[tip:perf/core] x86/events/amd/iommu.c: Modify functions to query max banks and counters

[tip-bot for Suravee Suthikulpanit]

Commit-ID:  f5863a00e73c432b91e4efe1d68778b4ace6a892
Gitweb:     http://git.kernel.org/tip/f5863a00e73c432b91e4efe1d68778b4ace6a892
Author:     Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
AuthorDate: Fri, 24 Feb 2017 02:48:18 -0600
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 30 Mar 2017 09:53:54 +0200

x86/events/amd/iommu.c: Modify functions to query max banks and counters

Currently, amd_iommu_pc_get_max_[banks|counters]() use end-point device
ID to locate an IOMMU and check the reported max banks/counters. The
logic assumes that the IOMMU_BASE_DEVID belongs to the first IOMMU, and
uses it to acquire a reference to the first IOMMU, which does not work
on certain systems. Instead, modify the function to take an IOMMU index,
and use it to query the corresponding AMD IOMMU instance.

Currently, hardcode the IOMMU index to 0 since the current AMD IOMMU
perf implementation supports only a single IOMMU. A subsequent patch
will add support for multiple IOMMUs, and will use a proper IOMMU index.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: JÃrg RÃdel <joro@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1487926102-13073-7-git-send-email-Suravee.Suthikulpanit@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/events/amd/iommu.c     | 17 +++++++----------
 arch/x86/events/amd/iommu.h     |  9 ++++-----
 drivers/iommu/amd_iommu_init.c  | 34 ++++++++++++++++++++--------------
 drivers/iommu/amd_iommu_proto.h |  2 --
 4 files changed, 31 insertions(+), 31 deletions(-)

diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c
index d4375da..10f67d3 100644
--- a/arch/x86/events/amd/iommu.c
+++ b/arch/x86/events/amd/iommu.c
@@ -239,14 +239,6 @@ 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;
@@ -448,6 +440,11 @@ static __init int _init_perf_amd_iommu(
 		return ret;
 	}
 
+	perf_iommu->max_banks    = amd_iommu_pc_get_max_banks(0);
+	perf_iommu->max_counters = amd_iommu_pc_get_max_counters(0);
+	if (!perf_iommu->max_banks || !perf_iommu->max_counters)
+		return -EINVAL;
+
 	perf_iommu->null_group = NULL;
 	perf_iommu->pmu.attr_groups = perf_iommu->attr_groups;
 
@@ -457,8 +454,8 @@ static __init int _init_perf_amd_iommu(
 		amd_iommu_pc_exit();
 	} else {
 		pr_info("Detected AMD IOMMU (%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(0),
+			amd_iommu_pc_get_max_counters(0));
 	}
 
 	return ret;
diff --git a/arch/x86/events/amd/iommu.h b/arch/x86/events/amd/iommu.h
index 5c5c932..b775107 100644
--- a/arch/x86/events/amd/iommu.h
+++ b/arch/x86/events/amd/iommu.h
@@ -24,19 +24,18 @@
 #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 int amd_iommu_get_num_iommus(void);
 
 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(unsigned int idx);
 
-extern u8 amd_iommu_pc_get_max_counters(u16 devid);
+extern u8 amd_iommu_pc_get_max_counters(unsigned int idx);
 
 extern int amd_iommu_pc_get_set_reg_val(u16 devid, u8 bank, u8 cntr,
 			u8 fxn, u64 *value, bool is_write);
 
+extern struct amd_iommu *get_amd_iommu(int idx);
+
 #endif /*_PERF_EVENT_AMD_IOMMU_H_*/
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index d3ec9c3..8fdf109 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -2718,6 +2718,18 @@ bool amd_iommu_v2_supported(void)
 }
 EXPORT_SYMBOL(amd_iommu_v2_supported);
 
+struct amd_iommu *get_amd_iommu(unsigned int idx)
+{
+	unsigned int i = 0;
+	struct amd_iommu *iommu;
+
+	for_each_iommu(iommu)
+		if (i++ == idx)
+			return iommu;
+	return NULL;
+}
+EXPORT_SYMBOL(get_amd_iommu);
+
 /****************************************************************************
  *
  * IOMMU EFR Performance Counter support functionality. This code allows
@@ -2725,17 +2737,14 @@ EXPORT_SYMBOL(amd_iommu_v2_supported);
  *
  ****************************************************************************/
 
-u8 amd_iommu_pc_get_max_banks(u16 devid)
+u8 amd_iommu_pc_get_max_banks(unsigned int idx)
 {
-	struct amd_iommu *iommu;
-	u8 ret = 0;
+	struct amd_iommu *iommu = get_amd_iommu(idx);
 
-	/* locate the iommu governing the devid */
-	iommu = amd_iommu_rlookup_table[devid];
 	if (iommu)
-		ret = iommu->max_banks;
+		return iommu->max_banks;
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(amd_iommu_pc_get_max_banks);
 
@@ -2745,17 +2754,14 @@ 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(unsigned int idx)
 {
-	struct amd_iommu *iommu;
-	u8 ret = 0;
+	struct amd_iommu *iommu = get_amd_iommu(idx);
 
-	/* locate the iommu governing the devid */
-	iommu = amd_iommu_rlookup_table[devid];
 	if (iommu)
-		ret = iommu->max_counters;
+		return iommu->max_counters;
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(amd_iommu_pc_get_max_counters);
 
diff --git a/drivers/iommu/amd_iommu_proto.h b/drivers/iommu/amd_iommu_proto.h
index e8f0710..cd2257e 100644
--- a/drivers/iommu/amd_iommu_proto.h
+++ b/drivers/iommu/amd_iommu_proto.h
@@ -59,8 +59,6 @@ extern struct iommu_domain *amd_iommu_get_v2_domain(struct pci_dev *pdev);
 
 /* IOMMU Performance Counter 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_counters(u16 devid);
 extern int amd_iommu_pc_get_set_reg_val(u16 devid, u8 bank, u8 cntr, u8 fxn,
 				    u64 *value, bool is_write);