Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 1 | /* -*- linux-c -*- |
| 2 | * linux/arch/blackfin/kernel/ipipe.c |
| 3 | * |
| 4 | * Copyright (C) 2005-2007 Philippe Gerum. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139, |
| 9 | * USA; either version 2 of the License, or (at your option) any later |
| 10 | * version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 20 | * |
| 21 | * Architecture-dependent I-pipe support for the Blackfin. |
| 22 | */ |
| 23 | |
| 24 | #include <linux/kernel.h> |
| 25 | #include <linux/sched.h> |
| 26 | #include <linux/module.h> |
| 27 | #include <linux/interrupt.h> |
| 28 | #include <linux/percpu.h> |
| 29 | #include <linux/bitops.h> |
| 30 | #include <linux/slab.h> |
| 31 | #include <linux/errno.h> |
| 32 | #include <linux/kthread.h> |
| 33 | #include <asm/unistd.h> |
| 34 | #include <asm/system.h> |
| 35 | #include <asm/atomic.h> |
| 36 | #include <asm/io.h> |
| 37 | |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 38 | DEFINE_PER_CPU(struct pt_regs, __ipipe_tick_regs); |
| 39 | |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 40 | asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs); |
| 41 | |
| 42 | static void __ipipe_no_irqtail(void); |
| 43 | |
| 44 | unsigned long __ipipe_irq_tail_hook = (unsigned long)&__ipipe_no_irqtail; |
| 45 | EXPORT_SYMBOL(__ipipe_irq_tail_hook); |
| 46 | |
| 47 | unsigned long __ipipe_core_clock; |
| 48 | EXPORT_SYMBOL(__ipipe_core_clock); |
| 49 | |
| 50 | unsigned long __ipipe_freq_scale; |
| 51 | EXPORT_SYMBOL(__ipipe_freq_scale); |
| 52 | |
| 53 | atomic_t __ipipe_irq_lvdepth[IVG15 + 1]; |
| 54 | |
| 55 | unsigned long __ipipe_irq_lvmask = __all_masked_irq_flags; |
| 56 | EXPORT_SYMBOL(__ipipe_irq_lvmask); |
| 57 | |
| 58 | static void __ipipe_ack_irq(unsigned irq, struct irq_desc *desc) |
| 59 | { |
| 60 | desc->ipipe_ack(irq, desc); |
| 61 | } |
| 62 | |
| 63 | /* |
| 64 | * __ipipe_enable_pipeline() -- We are running on the boot CPU, hw |
| 65 | * interrupts are off, and secondary CPUs are still lost in space. |
| 66 | */ |
| 67 | void __ipipe_enable_pipeline(void) |
| 68 | { |
| 69 | unsigned irq; |
| 70 | |
| 71 | __ipipe_core_clock = get_cclk(); /* Fetch this once. */ |
| 72 | __ipipe_freq_scale = 1000000000UL / __ipipe_core_clock; |
| 73 | |
| 74 | for (irq = 0; irq < NR_IRQS; ++irq) |
| 75 | ipipe_virtualize_irq(ipipe_root_domain, |
| 76 | irq, |
| 77 | (ipipe_irq_handler_t)&asm_do_IRQ, |
| 78 | NULL, |
| 79 | &__ipipe_ack_irq, |
| 80 | IPIPE_HANDLE_MASK | IPIPE_PASS_MASK); |
| 81 | } |
| 82 | |
| 83 | /* |
| 84 | * __ipipe_handle_irq() -- IPIPE's generic IRQ handler. An optimistic |
| 85 | * interrupt protection log is maintained here for each domain. Hw |
| 86 | * interrupts are masked on entry. |
| 87 | */ |
| 88 | void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs) |
| 89 | { |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 90 | struct ipipe_percpu_domain_data *p = ipipe_root_cpudom_ptr(); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 91 | struct ipipe_domain *this_domain, *next_domain; |
| 92 | struct list_head *head, *pos; |
| 93 | int m_ack, s = -1; |
| 94 | |
| 95 | /* |
| 96 | * Software-triggered IRQs do not need any ack. The contents |
| 97 | * of the register frame should only be used when processing |
| 98 | * the timer interrupt, but not for handling any other |
| 99 | * interrupt. |
| 100 | */ |
| 101 | m_ack = (regs == NULL || irq == IRQ_SYSTMR || irq == IRQ_CORETMR); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 102 | this_domain = ipipe_current_domain; |
| 103 | |
| 104 | if (unlikely(test_bit(IPIPE_STICKY_FLAG, &this_domain->irqs[irq].control))) |
