Re: [PATCH 3/4] arm-cci: Split the code for PMU vs driver support
From: Suzuki K. Poulose
Date: Wed Feb 25 2015 - 05:26:22 EST
On 24/02/15 22:17, Nicolas Pitre wrote:
On Tue, 24 Feb 2015, 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, and enables the CCI400-PMU for ARM64.
Introduces config options for both.
- ARM_CCI400_MCPM - controls the low level MCPM driver code for CCI
- ARM_CCI400_PMU - controls the PMU driver code
- ARM_CCI400_COMMON - CCI400 specific details shared by MCPM
and PMU
Changes:
- ARM_CCI - common code for probing the CCI devices
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Cc: Kukjin Kim <kgene@xxxxxxxxxx>
Cc: Abhilash Kesavan <a.kesavan@xxxxxxxxxxx>
Cc: Liviu Dudau <liviu.dudau@xxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@xxxxxxx>
Comments inline.
---
arch/arm/mach-exynos/Kconfig | 2 +-
arch/arm/mach-vexpress/Kconfig | 4 ++--
drivers/bus/Kconfig | 28 +++++++++++++++++++++++-----
drivers/bus/arm-cci.c | 25 +++++++++++++++++++++----
include/linux/arm-cci.h | 7 ++++++-
5 files changed, 53 insertions(+), 13 deletions(-)
diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index 603820e..9bc8b4d 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -123,7 +123,7 @@ config SOC_EXYNOS5800
config EXYNOS5420_MCPM
bool "Exynos5420 Multi-Cluster PM support"
depends on MCPM && SOC_EXYNOS5420
- select ARM_CCI
+ select ARM_CCI400_MCPM
select ARM_CPU_SUSPEND
help
This is needed to provide CPU and cluster power management
diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig
index d6b16d9..097912f 100644
--- a/arch/arm/mach-vexpress/Kconfig
+++ b/arch/arm/mach-vexpress/Kconfig
@@ -53,7 +53,7 @@ config ARCH_VEXPRESS_CORTEX_A5_A9_ERRATA
config ARCH_VEXPRESS_DCSCB
bool "Dual Cluster System Control Block (DCSCB) support"
depends on MCPM
- select ARM_CCI
+ select ARM_CCI400_MCPM
help
Support for the Dual Cluster System Configuration Block (DCSCB).
This is needed to provide CPU and cluster power management
@@ -71,7 +71,7 @@ config ARCH_VEXPRESS_SPC
config ARCH_VEXPRESS_TC2_PM
bool "Versatile Express TC2 power management"
depends on MCPM
- select ARM_CCI
+ select ARM_CCI400_MCPM
select ARCH_VEXPRESS_SPC
help
Support for CPU and cluster power management on Versatile Express
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index b99729e..91dd013 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -43,12 +43,30 @@ config OMAP_INTERCONNECT
help
Driver to enable OMAP interconnect error handling driver.
-config ARM_CCI
- bool "ARM CCI driver support"
- depends on ARM && OF && CPU_V7
+config ARM_CCI400_MCPM
+ bool
+ depends on ARM && OF && CPU_V7 && MCPM
MCPM is not an actual dependency and therefore should probably not be
added here.
OK, will remove that.
You removed the prompt string therefore this will only be
selectable explicitly as needed.
This was intentional, I missed mentioning about it. Do you think we
need to change it back ?
Also, shouldn't it select ARM_CCI400_COMMON ?
Thanks for that, yes it should.
+ 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
help
- 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
+
+config ARM_CCI400_COMMON
+ bool
+ select ARM_CCI
+
+config ARM_CCI
+ bool
Surely you could do with only one of ARM_CCI or ARM_CCI400_COMMON?
Personally I'd go with the later as it is more precise.
The ARM_CCI now stands for CCI version agnostic code. This can be used
for adding support for the newer versions, e.g CCI-500, which I am
planning to post, after this series gets sorted out.
config ARM_CCN
bool "ARM CCN driver support"
diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index fe9fa46..7e330fe 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -32,6 +32,7 @@
static void __iomem *cci_ctrl_base;
static unsigned long cci_ctrl_phys;
+#ifdef CONFIG_ARM_CCI400_MCPM
struct cci_nb_ports {
unsigned int nb_ace;
unsigned int nb_ace_lite;
@@ -42,12 +43,19 @@ static const struct cci_nb_ports cci400_ports = {
.nb_ace_lite = 3
};
+#define CCI400_MCPM_PORTS_DATA (&cci400_ports)
I'm a bit uneasy with the conflation of MCPM in here. Sure (most) MCPM
backends are the only users of this code, but that doesn't mean MCPM has
to have exclusive access. Having "MCPM" entranched into the code and
config symbols like that is misrepresenting this code somewhat.
So, would you like to change the ARM_CCI400_MCPM as well, to something like:
ARM_CCI400_DRIVER or even ARM_CCI400_LL_DRIVER ?
+#else
+#define CCI400_MCPM_PORTS_DATA (NULL)
+#endif
+
static const struct of_device_id arm_cci_matches[] = {
- {.compatible = "arm,cci-400", .data = &cci400_ports },
+#ifdef CONFIG_ARM_CCI400_COMMON
+ {.compatible = "arm,cci-400", .data = CCI400_MCPM_PORTS_DATA },
+#endif
{},
};
-#ifdef CONFIG_HW_PERF_EVENTS
+#ifdef CONFIG_ARM_CCI400_PMU
#define DRIVER_NAME "CCI-400"
#define DRIVER_NAME_PMU DRIVER_NAME " PMU"
@@ -981,6 +989,7 @@ static int cci_pmu_probe(struct platform_device *pdev)
if (ret)
return ret;
+ pr_info("ARM %s PMU driver probed", pmu->model->name);
Wouldn't this addition fit better in one of the previous patches?
Yes, it could have been moved to the previous one, will fix it in the
next revision.
Thanks
Suzuki
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