[V3][PATCH 2/7] perf, x86: Implement IBS initialization

Robert Richter
2011-09-21T10:56:49Z

This patch implements IBS feature detection and initialzation. The
code is shared between perf and oprofile. If ibs is available on the
system for perf, a pmu is setup.

V2:
* Remove printks in pmu function stubs.
* Modify perf_event_ibs_init() to use ibs_caps directly.

Signed-off-by: Robert Richter <robert.richter@amd.com>
---
arch/x86/include/asm/perf_event.h | 2 +
arch/x86/kernel/cpu/Makefile | 2 +-
arch/x86/kernel/cpu/perf_event_amd_ibs.c | 292 ++++++++++++++++++++++++++++++
arch/x86/oprofile/nmi_int.c | 2 -
arch/x86/oprofile/op_model_amd.c | 197 --------------------
arch/x86/oprofile/op_x86_model.h | 1 -
6 files changed, 295 insertions(+), 201 deletions(-)
create mode 100644 arch/x86/kernel/cpu/perf_event_amd_ibs.c

diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index bc801ac..e7d2f15 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -156,6 +156,8 @@ union cpuid10_edx {
#define IBS_OP_MAX_CNT 0x0000FFFFULL
#define IBS_OP_MAX_CNT_EXT 0x007FFFFFULL /* not a register bit mask */

+extern u32 get_ibs_caps(void);
+
#ifdef CONFIG_PERF_EVENTS
extern void perf_events_lapic_init(void);

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 6042981..ab70cd1 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -31,7 +31,7 @@ obj-$(CONFIG_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_X86_MCE) += mcheck/
obj-$(CONFIG_MTRR) += mtrr/

-obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o
+obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o perf_event_amd_ibs.o

