[PATCH v2 0/4] Enable DMA on STM32 MCU based on cortex-M7

[PATCH v2 0/4] Enable DMA on STM32 MCU based on cortex-M7

[Alexandre Torgue]

This series enable DMA on several STM32 MCU based on cortex-M7.
To make it possible, a dedicated dma pool memory area has to be
created. This patchset activate also ARM_MPU flag which will configure 
MPU (Memory Protection Unit) according to devicetree information (mem
and dma-pool). Note that on cortex-M7 DMA has to use a NO cache-able 
memory region.


v2:
-select ARM_MPU in mach-stm32 Kconfig instead of add it in stm32 defconfig
-Remove XIP configuration from stm32_defconfig: ARM_MPU flag imposes XIP image
to be aligned on 1MB. It is currently not the case. I had choice to either
modify current XIP start address to be aligned on 1MB or to remove global
configuration. I make choice to remove XIP configuration. Indeed, SD card
support has been recently added for most of STM32 MCU boards (except for
stm32f429-disco). As kernel is growing up for stm32 it will be more and more
difficult to flash it in embeded flash (max size: 2MB).
-fix typo in commit message

Regards
Alex

Alexandre Torgue (4):
  ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7
  ARM: configs: stm32: remove XIP configuration
  ARM: stm32: Select ARM_MPU for cortex-M7 machines
  ARM: dts: stm32: enable dma on MCU which embed a cortex-M7

 arch/arm/boot/dts/stm32746g-eval.dts   | 21 +++++++++++++++++++++
 arch/arm/boot/dts/stm32f769-disco.dts  | 21 +++++++++++++++++++++
 arch/arm/boot/dts/stm32h743i-disco.dts | 21 +++++++++++++++++++++
 arch/arm/boot/dts/stm32h743i-eval.dts  | 21 +++++++++++++++++++++
 arch/arm/configs/stm32_defconfig       |  2 --
 arch/arm/mach-stm32/Kconfig            |  3 +++
 6 files changed, 87 insertions(+), 2 deletions(-)

-- 
2.7.4

[PATCH v2 0/4] Enable DMA on STM32 MCU based on cortex-M7

[Alexandre Torgue]

This series enable DMA on several STM32 MCU based on cortex-M7.
To make it possible, a dedicated dma pool memory area has to be
created. This patchset activate also ARM_MPU flag which will configure 
MPU (Memory Protection Unit) according to devicetree information (mem
and dma-pool). Note that on cortex-M7 DMA has to use a NO cache-able 
memory region.


v2:
-select ARM_MPU in mach-stm32 Kconfig instead of add it in stm32 defconfig
-Remove XIP configuration from stm32_defconfig: ARM_MPU flag imposes XIP image
to be aligned on 1MB. It is currently not the case. I had choice to either
modify current XIP start address to be aligned on 1MB or to remove global
configuration. I make choice to remove XIP configuration. Indeed, SD card
support has been recently added for most of STM32 MCU boards (except for
stm32f429-disco). As kernel is growing up for stm32 it will be more and more
difficult to flash it in embeded flash (max size: 2MB).
-fix typo in commit message

Regards
Alex

Alexandre Torgue (4):
  ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7
  ARM: configs: stm32: remove XIP configuration
  ARM: stm32: Select ARM_MPU for cortex-M7 machines
  ARM: dts: stm32: enable dma on MCU which embed a cortex-M7

 arch/arm/boot/dts/stm32746g-eval.dts   | 21 +++++++++++++++++++++
 arch/arm/boot/dts/stm32f769-disco.dts  | 21 +++++++++++++++++++++
 arch/arm/boot/dts/stm32h743i-disco.dts | 21 +++++++++++++++++++++
 arch/arm/boot/dts/stm32h743i-eval.dts  | 21 +++++++++++++++++++++
 arch/arm/configs/stm32_defconfig       |  2 --
 arch/arm/mach-stm32/Kconfig            |  3 +++
 6 files changed, 87 insertions(+), 2 deletions(-)

-- 
2.7.4

[PATCH v2 1/4] ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7

[Alexandre Torgue]

On cortex-M7 MCU, DMA have to use a non cache-able memory area. For this
reason a dedicated memory pool is created for DMA.
This patch creates a DMA memory pool of 1MB of each STM32 MCU which
embeds a cortex-M7 except stm32f746-disco. Indeed, as stm32f746-disco has
only a 8MB SDRAM and it's tricky to reduce memory used by Kernel.

Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/boot/dts/stm32746g-eval.dts b/arch/arm/boot/dts/stm32746g-eval.dts
index e3f5a83..92651c3 100644
--- a/arch/arm/boot/dts/stm32746g-eval.dts
+++ b/arch/arm/boot/dts/stm32746g-eval.dts
@@ -58,6 +58,19 @@
 		reg = <0xc0000000 0x2000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc1f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
diff --git a/arch/arm/boot/dts/stm32f769-disco.dts b/arch/arm/boot/dts/stm32f769-disco.dts
index d712260..c526853 100644
--- a/arch/arm/boot/dts/stm32f769-disco.dts
+++ b/arch/arm/boot/dts/stm32f769-disco.dts
@@ -59,6 +59,19 @@
 		reg = <0xC0000000 0x1000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc0f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
diff --git a/arch/arm/boot/dts/stm32h743i-disco.dts b/arch/arm/boot/dts/stm32h743i-disco.dts
index 45e088c..3689e70 100644
--- a/arch/arm/boot/dts/stm32h743i-disco.dts
+++ b/arch/arm/boot/dts/stm32h743i-disco.dts
@@ -57,6 +57,19 @@
 		reg = <0xd0000000 0x2000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc1f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart2;
 	};
diff --git a/arch/arm/boot/dts/stm32h743i-eval.dts b/arch/arm/boot/dts/stm32h743i-eval.dts
index c7187e1..b9af696 100644
--- a/arch/arm/boot/dts/stm32h743i-eval.dts
+++ b/arch/arm/boot/dts/stm32h743i-eval.dts
@@ -57,6 +57,19 @@
 		reg = <0xd0000000 0x2000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc1f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
-- 
2.7.4

[PATCH v2 1/4] ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7

[Alexandre Torgue]

On cortex-M7 MCU, DMA have to use a non cache-able memory area. For this
reason a dedicated memory pool is created for DMA.
This patch creates a DMA memory pool of 1MB of each STM32 MCU which
embeds a cortex-M7 except stm32f746-disco. Indeed, as stm32f746-disco has
only a 8MB SDRAM and it's tricky to reduce memory used by Kernel.

Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/boot/dts/stm32746g-eval.dts b/arch/arm/boot/dts/stm32746g-eval.dts
index e3f5a83..92651c3 100644
--- a/arch/arm/boot/dts/stm32746g-eval.dts
+++ b/arch/arm/boot/dts/stm32746g-eval.dts
@@ -58,6 +58,19 @@
 		reg = <0xc0000000 0x2000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc1f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
diff --git a/arch/arm/boot/dts/stm32f769-disco.dts b/arch/arm/boot/dts/stm32f769-disco.dts
index d712260..c526853 100644
--- a/arch/arm/boot/dts/stm32f769-disco.dts
+++ b/arch/arm/boot/dts/stm32f769-disco.dts
@@ -59,6 +59,19 @@
 		reg = <0xC0000000 0x1000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc0f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
diff --git a/arch/arm/boot/dts/stm32h743i-disco.dts b/arch/arm/boot/dts/stm32h743i-disco.dts
index 45e088c..3689e70 100644
--- a/arch/arm/boot/dts/stm32h743i-disco.dts
+++ b/arch/arm/boot/dts/stm32h743i-disco.dts
@@ -57,6 +57,19 @@
 		reg = <0xd0000000 0x2000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc1f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart2;
 	};
diff --git a/arch/arm/boot/dts/stm32h743i-eval.dts b/arch/arm/boot/dts/stm32h743i-eval.dts
index c7187e1..b9af696 100644
--- a/arch/arm/boot/dts/stm32h743i-eval.dts
+++ b/arch/arm/boot/dts/stm32h743i-eval.dts
@@ -57,6 +57,19 @@
 		reg = <0xd0000000 0x2000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc1f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
-- 
2.7.4

