Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Xen SMP support |
| 3 | * |
| 4 | * This file implements the Xen versions of smp_ops. SMP under Xen is |
| 5 | * very straightforward. Bringing a CPU up is simply a matter of |
| 6 | * loading its initial context and setting it running. |
| 7 | * |
| 8 | * IPIs are handled through the Xen event mechanism. |
| 9 | * |
| 10 | * Because virtual CPUs can be scheduled onto any real CPU, there's no |
| 11 | * useful topology information for the kernel to make use of. As a |
| 12 | * result, all CPUs are treated as if they're single-core and |
| 13 | * single-threaded. |
| 14 | * |
| 15 | * This does not handle HOTPLUG_CPU yet. |
| 16 | */ |
| 17 | #include <linux/sched.h> |
Jeremy Fitzhardinge | 2d9e1e2 | 2008-07-07 12:07:53 -0700 | [diff] [blame] | 18 | #include <linux/kernel_stat.h> |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 19 | #include <linux/err.h> |
| 20 | #include <linux/smp.h> |
| 21 | |
| 22 | #include <asm/paravirt.h> |
| 23 | #include <asm/desc.h> |
| 24 | #include <asm/pgtable.h> |
| 25 | #include <asm/cpu.h> |
| 26 | |
| 27 | #include <xen/interface/xen.h> |
| 28 | #include <xen/interface/vcpu.h> |
| 29 | |
| 30 | #include <asm/xen/interface.h> |
| 31 | #include <asm/xen/hypercall.h> |
| 32 | |
| 33 | #include <xen/page.h> |
| 34 | #include <xen/events.h> |
| 35 | |
| 36 | #include "xen-ops.h" |
| 37 | #include "mmu.h" |
| 38 | |
Jeremy Fitzhardinge | 2d9e1e2 | 2008-07-07 12:07:53 -0700 | [diff] [blame] | 39 | static void __cpuinit xen_init_lock_cpu(int cpu); |
| 40 | |
Jeremy Fitzhardinge | 0e91398 | 2008-05-26 23:31:27 +0100 | [diff] [blame] | 41 | cpumask_t xen_cpu_initialized_map; |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 42 | |
| 43 | static DEFINE_PER_CPU(int, resched_irq); |
| 44 | static DEFINE_PER_CPU(int, callfunc_irq); |
| 45 | static DEFINE_PER_CPU(int, callfuncsingle_irq); |
Jeremy Fitzhardinge | ee523ca | 2008-03-17 16:37:18 -0700 | [diff] [blame] | 46 | static DEFINE_PER_CPU(int, debug_irq) = -1; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 47 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 48 | static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id); |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 49 | static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 50 | |
| 51 | /* |
| 52 | * Reschedule call back. Nothing to do, |
| 53 | * all the work is done automatically when |
| 54 | * we return from the interrupt. |
| 55 | */ |
| 56 | static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id) |
| 57 | { |
Jeremy Fitzhardinge | 38bb5ab | 2008-05-26 23:31:16 +0100 | [diff] [blame] | 58 | #ifdef CONFIG_X86_32 |
| 59 | __get_cpu_var(irq_stat).irq_resched_count++; |
| 60 | #else |
| 61 | add_pda(irq_resched_count, 1); |
| 62 | #endif |
| 63 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 64 | return IRQ_HANDLED; |
| 65 | } |
| 66 | |
| 67 | static __cpuinit void cpu_bringup_and_idle(void) |
| 68 | { |
| 69 | int cpu = smp_processor_id(); |
| 70 | |
| 71 | cpu_init(); |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 72 | preempt_disable(); |
| 73 | |
Jeremy Fitzhardinge | e2a81ba | 2008-03-17 16:37:17 -0700 | [diff] [blame] | 74 | xen_enable_sysenter(); |
Jeremy Fitzhardinge | 6fcac6d | 2008-07-08 15:07:14 -0700 | [diff] [blame] | 75 | xen_enable_syscall(); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 76 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 77 | cpu = smp_processor_id(); |
| 78 | smp_store_cpu_info(cpu); |
| 79 | cpu_data(cpu).x86_max_cores = 1; |
| 80 | set_cpu_sibling_map(cpu); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 81 | |
| 82 | xen_setup_cpu_clockevents(); |