quiet_cmd_mkcapflags = MKCAP $@
cmd_mkcapflags = $(PERL) $(srctree)/$(src)/mkcapflags.pl $< $@
diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
new file mode 100644
index 0000000..1ae5154
--- /dev/null
+++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
@@ -0,0 +1,292 @@
+/*
+ * Performance events - AMD IBS
+ *
+ * Copyright (C) 2011 Advanced Micro Devices, Inc., Robert Richter
+ *
+ * For licencing details see kernel-base/COPYING
+ */
+
+#include <linux/perf_event.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+static u32 ibs_caps;
+
+#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD)
+
+static struct pmu perf_ibs;
+
+static int perf_ibs_init(struct perf_event *event)
+{
+ if (perf_ibs.type != event->attr.type)
+ return -ENOENT;
+ return 0;
+}
+
+static int perf_ibs_add(struct perf_event *event, int flags)
+{
+ return 0;
+}
+
+static void perf_ibs_del(struct perf_event *event, int flags)
+{
+}
+
+static struct pmu perf_ibs = {
+ .event_init= perf_ibs_init,
+ .add= perf_ibs_add,
+ .del= perf_ibs_del,
+};
+
+static __init int perf_event_ibs_init(void)
+{
+ if (!ibs_caps)
+ return -ENODEV; /* ibs not supported by the cpu */
+
+ perf_pmu_register(&perf_ibs, "ibs", -1);
+ printk(KERN_INFO "perf: AMD IBS detected (0x%08x)\n", ibs_caps);
+
+ return 0;
+}
+
+#else /* defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD) */
+
+static __init int perf_event_ibs_init(void) { return 0; }
+
+#endif
+
+/* IBS - apic initialization, for perf and oprofile */
+
+static __init u32 __get_ibs_caps(void)
+{
+ u32 caps;
+ unsigned int max_level;
+
+ if (!boot_cpu_has(X86_FEATURE_IBS))
+ return 0;
+
+ /* check IBS cpuid feature flags */
+ max_level = cpuid_eax(0x80000000);
+ if (max_level < IBS_CPUID_FEATURES)
+ return IBS_CAPS_DEFAULT;
+
+ caps = cpuid_eax(IBS_CPUID_FEATURES);
+ if (!(caps & IBS_CAPS_AVAIL))
+ /* cpuid flags not valid */
+ return IBS_CAPS_DEFAULT;
+
+ return caps;
+}
+
+u32 get_ibs_caps(void)
+{
+ return ibs_caps;
+}
+
+EXPORT_SYMBOL(get_ibs_caps);
+
+static inline int get_eilvt(int offset)
+{
+ return !setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 1);
+}
+
+static inline int put_eilvt(int offset)
+{
+ return !setup_APIC_eilvt(offset, 0, 0, 1);
+}
+
+/*
+ * Check and reserve APIC extended interrupt LVT offset for IBS if available.
+ */
+static inline int ibs_eilvt_valid(void)
+{
+ int offset;
+ u64 val;
+ int valid = 0;
+
+ preempt_disable();
+
+ rdmsrl(MSR_AMD64_IBSCTL, val);
+ offset = val & IBSCTL_LVT_OFFSET_MASK;
+
+ if (!(val & IBSCTL_LVT_OFFSET_VALID)) {
+ pr_err(FW_BUG "cpu %d, invalid IBS interrupt offset %d (MSR%08X=0x%016llx)\n",
+ smp_processor_id(), offset, MSR_AMD64_IBSCTL, val);
+ goto out;
+ }
+
+ if (!get_eilvt(offset)) {
+ pr_err(FW_BUG "cpu %d, IBS interrupt offset %d not available (MSR%08X=0x%016llx)\n",
+ smp_processor_id(), offset, MSR_AMD64_IBSCTL, val);
+ goto out;
+ }
+
+ valid = 1;
+out:
+ preempt_enable();
+
+ return valid;
+}
+
+static int setup_ibs_ctl(int ibs_eilvt_off)
+{
+ struct pci_dev *cpu_cfg;
+ int nodes;
+ u32 value = 0;
+
+ nodes = 0;
+ cpu_cfg = NULL;
+ do {
+ cpu_cfg = pci_get_device(PCI_VENDOR_ID_AMD,
+ PCI_DEVICE_ID_AMD_10H_NB_MISC,
+ cpu_cfg);
+ if (!cpu_cfg)
+ break;
+ ++nodes;
+ pci_write_config_dword(cpu_cfg, IBSCTL, ibs_eilvt_off
+ | IBSCTL_LVT_OFFSET_VALID);
+ pci_read_config_dword(cpu_cfg, IBSCTL, &value);
+ if (value != (ibs_eilvt_off | IBSCTL_LVT_OFFSET_VALID)) {
+ pci_dev_put(cpu_cfg);
+ printk(KERN_DEBUG "Failed to setup IBS LVT offset, "
+ "IBSCTL = 0x%08x\n", value);
+ return -EINVAL;
+ }
+ } while (1);
+
+ if (!nodes) {
+ printk(KERN_DEBUG "No CPU node configured for IBS\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+/*
+ * This runs only on the current cpu. We try to find an LVT offset and
+ * setup the local APIC. For this we must disable preemption. On
+ * success we initialize all nodes with this offset. This updates then
+ * the offset in the IBS_CTL per-node msr. The per-core APIC setup of
+ * the IBS interrupt vector is handled by perf_ibs_cpu_notifier that
+ * is using the new offset.
+ */
+static int force_ibs_eilvt_setup(void)
+{
+ int offset;
+ int ret;
+
+ preempt_disable();
+ /* find the next free available EILVT entry, skip offset 0 */
+ for (offset = 1; offset < APIC_EILVT_NR_MAX; offset++) {
+ if (get_eilvt(offset))
+ break;
+ }
+ preempt_enable();
+
+ if (offset == APIC_EILVT_NR_MAX) {
+ printk(KERN_DEBUG "No EILVT entry available\n");
+ return -EBUSY;
+ }
+
+ ret = setup_ibs_ctl(offset);
+ if (ret)
+ goto out;
+
+ if (!ibs_eilvt_valid()) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ pr_err(FW_BUG "using offset %d for IBS interrupts\n", offset);
+ pr_err(FW_BUG "workaround enabled for IBS LVT offset\n");
+
+ return 0;
+out:
+ preempt_disable();
+ put_eilvt(offset);
+ preempt_enable();
+ return ret;
+}
+
+static inline int get_ibs_lvt_offset(void)
+{
+ u64 val;
+
+ rdmsrl(MSR_AMD64_IBSCTL, val);
+ if (!(val & IBSCTL_LVT_OFFSET_VALID))
+ return -EINVAL;
+
+ return val & IBSCTL_LVT_OFFSET_MASK;
+}
+
+static void setup_APIC_ibs(void *dummy)
+{
+ int offset;
+
+ offset = get_ibs_lvt_offset();
+ if (offset < 0)
+ goto failed;
+
+ if (!setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 0))
+ return;
+failed:
+ pr_warn("perf: IBS APIC setup failed on cpu #%d\n",
+ smp_processor_id());
+}
+
+static void clear_APIC_ibs(void *dummy)
+{
+ int offset;
+
+ offset = get_ibs_lvt_offset();
+ if (offset >= 0)
+ setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_FIX, 1);
+}
+
+static int __cpuinit
+perf_ibs_cpu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
+{
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_STARTING:
+ setup_APIC_ibs(NULL);
+ break;
+ case CPU_DYING:
+ clear_APIC_ibs(NULL);
+ break;
+ default:
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static __init int amd_ibs_init(void)
+{
+ u32 caps;
+ int ret;
+
+ caps = __get_ibs_caps();
+ if (!caps)
+ return -ENODEV; /* ibs not supported by the cpu */
+
+ if (!ibs_eilvt_valid()) {
+ ret = force_ibs_eilvt_setup();
+ if (ret) {
+ pr_err("Failed to setup IBS, %d\n", ret);
+ return ret;
+ }
+ }
+
+ get_online_cpus();
+ ibs_caps = caps;
+ /* make ibs_caps visible to other cpus: */
+ smp_mb();
+ perf_cpu_notifier(perf_ibs_cpu_notifier);
+ smp_call_function(setup_APIC_ibs, NULL, 1);
+ put_online_cpus();
+
+ return perf_event_ibs_init();
+}
+
+/* Since we need the pci subsystem to init ibs we can't do this earlier: */
+device_initcall(amd_ibs_init);
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index adf8fb3..c04dc14 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -385,8 +385,6 @@ static void nmi_cpu_shutdown(void *dummy)
apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
apic_write(APIC_LVTERR, v);
nmi_cpu_restore_registers(msrs);
- if (model->cpu_down)
- model->cpu_down();
}

