Thread (7 messages) 7 messages, 3 authors, 2020-02-03

Re: [PATCH 1/1] arm64: zynqmp: Add CoreSight components

From: Mathieu Poirier <mathieu.poirier@linaro.org>
Date: 2020-02-03 17:57:16
Also in: linux-devicetree

On Mon, 3 Feb 2020 at 00:12, Michal Simek [off-list ref] wrote:
On 31. 01. 20 20:37, Wojciech Żmuda wrote:
quoted
Hello Mathieu, thank you for quick review!
Please see my responses inline

On 31/01/2020, 19:47, "Mathieu Poirier" [off-list ref] wrote:
quoted
On Fri, 31 Jan 2020 at 11:36, Mathieu Poirier
[off-list ref] wrote:
quoted
Hi Wojciech,

On Thu, Jan 30, 2020 at 03:36:27PM +0000, Wojciech Żmuda wrote:
quoted
From: Wojciech Zmuda <redacted>

Add nodes for the following CoreSight components:
 - ETMs for A53 cores
 - debug components for A53 cores
 - funnel gathering outputs from A53 ETMs and SoC-wide funnels
 - the only replicator
 - all TMCs: 4k ETF, 8k ETF and ETR
 - TPIU

Signed-off-by: Wojciech Zmuda <redacted>
---
 arch/arm64/boot/dts/xilinx/zynqmp-coresight.dtsi | 272 +++++++++++++++++++++++
 arch/arm64/boot/dts/xilinx/zynqmp.dtsi           |   2 +
 2 files changed, 274 insertions(+)
 create mode 100644 arch/arm64/boot/dts/xilinx/zynqmp-coresight.dtsi
diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-coresight.dtsi b/arch/arm64/boot/dts/xilinx/zynqmp-coresight.dtsi
new file mode 100644
index 000000000000..8b7579ad89cc
--- /dev/null
+++ b/arch/arm64/boot/dts/xilinx/zynqmp-coresight.dtsi
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0+
+
Looking at other Xilinx DT files there is no space between the SPDX identifier
and the header of the file.
Ok, I'll remove the extra space.
quoted
quoted
quoted
+/*
+ * dtsi for Xilinx Ultrascale+ MPSoC CoreSight components
+ *
+ * Copyright (C) 2019-2020 N7 Space Sp. z o.o.
+ *
+ * Author: Wojciech Zmuda [off-list ref]
+ *
+ */
+/ {
+     etm0@fec40000 {
+             compatible = "arm,coresight-etm4x", "arm,primecell";
+             reg = <0 0xfec40000 0 0x1000>;
+             cpu = <&cpu0>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             out-ports {
+                     port {
+                             etm0_out_port: endpoint {
+                                     remote-endpoint = <&funnel1_in_port0>;
+                             };
+                     };
+             };
+     };
+
+     etm1@fed40000 {
+             compatible = "arm,coresight-etm4x", "arm,primecell";
+             reg = <0 0xfed40000 0 0x1000>;
+             cpu = <&cpu1>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             out-ports {
+                     port {
+                             etm1_out_port: endpoint {
+                                     remote-endpoint = <&funnel1_in_port1>;
+                             };
+                     };
+             };
+     };
+
+     etm2@fee40000 {
+             compatible = "arm,coresight-etm4x", "arm,primecell";
+             reg = <0 0xfee40000 0 0x1000>;
+             cpu = <&cpu2>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             out-ports {
+                     port {
+                             etm2_out_port: endpoint {
+                                     remote-endpoint = <&funnel1_in_port2>;
+                             };
+                     };
+             };
+     };
+
+     etm3@fef40000 {
+             compatible = "arm,coresight-etm4x", "arm,primecell";
+             reg = <0 0xfef40000 0 0x1000>;
+             cpu = <&cpu3>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             out-ports {
+                     port {
+                             etm3_out_port: endpoint {
+                                     remote-endpoint = <&funnel1_in_port3>;
+                             };
+                     };
+             };
+     };
+
+     debug0@fec10000 {
+             compatible = "arm,coresight-cpu-debug", "arm,primecell";
+             reg = <0 0xfec10000 0 0x1000>;
+             cpu = <&cpu0>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+     };
+
+     debug1@fed10000 {
+             compatible = "arm,coresight-cpu-debug", "arm,primecell";
+             reg = <0 0xfed10000 0 0x1000>;
+             cpu = <&cpu1>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+     };
+
+     debug2@fee10000 {
+             compatible = "arm,coresight-cpu-debug", "arm,primecell";
+             reg = <0 0xfee10000 0 0x1000>;
+             cpu = <&cpu2>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+     };
+
+     debug3@fee10000 {
+             compatible = "arm,coresight-cpu-debug", "arm,primecell";
+             reg = <0 0xfef10000 0 0x1000>;
+             cpu = <&cpu3>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+     };
+
+     funnel1@fe920000 {
+             compatible = "arm,coresight-dynamic-funnel", "arm,primecell";
+             reg = <0 0xfe920000 0 0x1000>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             in-ports {
+                     #address-cells = <0x1>;
+                     #size-cells = <0x0>;
+                     port@0 {
+                             reg = <0x0>;
+                             funnel1_in_port0: endpoint {
+                                     remote-endpoint = <&etm0_out_port>;
+                             };
+                     };
+                     port@1 {
+                             reg = <0x1>;
+                             funnel1_in_port1: endpoint {
+                                     remote-endpoint = <&etm1_out_port>;
+                             };
+                     };
+                     port@2 {
+                             reg = <0x2>;
+                             funnel1_in_port2: endpoint {
+                                     remote-endpoint = <&etm2_out_port>;
+                             };