[PATCH v2 2/4] ARM: configs: stm32: remove XIP configuration

[Alexandre Torgue]

Embedded flash becomes too small to be used as XIP support. SD card is now
available on most of stm32 boards and could be used as boot support.
Furthermore, ARM_MPU flags will be used by default and it imposes that XIP
image to be aligned on 1MB (which is not the case). For all those reasons
I prefer to remove XIP configuration from default stm32 config and let
user configure it if needed.

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/configs/stm32_defconfig b/arch/arm/configs/stm32_defconfig
index ba805b7..b162b8d 100644
--- a/arch/arm/configs/stm32_defconfig
+++ b/arch/arm/configs/stm32_defconfig
@@ -28,8 +28,6 @@ CONFIG_PREEMPT=y
 # CONFIG_ATAGS is not set
 CONFIG_ZBOOT_ROM_TEXT=0x0
 CONFIG_ZBOOT_ROM_BSS=0x0
-CONFIG_XIP_KERNEL=y
-CONFIG_XIP_PHYS_ADDR=0x08008000
 CONFIG_BINFMT_FLAT=y
 CONFIG_BINFMT_SHARED_FLAT=y
 # CONFIG_COREDUMP is not set
-- 
2.7.4

[PATCH v2 2/4] ARM: configs: stm32: remove XIP configuration

[Alexandre Torgue]

Embedded flash becomes too small to be used as XIP support. SD card is now
available on most of stm32 boards and could be used as boot support.
Furthermore, ARM_MPU flags will be used by default and it imposes that XIP
image to be aligned on 1MB (which is not the case). For all those reasons
I prefer to remove XIP configuration from default stm32 config and let
user configure it if needed.

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/configs/stm32_defconfig b/arch/arm/configs/stm32_defconfig
index ba805b7..b162b8d 100644
--- a/arch/arm/configs/stm32_defconfig
+++ b/arch/arm/configs/stm32_defconfig
@@ -28,8 +28,6 @@ CONFIG_PREEMPT=y
 # CONFIG_ATAGS is not set
 CONFIG_ZBOOT_ROM_TEXT=0x0
 CONFIG_ZBOOT_ROM_BSS=0x0
-CONFIG_XIP_KERNEL=y
-CONFIG_XIP_PHYS_ADDR=0x08008000
 CONFIG_BINFMT_FLAT=y
 CONFIG_BINFMT_SHARED_FLAT=y
 # CONFIG_COREDUMP is not set
-- 
2.7.4

[PATCH v2 3/4] ARM: stm32: Select ARM_MPU for cortex-M7 machines

[Alexandre Torgue]

STM32 MCUs embed a Memory Protection Unit. Enabling ARM_MPU flag will
allow the Kernel to configure the MPU according to the devicetree.

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/mach-stm32/Kconfig b/arch/arm/mach-stm32/Kconfig
index 713c068..c2ad8e9 100644
--- a/arch/arm/mach-stm32/Kconfig
+++ b/arch/arm/mach-stm32/Kconfig
@@ -29,15 +29,18 @@ config MACH_STM32F469
 config MACH_STM32F746
 	bool "STMicroelectronics STM32F746"
 	select ARM_AMBA
+	select ARM_MPU
 	default y
 
 config MACH_STM32F769
 	bool "STMicroelectronics STM32F769"
 	select ARM_AMBA
+	select ARM_MPU
 	default y
 
 config MACH_STM32H743
 	bool "STMicroelectronics STM32H743"
+	select ARM_MPU
 	default y
 
 endif # ARMv7-M
-- 
2.7.4

[PATCH v2 3/4] ARM: stm32: Select ARM_MPU for cortex-M7 machines

[Alexandre Torgue]

STM32 MCUs embed a Memory Protection Unit. Enabling ARM_MPU flag will
allow the Kernel to configure the MPU according to the devicetree.