static void nmi_cpu_up(void *dummy)
diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index e947e5c..303f086 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -74,27 +74,6 @@ static struct ibs_state ibs_state;
#define IBS_RANDOM_MASK ((1ULL << IBS_RANDOM_BITS) - 1)
#define IBS_RANDOM_MAXCNT_OFFSET (1ULL << (IBS_RANDOM_BITS - 5))

-static u32 get_ibs_caps(void)
-{
- u32 ibs_caps;
- unsigned int max_level;
-
- if (!boot_cpu_has(X86_FEATURE_IBS))
- return 0;
-
- /* check IBS cpuid feature flags */
- max_level = cpuid_eax(0x80000000);
- if (max_level < IBS_CPUID_FEATURES)
- return IBS_CAPS_DEFAULT;
-
- ibs_caps = cpuid_eax(IBS_CPUID_FEATURES);
- if (!(ibs_caps & IBS_CAPS_AVAIL))
- /* cpuid flags not valid */
- return IBS_CAPS_DEFAULT;
-
- return ibs_caps;
-}
-
/*
* 16-bit Linear Feedback Shift Register (LFSR)
*
@@ -285,81 +264,6 @@ static void op_amd_stop_ibs(void)
wrmsrl(MSR_AMD64_IBSOPCTL, 0);
}

-static inline int get_eilvt(int offset)
-{
- return !setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 1);
-}
-
-static inline int put_eilvt(int offset)
-{
- return !setup_APIC_eilvt(offset, 0, 0, 1);
-}
-
-static inline int ibs_eilvt_valid(void)
-{
- int offset;
- u64 val;
- int valid = 0;
-
- preempt_disable();
-
- rdmsrl(MSR_AMD64_IBSCTL, val);
- offset = val & IBSCTL_LVT_OFFSET_MASK;
-
- if (!(val & IBSCTL_LVT_OFFSET_VALID)) {
- pr_err(FW_BUG "cpu %d, invalid IBS interrupt offset %d (MSR%08X=0x%016llx)\n",
- smp_processor_id(), offset, MSR_AMD64_IBSCTL, val);
- goto out;
- }
-
- if (!get_eilvt(offset)) {
- pr_err(FW_BUG "cpu %d, IBS interrupt offset %d not available (MSR%08X=0x%016llx)\n",
- smp_processor_id(), offset, MSR_AMD64_IBSCTL, val);
- goto out;
- }
-
- valid = 1;
-out:
- preempt_enable();
-
- return valid;
-}
-
-static inline int get_ibs_offset(void)
-{
- u64 val;
-
- rdmsrl(MSR_AMD64_IBSCTL, val);
- if (!(val & IBSCTL_LVT_OFFSET_VALID))
- return -EINVAL;
-
- return val & IBSCTL_LVT_OFFSET_MASK;
-}
-
-static void setup_APIC_ibs(void)
-{
- int offset;
-
- offset = get_ibs_offset();
- if (offset < 0)
- goto failed;
-
- if (!setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 0))
- return;
-failed:
- pr_warn("oprofile: IBS APIC setup failed on cpu #%d\n",
- smp_processor_id());
-}
-
-static void clear_APIC_ibs(void)
-{
- int offset;
-
- offset = get_ibs_offset();
- if (offset >= 0)
- setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_FIX, 1);
-}
-
#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX

static void op_mux_switch_ctrl(struct op_x86_model_spec const *model,
@@ -473,15 +377,6 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
val |= op_x86_get_ctrl(model, &counter_config[virt]);
wrmsrl(msrs->controls[i].addr, val);
}
-
- if (ibs_caps)
- setup_APIC_ibs();
-}
-
-static void op_amd_cpu_shutdown(void)
-{
- if (ibs_caps)
- clear_APIC_ibs();
}

static int op_amd_check_ctrs(struct pt_regs * const regs,
@@ -544,86 +439,6 @@ static void op_amd_stop(struct op_msrs const * const msrs)
op_amd_stop_ibs();
}