| 83 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 84 | cpu_set(cpu, cpu_online_map); |
| 85 | x86_write_percpu(cpu_state, CPU_ONLINE); |
| 86 | wmb(); |
| 87 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 88 | /* We can take interrupts now: we're officially "up". */ |
| 89 | local_irq_enable(); |
| 90 | |
| 91 | wmb(); /* make sure everything is out */ |
| 92 | cpu_idle(); |
| 93 | } |
| 94 | |
| 95 | static int xen_smp_intr_init(unsigned int cpu) |
| 96 | { |
| 97 | int rc; |
Jeremy Fitzhardinge | ee523ca | 2008-03-17 16:37:18 -0700 | [diff] [blame] | 98 | const char *resched_name, *callfunc_name, *debug_name; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 99 | |
| 100 | resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu); |
| 101 | rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR, |
| 102 | cpu, |
| 103 | xen_reschedule_interrupt, |
| 104 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, |
| 105 | resched_name, |
| 106 | NULL); |
| 107 | if (rc < 0) |
| 108 | goto fail; |
| 109 | per_cpu(resched_irq, cpu) = rc; |
| 110 | |
| 111 | callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu); |
| 112 | rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR, |
| 113 | cpu, |
| 114 | xen_call_function_interrupt, |
| 115 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, |
| 116 | callfunc_name, |
| 117 | NULL); |
| 118 | if (rc < 0) |
| 119 | goto fail; |
| 120 | per_cpu(callfunc_irq, cpu) = rc; |
| 121 | |
Jeremy Fitzhardinge | ee523ca | 2008-03-17 16:37:18 -0700 | [diff] [blame] | 122 | debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu); |
| 123 | rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt, |
| 124 | IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING, |
| 125 | debug_name, NULL); |
| 126 | if (rc < 0) |
| 127 | goto fail; |
| 128 | per_cpu(debug_irq, cpu) = rc; |
| 129 | |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 130 | callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu); |
| 131 | rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR, |
| 132 | cpu, |
| 133 | xen_call_function_single_interrupt, |
| 134 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, |
| 135 | callfunc_name, |
| 136 | NULL); |
| 137 | if (rc < 0) |
| 138 | goto fail; |
| 139 | per_cpu(callfuncsingle_irq, cpu) = rc; |
| 140 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 141 | return 0; |
| 142 | |
| 143 | fail: |
| 144 | if (per_cpu(resched_irq, cpu) >= 0) |
| 145 | unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL); |
| 146 | if (per_cpu(callfunc_irq, cpu) >= 0) |
| 147 | unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL); |
Jeremy Fitzhardinge | ee523ca | 2008-03-17 16:37:18 -0700 | [diff] [blame] | 148 | if (per_cpu(debug_irq, cpu) >= 0) |
| 149 | unbind_from_irqhandler(per_cpu(debug_irq, cpu), NULL); |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 150 | if (per_cpu(callfuncsingle_irq, cpu) >= 0) |
| 151 | unbind_from_irqhandler(per_cpu(callfuncsingle_irq, cpu), NULL); |
| 152 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 153 | return rc; |
| 154 | } |
| 155 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 156 | static void __init xen_fill_possible_map(void) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 157 | { |
| 158 | int i, rc; |
| 159 | |
| 160 | for (i = 0; i < NR_CPUS; i++) { |
| 161 | rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL); |
Jeremy Fitzhardinge | 4560a29 | 2008-07-08 15:06:56 -0700 | [diff] [blame] | 162 | if (rc >= 0) { |
| 163 | num_processors++; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 164 | cpu_set(i, cpu_possible_map); |
Jeremy Fitzhardinge | 4560a29 | 2008-07-08 15:06:56 -0700 | [diff] [blame] | 165 | } |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 166 | } |