+                     };
+                     port@3 {
+                             reg = <0x3>;
+                             funnel1_in_port3: endpoint {
+                                     remote-endpoint = <&etm3_out_port>;
+                             };
+                     };
+             };
+             out-ports {
+                     port {
+                             funnel1_out_port0: endpoint {
+                                     remote-endpoint = <&etf1_in_port>;
+                             };
+                     };
+             };
+     };
+
+     funnel2@fe930000 {
+             compatible = "arm,coresight-dynamic-funnel", "arm,primecell";
+             reg = <0 0xfe930000 0 0x1000>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             in-ports {
+                     #address-cells = <0x1>;
+                     #size-cells = <0x0>;
+                     port@2 {
+                             reg = <0x2>;
+                             funnel2_in_port2: endpoint {
+                                     remote-endpoint = <&etf1_out_port>;
+                             };
+                     };
+                     // Funnel2 has another input port connected to
+                     // funnel0's output. Funnel0 gathers Cortex-R5 ETMs.
C++ style comments.
Ok, I'll go with:
/*
 * Funnel2 has another input port connected to
 * funnel0's output. Funnel0 gathers Cortex-R5 ETMs.
 */
quoted
quoted
quoted
+             };
+             out-ports {
+                     port {
+                             funnel2_out_port0: endpoint {
+                                     remote-endpoint = <&etf2_in_port>;
+                             };
+                     };
+             };
+     };
+
+     etf1@fe940000 {
+             compatible = "arm,coresight-tmc", "arm,primecell";
+             reg = <0 0xfe940000 0 0x1000>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             in-ports {
+                     port {
+                             etf1_in_port: endpoint {
+                                     remote-endpoint = <&funnel1_out_port0>;
+                             };
+                     };
+             };
+             out-ports {
+                     port {
+                             etf1_out_port: endpoint {
+                                     remote-endpoint = <&funnel2_in_port2>;
+                             };
+                     };
+             };
+     };
+
+     etf2@fe950000 {
+             compatible = "arm,coresight-tmc", "arm,primecell";
+             reg = <0 0xfe950000 0 0x1000>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             in-ports {
+                     port {
+                             etf2_in_port: endpoint {
+                                     remote-endpoint = <&funnel2_out_port0>;
+                             };
+                     };
+             };
+             out-ports {
+                     port {
+                             etf2_out_port: endpoint {
+                                     remote-endpoint =
+                                             <&replicator_in_port0>;
+                             };
+                     };
+             };
+     };
+
+     replicator {
+             compatible = "arm,coresight-static-replicator";
+             in-ports {
+                     port {
+                             replicator_in_port0: endpoint {
+                                     remote-endpoint = <&etf2_out_port>;
+                             };
+                     };
+             };
+             out-ports {
+                     #address-cells = <0x1>;
+                     #size-cells = <0x0>;
+                     port@0 {
+                             reg = <0x0>;
+                             replicator_out_port0: endpoint {
+                                     remote-endpoint = <&etr_in_port>;
+                             };
+                     };
+                     port@1 {
+                             reg = <0x1>;
+                             replicator_out_port1: endpoint {
+                                     remote-endpoint = <&tpiu_in_port>;
+                             };
+                     };
+             };
+     };
+
+     etr@fe970000 {
+             compatible = "arm,coresight-tmc", "arm,primecell";
+             reg = <0 0xfe970000 0 0x1000>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             in-ports {
+                     port {
+                             etr_in_port: endpoint {
+                                     remote-endpoint =
+                                             <&replicator_out_port0>;
+                             };
+                     };
+             };
+     };
+
+     tpiu@fe980000  {
+             compatible = "arm,coresight-tpiu", "arm,primecell";
+             reg = <0 0xfe980000 0 0x1000>;
+             clocks = <&clk100>;
+             clock-names = "apb_pclk";
+             in-ports {
+                     port {
+                             tpiu_in_port: endpoint {
+                                     remote-endpoint =
+                                             <&replicator_out_port1>;
+                             };
+                     };
+             };
+     };
+};
+
diff --git a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
index 3c731e73903a..ca0a6b9f4445 100644
--- a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
+++ b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
@@ -12,6 +12,8 @@
  * the License, or (at your option) any later version.
  */
 >
quoted
+#include "zynqmp-coresight.dtsi"
+
Those bindings are correctly used.  If Michal doesn't mind the nit-picks I have
highlighted above then

