On Wed, Jan 08, 2014 at 10:59:40PM +0000, Stephen Boyd wrote:

Add basic support for the Krait CPU PMU. This allows us to use
the architected functionality of the PMU.

This is based on code originally written by Ashwin Chaugule and
Neil Leeder [1].

[1] https://www.codeaurora.org/cgit/quic/la/kernel/msm/tree/arch/arm/kernel/perf_event_msm_krait.c?h=msm-3.4

Cc: Neil Leeder <redacted>
Cc: Ashwin Chaugule <redacted>
Signed-off-by: Stephen Boyd <redacted>
---
 arch/arm/kernel/perf_event_cpu.c |   1 +
 arch/arm/kernel/perf_event_v7.c  | 165 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 166 insertions(+)

[...]

+static int krait_pmu_init(struct arm_pmu *cpu_pmu)
+{
+	u32 id = read_cpuid_id() & 0xffffff00;
+
+	armv7pmu_init(cpu_pmu);
+	cpu_pmu->name		= "ARMv7 Krait";
+	/* Some early versions of Krait don't support PC write events */
+	if (id == 0x511f0400 || id == 0x510f0600)
+		cpu_pmu->map_event	= krait_map_event_no_branch;

Hmm, I'd really rather this information came via the DT. In fact, you could
just drop the branch event from your main map_event_function and keep things
simple. It depends how badly you want to advertise it in perf list :)

Will