| 167 | } |
| 168 | |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 169 | static void __init xen_smp_prepare_boot_cpu(void) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 170 | { |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 171 | BUG_ON(smp_processor_id() != 0); |
| 172 | native_smp_prepare_boot_cpu(); |
| 173 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 174 | /* We've switched to the "real" per-cpu gdt, so make sure the |
| 175 | old memory can be recycled */ |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 176 | make_lowmem_page_readwrite(&per_cpu_var(gdt_page)); |
Jeremy Fitzhardinge | 60223a3 | 2007-07-17 18:37:07 -0700 | [diff] [blame] | 177 | |
| 178 | xen_setup_vcpu_info_placement(); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 179 | } |
| 180 | |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 181 | static void __init xen_smp_prepare_cpus(unsigned int max_cpus) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 182 | { |
| 183 | unsigned cpu; |
| 184 | |
Jeremy Fitzhardinge | 2d9e1e2 | 2008-07-07 12:07:53 -0700 | [diff] [blame] | 185 | xen_init_lock_cpu(0); |
| 186 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 187 | smp_store_cpu_info(0); |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 188 | cpu_data(0).x86_max_cores = 1; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 189 | set_cpu_sibling_map(0); |
| 190 | |
| 191 | if (xen_smp_intr_init(0)) |
| 192 | BUG(); |
| 193 | |
Glauber Costa | ecaa6c9 | 2008-03-27 14:06:03 -0300 | [diff] [blame] | 194 | xen_cpu_initialized_map = cpumask_of_cpu(0); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 195 | |
| 196 | /* Restrict the possible_map according to max_cpus. */ |
| 197 | while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) { |
Akinobu Mita | 7c04e64 | 2008-04-19 23:55:17 +0900 | [diff] [blame] | 198 | for (cpu = NR_CPUS - 1; !cpu_possible(cpu); cpu--) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 199 | continue; |
| 200 | cpu_clear(cpu, cpu_possible_map); |
| 201 | } |
| 202 | |
| 203 | for_each_possible_cpu (cpu) { |
| 204 | struct task_struct *idle; |
| 205 | |
| 206 | if (cpu == 0) |
| 207 | continue; |
| 208 | |
| 209 | idle = fork_idle(cpu); |
| 210 | if (IS_ERR(idle)) |
| 211 | panic("failed fork for CPU %d", cpu); |
| 212 | |
| 213 | cpu_set(cpu, cpu_present_map); |
| 214 | } |
| 215 | |
| 216 | //init_xenbus_allowed_cpumask(); |
| 217 | } |
| 218 | |
| 219 | static __cpuinit int |
| 220 | cpu_initialize_context(unsigned int cpu, struct task_struct *idle) |
| 221 | { |
| 222 | struct vcpu_guest_context *ctxt; |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 223 | struct desc_struct *gdt; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 224 | |
Glauber Costa | ecaa6c9 | 2008-03-27 14:06:03 -0300 | [diff] [blame] | 225 | if (cpu_test_and_set(cpu, xen_cpu_initialized_map)) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 226 | return 0; |
| 227 | |
| 228 | ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL); |
| 229 | if (ctxt == NULL) |
| 230 | return -ENOMEM; |
| 231 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 232 | gdt = get_cpu_gdt_table(cpu); |
| 233 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 234 | ctxt->flags = VGCF_IN_KERNEL; |
| 235 | ctxt->user_regs.ds = __USER_DS; |
| 236 | ctxt->user_regs.es = __USER_DS; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 237 | ctxt->user_regs.ss = __KERNEL_DS; |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 238 | #ifdef CONFIG_X86_32 |
| 239 | ctxt->user_regs.fs = __KERNEL_PERCPU; |
| 240 | #endif |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 241 | ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle; |
