Re: [PATCH 4/5] arm-cci: Split the code for PMU vs driver support

From: Suzuki K. Poulose
Date: Wed Mar 04 2015 - 07:19:11 EST

On 03/03/15 15:53, Sudeep Holla wrote:

On 02/03/15 11:29, Suzuki K. Poulose wrote:
From: "Suzuki K. Poulose" <suzuki.poulose@xxxxxxx>

This patch separates the PMU driver code from the low level
CCI driver code.

Introduces config options for both.

ARM_CCI400_PORT_CTRL - controls the low level driver code for
CCI400 ports.
ARM_CCI400_PMU - controls the PMU driver code
ARM_CCI400_COMMON - Common defintions for CCI400

Also the ARM_CCI400_PORT_CTRL cannot be enabled by user. This
should be selected by platforms which need it.

This patch also changes:
ARM_CCI - common code for probing the CCI devices. This can be
used for adding support for newer CCI versions(e.g, CCI-500).

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@xxxxxxx>
arch/arm/mach-exynos/Kconfig | 2 +-
arch/arm/mach-vexpress/Kconfig | 4 ++--
drivers/bus/Kconfig | 27 +++++++++++++++++++++++----
drivers/bus/arm-cci.c | 24 ++++++++++++++++++++----
include/linux/arm-cci.h | 7 ++++++-
5 files changed, 52 insertions(+), 12 deletions(-)


diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index b99729e..bdc189f 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -43,12 +43,31 @@ config OMAP_INTERCONNECT
Driver to enable OMAP interconnect error handling driver.

-config ARM_CCI
- bool "ARM CCI driver support"
+config ARM_CCI400_PORT_CTRL
+ bool
depends on ARM && OF && CPU_V7
+ select ARM_CCI400_COMMON
+ help
+ Low level power management driver for CCI400 cache coherent
+ interconnect for ARM platforms.
+config ARM_CCI400_PMU
+ bool "ARM CCI400 PMU support"
+ depends on ARM || ARM64
+ depends on HW_PERF_EVENTS
+ select ARM_CCI400_COMMON
- Driver supporting the CCI cache coherent interconnect for ARM
- platforms.
+ Support for PMU events monitoring on the ARM CCI cache coherent
+ interconnect.
+ If unsure, say N

Just a query rather than comment. Before this change all platforms
having ARM_CCI and HW_PERF_EVENTS had CCI PMU enabled by default.
With this change, one has to select this option explicitly. I assume
that's fine, else this needs to be default 'y'

Yes, that makes sense. Now that we decide if we can access the CCI safely at runtime, it is safe to make this default.


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