On 26/02/2021 17:50, Madhavan Srinivasan wrote:
Add platform specific attr.config value checks. Patch
includes checks for both power9 and power10.

Signed-off-by: Madhavan Srinivasan <ma...@linux.ibm.com>
---
Changelog v1:
- No changes.

  arch/powerpc/perf/isa207-common.c | 41 +++++++++++++++++++++++++++++++
  arch/powerpc/perf/isa207-common.h |  2 ++
  arch/powerpc/perf/power10-pmu.c   | 13 ++++++++++
  arch/powerpc/perf/power9-pmu.c    | 13 ++++++++++
  4 files changed, 69 insertions(+)

diff --git a/arch/powerpc/perf/isa207-common.c 
b/arch/powerpc/perf/isa207-common.c
index e4f577da33d8..b255799f5b51 100644
--- a/arch/powerpc/perf/isa207-common.c
+++ b/arch/powerpc/perf/isa207-common.c
@@ -694,3 +694,44 @@ int isa207_get_alternatives(u64 event, u64 alt[], int 
size, unsigned int flags,
return num_alt;
  }
+
+int isa3_X_check_attr_config(struct perf_event *ev)


"isa300" is used everywhere else to refer to ISA 3.00.


+{
+       u64 val, sample_mode;
+       u64 event = ev->attr.config;
+
+       val = (event >> EVENT_SAMPLE_SHIFT) & EVENT_SAMPLE_MASK;

I am not familiar with the code - "Raw event encoding for Power9" from arch/powerpc/perf/power9-pmu.c - where is this from? Is this how linux defines encoding or it is P9 UM or something?

+       sample_mode = val & 0x3;
+
+       /*
+        * MMCRA[61:62] is Randome Sampling Mode (SM).
+        * value of 0b11 is reserved.
+        */
+       if (sample_mode == 0x3)
+               return -1;
+
+       /*
+        * Check for all reserved value
+        */
+       switch (val) {
+       case 0x5:
+       case 0x9:
+       case 0xD:
+       case 0x19:
+       case 0x1D:
+       case 0x1A:
+       case 0x1E:


What spec did these numbers come from?

+               return -1;
+       }
+
+       /*
+        * MMCRA[48:51]/[52:55]) Threshold Start/Stop
+        * Events Selection.
+        * 0b11110000/0b00001111 is reserved.

The mapping between the event and MMCRA is very unclear :) But there are more reserved values in MMCRA in PowerISA_public.v3.0B.pdf:

===
0000 Reserved

Problem state access (SPR 770)
1000 - 1111 - ReservedPrivileged access (SPR 770 or 786)
1000 - 1111 - Implementation-dependent
===

Do not you need to filter these too?

+        */
+       val = (event >> EVENT_THR_CTL_SHIFT) & EVENT_THR_CTL_MASK;
+       if (((val & 0xF0) == 0xF0) || ((val & 0xF) == 0xF))
+               return -1;

Since the filters may differ for problem and privileged, may be make these check_attr_config() hooks return EINVAL or EPERM and pass it on in the caller? Not sure there is much value in it though.


+
+       return 0;
+}
diff --git a/arch/powerpc/perf/isa207-common.h 
b/arch/powerpc/perf/isa207-common.h
index 1af0e8c97ac7..ae8eaf05efd1 100644
--- a/arch/powerpc/perf/isa207-common.h
+++ b/arch/powerpc/perf/isa207-common.h
@@ -280,4 +280,6 @@ void isa207_get_mem_data_src(union perf_mem_data_src *dsrc, 
u32 flags,
                                                        struct pt_regs *regs);
  void isa207_get_mem_weight(u64 *weight);
+int isa3_X_check_attr_config(struct perf_event *ev);
+
  #endif
diff --git a/arch/powerpc/perf/power10-pmu.c b/arch/powerpc/perf/power10-pmu.c
index a901c1348cad..bc64354cab6a 100644
--- a/arch/powerpc/perf/power10-pmu.c
+++ b/arch/powerpc/perf/power10-pmu.c
@@ -106,6 +106,18 @@ static int power10_get_alternatives(u64 event, unsigned 
int flags, u64 alt[])
        return num_alt;
  }
+static int power10_check_attr_config(struct perf_event *ev)
+{
+       u64 val;
+       u64 event = ev->attr.config;
+
+       val = (event >> EVENT_SAMPLE_SHIFT) & EVENT_SAMPLE_MASK;
+       if (val == 0x10 || isa3_X_check_attr_config(ev))
+               return -1;
+
+       return 0;
+}
+
  GENERIC_EVENT_ATTR(cpu-cycles,                        PM_RUN_CYC);
  GENERIC_EVENT_ATTR(instructions,              PM_RUN_INST_CMPL);
  GENERIC_EVENT_ATTR(branch-instructions,               PM_BR_CMPL);
@@ -559,6 +571,7 @@ static struct power_pmu power10_pmu = {
        .attr_groups            = power10_pmu_attr_groups,
        .bhrb_nr                = 32,
        .capabilities           = PERF_PMU_CAP_EXTENDED_REGS,
+       .check_attr_config      = power10_check_attr_config,
  };
int init_power10_pmu(void)
diff --git a/arch/powerpc/perf/power9-pmu.c b/arch/powerpc/perf/power9-pmu.c
index 2a57e93a79dc..b3b9b226d053 100644
--- a/arch/powerpc/perf/power9-pmu.c
+++ b/arch/powerpc/perf/power9-pmu.c
@@ -151,6 +151,18 @@ static int power9_get_alternatives(u64 event, unsigned int 
flags, u64 alt[])
        return num_alt;
  }
+static int power9_check_attr_config(struct perf_event *ev)
+{
+       u64 val;
+       u64 event = ev->attr.config;
+
+       val = (event >> EVENT_SAMPLE_SHIFT) & EVENT_SAMPLE_MASK;
+       if (val == 0xC || isa3_X_check_attr_config(ev))
+               return -1;
+
+       return 0;
+}
+
  GENERIC_EVENT_ATTR(cpu-cycles,                        PM_CYC);
  GENERIC_EVENT_ATTR(stalled-cycles-frontend,   PM_ICT_NOSLOT_CYC);
  GENERIC_EVENT_ATTR(stalled-cycles-backend,    PM_CMPLU_STALL);
@@ -437,6 +449,7 @@ static struct power_pmu power9_pmu = {
        .attr_groups            = power9_pmu_attr_groups,
        .bhrb_nr                = 32,
        .capabilities           = PERF_PMU_CAP_EXTENDED_REGS,
+       .check_attr_config      = power9_check_attr_config,
  };
int init_power9_pmu(void)


--
Alexey

Reply via email to