| 242 | ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */ |
| 243 | |
| 244 | memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt)); |
| 245 | |
| 246 | xen_copy_trap_info(ctxt->trap_ctxt); |
| 247 | |
| 248 | ctxt->ldt_ents = 0; |
| 249 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 250 | BUG_ON((unsigned long)gdt & ~PAGE_MASK); |
| 251 | make_lowmem_page_readonly(gdt); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 252 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 253 | ctxt->gdt_frames[0] = virt_to_mfn(gdt); |
| 254 | ctxt->gdt_ents = GDT_ENTRIES; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 255 | |
| 256 | ctxt->user_regs.cs = __KERNEL_CS; |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 257 | ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 258 | |
| 259 | ctxt->kernel_ss = __KERNEL_DS; |
H. Peter Anvin | faca622 | 2008-01-30 13:31:02 +0100 | [diff] [blame] | 260 | ctxt->kernel_sp = idle->thread.sp0; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 261 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 262 | #ifdef CONFIG_X86_32 |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 263 | ctxt->event_callback_cs = __KERNEL_CS; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 264 | ctxt->failsafe_callback_cs = __KERNEL_CS; |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 265 | #endif |
| 266 | ctxt->event_callback_eip = (unsigned long)xen_hypervisor_callback; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 267 | ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback; |
| 268 | |
| 269 | per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir); |
| 270 | ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir)); |
| 271 | |
| 272 | if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt)) |
| 273 | BUG(); |
| 274 | |
| 275 | kfree(ctxt); |
| 276 | return 0; |
| 277 | } |
| 278 | |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 279 | static int __cpuinit xen_cpu_up(unsigned int cpu) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 280 | { |
| 281 | struct task_struct *idle = idle_task(cpu); |
| 282 | int rc; |
| 283 | |
| 284 | #if 0 |
| 285 | rc = cpu_up_check(cpu); |
| 286 | if (rc) |
| 287 | return rc; |
| 288 | #endif |
| 289 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 290 | #ifdef CONFIG_X86_64 |
| 291 | /* Allocate node local memory for AP pdas */ |
| 292 | WARN_ON(cpu == 0); |
| 293 | if (cpu > 0) { |
| 294 | rc = get_local_pda(cpu); |
| 295 | if (rc) |
| 296 | return rc; |
| 297 | } |
| 298 | #endif |
| 299 | |
| 300 | #ifdef CONFIG_X86_32 |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 301 | init_gdt(cpu); |
| 302 | per_cpu(current_task, cpu) = idle; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 303 | irq_ctx_init(cpu); |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 304 | #else |
| 305 | cpu_pda(cpu)->pcurrent = idle; |
| 306 | clear_tsk_thread_flag(idle, TIF_FORK); |
| 307 | #endif |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 308 | xen_setup_timer(cpu); |
Jeremy Fitzhardinge | 2d9e1e2 | 2008-07-07 12:07:53 -0700 | [diff] [blame] | 309 | xen_init_lock_cpu(cpu); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 310 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 311 | per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; |
| 312 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 313 | /* make sure interrupts start blocked */ |
| 314 | per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1; |
| 315 | |
| 316 | rc = cpu_initialize_context(cpu, idle); |
| 317 | if (rc) |
| 318 | return rc; |
| 319 | |
| 320 | if (num_online_cpus() == 1) |
| 321 | alternatives_smp_switch(1); |
