perf, x86: Implement initial P4 PMU driver

The netburst PMU is way different from the "architectural
perfomance monitoring" specification that current CPUs use.
P4 uses a tuple of ESCR+CCCR+COUNTER MSR registers to handle
perfomance monitoring events.

A few implementational details:

1) We need a separate x86_pmu::hw_config helper in struct
   x86_pmu since register bit-fields are quite different from P6,
   Core and later cpu series.

2) For the same reason is a x86_pmu::schedule_events helper
   introduced.

3) hw_perf_event::config consists of packed ESCR+CCCR values.
   It's allowed since in reality both registers only use a half
   of their size. Of course before making a real write into a
   particular MSR we need to unpack the value and extend it to
   a proper size.

4) The tuple of packed ESCR+CCCR in hw_perf_event::config
   doesn't describe the memory address of ESCR MSR register
   so that we need to keep a mapping between these tuples
   used and available ESCR (various P4 events may use same
   ESCRs but not simultaneously), for this sake every active
   event has a per-cpu map of hw_perf_event::idx <--> ESCR
   addresses.

5) Since hw_perf_event::idx is an offset to counter/control register
   we need to lift X86_PMC_MAX_GENERIC up, otherwise kernel
   strips it down to 8 registers and event armed may never be turned
   off (ie the bit in active_mask is set but the loop never reaches
   this index to check), thanks to Peter Zijlstra

Restrictions:

 - No cascaded counters support (do we ever need them?)
 - No dependent events support (so PERF_COUNT_HW_INSTRUCTIONS
   doesn't work for now)
 - There are events with same counters which can't work simultaneously
   (need to use intersected ones due to broken counter 1)
 - No PERF_COUNT_HW_CACHE_ events yet

Todo:

 - Implement dependent events
 - Need proper hashing for event opcodes (no linear search, good for
   debugging stage but not in real loads)
 - Some events counted during a clock cycle -- need to set threshold
   for them and count every clock cycle just to get summary statistics
   (ie to behave the same way as other PMUs do)
 - Need to swicth to use event_constraints
 - To support RAW events we need to encode a global list of P4 events
   into p4_templates
 - Cache events need to be added

Event support status matrix:

 Event			status
 -----------------------------
 cycles			works
 cache-references	works
 cache-misses		works
 branch-misses		works
 bus-cycles		partially (does not work on 64bit cpu with HT enabled)
 instruction		doesnt work (needs dependent event [mop tagging])
 branches		doesnt work
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100311165439.GB5129@lenovo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/include/asm/perf_event.h

@@ -5,7 +5,7 @@
  * Performance event hw details:
  */
 
-#define X86_PMC_MAX_GENERIC					8
+#define X86_PMC_MAX_GENERIC				       32
 #define X86_PMC_MAX_FIXED					3
 
 #define X86_PMC_IDX_GENERIC				        0

arch/x86/kernel/cpu/perf_event.c

@@ -190,6 +190,8 @@ struct x86_pmu {
 	void		(*enable_all)(void);
 	void		(*enable)(struct perf_event *);
 	void		(*disable)(struct perf_event *);
+	int		(*hw_config)(struct perf_event_attr *attr, struct hw_perf_event *hwc);
+	int		(*schedule_events)(struct cpu_hw_events *cpuc, int n, int *assign);
 	unsigned	eventsel;
 	unsigned	perfctr;
 	u64		(*event_map)(int);
@@ -415,6 +417,25 @@ set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event_attr *attr)
 	return 0;
 }
 
+static int x86_hw_config(struct perf_event_attr *attr, struct hw_perf_event *hwc)
+{
+	/*
+	 * Generate PMC IRQs:
+	 * (keep 'enabled' bit clear for now)
+	 */
+	hwc->config = ARCH_PERFMON_EVENTSEL_INT;
+
+	/*
+	 * Count user and OS events unless requested not to
+	 */
+	if (!attr->exclude_user)
+		hwc->config |= ARCH_PERFMON_EVENTSEL_USR;
+	if (!attr->exclude_kernel)
+		hwc->config |= ARCH_PERFMON_EVENTSEL_OS;
+
+	return 0;
+}
+
 /*
  * Setup the hardware configuration for a given attr_type
  */
@@ -446,23 +467,13 @@ static int __hw_perf_event_init(struct perf_event *event)
 
 	event->destroy = hw_perf_event_destroy;
 
