[PATCH 11/11] riscv: dts: starfive: jh7100: Use physical memory ranges for DMA

Samuel Holland posted 11 patches 3 weeks, 1 day ago
[PATCH 11/11] riscv: dts: starfive: jh7100: Use physical memory ranges for DMA
Posted by Samuel Holland 3 weeks, 1 day ago
JH7100 provides a physical memory region which is a noncached alias of
normal cacheable DRAM. Now that Linux can apply PMAs by selecting
between aliases of a physical memory region, any page of DRAM can be
marked as noncached for use with DMA, and the preallocated DMA pool is
no longer needed. This allows portable kernels to boot on JH7100 boards.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
---

 arch/riscv/Kconfig.errata                     | 19 ------------
 .../boot/dts/starfive/jh7100-common.dtsi      | 30 ++++---------------
 2 files changed, 6 insertions(+), 43 deletions(-)

diff --git a/arch/riscv/Kconfig.errata b/arch/riscv/Kconfig.errata
index 2806ed7916c7..fc2c7fb2caff 100644
--- a/arch/riscv/Kconfig.errata
+++ b/arch/riscv/Kconfig.errata
@@ -53,25 +53,6 @@ config ERRATA_SIFIVE_CIP_1200
 
 	  If you don't know what to do here, say "Y".
 
-config ERRATA_STARFIVE_JH7100
-	bool "StarFive JH7100 support"
-	depends on ARCH_STARFIVE
-	depends on !DMA_DIRECT_REMAP
-	depends on NONPORTABLE
-	select DMA_GLOBAL_POOL
-	select RISCV_DMA_NONCOHERENT
-	select RISCV_NONSTANDARD_CACHE_OPS
-	select SIFIVE_CCACHE
-	default n
-	help
-	  The StarFive JH7100 was a test chip for the JH7110 and has
-	  caches that are non-coherent with respect to peripheral DMAs.
-	  It was designed before the Zicbom extension so needs non-standard
-	  cache operations through the SiFive cache controller.
-
-	  Say "Y" if you want to support the BeagleV Starlight and/or
-	  StarFive VisionFive V1 boards.
-
 config ERRATA_THEAD
 	bool "T-HEAD errata"
 	depends on RISCV_ALTERNATIVE
diff --git a/arch/riscv/boot/dts/starfive/jh7100-common.dtsi b/arch/riscv/boot/dts/starfive/jh7100-common.dtsi
index ae1a6aeb0aea..34885fe40e2d 100644
--- a/arch/riscv/boot/dts/starfive/jh7100-common.dtsi
+++ b/arch/riscv/boot/dts/starfive/jh7100-common.dtsi
@@ -9,8 +9,14 @@
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/leds/common.h>
 #include <dt-bindings/pinctrl/pinctrl-starfive-jh7100.h>
+#include <dt-bindings/riscv/physical-memory.h>
 
 / {
+	riscv,physical-memory-regions =
+		<0x00 0x00000000 0x40 0x00000000 (PMA_RW | PMA_IO) 0x0>,
+		<0x00 0x80000000 0x08 0x00000000 (PMA_RWXA | PMA_NONCOHERENT_MEMORY) 0x0>,
+		<0x10 0x00000000 0x08 0x00000000 (PMA_RWX | PMA_NONCACHEABLE_MEMORY | PMR_ALIAS(1)) 0x0>;
+
 	aliases {
 		mmc0 = &sdio0;
 		mmc1 = &sdio1;
@@ -42,30 +48,6 @@ led-ack {
 		};
 	};
 
-	reserved-memory {
-		#address-cells = <2>;
-		#size-cells = <2>;
-		ranges;
-
-		dma-reserved@fa000000 {
-			reg = <0x0 0xfa000000 0x0 0x1000000>;
-			no-map;
-		};
-
-		linux,dma@107a000000 {
-			compatible = "shared-dma-pool";
-			reg = <0x10 0x7a000000 0x0 0x1000000>;
-			no-map;
-			linux,dma-default;
-		};
-	};
-
-	soc {
-		dma-ranges = <0x00 0x80000000 0x00 0x80000000 0x00 0x7a000000>,
-			     <0x00 0xfa000000 0x10 0x7a000000 0x00 0x01000000>,
-			     <0x00 0xfb000000 0x00 0xfb000000 0x07 0x85000000>;
-	};
-
 	wifi_pwrseq: wifi-pwrseq {
 		compatible = "mmc-pwrseq-simple";
 		reset-gpios = <&gpio 37 GPIO_ACTIVE_LOW>;
-- 
2.45.1
Re: [PATCH 11/11] riscv: dts: starfive: jh7100: Use physical memory ranges for DMA
Posted by Emil Renner Berthing 2 weeks, 6 days ago
Samuel Holland wrote:
> JH7100 provides a physical memory region which is a noncached alias of
> normal cacheable DRAM. Now that Linux can apply PMAs by selecting
> between aliases of a physical memory region, any page of DRAM can be
> marked as noncached for use with DMA, and the preallocated DMA pool is
> no longer needed. This allows portable kernels to boot on JH7100 boards.
>
> Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
> ---
>
>  arch/riscv/Kconfig.errata                     | 19 ------------
>  .../boot/dts/starfive/jh7100-common.dtsi      | 30 ++++---------------
>  2 files changed, 6 insertions(+), 43 deletions(-)
>
> diff --git a/arch/riscv/Kconfig.errata b/arch/riscv/Kconfig.errata
> index 2806ed7916c7..fc2c7fb2caff 100644
> --- a/arch/riscv/Kconfig.errata
> +++ b/arch/riscv/Kconfig.errata
> @@ -53,25 +53,6 @@ config ERRATA_SIFIVE_CIP_1200
>
>  	  If you don't know what to do here, say "Y".
>
> -config ERRATA_STARFIVE_JH7100
> -	bool "StarFive JH7100 support"
> -	depends on ARCH_STARFIVE
> -	depends on !DMA_DIRECT_REMAP
> -	depends on NONPORTABLE
> -	select DMA_GLOBAL_POOL