| 322 | |
| 323 | rc = xen_smp_intr_init(cpu); |
| 324 | if (rc) |
| 325 | return rc; |
| 326 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 327 | rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL); |
| 328 | BUG_ON(rc); |
| 329 | |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 330 | while(per_cpu(cpu_state, cpu) != CPU_ONLINE) { |
| 331 | HYPERVISOR_sched_op(SCHEDOP_yield, 0); |
| 332 | barrier(); |
| 333 | } |
| 334 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 335 | return 0; |
| 336 | } |
| 337 | |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 338 | static void xen_smp_cpus_done(unsigned int max_cpus) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 339 | { |
| 340 | } |
| 341 | |
| 342 | static void stop_self(void *v) |
| 343 | { |
| 344 | int cpu = smp_processor_id(); |
| 345 | |
| 346 | /* make sure we're not pinning something down */ |
| 347 | load_cr3(swapper_pg_dir); |
| 348 | /* should set up a minimal gdt */ |
| 349 | |
| 350 | HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL); |
| 351 | BUG(); |
| 352 | } |
| 353 | |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 354 | static void xen_smp_send_stop(void) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 355 | { |
Jens Axboe | 8691e5a | 2008-06-06 11:18:06 +0200 | [diff] [blame] | 356 | smp_call_function(stop_self, NULL, 0); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 357 | } |
| 358 | |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 359 | static void xen_smp_send_reschedule(int cpu) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 360 | { |
| 361 | xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR); |
| 362 | } |
| 363 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 364 | static void xen_send_IPI_mask(cpumask_t mask, enum ipi_vector vector) |
| 365 | { |
| 366 | unsigned cpu; |
| 367 | |
| 368 | cpus_and(mask, mask, cpu_online_map); |
| 369 | |
Mike Travis | 334ef7a | 2008-05-12 21:21:13 +0200 | [diff] [blame] | 370 | for_each_cpu_mask_nr(cpu, mask) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 371 | xen_send_IPI_one(cpu, vector); |
| 372 | } |
| 373 | |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 374 | static void xen_smp_send_call_function_ipi(cpumask_t mask) |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 375 | { |
| 376 | int cpu; |
| 377 | |
| 378 | xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR); |
| 379 | |
| 380 | /* Make sure other vcpus get a chance to run if they need to. */ |
Ingo Molnar | 8263884 | 2008-07-16 00:29:07 +0200 | [diff] [blame] | 381 | for_each_cpu_mask_nr(cpu, mask) { |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 382 | if (xen_vcpu_stolen(cpu)) { |
| 383 | HYPERVISOR_sched_op(SCHEDOP_yield, 0); |
| 384 | break; |
| 385 | } |
| 386 | } |
| 387 | } |
| 388 | |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 389 | static void xen_smp_send_call_function_single_ipi(int cpu) |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 390 | { |
| 391 | xen_send_IPI_mask(cpumask_of_cpu(cpu), XEN_CALL_FUNCTION_SINGLE_VECTOR); |
| 392 | } |
| 393 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 394 | static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id) |
| 395 | { |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 396 | irq_enter(); |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 397 | generic_smp_call_function_interrupt(); |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 398 | #ifdef CONFIG_X86_32 |
Joe Korty | 38e760a | 2007-10-17 18:04:40 +0200 | [diff] [blame] | 399 | __get_cpu_var(irq_stat).irq_call_count++; |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 400 | #else |
| 401 | add_pda(irq_call_count, 1); |