-	/*
-	 * Generate PMC IRQs:
-	 * (keep 'enabled' bit clear for now)
-	 */
-	hwc->config = ARCH_PERFMON_EVENTSEL_INT;
-
 	hwc->idx = -1;
 	hwc->last_cpu = -1;
 	hwc->last_tag = ~0ULL;
 
-	/*
-	 * Count user and OS events unless requested not to.
-	 */
-	if (!attr->exclude_user)
-		hwc->config |= ARCH_PERFMON_EVENTSEL_USR;
-	if (!attr->exclude_kernel)
-		hwc->config |= ARCH_PERFMON_EVENTSEL_OS;
+	/* Processor specifics */
+	if (x86_pmu.hw_config(attr, hwc))
+		return -EOPNOTSUPP;
 
 	if (!hwc->sample_period) {
 		hwc->sample_period = x86_pmu.max_period;
@@ -517,7 +528,7 @@ static int __hw_perf_event_init(struct perf_event *event)
 			return -EOPNOTSUPP;
 
 		/* BTS is currently only allowed for user-mode. */
-		if (hwc->config & ARCH_PERFMON_EVENTSEL_OS)
+		if (!attr->exclude_kernel)
 			return -EOPNOTSUPP;
 	}
 
@@ -931,7 +942,7 @@ static int x86_pmu_enable(struct perf_event *event)
 	if (n < 0)
 		return n;
 
-	ret = x86_schedule_events(cpuc, n, assign);
+	ret = x86_pmu.schedule_events(cpuc, n, assign);
 	if (ret)
 		return ret;
 	/*
@@ -1263,7 +1274,7 @@ int hw_perf_group_sched_in(struct perf_event *leader,
 	if (n0 < 0)
 		return n0;
 
-	ret = x86_schedule_events(cpuc, n0, assign);
+	ret = x86_pmu.schedule_events(cpuc, n0, assign);
 	if (ret)
 		return ret;
 
@@ -1313,6 +1324,7 @@ int hw_perf_group_sched_in(struct perf_event *leader,
 
 #include "perf_event_amd.c"
 #include "perf_event_p6.c"
+#include "perf_event_p4.c"
 #include "perf_event_intel_lbr.c"
 #include "perf_event_intel_ds.c"
 #include "perf_event_intel.c"
@@ -1515,7 +1527,7 @@ static int validate_group(struct perf_event *event)
 
 	fake_cpuc->n_events = n;
 
-	ret = x86_schedule_events(fake_cpuc, n, NULL);
+	ret = x86_pmu.schedule_events(fake_cpuc, n, NULL);
 
 out_free:
 	kfree(fake_cpuc);

arch/x86/kernel/cpu/perf_event_amd.c

@@ -363,6 +363,8 @@ static __initconst struct x86_pmu amd_pmu = {
 	.enable_all		= x86_pmu_enable_all,
 	.enable			= x86_pmu_enable_event,
 	.disable		= x86_pmu_disable_event,
+	.hw_config		= x86_hw_config,
+	.schedule_events	= x86_schedule_events,
 	.eventsel		= MSR_K7_EVNTSEL0,
 	.perfctr		= MSR_K7_PERFCTR0,
 	.event_map		= amd_pmu_event_map,

arch/x86/kernel/cpu/perf_event_intel.c

@@ -749,6 +749,8 @@ static __initconst struct x86_pmu core_pmu = {
 	.enable_all		= x86_pmu_enable_all,
 	.enable			= x86_pmu_enable_event,
 	.disable		= x86_pmu_disable_event,
+	.hw_config		= x86_hw_config,
+	.schedule_events	= x86_schedule_events,
 	.eventsel		= MSR_ARCH_PERFMON_EVENTSEL0,
 	.perfctr		= MSR_ARCH_PERFMON_PERFCTR0,
 	.event_map		= intel_pmu_event_map,
@@ -786,6 +788,8 @@ static __initconst struct x86_pmu intel_pmu = {
 	.enable_all		= intel_pmu_enable_all,
 	.enable			= intel_pmu_enable_event,
 	.disable		= intel_pmu_disable_event,
+	.hw_config		= x86_hw_config,
+	.schedule_events	= x86_schedule_events,
 	.eventsel		= MSR_ARCH_PERFMON_EVENTSEL0,
 	.perfctr		= MSR_ARCH_PERFMON_PERFCTR0,
 	.event_map		= intel_pmu_event_map,
@@ -839,12 +843,13 @@ static __init int intel_pmu_init(void)
 	int version;
 
 	if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
-		/* check for P6 processor family */
-	   if (boot_cpu_data.x86 == 6) {
-		return p6_pmu_init();
-	   } else {
+		switch (boot_cpu_data.x86) {
+		case 0x6:
+			return p6_pmu_init();
+		case 0xf:
+			return p4_pmu_init();
+		}
 		return -ENODEV;
-	   }
 	}
 