Hi Samuel,

Thank you for working on this!

The JH7100 still need the RISCV_NONSTANDARD_CACHE_OPS from the sifive-ccache
driver for streaming DMA, so if I just remove the 3 lines above instead of the
whole ERRATE_STARFIVE_JH7110 (and enable RISCV_ISA_SVPBMT) this series works on
my Starlight board.

> -	select RISCV_DMA_NONCOHERENT
> -	select RISCV_NONSTANDARD_CACHE_OPS
> -	select SIFIVE_CCACHE
> -	default n
> -	help
> -	  The StarFive JH7100 was a test chip for the JH7110 and has
> -	  caches that are non-coherent with respect to peripheral DMAs.
> -	  It was designed before the Zicbom extension so needs non-standard
> -	  cache operations through the SiFive cache controller.
> -
> -	  Say "Y" if you want to support the BeagleV Starlight and/or
> -	  StarFive VisionFive V1 boards.
> -
>  config ERRATA_THEAD
>  	bool "T-HEAD errata"
>  	depends on RISCV_ALTERNATIVE
> diff --git a/arch/riscv/boot/dts/starfive/jh7100-common.dtsi b/arch/riscv/boot/dts/starfive/jh7100-common.dtsi
> index ae1a6aeb0aea..34885fe40e2d 100644
> --- a/arch/riscv/boot/dts/starfive/jh7100-common.dtsi
> +++ b/arch/riscv/boot/dts/starfive/jh7100-common.dtsi
> @@ -9,8 +9,14 @@
>  #include <dt-bindings/gpio/gpio.h>
>  #include <dt-bindings/leds/common.h>
>  #include <dt-bindings/pinctrl/pinctrl-starfive-jh7100.h>
> +#include <dt-bindings/riscv/physical-memory.h>
>
>  / {
> +	riscv,physical-memory-regions =
> +		<0x00 0x00000000 0x40 0x00000000 (PMA_RW | PMA_IO) 0x0>,
> +		<0x00 0x80000000 0x08 0x00000000 (PMA_RWXA | PMA_NONCOHERENT_MEMORY) 0x0>,
> +		<0x10 0x00000000 0x08 0x00000000 (PMA_RWX | PMA_NONCACHEABLE_MEMORY | PMR_ALIAS(1)) 0x0>;
> +

The size and placement of the DMA pool was kind of arbitrary but the above is
a feature of the SoC, so should be moved to jh7100.dtsi instead.

>  	aliases {
>  		mmc0 = &sdio0;
>  		mmc1 = &sdio1;
> @@ -42,30 +48,6 @@ led-ack {
>  		};
>  	};
>
> -	reserved-memory {
> -		#address-cells = <2>;
> -		#size-cells = <2>;
> -		ranges;
> -
> -		dma-reserved@fa000000 {
> -			reg = <0x0 0xfa000000 0x0 0x1000000>;
> -			no-map;
> -		};
> -
> -		linux,dma@107a000000 {
> -			compatible = "shared-dma-pool";
> -			reg = <0x10 0x7a000000 0x0 0x1000000>;
> -			no-map;
> -			linux,dma-default;
> -		};
> -	};
> -
> -	soc {
> -		dma-ranges = <0x00 0x80000000 0x00 0x80000000 0x00 0x7a000000>,
> -			     <0x00 0xfa000000 0x10 0x7a000000 0x00 0x01000000>,
> -			     <0x00 0xfb000000 0x00 0xfb000000 0x07 0x85000000>;
> -	};
> -
>  	wifi_pwrseq: wifi-pwrseq {
>  		compatible = "mmc-pwrseq-simple";
>  		reset-gpios = <&gpio 37 GPIO_ACTIVE_LOW>;
> --
> 2.45.1
>