2 * Performance events - AMD IBS
4 * Copyright (C) 2011 Advanced Micro Devices, Inc., Robert Richter
6 * For licencing details see kernel-base/COPYING
9 #include <linux/perf_event.h>
10 #include <linux/module.h>
11 #include <linux/pci.h>
12 #include <linux/syscore_ops.h>
18 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD)
20 static struct pmu perf_ibs;
22 static int perf_ibs_init(struct perf_event *event)
24 if (perf_ibs.type != event->attr.type)
29 static int perf_ibs_add(struct perf_event *event, int flags)
34 static void perf_ibs_del(struct perf_event *event, int flags)
38 static struct pmu perf_ibs = {
39 .event_init= perf_ibs_init,
44 static __init int perf_event_ibs_init(void)
47 return -ENODEV; /* ibs not supported by the cpu */
49 perf_pmu_register(&perf_ibs, "ibs", -1);
50 printk(KERN_INFO "perf: AMD IBS detected (0x%08x)\n", ibs_caps);
55 #else /* defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD) */
57 static __init int perf_event_ibs_init(void) { return 0; }
61 /* IBS - apic initialization, for perf and oprofile */
63 static __init u32 __get_ibs_caps(void)
66 unsigned int max_level;
68 if (!boot_cpu_has(X86_FEATURE_IBS))
71 /* check IBS cpuid feature flags */
72 max_level = cpuid_eax(0x80000000);
73 if (max_level < IBS_CPUID_FEATURES)
74 return IBS_CAPS_DEFAULT;
76 caps = cpuid_eax(IBS_CPUID_FEATURES);
77 if (!(caps & IBS_CAPS_AVAIL))
78 /* cpuid flags not valid */
79 return IBS_CAPS_DEFAULT;
84 u32 get_ibs_caps(void)
89 EXPORT_SYMBOL(get_ibs_caps);
91 static inline int get_eilvt(int offset)
93 return !setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 1);
96 static inline int put_eilvt(int offset)
98 return !setup_APIC_eilvt(offset, 0, 0, 1);
102 * Check and reserve APIC extended interrupt LVT offset for IBS if available.
104 static inline int ibs_eilvt_valid(void)
112 rdmsrl(MSR_AMD64_IBSCTL, val);
113 offset = val & IBSCTL_LVT_OFFSET_MASK;
115 if (!(val & IBSCTL_LVT_OFFSET_VALID)) {
116 pr_err(FW_BUG "cpu %d, invalid IBS interrupt offset %d (MSR%08X=0x%016llx)\n",
117 smp_processor_id(), offset, MSR_AMD64_IBSCTL, val);
121 if (!get_eilvt(offset)) {
122 pr_err(FW_BUG "cpu %d, IBS interrupt offset %d not available (MSR%08X=0x%016llx)\n",
123 smp_processor_id(), offset, MSR_AMD64_IBSCTL, val);
134 static int setup_ibs_ctl(int ibs_eilvt_off)
136 struct pci_dev *cpu_cfg;
143 cpu_cfg = pci_get_device(PCI_VENDOR_ID_AMD,
144 PCI_DEVICE_ID_AMD_10H_NB_MISC,
149 pci_write_config_dword(cpu_cfg, IBSCTL, ibs_eilvt_off
150 | IBSCTL_LVT_OFFSET_VALID);
151 pci_read_config_dword(cpu_cfg, IBSCTL, &value);
152 if (value != (ibs_eilvt_off | IBSCTL_LVT_OFFSET_VALID)) {
153 pci_dev_put(cpu_cfg);
154 printk(KERN_DEBUG "Failed to setup IBS LVT offset, "
155 "IBSCTL = 0x%08x\n", value);
161 printk(KERN_DEBUG "No CPU node configured for IBS\n");
169 * This runs only on the current cpu. We try to find an LVT offset and
170 * setup the local APIC. For this we must disable preemption. On
171 * success we initialize all nodes with this offset. This updates then
172 * the offset in the IBS_CTL per-node msr. The per-core APIC setup of
173 * the IBS interrupt vector is handled by perf_ibs_cpu_notifier that
174 * is using the new offset.
176 static int force_ibs_eilvt_setup(void)
182 /* find the next free available EILVT entry, skip offset 0 */
183 for (offset = 1; offset < APIC_EILVT_NR_MAX; offset++) {
184 if (get_eilvt(offset))
189 if (offset == APIC_EILVT_NR_MAX) {
190 printk(KERN_DEBUG "No EILVT entry available\n");
194 ret = setup_ibs_ctl(offset);
198 if (!ibs_eilvt_valid()) {
203 pr_info("IBS: LVT offset %d assigned\n", offset);
213 static void ibs_eilvt_setup(void)
216 * Force LVT offset assignment for family 10h: The offsets are
217 * not assigned by the BIOS for this family, so the OS is
218 * responsible for doing it. If the OS assignment fails, fall
219 * back to BIOS settings and try to setup this.
221 if (boot_cpu_data.x86 == 0x10)
222 force_ibs_eilvt_setup();
225 static inline int get_ibs_lvt_offset(void)
229 rdmsrl(MSR_AMD64_IBSCTL, val);
230 if (!(val & IBSCTL_LVT_OFFSET_VALID))
233 return val & IBSCTL_LVT_OFFSET_MASK;
236 static void setup_APIC_ibs(void *dummy)
240 offset = get_ibs_lvt_offset();
244 if (!setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 0))
247 pr_warn("perf: IBS APIC setup failed on cpu #%d\n",
251 static void clear_APIC_ibs(void *dummy)
255 offset = get_ibs_lvt_offset();
257 setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_FIX, 1);
262 static int perf_ibs_suspend(void)
264 clear_APIC_ibs(NULL);
268 static void perf_ibs_resume(void)
271 setup_APIC_ibs(NULL);
274 static struct syscore_ops perf_ibs_syscore_ops = {
275 .resume = perf_ibs_resume,
276 .suspend = perf_ibs_suspend,
279 static void perf_ibs_pm_init(void)
281 register_syscore_ops(&perf_ibs_syscore_ops);
286 static inline void perf_ibs_pm_init(void) { }
291 perf_ibs_cpu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
293 switch (action & ~CPU_TASKS_FROZEN) {
295 setup_APIC_ibs(NULL);
298 clear_APIC_ibs(NULL);
307 static __init int amd_ibs_init(void)
312 caps = __get_ibs_caps();
314 return -ENODEV; /* ibs not supported by the cpu */
318 if (!ibs_eilvt_valid())
324 /* make ibs_caps visible to other cpus: */
326 perf_cpu_notifier(perf_ibs_cpu_notifier);
327 smp_call_function(setup_APIC_ibs, NULL, 1);
330 ret = perf_event_ibs_init();
333 pr_err("Failed to setup IBS, %d\n", ret);
337 /* Since we need the pci subsystem to init ibs we can't do this earlier: */
338 device_initcall(amd_ibs_init);