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/mach-stm32/Kconfig b/arch/arm/mach-stm32/Kconfig
index 713c068..c2ad8e9 100644
--- a/arch/arm/mach-stm32/Kconfig
+++ b/arch/arm/mach-stm32/Kconfig
@@ -29,15 +29,18 @@ config MACH_STM32F469
 config MACH_STM32F746
 	bool "STMicroelectronics STM32F746"
 	select ARM_AMBA
+	select ARM_MPU
 	default y
 
 config MACH_STM32F769
 	bool "STMicroelectronics STM32F769"
 	select ARM_AMBA
+	select ARM_MPU
 	default y
 
 config MACH_STM32H743
 	bool "STMicroelectronics STM32H743"
+	select ARM_MPU
 	default y
 
 endif # ARMv7-M
-- 
2.7.4

[PATCH v2 4/4] ARM: dts: stm32: enable dma on MCU which embed a cortex-M7

[Alexandre Torgue]

Enable dma1 and dma2 on:
-stm32746g-eval board
-stm32f769-disco board
-stm32h743i-disco board
-stm32h743i-eval board

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/boot/dts/stm32746g-eval.dts b/arch/arm/boot/dts/stm32746g-eval.dts
index 92651c3..c87e289 100644
--- a/arch/arm/boot/dts/stm32746g-eval.dts
+++ b/arch/arm/boot/dts/stm32746g-eval.dts
@@ -114,6 +114,14 @@
 	status = "okay";
 };
 
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
 &i2c1 {
 	pinctrl-0 = <&i2c1_pins_b>;
 	pinctrl-names = "default";
diff --git a/arch/arm/boot/dts/stm32f769-disco.dts b/arch/arm/boot/dts/stm32f769-disco.dts
index c526853..3985c6d 100644
--- a/arch/arm/boot/dts/stm32f769-disco.dts
+++ b/arch/arm/boot/dts/stm32f769-disco.dts
@@ -117,6 +117,14 @@
 	clock-frequency = <25000000>;
 };
 
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
 &rtc {
 	status = "okay";
 };
diff --git a/arch/arm/boot/dts/stm32h743i-disco.dts b/arch/arm/boot/dts/stm32h743i-disco.dts
index 3689e70..e1623e3 100644
--- a/arch/arm/boot/dts/stm32h743i-disco.dts
+++ b/arch/arm/boot/dts/stm32h743i-disco.dts
@@ -79,6 +79,14 @@
 	clock-frequency = <25000000>;
 };
 
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
 &usart2 {
 	pinctrl-0 = <&usart2_pins>;
 	pinctrl-names = "default";
diff --git a/arch/arm/boot/dts/stm32h743i-eval.dts b/arch/arm/boot/dts/stm32h743i-eval.dts
index b9af696..3a1f471 100644
--- a/arch/arm/boot/dts/stm32h743i-eval.dts
+++ b/arch/arm/boot/dts/stm32h743i-eval.dts
@@ -105,6 +105,14 @@
 	clock-frequency = <25000000>;
 };
 
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
 &rtc {
 	status = "okay";
 };
-- 
2.7.4

[PATCH v2 4/4] ARM: dts: stm32: enable dma on MCU which embed a cortex-M7

[Alexandre Torgue]

Enable dma1 and dma2 on:
-stm32746g-eval board
-stm32f769-disco board
-stm32h743i-disco board
-stm32h743i-eval board

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/boot/dts/stm32746g-eval.dts b/arch/arm/boot/dts/stm32746g-eval.dts
index 92651c3..c87e289 100644
--- a/arch/arm/boot/dts/stm32746g-eval.dts
+++ b/arch/arm/boot/dts/stm32746g-eval.dts
@@ -114,6 +114,14 @@
 	status = "okay";
 };
 