| 105 | head = &this_domain->p_link; |
| 106 | else { |
| 107 | head = __ipipe_pipeline.next; |
| 108 | next_domain = list_entry(head, struct ipipe_domain, p_link); |
| 109 | if (likely(test_bit(IPIPE_WIRED_FLAG, &next_domain->irqs[irq].control))) { |
| 110 | if (!m_ack && next_domain->irqs[irq].acknowledge != NULL) |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 111 | next_domain->irqs[irq].acknowledge(irq, irq_to_desc(irq)); |
| 112 | if (test_bit(IPIPE_SYNCDEFER_FLAG, &p->status)) |
| 113 | s = __test_and_set_bit(IPIPE_STALL_FLAG, &p->status); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 114 | __ipipe_dispatch_wired(next_domain, irq); |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 115 | goto out; |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 116 | } |
| 117 | } |
| 118 | |
| 119 | /* Ack the interrupt. */ |
| 120 | |
| 121 | pos = head; |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 122 | while (pos != &__ipipe_pipeline) { |
| 123 | next_domain = list_entry(pos, struct ipipe_domain, p_link); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 124 | if (test_bit(IPIPE_HANDLE_FLAG, &next_domain->irqs[irq].control)) { |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 125 | __ipipe_set_irq_pending(next_domain, irq); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 126 | if (!m_ack && next_domain->irqs[irq].acknowledge != NULL) { |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 127 | next_domain->irqs[irq].acknowledge(irq, irq_to_desc(irq)); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 128 | m_ack = 1; |
| 129 | } |
| 130 | } |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 131 | if (!test_bit(IPIPE_PASS_FLAG, &next_domain->irqs[irq].control)) |
| 132 | break; |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 133 | pos = next_domain->p_link.next; |
| 134 | } |
| 135 | |
| 136 | /* |
| 137 | * Now walk the pipeline, yielding control to the highest |
| 138 | * priority domain that has pending interrupt(s) or |
| 139 | * immediately to the current domain if the interrupt has been |
| 140 | * marked as 'sticky'. This search does not go beyond the |
| 141 | * current domain in the pipeline. We also enforce the |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 142 | * additional root stage lock (blackfin-specific). |
| 143 | */ |
| 144 | if (test_bit(IPIPE_SYNCDEFER_FLAG, &p->status)) |
| 145 | s = __test_and_set_bit(IPIPE_STALL_FLAG, &p->status); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 146 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 147 | /* |
| 148 | * If the interrupt preempted the head domain, then do not |
| 149 | * even try to walk the pipeline, unless an interrupt is |
| 150 | * pending for it. |
| 151 | */ |
| 152 | if (test_bit(IPIPE_AHEAD_FLAG, &this_domain->flags) && |
| 153 | ipipe_head_cpudom_var(irqpend_himask) == 0) |
| 154 | goto out; |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 155 | |
| 156 | __ipipe_walk_pipeline(head); |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 157 | out: |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 158 | if (!s) |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 159 | __clear_bit(IPIPE_STALL_FLAG, &p->status); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 160 | } |
| 161 | |
| 162 | int __ipipe_check_root(void) |
| 163 | { |
| 164 | return ipipe_root_domain_p; |
| 165 | } |
| 166 | |
| 167 | void __ipipe_enable_irqdesc(struct ipipe_domain *ipd, unsigned irq) |
| 168 | { |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 169 | struct irq_desc *desc = irq_to_desc(irq); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 170 | int prio = desc->ic_prio; |
