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[PATCH v2 2/6] perf/amd/iommu: Modify functions to query max banks and counters

From Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Newsgroups linux.kernel
Subject [PATCH v2 2/6] perf/amd/iommu: Modify functions to query max banks and counters
Date 2016-01-01 19:30 +0100
Message-ID <qMcCD-5Xq-41@gated-at.bofh.it> (permalink)
References <qMcCC-5Xq-13@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Currently, amd_iommu_pc_get_max_[banks|counters]() require devid,
which should not be the case. Also, these don't properly support
multi-IOMMU system.

Current and future AMD systems with IOMMU that support perf counter
would likely contain homogeneous IOMMUs where multiple IOMMUs are
availalbe. So, this patch modifies these function to iterate all IOMMU
to check the max banks and counters reported by the hardware.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 arch/x86/kernel/cpu/perf_event_amd_iommu.c | 17 +++++++----------
 drivers/iommu/amd_iommu_init.c             | 20 ++++++++++++--------
 include/linux/perf/perf_event_amd_iommu.h  |  7 ++-----
 3 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_amd_iommu.c b/arch/x86/kernel/cpu/perf_event_amd_iommu.c
index 1192f1d..e6d2485 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_iommu.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_iommu.c
@@ -237,14 +237,6 @@ static int perf_iommu_event_init(struct perf_event *event)
 		return -EINVAL;
 	}
 
-	/* integrate with iommu base devid (0000), assume one iommu */
-	perf_iommu->max_banks =
-		amd_iommu_pc_get_max_banks(IOMMU_BASE_DEVID);
-	perf_iommu->max_counters =
-		amd_iommu_pc_get_max_counters(IOMMU_BASE_DEVID);
-	if ((perf_iommu->max_banks == 0) || (perf_iommu->max_counters == 0))
-		return -EINVAL;
-
 	/* update the hw_perf_event struct with the iommu config data */
 	hwc->config = config;
 	hwc->extra_reg.config = config1;
@@ -455,6 +447,11 @@ static __init int _init_perf_amd_iommu(
 	if (_init_events_attrs(perf_iommu) != 0)
 		pr_err("perf: amd_iommu: Only support raw events.\n");
 
+	perf_iommu->max_banks = amd_iommu_pc_get_max_banks();
+	perf_iommu->max_counters = amd_iommu_pc_get_max_counters();
+	if ((perf_iommu->max_banks == 0) || (perf_iommu->max_counters == 0))
+		return -EINVAL;
+
 	/* Init null attributes */
 	perf_iommu->null_group = NULL;
 	perf_iommu->pmu.attr_groups = perf_iommu->attr_groups;
@@ -465,8 +462,8 @@ static __init int _init_perf_amd_iommu(
 		amd_iommu_pc_exit();
 	} else {
 		pr_info("perf: amd_iommu: Detected. (%d banks, %d counters/bank)\n",
-			amd_iommu_pc_get_max_banks(IOMMU_BASE_DEVID),
-			amd_iommu_pc_get_max_counters(IOMMU_BASE_DEVID));
+			amd_iommu_pc_get_max_banks(),
+			amd_iommu_pc_get_max_counters());
 	}
 
 	return ret;
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index b6d684c..275c0f5 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -2251,15 +2251,17 @@ EXPORT_SYMBOL(amd_iommu_v2_supported);
  *
  ****************************************************************************/
 
-u8 amd_iommu_pc_get_max_banks(u16 devid)
+u8 amd_iommu_pc_get_max_banks(void)
 {
 	struct amd_iommu *iommu;
 	u8 ret = 0;
 
-	/* locate the iommu governing the devid */
-	iommu = amd_iommu_rlookup_table[devid];
-	if (iommu)
+	for_each_iommu(iommu) {
+		if (!iommu->max_banks ||
+		    (ret && (iommu->max_banks != ret)))
+			return 0;
 		ret = iommu->max_banks;
+	}
 
 	return ret;
 }
@@ -2271,15 +2273,17 @@ bool amd_iommu_pc_supported(void)
 }
 EXPORT_SYMBOL(amd_iommu_pc_supported);
 