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
 &i2c1 {
 	pinctrl-0 = <&i2c1_pins_b>;
 	pinctrl-names = "default";
diff --git a/arch/arm/boot/dts/stm32f769-disco.dts b/arch/arm/boot/dts/stm32f769-disco.dts
index c526853..3985c6d 100644
--- a/arch/arm/boot/dts/stm32f769-disco.dts
+++ b/arch/arm/boot/dts/stm32f769-disco.dts
@@ -117,6 +117,14 @@
 	clock-frequency = <25000000>;
 };
 
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
 &rtc {
 	status = "okay";
 };
diff --git a/arch/arm/boot/dts/stm32h743i-disco.dts b/arch/arm/boot/dts/stm32h743i-disco.dts
index 3689e70..e1623e3 100644
--- a/arch/arm/boot/dts/stm32h743i-disco.dts
+++ b/arch/arm/boot/dts/stm32h743i-disco.dts
@@ -79,6 +79,14 @@
 	clock-frequency = <25000000>;
 };
 
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
 &usart2 {
 	pinctrl-0 = <&usart2_pins>;
 	pinctrl-names = "default";
diff --git a/arch/arm/boot/dts/stm32h743i-eval.dts b/arch/arm/boot/dts/stm32h743i-eval.dts
index b9af696..3a1f471 100644
--- a/arch/arm/boot/dts/stm32h743i-eval.dts
+++ b/arch/arm/boot/dts/stm32h743i-eval.dts
@@ -105,6 +105,14 @@
 	clock-frequency = <25000000>;
 };
 
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
 &rtc {
 	status = "okay";
 };
-- 
2.7.4

Re: [PATCH v2 0/4] Enable DMA on STM32 MCU based on cortex-M7

[Vladimir Murzin]

On 28/02/18 13:10, Alexandre Torgue wrote:
> This series enable DMA on several STM32 MCU based on cortex-M7.
> To make it possible, a dedicated dma pool memory area has to be
> created. This patchset activate also ARM_MPU flag which will configure 
> MPU (Memory Protection Unit) according to devicetree information (mem
> and dma-pool). Note that on cortex-M7 DMA has to use a NO cache-able 
> memory region.
> 
> 
> v2:
> -select ARM_MPU in mach-stm32 Kconfig instead of add it in stm32 defconfig
> -Remove XIP configuration from stm32_defconfig: ARM_MPU flag imposes XIP image
> to be aligned on 1MB. It is currently not the case. I had choice to either
> modify current XIP start address to be aligned on 1MB or to remove global
> configuration. I make choice to remove XIP configuration. Indeed, SD card
> support has been recently added for most of STM32 MCU boards (except for
> stm32f429-disco). As kernel is growing up for stm32 it will be more and more
> difficult to flash it in embeded flash (max size: 2MB).

It is sad we are loosing XIP configuration - it used to uncover some bugs
in a past. Probably, you might consider to have stm32 tiny (+xip) defconfig
for those who do not want/need all-in-one kernel.

Cheers
Vladimir

> -fix typo in commit message
> 
> Regards
> Alex
> 
> Alexandre Torgue (4):
>   ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7
>   ARM: configs: stm32: remove XIP configuration
>   ARM: stm32: Select ARM_MPU for cortex-M7 machines
>   ARM: dts: stm32: enable dma on MCU which embed a cortex-M7
> 
>  arch/arm/boot/dts/stm32746g-eval.dts   | 21 +++++++++++++++++++++
>  arch/arm/boot/dts/stm32f769-disco.dts  | 21 +++++++++++++++++++++
>  arch/arm/boot/dts/stm32h743i-disco.dts | 21 +++++++++++++++++++++
>  arch/arm/boot/dts/stm32h743i-eval.dts  | 21 +++++++++++++++++++++
>  arch/arm/configs/stm32_defconfig       |  2 --
>  arch/arm/mach-stm32/Kconfig            |  3 +++
>  6 files changed, 87 insertions(+), 2 deletions(-)
> 

[PATCH v2 0/4] Enable DMA on STM32 MCU based on cortex-M7

[Vladimir Murzin]

