Commit 24919fde authored by Kan Liang's avatar Kan Liang Committed by Peter Zijlstra
Browse files

perf/x86/intel: Fix unchecked MSR access error for Alder Lake N 



For some Alder Lake N machine, the below unchecked MSR access error may be
triggered.

[ 0.088017] rcu: Hierarchical SRCU implementation.
[ 0.088017] unchecked MSR access error: WRMSR to 0x38f (tried to write
0x0001000f0000003f) at rIP: 0xffffffffb5684de8 (native_write_msr+0x8/0x30)
[ 0.088017] Call Trace:
[ 0.088017] <TASK>
[ 0.088017] __intel_pmu_enable_all.constprop.46+0x4a/0xa0

The Alder Lake N only has e-cores. The X86_FEATURE_HYBRID_CPU flag is
not set. The perf cannot retrieve the correct CPU type via
get_this_hybrid_cpu_type(). The model specific get_hybrid_cpu_type() is
hardcode to p-core. The wrong CPU type is given to the PMU of the
Alder Lake N.

Since Alder Lake N isn't in fact a hybrid CPU, remove ALDERLAKE_N from
the rest of {ALDER,RAPTOP}LAKE and create a non-hybrid PMU setup.

The differences between Gracemont and the previous Tremont are,
- Number of GP counters
- Load and store latency Events
- PEBS event_constraints
- Instruction Latency support
- Data source encoding
- Memory access latency encoding

Fixes: c2a960f7 ("perf/x86: Add new Alder Lake and Raptor Lake support")
Reported-by: default avatarJianfeng Gao <jianfeng.gao@intel.com>
Suggested-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarKan Liang <kan.liang@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220831142702.153110-1-kan.liang@linux.intel.com
parent b90cb105

arch/x86/events/intel/core.c

+39 −1
Original line number Diff line number Diff line
@@ -2102,6 +2102,15 @@ static struct extra_reg intel_tnt_extra_regs[] __read_mostly = { 
	EVENT_EXTRA_END

};



EVENT_ATTR_STR(mem-loads,	mem_ld_grt,	"event=0xd0,umask=0x5,ldlat=3");

EVENT_ATTR_STR(mem-stores,	mem_st_grt,	"event=0xd0,umask=0x6");



static struct attribute *grt_mem_attrs[] = {

	EVENT_PTR(mem_ld_grt),

	EVENT_PTR(mem_st_grt),

	NULL

};



static struct extra_reg intel_grt_extra_regs[] __read_mostly = {

	/* must define OFFCORE_RSP_X first, see intel_fixup_er() */

	INTEL_UEVENT_EXTRA_REG(0x01b7, MSR_OFFCORE_RSP_0, 0x3fffffffffull, RSP_0),
@@ -5974,6 +5983,36 @@ __init int intel_pmu_init(void) 
		name = "Tremont";

		break;



	case INTEL_FAM6_ALDERLAKE_N:

		x86_pmu.mid_ack = true;

		memcpy(hw_cache_event_ids, glp_hw_cache_event_ids,

		       sizeof(hw_cache_event_ids));

		memcpy(hw_cache_extra_regs, tnt_hw_cache_extra_regs,

		       sizeof(hw_cache_extra_regs));

		hw_cache_event_ids[C(ITLB)][C(OP_READ)][C(RESULT_ACCESS)] = -1;



		x86_pmu.event_constraints = intel_slm_event_constraints;

		x86_pmu.pebs_constraints = intel_grt_pebs_event_constraints;

		x86_pmu.extra_regs = intel_grt_extra_regs;



		x86_pmu.pebs_aliases = NULL;

		x86_pmu.pebs_prec_dist = true;

		x86_pmu.pebs_block = true;

		x86_pmu.lbr_pt_coexist = true;

		x86_pmu.flags |= PMU_FL_HAS_RSP_1;

		x86_pmu.flags |= PMU_FL_INSTR_LATENCY;



		intel_pmu_pebs_data_source_grt();

		x86_pmu.pebs_latency_data = adl_latency_data_small;

		x86_pmu.get_event_constraints = tnt_get_event_constraints;

		x86_pmu.limit_period = spr_limit_period;

		td_attr = tnt_events_attrs;

		mem_attr = grt_mem_attrs;

		extra_attr = nhm_format_attr;

		pr_cont("Gracemont events, ");

		name = "gracemont";

		break;



	case INTEL_FAM6_WESTMERE:

	case INTEL_FAM6_WESTMERE_EP:

	case INTEL_FAM6_WESTMERE_EX:
@@ -6316,7 +6355,6 @@ __init int intel_pmu_init(void) 


	case INTEL_FAM6_ALDERLAKE:

	case INTEL_FAM6_ALDERLAKE_L:

	case INTEL_FAM6_ALDERLAKE_N:

	case INTEL_FAM6_RAPTORLAKE:

	case INTEL_FAM6_RAPTORLAKE_P:

		/*

arch/x86/events/intel/ds.c

+7 −2
Original line number Diff line number Diff line
@@ -110,13 +110,18 @@ void __init intel_pmu_pebs_data_source_skl(bool pmem) 
	__intel_pmu_pebs_data_source_skl(pmem, pebs_data_source);

}



static void __init intel_pmu_pebs_data_source_grt(u64 *data_source)

static void __init __intel_pmu_pebs_data_source_grt(u64 *data_source)

{

	data_source[0x05] = OP_LH | P(LVL, L3) | LEVEL(L3) | P(SNOOP, HIT);

	data_source[0x06] = OP_LH | P(LVL, L3) | LEVEL(L3) | P(SNOOP, HITM);

	data_source[0x08] = OP_LH | P(LVL, L3) | LEVEL(L3) | P(SNOOPX, FWD);

}



void __init intel_pmu_pebs_data_source_grt(void)

{

	__intel_pmu_pebs_data_source_grt(pebs_data_source);

}



void __init intel_pmu_pebs_data_source_adl(void)

{

	u64 *data_source;
@@ -127,7 +132,7 @@ void __init intel_pmu_pebs_data_source_adl(void) 


	data_source = x86_pmu.hybrid_pmu[X86_HYBRID_PMU_ATOM_IDX].pebs_data_source;

	memcpy(data_source, pebs_data_source, sizeof(pebs_data_source));

	intel_pmu_pebs_data_source_grt(data_source);

	__intel_pmu_pebs_data_source_grt(data_source);

}



static u64 precise_store_data(u64 status)

arch/x86/events/perf_event.h

+2 −0
Original line number Diff line number Diff line
@@ -1516,6 +1516,8 @@ void intel_pmu_pebs_data_source_skl(bool pmem); 


void intel_pmu_pebs_data_source_adl(void);



void intel_pmu_pebs_data_source_grt(void);



int intel_pmu_setup_lbr_filter(struct perf_event *event);



void intel_pt_interrupt(void);