 	/*

arch/x86/kernel/cpu/perf_event_p4.c

+/*
+ * Netburst Perfomance Events (P4, old Xeon)
+ *
+ *  Copyright (C) 2010 Parallels, Inc., Cyrill Gorcunov <gorcunov@openvz.org>
+ *  Copyright (C) 2010 Intel Corporation, Lin Ming <ming.m.lin@intel.com>
+ *
+ *  For licencing details see kernel-base/COPYING
+ */
+
+#ifdef CONFIG_CPU_SUP_INTEL
+
+#include <asm/perf_event_p4.h>
+
+/*
+ * array indices: 0,1 - HT threads, used with HT enabled cpu
+ */
+struct p4_event_template {
+	u32 opcode;			/* ESCR event + CCCR selector */
+	u64 config;			/* packed predefined bits */
+	int dep;			/* upstream dependency event index */
+	unsigned int emask;		/* ESCR EventMask */
+	unsigned int escr_msr[2];	/* ESCR MSR for this event */
+	unsigned int cntr[2];		/* counter index (offset) */
+};
+
+struct p4_pmu_res {
+	/* maps hw_conf::idx into template for ESCR sake */
+	struct p4_event_template *tpl[ARCH_P4_MAX_CCCR];
+};
+
+static DEFINE_PER_CPU(struct p4_pmu_res, p4_pmu_config);
+
+/*
+ * WARN: CCCR1 doesn't have a working enable bit so try to not
+ * use it if possible
+ *
+ * Also as only we start to support raw events we will need to
+ * append _all_ P4_EVENT_PACK'ed events here
+ */
+struct p4_event_template p4_templates[] = {
+	[0] = {
+		.opcode	= P4_UOP_TYPE,
+		.config	= 0,
+		.dep	= -1,
+		.emask	=
+			P4_EVENT_ATTR(P4_UOP_TYPE, TAGLOADS)	|
+			P4_EVENT_ATTR(P4_UOP_TYPE, TAGSTORES),
+		.escr_msr	= { MSR_P4_RAT_ESCR0, MSR_P4_RAT_ESCR1 },
+		.cntr		= { 16, 17 },
+	},
+	[1] = {
+		.opcode	= P4_GLOBAL_POWER_EVENTS,
+		.config	= 0,
+		.dep	= -1,
+		.emask	=
+			P4_EVENT_ATTR(P4_GLOBAL_POWER_EVENTS, RUNNING),
+		.escr_msr	= { MSR_P4_FSB_ESCR0, MSR_P4_FSB_ESCR1 },
+		.cntr		= { 0, 2 },
+	},
+	[2] = {
+		.opcode	= P4_INSTR_RETIRED,
+		.config	= 0,
+		.dep	= 0, /* needs front-end tagging */
+		.emask	=
+			P4_EVENT_ATTR(P4_INSTR_RETIRED, NBOGUSNTAG)	|
+			P4_EVENT_ATTR(P4_INSTR_RETIRED, NBOGUSTAG)	|
+			P4_EVENT_ATTR(P4_INSTR_RETIRED, BOGUSNTAG)	|
+			P4_EVENT_ATTR(P4_INSTR_RETIRED, BOGUSTAG),
+		.escr_msr	= { MSR_P4_CRU_ESCR2, MSR_P4_CRU_ESCR3 },
+		.cntr		= { 12, 14 },
+	},
+	[3] = {
+		.opcode	= P4_BSQ_CACHE_REFERENCE,
+		.config	= 0,
+		.dep	= -1,
+		.emask	=
+			P4_EVENT_ATTR(P4_BSQ_CACHE_REFERENCE, RD_2ndL_HITS)	|
+			P4_EVENT_ATTR(P4_BSQ_CACHE_REFERENCE, RD_2ndL_HITE)	|
+			P4_EVENT_ATTR(P4_BSQ_CACHE_REFERENCE, RD_2ndL_HITM)	|
+			P4_EVENT_ATTR(P4_BSQ_CACHE_REFERENCE, RD_3rdL_HITS)	|
+			P4_EVENT_ATTR(P4_BSQ_CACHE_REFERENCE, RD_3rdL_HITE)	|
+			P4_EVENT_ATTR(P4_BSQ_CACHE_REFERENCE, RD_3rdL_HITM),
+		.escr_msr	= { MSR_P4_BSU_ESCR0, MSR_P4_BSU_ESCR1 },
+		.cntr		= { 0, 2 },
+	},
+	[4] = {
+		.opcode	= P4_BSQ_CACHE_REFERENCE,
+		.config	= 0,
+		.dep	= -1,
+		.emask	=
+			P4_EVENT_ATTR(P4_BSQ_CACHE_REFERENCE, RD_2ndL_MISS)	|
+			P4_EVENT_ATTR(P4_BSQ_CACHE_REFERENCE, RD_3rdL_MISS)	|