-u8 amd_iommu_pc_get_max_counters(u16 devid)
+u8 amd_iommu_pc_get_max_counters(void)
 {
 	struct amd_iommu *iommu;
 	u8 ret = 0;
 
-	/* locate the iommu governing the devid */
-	iommu = amd_iommu_rlookup_table[devid];
-	if (iommu)
+	for_each_iommu(iommu) {
+		if (!iommu->max_counters ||
+		    (ret && (iommu->max_counters != ret)))
+			return 0;
 		ret = iommu->max_counters;
+	}
 
 	return ret;
 }
diff --git a/include/linux/perf/perf_event_amd_iommu.h b/include/linux/perf/perf_event_amd_iommu.h
index 845d173..815eabb 100644
--- a/include/linux/perf/perf_event_amd_iommu.h
+++ b/include/linux/perf/perf_event_amd_iommu.h
@@ -24,15 +24,12 @@
 #define PC_MAX_SPEC_BNKS			64
 #define PC_MAX_SPEC_CNTRS			16
 
-/* iommu pc reg masks*/
-#define IOMMU_BASE_DEVID			0x0000
-
 /* amd_iommu_init.c external support functions */
 extern bool amd_iommu_pc_supported(void);
 
-extern u8 amd_iommu_pc_get_max_banks(u16 devid);
+extern u8 amd_iommu_pc_get_max_banks(void);
 
-extern u8 amd_iommu_pc_get_max_counters(u16 devid);
+extern u8 amd_iommu_pc_get_max_counters(void);
 
 extern int amd_iommu_pc_get_set_reg_val(u16 devid, u8 bank, u8 cntr,
 			u8 fxn, u64 *value, bool is_write);
-- 
1.9.1

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Thread

[PATCH v2 0/6] perf/amd/iommu: Enable multi-IOMMU support Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> - 2016-01-01 19:30 +0100
  [PATCH v2 5/6] perf/amd/iommu: Introduce get_iommu_bnk_cnt_evt_idx Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> - 2016-01-01 19:30 +0100
  [PATCH v2 3/6] iommu/amd: Introduce amd_iommu_get_num_iommus() Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> - 2016-01-01 19:30 +0100
    Re: [PATCH v2 3/6] iommu/amd: Introduce amd_iommu_get_num_iommus() Joerg Roedel <joro@8bytes.org> - 2016-01-07 13:20 +0100
  [PATCH v2 6/6] perf/amd/iommu: Enable support for multiple IOMMUs Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> - 2016-01-01 19:30 +0100
  [PATCH v2 4/6] perf/amd/iommu: Introduce data structure for tracking prev count. Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> - 2016-01-01 19:30 +0100
    Re: [PATCH v2 4/6] perf/amd/iommu: Introduce data structure for  tracking prev count. Joerg Roedel <joro@8bytes.org> - 2016-01-07 13:30 +0100
  [PATCH v2 2/6] perf/amd/iommu: Modify functions to query max banks and counters Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> - 2016-01-01 19:30 +0100
    Re: [PATCH v2 2/6] perf/amd/iommu: Modify functions to query max  banks and counters Joerg Roedel <joro@8bytes.org> - 2016-01-07 13:40 +0100
      Re: [PATCH v2 2/6] perf/amd/iommu: Modify functions to query max  banks and counters Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> - 2016-01-07 16:30 +0100
  [PATCH v2 1/6] perf/amd/iommu: Consolidate and move perf_event_amd_iommu header Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> - 2016-01-01 19:30 +0100
    Re: [PATCH v2 1/6] perf/amd/iommu: Consolidate and move  perf_event_amd_iommu header Joerg Roedel <joro@8bytes.org> - 2016-01-07 13:40 +0100

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