[PATCH V4 2/6] perf/amd/iommu: Modify functions to query max banks and counters

[Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>]

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.

Reviewed-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 arch/x86/events/amd/iommu.c           | 17 +++++++----------
 arch/x86/include/asm/perf/amd/iommu.h |  7 ++-----
 drivers/iommu/amd_iommu_init.c        | 20 ++++++++++++--------
 3 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c
index 2f96072..debf22d 100644
--- a/arch/x86/events/amd/iommu.c
+++ b/arch/x86/events/amd/iommu.c
@@ -232,14 +232,6 @@ 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;
@@ -450,6 +442,11 @@ 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;
@@ -460,8 +457,8 @@ 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/arch/x86/include/asm/perf/amd/iommu.h b/arch/x86/include/asm/perf/amd/iommu.h
index 72f64b7..97e1be5 100644
--- a/arch/x86/include/asm/perf/amd/iommu.h
+++ b/arch/x86/include/asm/perf/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 */
 bool amd_iommu_pc_supported(void);
 
-u8 amd_iommu_pc_get_max_banks(u16 devid);
+u8 amd_iommu_pc_get_max_banks(void);
 
-u8 amd_iommu_pc_get_max_counters(u16 devid);
+u8 amd_iommu_pc_get_max_counters(void);
 
 int amd_iommu_pc_set_reg_val(u16 devid, u8 bank, u8 cntr, u8 fxn, u64 *value);
 
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index d30f4b2..a62b5ce 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;
 }
-- 
2.5.0