[meta-freescale] [meta-fsl-arm-extra][PATCH] linux-wandboard: Configure the ARM core to use hardware performance counters.

[Alex Gonzalez]

Without this patch the performance counters in the Cortex A9 core always
return zero.

Signed-off-by: Alex Gonzalez <alex.gonzalez at digi.com>
---
 ...6q-Set-non-invasive-debug-configuration-p.patch | 42 ++++++++++++++++++++++
 recipes-kernel/linux/linux-wandboard_3.10.17.bb    |  2 ++
 2 files changed, 44 insertions(+)
 create mode 100644 recipes-kernel/linux/linux-wandboard-3.10.17/0001-ARM-imx-imx6q-Set-non-invasive-debug-configuration-p.patch

diff --git a/recipes-kernel/linux/linux-wandboard-3.10.17/0001-ARM-imx-imx6q-Set-non-invasive-debug-configuration-p.patch b/recipes-kernel/linux/linux-wandboard-3.10.17/0001-ARM-imx-imx6q-Set-non-invasive-debug-configuration-p.patch
new file mode 100644
index 000000000000..69826afe25e2
--- /dev/null
+++ b/recipes-kernel/linux/linux-wandboard-3.10.17/0001-ARM-imx-imx6q-Set-non-invasive-debug-configuration-p.patch
@@ -0,0 +1,42 @@
+From: Alex Gonzalez <alex.gonzalez at digi.com>
+Date: Sun, 21 Dec 2014 16:04:56 +0100
+Subject: [PATCH] ARM: imx: imx6q: Set non invasive debug configuration
+ permission bits.
+
+This is needed in order to use the hardware performance events counters.
+
+http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka16431.html
+
+Signed-off-by: Alex Gonzalez <alex.gonzalez at digi.com>
+---
+ arch/arm/mach-imx/mach-imx6q.c | 10 ++++++++++
+ 1 file changed, 10 insertions(+)
+
+diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
+index 5fb11af5643d..e54906a8d442 100644
+--- a/arch/arm/mach-imx/mach-imx6q.c
++++ b/arch/arm/mach-imx/mach-imx6q.c
+@@ -304,6 +304,15 @@ static const struct of_dev_auxdata imx6q_auxdata_lookup[] __initconst = {
+ 	{ /* sentinel */ }
+ };
+ 
++static void imx6q_armpmu_init(void)
++{
++	/* Configure the non invasive debug configuration registers */
++	if (IS_ENABLED(CONFIG_HW_PERF_EVENTS)) {
++		u32 val = 0b11;
++		asm volatile("mcr p15, 0, %0, c1, c1, 1" : : "r" (val));
++	}
++}
++
+ static void __init imx6q_init_machine(void)
+ {
+ 	struct device *parent;
+@@ -320,6 +329,7 @@ static void __init imx6q_init_machine(void)
+ 	imx_anatop_init();
+ 	imx6_pm_init();
+ 	imx6q_csi_mux_init();
++	imx6q_armpmu_init();
+ }
+ 
+ #define OCOTP_CFG3			0x440
diff --git a/recipes-kernel/linux/linux-wandboard_3.10.17.bb b/recipes-kernel/linux/linux-wandboard_3.10.17.bb
index 30483f18d6b9..347bad8dfee7 100644
--- a/recipes-kernel/linux/linux-wandboard_3.10.17.bb
+++ b/recipes-kernel/linux/linux-wandboard_3.10.17.bb
@@ -6,6 +6,8 @@ require recipes-kernel/linux/linux-dtb.inc
 
 DEPENDS += "lzop-native bc-native"
 
+SRC_URI += "file://0001-ARM-imx-imx6q-Set-non-invasive-debug-configuration-p.patch"
+
 # Wandboard branch - based on 3.10.17_1.0.1_ga from Freescale git
 SRCBRANCH = "wandboard_imx_3.10.17_1.0.1_ga"
 SRCREV = "a6e7fc58e6912986d003598ed79bb6a391a2113c"