| 402 | #endif |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 403 | irq_exit(); |
| 404 | |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 405 | return IRQ_HANDLED; |
| 406 | } |
| 407 | |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 408 | static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id) |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 409 | { |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 410 | irq_enter(); |
| 411 | generic_smp_call_function_single_interrupt(); |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 412 | #ifdef CONFIG_X86_32 |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 413 | __get_cpu_var(irq_stat).irq_call_count++; |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 414 | #else |
| 415 | add_pda(irq_call_count, 1); |
| 416 | #endif |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 417 | irq_exit(); |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 418 | |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 419 | return IRQ_HANDLED; |
Jeremy Fitzhardinge | f87e4ca | 2007-07-17 18:37:06 -0700 | [diff] [blame] | 420 | } |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 421 | |
Jeremy Fitzhardinge | 2d9e1e2 | 2008-07-07 12:07:53 -0700 | [diff] [blame] | 422 | struct xen_spinlock { |
| 423 | unsigned char lock; /* 0 -> free; 1 -> locked */ |
| 424 | unsigned short spinners; /* count of waiting cpus */ |
| 425 | }; |
| 426 | |
| 427 | static int xen_spin_is_locked(struct raw_spinlock *lock) |
| 428 | { |
| 429 | struct xen_spinlock *xl = (struct xen_spinlock *)lock; |
| 430 | |
| 431 | return xl->lock != 0; |
| 432 | } |
| 433 | |
| 434 | static int xen_spin_is_contended(struct raw_spinlock *lock) |
| 435 | { |
| 436 | struct xen_spinlock *xl = (struct xen_spinlock *)lock; |
| 437 | |
| 438 | /* Not strictly true; this is only the count of contended |
| 439 | lock-takers entering the slow path. */ |
| 440 | return xl->spinners != 0; |
| 441 | } |
| 442 | |
| 443 | static int xen_spin_trylock(struct raw_spinlock *lock) |
| 444 | { |
| 445 | struct xen_spinlock *xl = (struct xen_spinlock *)lock; |
| 446 | u8 old = 1; |
| 447 | |
| 448 | asm("xchgb %b0,%1" |
| 449 | : "+q" (old), "+m" (xl->lock) : : "memory"); |
| 450 | |
| 451 | return old == 0; |
| 452 | } |
| 453 | |
| 454 | static DEFINE_PER_CPU(int, lock_kicker_irq) = -1; |
| 455 | static DEFINE_PER_CPU(struct xen_spinlock *, lock_spinners); |
| 456 | |
| 457 | static inline void spinning_lock(struct xen_spinlock *xl) |
| 458 | { |
| 459 | __get_cpu_var(lock_spinners) = xl; |
| 460 | wmb(); /* set lock of interest before count */ |
| 461 | asm(LOCK_PREFIX " incw %0" |
| 462 | : "+m" (xl->spinners) : : "memory"); |
| 463 | } |
| 464 | |
| 465 | static inline void unspinning_lock(struct xen_spinlock *xl) |
| 466 | { |
| 467 | asm(LOCK_PREFIX " decw %0" |
| 468 | : "+m" (xl->spinners) : : "memory"); |
| 469 | wmb(); /* decrement count before clearing lock */ |
| 470 | __get_cpu_var(lock_spinners) = NULL; |
| 471 | } |
| 472 | |
| 473 | static noinline int xen_spin_lock_slow(struct raw_spinlock *lock) |
| 474 | { |
| 475 | struct xen_spinlock *xl = (struct xen_spinlock *)lock; |
| 476 | int irq = __get_cpu_var(lock_kicker_irq); |
| 477 | int ret; |
| 478 | |
| 479 | /* If kicker interrupts not initialized yet, just spin */ |
| 480 | if (irq == -1) |
| 481 | return 0; |
| 482 | |
| 483 | /* announce we're spinning */ |
| 484 | spinning_lock(xl); |
| 485 | |
| 486 | /* clear pending */ |
| 487 | xen_clear_irq_pending(irq); |
| 488 | |
| 489 | /* check again make sure it didn't become free while |
| 490 | we weren't looking */ |
| 491 | ret = xen_spin_trylock(lock); |
| 492 | if (ret) |
| 493 | goto out; |
| 494 | |