-static int setup_ibs_ctl(int ibs_eilvt_off)
-{
- struct pci_dev *cpu_cfg;
- int nodes;
- u32 value = 0;
-
- nodes = 0;
- cpu_cfg = NULL;
- do {
- cpu_cfg = pci_get_device(PCI_VENDOR_ID_AMD,
- PCI_DEVICE_ID_AMD_10H_NB_MISC,
- cpu_cfg);
- if (!cpu_cfg)
- break;
- ++nodes;
- pci_write_config_dword(cpu_cfg, IBSCTL, ibs_eilvt_off
- | IBSCTL_LVT_OFFSET_VALID);
- pci_read_config_dword(cpu_cfg, IBSCTL, &value);
- if (value != (ibs_eilvt_off | IBSCTL_LVT_OFFSET_VALID)) {
- pci_dev_put(cpu_cfg);
- printk(KERN_DEBUG "Failed to setup IBS LVT offset, "
- "IBSCTL = 0x%08x\n", value);
- return -EINVAL;
- }
- } while (1);
-
- if (!nodes) {
- printk(KERN_DEBUG "No CPU node configured for IBS\n");
- return -ENODEV;
- }
-
- return 0;
-}
-
-/*
- * This runs only on the current cpu. We try to find an LVT offset and
- * setup the local APIC. For this we must disable preemption. On
- * success we initialize all nodes with this offset. This updates then
- * the offset in the IBS_CTL per-node msr. The per-core APIC setup of
- * the IBS interrupt vector is called from op_amd_setup_ctrs()/op_-
- * amd_cpu_shutdown() using the new offset.
- */
-static int force_ibs_eilvt_setup(void)
-{
- int offset;
- int ret;
-
- preempt_disable();
- /* find the next free available EILVT entry, skip offset 0 */
- for (offset = 1; offset < APIC_EILVT_NR_MAX; offset++) {
- if (get_eilvt(offset))
- break;
- }
- preempt_enable();
-
- if (offset == APIC_EILVT_NR_MAX) {
- printk(KERN_DEBUG "No EILVT entry available\n");
- return -EBUSY;
- }
-
- ret = setup_ibs_ctl(offset);
- if (ret)
- goto out;
-
- if (!ibs_eilvt_valid()) {
- ret = -EFAULT;
- goto out;
- }
-
- pr_err(FW_BUG "using offset %d for IBS interrupts\n", offset);
- pr_err(FW_BUG "workaround enabled for IBS LVT offset\n");
-
- return 0;
-out:
- preempt_disable();
- put_eilvt(offset);
- preempt_enable();
- return ret;
-}
-
/*
* check and reserve APIC extended interrupt LVT offset for IBS if
* available
@@ -636,17 +451,6 @@ static void init_ibs(void)
if (!ibs_caps)
return;

- if (ibs_eilvt_valid())
- goto out;
-
- if (!force_ibs_eilvt_setup())
- goto out;
-
- /* Failed to setup ibs */
- ibs_caps = 0;
- return;
-
-out:
printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n", ibs_caps);
}

@@ -729,7 +533,6 @@ struct op_x86_model_spec op_amd_spec = {
.init = op_amd_init,
.fill_in_addresses = &op_amd_fill_in_addresses,
.setup_ctrs = &op_amd_setup_ctrs,
- .cpu_down = &op_amd_cpu_shutdown,
.check_ctrs = &op_amd_check_ctrs,
.start = &op_amd_start,
.stop = &op_amd_stop,
diff --git a/arch/x86/oprofile/op_x86_model.h b/arch/x86/oprofile/op_x86_model.h
index 89017fa..71e8a67 100644
--- a/arch/x86/oprofile/op_x86_model.h
+++ b/arch/x86/oprofile/op_x86_model.h
@@ -43,7 +43,6 @@ struct op_x86_model_spec {
int (*fill_in_addresses)(struct op_msrs * const msrs);
void (*setup_ctrs)(struct op_x86_model_spec const *model,
struct op_msrs const * const msrs);
- void (*cpu_down)(void);
int (*check_ctrs)(struct pt_regs * const regs,
struct op_msrs const * const msrs);
void (*start)(struct op_msrs const * const msrs);
--
1.7.6.1