| 171 | |
| 172 | desc->depth = 0; |
| 173 | if (ipd != &ipipe_root && |
| 174 | atomic_inc_return(&__ipipe_irq_lvdepth[prio]) == 1) |
| 175 | __set_bit(prio, &__ipipe_irq_lvmask); |
| 176 | } |
| 177 | EXPORT_SYMBOL(__ipipe_enable_irqdesc); |
| 178 | |
| 179 | void __ipipe_disable_irqdesc(struct ipipe_domain *ipd, unsigned irq) |
| 180 | { |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 181 | struct irq_desc *desc = irq_to_desc(irq); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 182 | int prio = desc->ic_prio; |
| 183 | |
| 184 | if (ipd != &ipipe_root && |
| 185 | atomic_dec_and_test(&__ipipe_irq_lvdepth[prio])) |
| 186 | __clear_bit(prio, &__ipipe_irq_lvmask); |
| 187 | } |
| 188 | EXPORT_SYMBOL(__ipipe_disable_irqdesc); |
| 189 | |
| 190 | void __ipipe_stall_root_raw(void) |
| 191 | { |
| 192 | /* |
| 193 | * This code is called by the ins{bwl} routines (see |
| 194 | * arch/blackfin/lib/ins.S), which are heavily used by the |
| 195 | * network stack. It masks all interrupts but those handled by |
| 196 | * non-root domains, so that we keep decent network transfer |
| 197 | * rates for Linux without inducing pathological jitter for |
| 198 | * the real-time domain. |
| 199 | */ |
| 200 | __asm__ __volatile__ ("sti %0;" : : "d"(__ipipe_irq_lvmask)); |
| 201 | |
| 202 | __set_bit(IPIPE_STALL_FLAG, |
| 203 | &ipipe_root_cpudom_var(status)); |
| 204 | } |
| 205 | |
| 206 | void __ipipe_unstall_root_raw(void) |
| 207 | { |
| 208 | __clear_bit(IPIPE_STALL_FLAG, |
| 209 | &ipipe_root_cpudom_var(status)); |
| 210 | |
| 211 | __asm__ __volatile__ ("sti %0;" : : "d"(bfin_irq_flags)); |
| 212 | } |
| 213 | |
| 214 | int __ipipe_syscall_root(struct pt_regs *regs) |
| 215 | { |
| 216 | unsigned long flags; |
| 217 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 218 | /* |
| 219 | * We need to run the IRQ tail hook whenever we don't |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 220 | * propagate a syscall to higher domains, because we know that |
| 221 | * important operations might be pending there (e.g. Xenomai |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 222 | * deferred rescheduling). |
| 223 | */ |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 224 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 225 | if (regs->orig_p0 < NR_syscalls) { |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 226 | void (*hook)(void) = (void (*)(void))__ipipe_irq_tail_hook; |
| 227 | hook(); |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 228 | if ((current->flags & PF_EVNOTIFY) == 0) |
| 229 | return 0; |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 230 | } |
| 231 | |
| 232 | /* |
| 233 | * This routine either returns: |
| 234 | * 0 -- if the syscall is to be passed to Linux; |
| 235 | * 1 -- if the syscall should not be passed to Linux, and no |
| 236 | * tail work should be performed; |
| 237 | * -1 -- if the syscall should not be passed to Linux but the |
| 238 | * tail work has to be performed (for handling signals etc). |
| 239 | */ |
| 240 | |
| 241 | if (__ipipe_event_monitored_p(IPIPE_EVENT_SYSCALL) && |
| 242 | __ipipe_dispatch_event(IPIPE_EVENT_SYSCALL, regs) > 0) { |
| 243 | if (ipipe_root_domain_p && !in_atomic()) { |
| 244 | /* |
| 245 | * Sync pending VIRQs before _TIF_NEED_RESCHED |
| 246 | * is tested. |
| 247 | */ |
| 248 | local_irq_save_hw(flags); |
| 249 | if ((ipipe_root_cpudom_var(irqpend_himask) & IPIPE_IRQMASK_VIRT) != 0) |
| 250 | __ipipe_sync_pipeline(IPIPE_IRQMASK_VIRT); |
| 251 | local_irq_restore_hw(flags); |
| 252 | return -1; |
| 253 | } |
| 254 | return 1; |
