (current->thread.hardwall != rect) |
| 755 | return -EINVAL; |
| 756 | return hardwall_deactivate(current); |
| 757 | |
Chris Metcalf | f133ecc | 2011-05-26 12:40:09 -0400 | [diff] [blame] | 758 | case _HARDWALL_GET_ID: |
| 759 | return rect ? rect->id : -EINVAL; |
| 760 | |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 761 | default: |
| 762 | return -EINVAL; |
| 763 | } |
| 764 | } |
| 765 | |
| 766 | #ifdef CONFIG_COMPAT |
| 767 | static long hardwall_compat_ioctl(struct file *file, |
| 768 | unsigned int a, unsigned long b) |
| 769 | { |
| 770 | /* Sign-extend the argument so it can be used as a pointer. */ |
| 771 | return hardwall_ioctl(file, a, (unsigned long)compat_ptr(b)); |
| 772 | } |
| 773 | #endif |
| 774 | |
| 775 | /* The user process closed the file; revoke access to user networks. */ |
| 776 | static int hardwall_flush(struct file *file, fl_owner_t owner) |
| 777 | { |
| 778 | struct hardwall_info *rect = file->private_data; |
| 779 | struct task_struct *task, *tmp; |
| 780 | unsigned long flags; |
| 781 | |
| 782 | if (rect) { |
| 783 | /* |
| 784 | * NOTE: if multiple threads are activated on this hardwall |
| 785 | * file, the other threads will continue having access to the |
| 786 | * UDN until they are context-switched out and back in again. |
| 787 | * |
| 788 | * NOTE: A NULL files pointer means the task is being torn |
| 789 | * down, so in that case we also deactivate it. |
| 790 | */ |
| 791 | spin_lock_irqsave(&hardwall_lock, flags); |
| 792 | list_for_each_entry_safe(task, tmp, &rect->task_head, |
| 793 | thread.hardwall_list) { |
| 794 | if (task->files == owner || task->files == NULL) |
| 795 | _hardwall_deactivate(task); |
| 796 | } |
| 797 | spin_unlock_irqrestore(&hardwall_lock, flags); |
| 798 | } |
| 799 | |
| 800 | return 0; |
| 801 | } |
| 802 | |
| 803 | /* This hardwall is gone, so destroy it. */ |
| 804 | static int hardwall_release(struct inode *inode, struct file *file) |
| 805 | { |
| 806 | hardwall_destroy(file->private_data); |
| 807 | return 0; |
| 808 | } |
| 809 | |
| 810 | static const struct file_operations dev_hardwall_fops = { |
Chris Metcalf | d02db4f8 | 2010-11-01 12:46:10 -0400 | [diff] [blame] | 811 | .open = nonseekable_open, |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 812 | .unlocked_ioctl = hardwall_ioctl, |
| 813 | #ifdef CONFIG_COMPAT |
| 814 | .compat_ioctl = hardwall_compat_ioctl, |
| 815 | #endif |
| 816 | .flush = hardwall_flush, |
| 817 | .release = hardwall_release, |
Chris Metcalf | 9f9c038 | 2010-06-25 17:00:56 -0400 | [diff] [blame] | 818 | }; |
| 819 | |
| 820 | static struct cdev hardwall_dev; |
| 821 | |
| 822 | static int __init dev_hardwall_init(void) |
| 823 | { |
| 824 | int rc; |
| 825 | dev_t dev; |
| 826 | |
| 827 | rc = alloc_chrdev_region(&dev, 0, 1, "hardwall"); |
| 828 | if (rc < 0) |
| 829 | return rc; |
| 830 | cdev_init(&hardwall_dev, &dev_hardwall_fops); |
| 831 | rc = cdev_add(&hardwall_dev, dev, 1); |
| 832 | if (rc < 0) |
| 833 | return rc; |
| 834 | |
| 835 | return 0; |
| 836 | } |
| 837 | late_initcall(dev_hardwall_init); |