+			P4_EVENT_ATTR(P4_BSQ_CACHE_REFERENCE, WR_2ndL_MISS),
+		.escr_msr	= { MSR_P4_BSU_ESCR0, MSR_P4_BSU_ESCR1 },
+		.cntr		= { 0, 3 },
+	},
+	[5] = {
+		.opcode	= P4_RETIRED_BRANCH_TYPE,
+		.config	= 0,
+		.dep	= -1,
+		.emask	=
+			P4_EVENT_ATTR(P4_RETIRED_BRANCH_TYPE, CONDITIONAL)	|
+			P4_EVENT_ATTR(P4_RETIRED_BRANCH_TYPE, CALL)		|
+			P4_EVENT_ATTR(P4_RETIRED_BRANCH_TYPE, RETURN)		|
+			P4_EVENT_ATTR(P4_RETIRED_BRANCH_TYPE, INDIRECT),
+		.escr_msr	= { MSR_P4_TBPU_ESCR0, MSR_P4_TBPU_ESCR1 },
+		.cntr		= { 4, 6 },
+	},
+	[6] = {
+		.opcode	= P4_MISPRED_BRANCH_RETIRED,
+		.config	= 0,
+		.dep	= -1,
+		.emask	=
+			P4_EVENT_ATTR(P4_MISPRED_BRANCH_RETIRED, NBOGUS),
+		.escr_msr	= { MSR_P4_CRU_ESCR0, MSR_P4_CRU_ESCR1 },
+		.cntr		= { 12, 14 },
+	},
+	[7] = {
+		.opcode	= P4_FSB_DATA_ACTIVITY,
+		.config	= p4_config_pack_cccr(P4_CCCR_EDGE | P4_CCCR_COMPARE),
+		.dep	= -1,
+		.emask	=
+			P4_EVENT_ATTR(P4_FSB_DATA_ACTIVITY, DRDY_DRV)	|
+			P4_EVENT_ATTR(P4_FSB_DATA_ACTIVITY, DRDY_OWN),
+		.escr_msr	= { MSR_P4_FSB_ESCR0, MSR_P4_FSB_ESCR1 },
+		.cntr		= { 0, 2 },
+	},
+};
+
+static struct p4_event_template *p4_event_map[PERF_COUNT_HW_MAX] = {
+	/* non-halted CPU clocks */
+	[PERF_COUNT_HW_CPU_CYCLES]		= &p4_templates[1],
+
+	/* retired instructions: dep on tagging the FSB */
+	[PERF_COUNT_HW_INSTRUCTIONS]		= &p4_templates[2],
+
+	/* cache hits */
+	[PERF_COUNT_HW_CACHE_REFERENCES]	= &p4_templates[3],
+
+	/* cache misses */
+	[PERF_COUNT_HW_CACHE_MISSES]		= &p4_templates[4],
+
+	/* branch instructions retired */
+	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= &p4_templates[5],
+
+	/* mispredicted branches retired */
+	[PERF_COUNT_HW_BRANCH_MISSES]		= &p4_templates[6],
+
+	/* bus ready clocks (cpu is driving #DRDY_DRV\#DRDY_OWN):  */
+	[PERF_COUNT_HW_BUS_CYCLES]		= &p4_templates[7],
+};
+
+static u64 p4_pmu_event_map(int hw_event)
+{
+	struct p4_event_template *tpl;
+	u64 config;
+
+	if (hw_event > ARRAY_SIZE(p4_event_map)) {
+		printk_once(KERN_ERR "PMU: Incorrect event index\n");
+		return 0;
+	}
+	tpl = p4_event_map[hw_event];
+
+	/*
+	 * fill config up according to
+	 * a predefined event template
+	 */
+	config  = tpl->config;
+	config |= p4_config_pack_escr(P4_EVENT_UNPACK_EVENT(tpl->opcode) << P4_EVNTSEL_EVENT_SHIFT);
+	config |= p4_config_pack_escr(tpl->emask << P4_EVNTSEL_EVENTMASK_SHIFT);
+	config |= p4_config_pack_cccr(P4_EVENT_UNPACK_SELECTOR(tpl->opcode) << P4_CCCR_ESCR_SELECT_SHIFT);
+
+	/* on HT machine we need a special bit */
+	if (p4_ht_active() && p4_ht_thread(raw_smp_processor_id()))
+		config = p4_set_ht_bit(config);
+
+	return config;
+}
+
+/*
+ * Note that we still have 5 events (from global events SDM list)
+ * intersected in opcode+emask bits so we will need another
+ * scheme there do distinguish templates.
+ */
+static inline int p4_pmu_emask_match(unsigned int dst, unsigned int src)