| 255 | } |
| 256 | |
| 257 | return 0; |
| 258 | } |
| 259 | |
| 260 | unsigned long ipipe_critical_enter(void (*syncfn) (void)) |
| 261 | { |
| 262 | unsigned long flags; |
| 263 | |
| 264 | local_irq_save_hw(flags); |
| 265 | |
| 266 | return flags; |
| 267 | } |
| 268 | |
| 269 | void ipipe_critical_exit(unsigned long flags) |
| 270 | { |
| 271 | local_irq_restore_hw(flags); |
| 272 | } |
| 273 | |
| 274 | static void __ipipe_no_irqtail(void) |
| 275 | { |
| 276 | } |
| 277 | |
| 278 | int ipipe_get_sysinfo(struct ipipe_sysinfo *info) |
| 279 | { |
| 280 | info->ncpus = num_online_cpus(); |
| 281 | info->cpufreq = ipipe_cpu_freq(); |
| 282 | info->archdep.tmirq = IPIPE_TIMER_IRQ; |
| 283 | info->archdep.tmfreq = info->cpufreq; |
| 284 | |
| 285 | return 0; |
| 286 | } |
| 287 | |
| 288 | /* |
| 289 | * ipipe_trigger_irq() -- Push the interrupt at front of the pipeline |
| 290 | * just like if it has been actually received from a hw source. Also |
| 291 | * works for virtual interrupts. |
| 292 | */ |
| 293 | int ipipe_trigger_irq(unsigned irq) |
| 294 | { |
| 295 | unsigned long flags; |
| 296 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 297 | #ifdef CONFIG_IPIPE_DEBUG |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 298 | if (irq >= IPIPE_NR_IRQS || |
| 299 | (ipipe_virtual_irq_p(irq) |
| 300 | && !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map))) |
| 301 | return -EINVAL; |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 302 | #endif |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 303 | |
| 304 | local_irq_save_hw(flags); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 305 | __ipipe_handle_irq(irq, NULL); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 306 | local_irq_restore_hw(flags); |
| 307 | |
| 308 | return 1; |
| 309 | } |
| 310 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 311 | asmlinkage void __ipipe_sync_root(void) |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 312 | { |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 313 | unsigned long flags; |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 314 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 315 | BUG_ON(irqs_disabled()); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 316 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 317 | local_irq_save_hw(flags); |
| 318 | |
| 319 | clear_thread_flag(TIF_IRQ_SYNC); |
| 320 | |
| 321 | if (ipipe_root_cpudom_var(irqpend_himask) != 0) |
| 322 | __ipipe_sync_pipeline(IPIPE_IRQMASK_ANY); |
| 323 | |
| 324 | local_irq_restore_hw(flags); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 325 | } |
| 326 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 327 | void ___ipipe_sync_pipeline(unsigned long syncmask) |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 328 | { |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 329 | struct ipipe_domain *ipd = ipipe_current_domain; |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 330 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 331 | if (ipd == ipipe_root_domain) { |
| 332 | if (test_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status))) |
| 333 | return; |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 334 | } |
| 335 | |
Philippe Gerum | 9bd50df | 2009-03-04 16:52:38 +0800 | [diff] [blame^] | 336 | __ipipe_sync_stage(syncmask); |
Yi Li | 6a01f23 | 2009-01-07 23:14:39 +0800 | [diff] [blame] | 337 | } |
| 338 | |
| 339 | EXPORT_SYMBOL(show_stack); |
| 340 | |
| 341 | #ifdef CONFIG_IPIPE_TRACE_MCOUNT |
| 342 | void notrace _mcount(void); |
| 343 | EXPORT_SYMBOL(_mcount); |
| 344 | #endif /* CONFIG_IPIPE_TRACE_MCOUNT */ |