[PATCH] perf/x86/intel/uncore: allocate pmu index for pci device dynamically

[Eric Ren]

Some boxes/devices of uncore are exported as pcie devices. However,
the box number is different on different micro-architecture. For
example, the max memory channels for Broadwell is up to 8. However,
there are only 2 channels for Broadwell-DE, 4 channels for Broadwell-EP,
and 8 channels for Broadwell-EX.

The current code allocates pmu index statically so that on Broadwell-EP
machine "perf list|grep uncore" shows discontinuous iMC number, which
doesn't look nice:

Test on Broadwell-EP using "ls /sys/devices | grep -i imc":

Without this patch,
    uncore_imc_0
    uncore_imc_1
    uncore_imc_4
    uncore_imc_5

To maintain pmu index dynamically, move index allocation logic to
uncore_pci_probe(). As a result, we can get continuous index of iMC
devices under /sys/devices directory:

Applied this patch:,
    uncore_imc_0
    uncore_imc_1
    uncore_imc_2
    uncore_imc_3

Signed-off-by: Shanpei Chen <shanp...@linux.alibaba.com>
Signed-off-by: Eric Ren <renz...@linux.alibaba.com>
---
 arch/x86/events/intel/uncore.c | 7 ++++++-
 arch/x86/events/intel/uncore.h | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index a7956fc..88d390e 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -818,7 +818,9 @@ static int __init uncore_type_init(struct intel_uncore_type 
*type, bool setid)
 
        for (i = 0; i < type->num_boxes; i++) {
                pmus[i].func_id = setid ? i : -1;
-               pmus[i].pmu_idx = i;
+               /* The pmu idx will be decided at probe for pci device. */
+               if (setid)
+                       pmus[i].pmu_idx = i;
                pmus[i].type    = type;
                pmus[i].boxes   = kzalloc(size, GFP_KERNEL);
                if (!pmus[i].boxes)
@@ -957,6 +959,9 @@ static int uncore_pci_probe(struct pci_dev *pdev, const 
struct pci_device_id *id
        if (atomic_inc_return(&pmu->activeboxes) > 1)
                return 0;
 
+       /*  Count the real number of pmus for pci uncore device */
+       pmu->pmu_idx = type->num_pmus++;
+
        /* First active box registers the pmu */
        ret = uncore_pmu_register(pmu);
        if (ret) {
diff --git a/arch/x86/events/intel/uncore.h b/arch/x86/events/intel/uncore.h
index 414dc7e..c4f54fb 100644
--- a/arch/x86/events/intel/uncore.h
+++ b/arch/x86/events/intel/uncore.h
@@ -40,6 +40,7 @@ struct intel_uncore_type {
        const char *name;
        int num_counters;
        int num_boxes;
+       int num_pmus; /* for pci uncore device */
        int perf_ctr_bits;
        int fixed_ctr_bits;
        unsigned perf_ctr;
-- 
1.8.3.1