+{
+	return dst & src;
+}
+
+static struct p4_event_template *p4_pmu_template_lookup(u64 config)
+{
+	u32 opcode = p4_config_unpack_opcode(config);
+	unsigned int emask = p4_config_unpack_emask(config);
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(p4_templates); i++) {
+		if (opcode == p4_templates[i].opcode &&
+			p4_pmu_emask_match(emask, p4_templates[i].emask))
+			return &p4_templates[i];
+	}
+
+	return NULL;
+}
+
+/*
+ * We don't control raw events so it's up to the caller
+ * to pass sane values (and we don't count the thread number
+ * on HT machine but allow HT-compatible specifics to be
+ * passed on)
+ */
+static u64 p4_pmu_raw_event(u64 hw_event)
+{
+	return hw_event &
+		(p4_config_pack_escr(P4_EVNTSEL_MASK_HT) |
+		 p4_config_pack_cccr(P4_CCCR_MASK_HT));
+}
+
+static int p4_hw_config(struct perf_event_attr *attr, struct hw_perf_event *hwc)
+{
+	int cpu = raw_smp_processor_id();
+
+	/*
+	 * the reason we use cpu that early is that: if we get scheduled
+	 * first time on the same cpu -- we will not need swap thread
+	 * specific flags in config (and will save some cpu cycles)
+	 */
+
+	/* CCCR by default */
+	hwc->config = p4_config_pack_cccr(p4_default_cccr_conf(cpu));
+
+	/* Count user and OS events unless not requested to */
+	hwc->config |= p4_config_pack_escr(p4_default_escr_conf(cpu, attr->exclude_kernel,
+								attr->exclude_user));
+	return 0;
+}
+
+static inline void p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc)
+{
+	unsigned long dummy;
+
+	rdmsrl(hwc->config_base + hwc->idx, dummy);
+	if (dummy & P4_CCCR_OVF) {
+		(void)checking_wrmsrl(hwc->config_base + hwc->idx,
+			((u64)dummy) & ~P4_CCCR_OVF);
+	}
+}
+
+static inline void p4_pmu_disable_event(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	/*
+	 * If event gets disabled while counter is in overflowed
+	 * state we need to clear P4_CCCR_OVF, otherwise interrupt get
+	 * asserted again and again
+	 */
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx,
+		(u64)(p4_config_unpack_cccr(hwc->config)) &
+			~P4_CCCR_ENABLE & ~P4_CCCR_OVF);
+}
+
+static void p4_pmu_disable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	int idx;
+
+	for (idx = 0; idx < x86_pmu.num_events; idx++) {
+		struct perf_event *event = cpuc->events[idx];
+		if (!test_bit(idx, cpuc->active_mask))
+			continue;
+		p4_pmu_disable_event(event);
+	}
+}
+
+static void p4_pmu_enable_event(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	int thread = p4_ht_config_thread(hwc->config);
+	u64 escr_conf = p4_config_unpack_escr(p4_clear_ht_bit(hwc->config));
+	u64 escr_base;
+	struct p4_event_template *tpl;
+	struct p4_pmu_res *c;
+
+	/*
+	 * some preparation work from per-cpu private fields
+	 * since we need to find out which ESCR to use
+	 */
+	c = &__get_cpu_var(p4_pmu_config);
+	tpl = c->tpl[hwc->idx];
+	if (!tpl) {
