Introduce a helper function to calculate bit-index for assigning
performance counter assignment.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
---
 arch/x86/kernel/cpu/perf_event_amd_iommu.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_amd_iommu.c 
b/arch/x86/kernel/cpu/perf_event_amd_iommu.c
index 99fcd10..8af7149 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_iommu.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_iommu.c
@@ -153,18 +153,28 @@ static struct attribute_group amd_iommu_cpumask_group = {
 
 /*---------------------------------------------*/
 
+static inline
+int get_iommu_bnk_cnt_evt_idx(struct perf_amd_iommu *perf_iommu,
+                                 int iommu_index, int bank_index,
+                                 int cntr_index)
+{
+       int cntrs_per_iommu = perf_iommu->max_banks * perf_iommu->max_counters;
+       int index = (perf_iommu->max_counters * bank_index) + cntr_index;
+
+       return (cntrs_per_iommu * iommu_index) + index;
+}
+
 static int get_next_avail_iommu_bnk_cntr(struct perf_amd_iommu *perf_iommu)
 {
        unsigned long flags;
        int shift, bank, cntr, retval;
-       int max_banks = perf_iommu->max_banks;
-       int max_cntrs = perf_iommu->max_counters;
 
        raw_spin_lock_irqsave(&perf_iommu->lock, flags);
 
-       for (bank = 0, shift = 0; bank < max_banks; bank++) {
-               for (cntr = 0; cntr < max_cntrs; cntr++) {
-                       shift = bank + (bank*3) + cntr;
+       for (bank = 0, shift = 0; bank < perf_iommu->max_banks; bank++) {
+               for (cntr = 0; cntr < perf_iommu->max_counters; cntr++) {
+                       shift = get_iommu_bnk_cnt_evt_idx(perf_iommu,
+                                                             0, bank, cntr);
                        if (perf_iommu->cntr_assign_mask & (1ULL<<shift)) {
                                continue;
                        } else {
-- 
1.9.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Reply via email to