[PATCH v5 19/29] x86/resctrl: Complete telemetry event enumeration

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

Counters for telemetry events are in MMIO space. Each telemetry_region
structure returned in the pmt_feature_group returned from OOBMSM
contains the base MMIO address for the counters.

Scan all the telemetry_region structures again and gather these
addresses into a more convenient structure with addresses for
each aggregator indexed by package id. Note that there may be
multiple aggregators per package.

Completed structure for each event group looks like this:

             +---------------------+---------------------+
pkginfo** -->|   pkginfo[0]         |    pkginfo[1]      |
             +---------------------+---------------------+
                        |                     |
                        v                     v
                +----------------+    +----------------+
                |struct mmio_info|    |struct mmio_info|
                +----------------+    +----------------+
                |   count = N    |    |   count = N    |
                |  addrs[0]      |    |  addrs[0]      |
                |  addrs[0]      |    |  addrs[0]      |
                |    ...         |    |    ...         |
                |  addrs[N-1]    |    |  addrs[N-1]    |
                +----------------+    +----------------+

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 arch/x86/kernel/cpu/resctrl/intel_aet.c | 65 ++++++++++++++++++++++++-
 1 file changed, 64 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/intel_aet.c b/arch/x86/kernel/cpu/resctrl/intel_aet.c
index ffcb54be54ea..2316198eb69e 100644
--- a/arch/x86/kernel/cpu/resctrl/intel_aet.c
+++ b/arch/x86/kernel/cpu/resctrl/intel_aet.c
@@ -21,17 +21,32 @@
 
 #include "internal.h"
 
+/**
+ * struct mmio_info - Array of MMIO addresses for one event group for a package
+ * @count:		Number of addresses on this package
+ * @addrs:		The MMIO addresses
+ *
+ * Provides convenient access to all MMIO addresses of one event group
+ * for one package. Used when reading event data on a package.
+ */
+struct mmio_info {
+	int		count;
+	void __iomem	*addrs[] __counted_by(count);
+};
+
 /**
  * struct event_group - All information about a group of telemetry events.
  * @pfg:		Points to the aggregated telemetry space information
  *			within the OOBMSM driver that contains data for all
  *			telemetry regions.
+ * @pkginfo:		Per-package MMIO addresses of telemetry regions belonging to this group
  * @guid:		Unique number per XML description file.
  * @mmio_size:		Number of bytes of MMIO registers for this group.
  */
 struct event_group {
 	/* Data fields used by this code. */
 	struct pmt_feature_group	*pfg;
+	struct mmio_info		**pkginfo;
 
 	/* Remaining fields initialized from XML file. */
 	u32				guid;
@@ -80,6 +95,20 @@ static bool skip_this_region(struct telemetry_region *tr, struct event_group *e)
 	return false;
 }
 
+static void free_mmio_info(struct mmio_info **mmi)
+{
+	int num_pkgs = topology_max_packages();
+
+	if (!mmi)
+		return;
+
+	for (int i = 0; i < num_pkgs; i++)
+		kfree(mmi[i]);
+	kfree(mmi);
+}
+
+DEFINE_FREE(mmio_info, struct mmio_info **, free_mmio_info(_T))
+
 /*
  * Configure events from one pmt_feature_group.
  * 1) Count how many per package.
@@ -87,10 +116,17 @@ static bool skip_this_region(struct telemetry_region *tr, struct event_group *e)
  */
 static int configure_events(struct event_group *e, struct pmt_feature_group *p)
 {
+	struct mmio_info __free(mmio_info) **pkginfo = NULL;
 	int *pkgcounts __free(kfree) = NULL;
 	struct telemetry_region *tr;
+	struct mmio_info *mmi;
 	int num_pkgs;
 
+	if (e->pkginfo) {
+		pr_warn("Duplicate telemetry information for guid 0x%x\n", e->guid);
+		return -EINVAL;
+	}
+
 	num_pkgs = topology_max_packages();
 	pkgcounts = kcalloc(num_pkgs, sizeof(*pkgcounts), GFP_KERNEL);
 	if (!pkgcounts)
@@ -104,7 +140,33 @@ static int configure_events(struct event_group *e, struct pmt_feature_group *p)
 		pkgcounts[tr->plat_info.package_id]++;
 	}
 
-	return -EINVAL;
+	/* Allocate array for per-package struct mmio_info data */
+	pkginfo = kcalloc(num_pkgs, sizeof(*pkginfo), GFP_KERNEL);
+	if (!pkginfo)
+		return -ENOMEM;
+
+	/*
+	 * Allocate per-package mmio_info structures and initialize
+	 * count of telemetry_regions in each one.
+	 */
+	for (int i = 0; i < num_pkgs; i++) {
+		pkginfo[i] = kzalloc(struct_size(pkginfo[i], addrs, pkgcounts[i]), GFP_KERNEL);
+		if (!pkginfo[i])
+			return -ENOMEM;
+		pkginfo[i]->count = pkgcounts[i];
+	}
+
+	/* Save MMIO address(es) for each telemetry region in per-package structures */
+	for (int i = 0; i < p->count; i++) {
+		tr = &p->regions[i];
+		if (skip_this_region(tr, e))
+			continue;
+		mmi = pkginfo[tr->plat_info.package_id];
+		mmi->addrs[--pkgcounts[tr->plat_info.package_id]] = tr->addr;
+	}
+	e->pkginfo = no_free_ptr(pkginfo);
+
+	return 0;
 }
 
 DEFINE_FREE(intel_pmt_put_feature_group, struct pmt_feature_group *,	\
@@ -168,5 +230,6 @@ void __exit intel_aet_exit(void)
 			intel_pmt_put_feature_group((*peg)->pfg);
 			(*peg)->pfg = NULL;
 		}
+		free_mmio_info((*peg)->pkginfo);
 	}
 }
-- 
2.49.0