+		pr_crit("%s: Wrong index: %d\n", __func__, hwc->idx);
+		return;
+	}
+	escr_base = (u64)tpl->escr_msr[thread];
+
+	/*
+	 * - we dont support cascaded counters yet
+	 * - and counter 1 is broken (erratum)
+	 */
+	WARN_ON_ONCE(p4_is_event_cascaded(hwc->config));
+	WARN_ON_ONCE(hwc->idx == 1);
+
+	(void)checking_wrmsrl(escr_base, escr_conf);
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx,
+		(u64)(p4_config_unpack_cccr(hwc->config)) | P4_CCCR_ENABLE);
+}
+
+static void p4_pmu_enable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	int idx;
+
+	for (idx = 0; idx < x86_pmu.num_events; idx++) {
+		struct perf_event *event = cpuc->events[idx];
+		if (!test_bit(idx, cpuc->active_mask))
+			continue;
+		p4_pmu_enable_event(event);
+	}
+}
+
+static int p4_pmu_handle_irq(struct pt_regs *regs)
+{
+	struct perf_sample_data data;
+	struct cpu_hw_events *cpuc;
+	struct perf_event *event;
+	struct hw_perf_event *hwc;
+	int idx, handled = 0;
+	u64 val;
+
+	data.addr = 0;
+	data.raw = NULL;
+
+	cpuc = &__get_cpu_var(cpu_hw_events);
+
+	for (idx = 0; idx < x86_pmu.num_events; idx++) {
+
+		if (!test_bit(idx, cpuc->active_mask))
+			continue;
+
+		event = cpuc->events[idx];
+		hwc = &event->hw;
+
+		WARN_ON_ONCE(hwc->idx != idx);
+
+		/*
+		 * FIXME: Redundant call, actually not needed
+		 * but just to check if we're screwed
+		 */
+		p4_pmu_clear_cccr_ovf(hwc);
+
+		val = x86_perf_event_update(event);
+		if (val & (1ULL << (x86_pmu.event_bits - 1)))
+			continue;
+
+		/*
+		 * event overflow
+		 */
+		handled		= 1;
+		data.period	= event->hw.last_period;
+
+		if (!x86_perf_event_set_period(event))
+			continue;
+		if (perf_event_overflow(event, 1, &data, regs))
+			p4_pmu_disable_event(event);
+	}
+
+	if (handled) {
+		/* p4 quirk: unmask it again */
+		apic_write(APIC_LVTPC, apic_read(APIC_LVTPC) & ~APIC_LVT_MASKED);
+		inc_irq_stat(apic_perf_irqs);
+	}
+
+	return handled;
+}
+
+/*
+ * swap thread specific fields according to a thread
+ * we are going to run on
+ */
+static void p4_pmu_swap_config_ts(struct hw_perf_event *hwc, int cpu)
+{
+	u32 escr, cccr;
+
+	/*
+	 * we either lucky and continue on same cpu or no HT support
+	 */
+	if (!p4_should_swap_ts(hwc->config, cpu))
+		return;
+
+	/*
+	 * the event is migrated from an another logical
+	 * cpu, so we need to swap thread specific flags
+	 */
+
+	escr = p4_config_unpack_escr(hwc->config);
+	cccr = p4_config_unpack_cccr(hwc->config);
+
+	if (p4_ht_thread(cpu)) {
+		cccr &= ~P4_CCCR_OVF_PMI_T0;
+		cccr |= P4_CCCR_OVF_PMI_T1;
+		if (escr & P4_EVNTSEL_T0_OS) {
+			escr &= ~P4_EVNTSEL_T0_OS;
+			escr |= P4_EVNTSEL_T1_OS;
+		}
+		if (escr & P4_EVNTSEL_T0_USR) {
+			escr &= ~P4_EVNTSEL_T0_USR;
+			escr |= P4_EVNTSEL_T1_USR;
+		}
+		hwc->config  = p4_config_pack_escr(escr);
+		hwc->config |= p4_config_pack_cccr(cccr);
+		hwc->config |= P4_CONFIG_HT;