| 495 | /* block until irq becomes pending */ |
| 496 | xen_poll_irq(irq); |
| 497 | kstat_this_cpu.irqs[irq]++; |
| 498 | |
| 499 | out: |
| 500 | unspinning_lock(xl); |
| 501 | return ret; |
| 502 | } |
| 503 | |
| 504 | static void xen_spin_lock(struct raw_spinlock *lock) |
| 505 | { |
| 506 | struct xen_spinlock *xl = (struct xen_spinlock *)lock; |
| 507 | int timeout; |
| 508 | u8 oldval; |
| 509 | |
| 510 | do { |
| 511 | timeout = 1 << 10; |
| 512 | |
| 513 | asm("1: xchgb %1,%0\n" |
| 514 | " testb %1,%1\n" |
| 515 | " jz 3f\n" |
| 516 | "2: rep;nop\n" |
| 517 | " cmpb $0,%0\n" |
| 518 | " je 1b\n" |
| 519 | " dec %2\n" |
| 520 | " jnz 2b\n" |
| 521 | "3:\n" |
| 522 | : "+m" (xl->lock), "=q" (oldval), "+r" (timeout) |
| 523 | : "1" (1) |
| 524 | : "memory"); |
| 525 | |
| 526 | } while (unlikely(oldval != 0 && !xen_spin_lock_slow(lock))); |
| 527 | } |
| 528 | |
| 529 | static noinline void xen_spin_unlock_slow(struct xen_spinlock *xl) |
| 530 | { |
| 531 | int cpu; |
| 532 | |
| 533 | for_each_online_cpu(cpu) { |
| 534 | /* XXX should mix up next cpu selection */ |
| 535 | if (per_cpu(lock_spinners, cpu) == xl) { |
| 536 | xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR); |
| 537 | break; |
| 538 | } |
| 539 | } |
| 540 | } |
| 541 | |
| 542 | static void xen_spin_unlock(struct raw_spinlock *lock) |
| 543 | { |
| 544 | struct xen_spinlock *xl = (struct xen_spinlock *)lock; |
| 545 | |
| 546 | smp_wmb(); /* make sure no writes get moved after unlock */ |
| 547 | xl->lock = 0; /* release lock */ |
| 548 | |
| 549 | /* make sure unlock happens before kick */ |
| 550 | barrier(); |
| 551 | |
| 552 | if (unlikely(xl->spinners)) |
| 553 | xen_spin_unlock_slow(xl); |
| 554 | } |
| 555 | |
| 556 | static __cpuinit void xen_init_lock_cpu(int cpu) |
| 557 | { |
| 558 | int irq; |
| 559 | const char *name; |
| 560 | |
| 561 | name = kasprintf(GFP_KERNEL, "spinlock%d", cpu); |
| 562 | irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR, |
| 563 | cpu, |
| 564 | xen_reschedule_interrupt, |
| 565 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, |
| 566 | name, |
| 567 | NULL); |
| 568 | |
| 569 | if (irq >= 0) { |
| 570 | disable_irq(irq); /* make sure it's never delivered */ |
| 571 | per_cpu(lock_kicker_irq, cpu) = irq; |
| 572 | } |
| 573 | |
| 574 | printk("cpu %d spinlock event irq %d\n", cpu, irq); |
| 575 | } |
| 576 | |
| 577 | static void __init xen_init_spinlocks(void) |
| 578 | { |
| 579 | pv_lock_ops.spin_is_locked = xen_spin_is_locked; |
| 580 | pv_lock_ops.spin_is_contended = xen_spin_is_contended; |
| 581 | pv_lock_ops.spin_lock = xen_spin_lock; |
| 582 | pv_lock_ops.spin_trylock = xen_spin_trylock; |
| 583 | pv_lock_ops.spin_unlock = xen_spin_unlock; |
| 584 | } |
| 585 | |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 586 | static const struct smp_ops xen_smp_ops __initdata = { |
| 587 | .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu, |
| 588 | .smp_prepare_cpus = xen_smp_prepare_cpus, |
| 589 | .cpu_up = xen_cpu_up, |
| 590 | .smp_cpus_done = xen_smp_cpus_done, |
| 591 | |
| 592 | .smp_send_stop = xen_smp_send_stop, |
| 593 | .smp_send_reschedule = xen_smp_send_reschedule, |
| 594 | |
| 595 | .send_call_func_ipi = xen_smp_send_call_function_ipi, |
| 596 | .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi, |
| 597 | }; |
| 598 | |
| 599 | void __init xen_smp_init(void) |
| 600 | { |
| 601 | smp_ops = xen_smp_ops; |
Jeremy Fitzhardinge | c7b7594 | 2008-07-08 15:06:43 -0700 | [diff] [blame] | 602 | xen_fill_possible_map(); |
Jeremy Fitzhardinge | 2d9e1e2 | 2008-07-07 12:07:53 -0700 | [diff] [blame] | 603 | xen_init_spinlocks(); |
Jeremy Fitzhardinge | a9e7062 | 2008-07-08 15:06:41 -0700 | [diff] [blame] | 604 | } |