On 28/02/18 13:10, Alexandre Torgue wrote:
> This series enable DMA on several STM32 MCU based on cortex-M7.
> To make it possible, a dedicated dma pool memory area has to be
> created. This patchset activate also ARM_MPU flag which will configure 
> MPU (Memory Protection Unit) according to devicetree information (mem
> and dma-pool). Note that on cortex-M7 DMA has to use a NO cache-able 
> memory region.
> 
> 
> v2:
> -select ARM_MPU in mach-stm32 Kconfig instead of add it in stm32 defconfig
> -Remove XIP configuration from stm32_defconfig: ARM_MPU flag imposes XIP image
> to be aligned on 1MB. It is currently not the case. I had choice to either
> modify current XIP start address to be aligned on 1MB or to remove global
> configuration. I make choice to remove XIP configuration. Indeed, SD card
> support has been recently added for most of STM32 MCU boards (except for
> stm32f429-disco). As kernel is growing up for stm32 it will be more and more
> difficult to flash it in embeded flash (max size: 2MB).

It is sad we are loosing XIP configuration - it used to uncover some bugs
in a past. Probably, you might consider to have stm32 tiny (+xip) defconfig
for those who do not want/need all-in-one kernel.

Cheers
Vladimir

> -fix typo in commit message
> 
> Regards
> Alex
> 
> Alexandre Torgue (4):
>   ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7
>   ARM: configs: stm32: remove XIP configuration
>   ARM: stm32: Select ARM_MPU for cortex-M7 machines
>   ARM: dts: stm32: enable dma on MCU which embed a cortex-M7
> 
>  arch/arm/boot/dts/stm32746g-eval.dts   | 21 +++++++++++++++++++++
>  arch/arm/boot/dts/stm32f769-disco.dts  | 21 +++++++++++++++++++++
>  arch/arm/boot/dts/stm32h743i-disco.dts | 21 +++++++++++++++++++++
>  arch/arm/boot/dts/stm32h743i-eval.dts  | 21 +++++++++++++++++++++
>  arch/arm/configs/stm32_defconfig       |  2 --
>  arch/arm/mach-stm32/Kconfig            |  3 +++
>  6 files changed, 87 insertions(+), 2 deletions(-)
> 

Re: [PATCH v2 0/4] Enable DMA on STM32 MCU based on cortex-M7

[Alexandre Torgue]

Hi Vlad

On 02/28/2018 02:22 PM, Vladimir Murzin wrote:
> On 28/02/18 13:10, Alexandre Torgue wrote:
>> This series enable DMA on several STM32 MCU based on cortex-M7.
>> To make it possible, a dedicated dma pool memory area has to be
>> created. This patchset activate also ARM_MPU flag which will configure
>> MPU (Memory Protection Unit) according to devicetree information (mem
>> and dma-pool). Note that on cortex-M7 DMA has to use a NO cache-able
>> memory region.
>>
>>
>> v2:
>> -select ARM_MPU in mach-stm32 Kconfig instead of add it in stm32 defconfig
>> -Remove XIP configuration from stm32_defconfig: ARM_MPU flag imposes XIP image
>> to be aligned on 1MB. It is currently not the case. I had choice to either
>> modify current XIP start address to be aligned on 1MB or to remove global
>> configuration. I make choice to remove XIP configuration. Indeed, SD card
>> support has been recently added for most of STM32 MCU boards (except for
>> stm32f429-disco). As kernel is growing up for stm32 it will be more and more
>> difficult to flash it in embeded flash (max size: 2MB).
> 
> It is sad we are loosing XIP configuration - it used to uncover some bugs
> in a past. Probably, you might consider to have stm32 tiny (+xip) defconfig
> for those who do not want/need all-in-one kernel.

I agree and I don't want to loose XIP configuration. I just want that 
default stm32_defconfig covers the main MCU boards and the maximum 
IPs/driver for those boards. SD cards will be the boot support that will 
be supported in buildroot (except for stm32f429-disco).

But I agree, I could maybe use a frag to have a tiny configuration for 
stm32 to be able to flash xip in embeded flash and provide a "basic" 
support (kernel boot + console).