+	} else {
+		cccr &= ~P4_CCCR_OVF_PMI_T1;
+		cccr |= P4_CCCR_OVF_PMI_T0;
+		if (escr & P4_EVNTSEL_T1_OS) {
+			escr &= ~P4_EVNTSEL_T1_OS;
+			escr |= P4_EVNTSEL_T0_OS;
+		}
+		if (escr & P4_EVNTSEL_T1_USR) {
+			escr &= ~P4_EVNTSEL_T1_USR;
+			escr |= P4_EVNTSEL_T0_USR;
+		}
+		hwc->config  = p4_config_pack_escr(escr);
+		hwc->config |= p4_config_pack_cccr(cccr);
+		hwc->config &= ~P4_CONFIG_HT;
+	}
+}
+
+/* ESCRs are not sequential in memory so we need a map */
+static unsigned int p4_escr_map[ARCH_P4_TOTAL_ESCR] = {
+	MSR_P4_ALF_ESCR0,	/*  0 */
+	MSR_P4_ALF_ESCR1,	/*  1 */
+	MSR_P4_BPU_ESCR0,	/*  2 */
+	MSR_P4_BPU_ESCR1,	/*  3 */
+	MSR_P4_BSU_ESCR0,	/*  4 */
+	MSR_P4_BSU_ESCR1,	/*  5 */
+	MSR_P4_CRU_ESCR0,	/*  6 */
+	MSR_P4_CRU_ESCR1,	/*  7 */
+	MSR_P4_CRU_ESCR2,	/*  8 */
+	MSR_P4_CRU_ESCR3,	/*  9 */
+	MSR_P4_CRU_ESCR4,	/* 10 */
+	MSR_P4_CRU_ESCR5,	/* 11 */
+	MSR_P4_DAC_ESCR0,	/* 12 */
+	MSR_P4_DAC_ESCR1,	/* 13 */
+	MSR_P4_FIRM_ESCR0,	/* 14 */
+	MSR_P4_FIRM_ESCR1,	/* 15 */
+	MSR_P4_FLAME_ESCR0,	/* 16 */
+	MSR_P4_FLAME_ESCR1,	/* 17 */
+	MSR_P4_FSB_ESCR0,	/* 18 */
+	MSR_P4_FSB_ESCR1,	/* 19 */
+	MSR_P4_IQ_ESCR0,	/* 20 */
+	MSR_P4_IQ_ESCR1,	/* 21 */
+	MSR_P4_IS_ESCR0,	/* 22 */
+	MSR_P4_IS_ESCR1,	/* 23 */
+	MSR_P4_ITLB_ESCR0,	/* 24 */
+	MSR_P4_ITLB_ESCR1,	/* 25 */
+	MSR_P4_IX_ESCR0,	/* 26 */
+	MSR_P4_IX_ESCR1,	/* 27 */
+	MSR_P4_MOB_ESCR0,	/* 28 */
+	MSR_P4_MOB_ESCR1,	/* 29 */
+	MSR_P4_MS_ESCR0,	/* 30 */
+	MSR_P4_MS_ESCR1,	/* 31 */
+	MSR_P4_PMH_ESCR0,	/* 32 */
+	MSR_P4_PMH_ESCR1,	/* 33 */
+	MSR_P4_RAT_ESCR0,	/* 34 */
+	MSR_P4_RAT_ESCR1,	/* 35 */
+	MSR_P4_SAAT_ESCR0,	/* 36 */
+	MSR_P4_SAAT_ESCR1,	/* 37 */
+	MSR_P4_SSU_ESCR0,	/* 38 */
+	MSR_P4_SSU_ESCR1,	/* 39 */
+	MSR_P4_TBPU_ESCR0,	/* 40 */
+	MSR_P4_TBPU_ESCR1,	/* 41 */
+	MSR_P4_TC_ESCR0,	/* 42 */
+	MSR_P4_TC_ESCR1,	/* 43 */
+	MSR_P4_U2L_ESCR0,	/* 44 */
+	MSR_P4_U2L_ESCR1,	/* 45 */
+};
+
+static int p4_get_escr_idx(unsigned int addr)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(p4_escr_map); i++) {
+		if (addr == p4_escr_map[i])
+			return i;
+	}
+
+	return -1;
+}
+
+static int p4_pmu_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
+{
+	unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
+	unsigned long escr_mask[BITS_TO_LONGS(ARCH_P4_TOTAL_ESCR)];
+
+	struct hw_perf_event *hwc;
+	struct p4_event_template *tpl;
+	struct p4_pmu_res *c;
+	int cpu = raw_smp_processor_id();
+	int escr_idx, thread, i, num;
+
+	bitmap_zero(used_mask, X86_PMC_IDX_MAX);
+	bitmap_zero(escr_mask, ARCH_P4_TOTAL_ESCR);
+
+	c = &__get_cpu_var(p4_pmu_config);
+	/*
+	 * Firstly find out which resource events are going
+	 * to use, if ESCR+CCCR tuple is already borrowed
+	 * then get out of here
+	 */
+	for (i = 0, num = n; i < n; i++, num--) {
+		hwc = &cpuc->event_list[i]->hw;
+		tpl = p4_pmu_template_lookup(hwc->config);
+		if (!tpl)
+			goto done;