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Otherwise feel free to add my tag to your next revision, which I advise you to
send out once v5.6-rc1 comes out.
Great, thanks. I'll keep an eye for v5.6-rc1.
quoted
I forgot...  How does power management work on this board?  Is the
power domain where the CS blocks are powered up by the FW?  And what
about state retention when processors go idle?  Should this be taken
care of in the drivers or is the PMIC properly handling low retention
states?  Failure to properly address both cases will likely hang the
board (at boot time of when processors are idled).
To be honest, I don't know. I use kernel with CPU idle permanently disabled, as was
advised somewhere in CoreSight-related documents I found at the beginning of my
experiments. It might've been a presentation from Linaro Connect, either yours or Leo's.
I didn't do any extra steps to power CS blocks on, so I guess they're either powered on
by default, or it's taken care of by either FSBL, U-boot or ATF. I use those three provided
by Xilinx. I didn't experiment with vanilla U-boot or ATF.

Can you please suggest some experiments I in this matter? Would turning off CPU idle
in kernel's config and tracing a migrating process be sufficient for such test?
This is a fairly new feature that Andrew finished in September [1].
It allows to save/restore the coresight tracers' configuration when
CPUs enter idle states, allowing coresight to be used when CPUIdle is
enabled.  This is necessary when the HW line driven by the PU bit of
configuration register TRCPDCR is not connected to a PMIC or the
PMIC's firmware is ignoring the signal.  It is very likely that either
one of those scenarios are enacted on this platform.

To deal with power management issues on the ETM blocks, re-enable
CPUIdle and add "arm,coresight-loses-context-with-cpu;" to each of the
ETM node specification in the DT (see bindings for details).  That
should take care of the ETMs only, which are usually in the CPU power
domain.  The rest of the coresight blocks are generally located in the
debug power domain, something I can't help with.  It is either enabled
at boot time by the boot loader or the kernel, or handled dynamically
at run time.  See the "power-domains" property in the Juno coresight
specification[2].

[1]. https://www.spinics.net/lists/devicetree/msg309139.html
[2]. https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/arm/juno-base.dtsi#L169
Jolly: Can you please take a look how this block is powered and how
power stuff should be handled?

Thanks,
Michal
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