[PATCH v5 21/29] x86/resctrl: x86/resctrl: Read core telemetry events

[Tony Luck <tony.luck@intel.com>]

The resctrl file system passes requests to read event monitor files to
the architecture resctrl_arch_rmid_read() to collect values
from hardware counters.

Use the resctrl resource to differentiate between calls to read legacy
L3 events from the new telemetry events (which are attached to
RDT_RESOURCE_PERF_PKG).

There may be multiple aggregators tracking each package, so scan all of
them and add up all counters.

At run time when a user reads an event file the file system code
provides the enum resctrl_event_id for the event.

Create a lookup table indexed by event id to provide the telem_entry
structure and the event index into MMIO space.

Enable the events marked as readable from any CPU.

Resctrl now uses readq() so depends on X86_64. Update Kconfig.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 arch/x86/kernel/cpu/resctrl/internal.h  |  1 +
 arch/x86/kernel/cpu/resctrl/intel_aet.c | 53 +++++++++++++++++++++++++
 arch/x86/kernel/cpu/resctrl/monitor.c   |  6 +++
 arch/x86/Kconfig                        |  2 +-
 4 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 2b2d4b5a4643..42da0a222c7c 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -169,5 +169,6 @@ void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
 
 bool intel_aet_get_events(void);
 void __exit intel_aet_exit(void);
+int intel_aet_read_event(int domid, int rmid, enum resctrl_event_id evtid, u64 *val);
 
 #endif /* _ASM_X86_RESCTRL_INTERNAL_H */
diff --git a/arch/x86/kernel/cpu/resctrl/intel_aet.c b/arch/x86/kernel/cpu/resctrl/intel_aet.c
index bf8e2a6126d2..be52c9302a80 100644
--- a/arch/x86/kernel/cpu/resctrl/intel_aet.c
+++ b/arch/x86/kernel/cpu/resctrl/intel_aet.c
@@ -13,6 +13,7 @@
 
 #include <linux/cleanup.h>
 #include <linux/cpu.h>
+#include <linux/io.h>
 #include <linux/resctrl.h>
 #include <linux/slab.h>
 
@@ -128,6 +129,16 @@ static bool skip_this_region(struct telemetry_region *tr, struct event_group *e)
 	return false;
 }
 
+/**
+ * struct evtinfo - lookup table from resctrl_event_id to useful information
+ * @event_group:	Pointer to the telem_entry structure for this event
+ * @idx:		Counter index within each per-RMID block of counters
+ */
+static struct evtinfo {
+	struct event_group	*event_group;
+	int			idx;
+} evtinfo[QOS_NUM_EVENTS];
+
 static void free_mmio_info(struct mmio_info **mmi)
 {
 	int num_pkgs = topology_max_packages();
@@ -199,6 +210,15 @@ static int configure_events(struct event_group *e, struct pmt_feature_group *p)
 	}
 	e->pkginfo = no_free_ptr(pkginfo);
 
+	for (int i = 0; i < e->num_events; i++) {
+		enum resctrl_event_id evt;
+
+		evt = e->evts[i].evtid;
+		evtinfo[evt].event_group = e;
+		evtinfo[evt].idx = e->evts[i].evt_idx;
+		resctrl_enable_mon_event(evt, true, e->evts[i].bin_bits);
+	}
+
 	return 0;
 }
 
@@ -266,3 +286,36 @@ void __exit intel_aet_exit(void)
 		free_mmio_info((*peg)->pkginfo);
 	}
 }
+
+#define DATA_VALID	BIT_ULL(63)
+#define DATA_BITS	GENMASK_ULL(62, 0)
+
+/*
+ * Read counter for an event on a domain (summing all aggregators
+ * on the domain).
+ */
+int intel_aet_read_event(int domid, int rmid, enum resctrl_event_id evtid, u64 *val)
+{
+	struct evtinfo *info = &evtinfo[evtid];
+	struct mmio_info *mmi;
+	u64 evtcount;
+	int idx;
+
+	idx = rmid * info->event_group->num_events;
+	idx += info->idx;
+	mmi = info->event_group->pkginfo[domid];
+
+	if (idx * sizeof(u64) + sizeof(u64) > info->event_group->mmio_size) {
+		pr_warn_once("MMIO index %d out of range\n", idx);
+		return -EIO;
+	}
+
+	for (int i = 0; i < mmi->count; i++) {
+		evtcount = readq(mmi->addrs[i] + idx * sizeof(u64));
+		if (!(evtcount & DATA_VALID))
+			return -EINVAL;
+		*val += evtcount & DATA_BITS;
+	}
+
+	return 0;
+}
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 1f6dc253112f..c99aa9dacfd8 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -230,6 +230,12 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
 
 	resctrl_arch_rmid_read_context_check();
 
+	if (r->rid == RDT_RESOURCE_PERF_PKG)
+		return intel_aet_read_event(d->hdr.id, rmid, eventid, val);
+
+	if (r->rid != RDT_RESOURCE_L3)
+		return -EIO;
+
 	prmid = logical_rmid_to_physical_rmid(cpu, rmid);
 	ret = __rmid_read_phys(prmid, eventid, &msr_val);
 	if (ret)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 52cfb69c343f..24df3f04a115 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -506,7 +506,7 @@ config X86_MPPARSE
 
 config X86_CPU_RESCTRL
 	bool "x86 CPU resource control support"
-	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
+	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
 	depends on MISC_FILESYSTEMS
 	select ARCH_HAS_CPU_RESCTRL
 	select RESCTRL_FS
-- 
2.49.0