+		thread = p4_ht_thread(cpu);
+		escr_idx = p4_get_escr_idx(tpl->escr_msr[thread]);
+		if (escr_idx == -1)
+			goto done;
+
+		/* already allocated and remains on the same cpu */
+		if (hwc->idx != -1 && !p4_should_swap_ts(hwc->config, cpu)) {
+			if (assign)
+				assign[i] = hwc->idx;
+			/* upstream dependent event */
+			if (unlikely(tpl->dep != -1))
+				printk_once(KERN_WARNING "PMU: Dep events are "
+					"not implemented yet\n");
+			goto reserve;
+		}
+
+		/* it may be already borrowed */
+		if (test_bit(tpl->cntr[thread], used_mask) ||
+			test_bit(escr_idx, escr_mask))
+			goto done;
+
+		/*
+		 * ESCR+CCCR+COUNTERs are available to use lets swap
+		 * thread specific bits, push assigned bits
+		 * back and save template into per-cpu
+		 * area (which will allow us to find out the ESCR
+		 * to be used at moment of "enable event via real MSR")
+		 */
+		p4_pmu_swap_config_ts(hwc, cpu);
+		if (assign) {
+			assign[i] = tpl->cntr[thread];
+			c->tpl[assign[i]] = tpl;
+		}
+reserve:
+		set_bit(tpl->cntr[thread], used_mask);
+		set_bit(escr_idx, escr_mask);
+	}
+
+done:
+	return num ? -ENOSPC : 0;
+}
+
+static __initconst struct x86_pmu p4_pmu = {
+	.name			= "Netburst P4/Xeon",
+	.handle_irq		= p4_pmu_handle_irq,
+	.disable_all		= p4_pmu_disable_all,
+	.enable_all		= p4_pmu_enable_all,
+	.enable			= p4_pmu_enable_event,
+	.disable		= p4_pmu_disable_event,
+	.eventsel		= MSR_P4_BPU_CCCR0,
+	.perfctr		= MSR_P4_BPU_PERFCTR0,
+	.event_map		= p4_pmu_event_map,
+	.raw_event		= p4_pmu_raw_event,
+	.max_events		= ARRAY_SIZE(p4_event_map),
+	.get_event_constraints	= x86_get_event_constraints,
+	/*
+	 * IF HT disabled we may need to use all
+	 * ARCH_P4_MAX_CCCR counters simulaneously
+	 * though leave it restricted at moment assuming
+	 * HT is on
+	 */
+	.num_events		= ARCH_P4_MAX_CCCR,
+	.apic			= 1,
+	.event_bits		= 40,
+	.event_mask		= (1ULL << 40) - 1,
+	.max_period		= (1ULL << 39) - 1,
+	.hw_config		= p4_hw_config,
+	.schedule_events	= p4_pmu_schedule_events,
+};
+
+static __init int p4_pmu_init(void)
+{
+	unsigned int low, high;
+
+	/* If we get stripped -- indexig fails */
+	BUILD_BUG_ON(ARCH_P4_MAX_CCCR > X86_PMC_MAX_GENERIC);
+
+	rdmsr(MSR_IA32_MISC_ENABLE, low, high);
+	if (!(low & (1 << 7))) {
+		pr_cont("unsupported Netburst CPU model %d ",
+			boot_cpu_data.x86_model);
+		return -ENODEV;
+	}
+
+	pr_cont("Netburst events, ");
+
+	x86_pmu = p4_pmu;
+
+	return 0;
+}
+
+#endif /* CONFIG_CPU_SUP_INTEL */

arch/x86/kernel/cpu/perf_event_p6.c

@@ -109,6 +109,8 @@ static __initconst struct x86_pmu p6_pmu = {
 	.enable_all		= p6_pmu_enable_all,
 	.enable			= p6_pmu_enable_event,
 	.disable		= p6_pmu_disable_event,
+	.hw_config		= x86_hw_config,
+	.schedule_events	= x86_schedule_events,
 	.eventsel		= MSR_P6_EVNTSEL0,
 	.perfctr		= MSR_P6_PERFCTR0,
 	.event_map		= p6_pmu_event_map,