Regards
Alex
> 
> Cheers
> Vladimir
> 
>> -fix typo in commit message
>>
>> Regards
>> Alex
>>
>> Alexandre Torgue (4):
>>    ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7
>>    ARM: configs: stm32: remove XIP configuration
>>    ARM: stm32: Select ARM_MPU for cortex-M7 machines
>>    ARM: dts: stm32: enable dma on MCU which embed a cortex-M7
>>
>>   arch/arm/boot/dts/stm32746g-eval.dts   | 21 +++++++++++++++++++++
>>   arch/arm/boot/dts/stm32f769-disco.dts  | 21 +++++++++++++++++++++
>>   arch/arm/boot/dts/stm32h743i-disco.dts | 21 +++++++++++++++++++++
>>   arch/arm/boot/dts/stm32h743i-eval.dts  | 21 +++++++++++++++++++++
>>   arch/arm/configs/stm32_defconfig       |  2 --
>>   arch/arm/mach-stm32/Kconfig            |  3 +++
>>   6 files changed, 87 insertions(+), 2 deletions(-)
>>
> 

[PATCH v2 0/4] Enable DMA on STM32 MCU based on cortex-M7

[Alexandre Torgue]

Hi Vlad

On 02/28/2018 02:22 PM, Vladimir Murzin wrote:
> On 28/02/18 13:10, Alexandre Torgue wrote:
>> This series enable DMA on several STM32 MCU based on cortex-M7.
>> To make it possible, a dedicated dma pool memory area has to be
>> created. This patchset activate also ARM_MPU flag which will configure
>> MPU (Memory Protection Unit) according to devicetree information (mem
>> and dma-pool). Note that on cortex-M7 DMA has to use a NO cache-able
>> memory region.
>>
>>
>> v2:
>> -select ARM_MPU in mach-stm32 Kconfig instead of add it in stm32 defconfig
>> -Remove XIP configuration from stm32_defconfig: ARM_MPU flag imposes XIP image
>> to be aligned on 1MB. It is currently not the case. I had choice to either
>> modify current XIP start address to be aligned on 1MB or to remove global
>> configuration. I make choice to remove XIP configuration. Indeed, SD card
>> support has been recently added for most of STM32 MCU boards (except for
>> stm32f429-disco). As kernel is growing up for stm32 it will be more and more
>> difficult to flash it in embeded flash (max size: 2MB).
> 
> It is sad we are loosing XIP configuration - it used to uncover some bugs
> in a past. Probably, you might consider to have stm32 tiny (+xip) defconfig
> for those who do not want/need all-in-one kernel.

I agree and I don't want to loose XIP configuration. I just want that 
default stm32_defconfig covers the main MCU boards and the maximum 
IPs/driver for those boards. SD cards will be the boot support that will 
be supported in buildroot (except for stm32f429-disco).

But I agree, I could maybe use a frag to have a tiny configuration for 
stm32 to be able to flash xip in embeded flash and provide a "basic" 
support (kernel boot + console).


Regards
Alex
> 
> Cheers
> Vladimir
> 
>> -fix typo in commit message
>>
>> Regards
>> Alex
>>
>> Alexandre Torgue (4):
>>    ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7
>>    ARM: configs: stm32: remove XIP configuration
>>    ARM: stm32: Select ARM_MPU for cortex-M7 machines
>>    ARM: dts: stm32: enable dma on MCU which embed a cortex-M7
>>
>>   arch/arm/boot/dts/stm32746g-eval.dts   | 21 +++++++++++++++++++++
>>   arch/arm/boot/dts/stm32f769-disco.dts  | 21 +++++++++++++++++++++
>>   arch/arm/boot/dts/stm32h743i-disco.dts | 21 +++++++++++++++++++++
>>   arch/arm/boot/dts/stm32h743i-eval.dts  | 21 +++++++++++++++++++++
>>   arch/arm/configs/stm32_defconfig       |  2 --
>>   arch/arm/mach-stm32/Kconfig            |  3 +++
>>   6 files changed, 87 insertions(+), 2 deletions(-)
>>
>