From 8aeab995fa142523f376369e4ce0608df6727706 Mon Sep 17 00:00:00 2001 From: Alexey Brodkin Date: Wed, 27 Apr 2016 16:02:39 +0300 Subject: [PATCH 1/2] drm/arcpgu: use dedicated memory area for frame buffer Now when ARC supports reserved memory areas and per-device coherent DMA allocations we may switch ARC PGU to use of those dedicated areas. One of the benefits we may move frame-buffer area out from IO Coherency aperture and so significantly reduce IOC utilization allowing less demanding peripherals to use all perks of IOC. Signed-off-by: Alexey Brodkin Cc: Dave Airlie Cc: Daniel Vetter Cc: linux-kernel@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org --- drivers/gpu/drm/arc/arcpgu_drv.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/arc/arcpgu_drv.c b/drivers/gpu/drm/arc/arcpgu_drv.c index 5b35e5dbae380..76e187a5bde02 100644 --- a/drivers/gpu/drm/arc/arcpgu_drv.c +++ b/drivers/gpu/drm/arc/arcpgu_drv.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "arcpgu.h" #include "arcpgu_regs.h" @@ -135,6 +136,11 @@ static int arcpgu_load(struct drm_device *drm) dev_info(drm->dev, "arc_pgu ID: 0x%x\n", arc_pgu_read(arcpgu, ARCPGU_REG_ID)); + /* Get the optional framebuffer memory resource */ + ret = of_reserved_mem_device_init(drm->dev); + if (ret && ret != -ENODEV) + return ret; + if (dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32))) return -ENODEV; From cb2ad5e5339c5122166265cea579cc6a356d46de Mon Sep 17 00:00:00 2001 From: Alexey Brodkin Date: Wed, 27 Apr 2016 16:59:50 +0300 Subject: [PATCH 2/2] ARC: [axs10x] Specify reserved memory for frame buffer Allocation of a frame buffer memory in a special memory region allows bypassing of so-called IO Coherency aperture which is typically set as a range 0x8z-0xAz. I.e. all data traffic to PGU bypasses IO Coherency block and saves its bandwidth for other peripherals. Even though for AXS101 (which sorts ARC770 CPU) IOC is not an option for a sake of keeping one DT description for the base-board (axs10x_mb.dtsi) we're still defining reserved memory location in the very end of DDR. Signed-off-by: Alexey Brodkin Acked-by: Vineet Gupta Cc: devicetree@vger.kernel.org --- arch/arc/boot/dts/axc001.dtsi | 22 ++++++++++++++++++++-- arch/arc/boot/dts/axc003.dtsi | 14 ++++++++++++++ arch/arc/boot/dts/axc003_idu.dtsi | 14 ++++++++++++++ arch/arc/boot/dts/axs10x_mb.dtsi | 2 +- 4 files changed, 49 insertions(+), 3 deletions(-) diff --git a/arch/arc/boot/dts/axc001.dtsi b/arch/arc/boot/dts/axc001.dtsi index 420dcfde289fe..262496ac2628e 100644 --- a/arch/arc/boot/dts/axc001.dtsi +++ b/arch/arc/boot/dts/axc001.dtsi @@ -93,8 +93,26 @@ memory { #address-cells = <1>; #size-cells = <1>; - ranges = <0x00000000 0x80000000 0x40000000>; + ranges = <0x00000000 0x80000000 0x20000000>; device_type = "memory"; - reg = <0x80000000 0x20000000>; /* 512MiB */ + reg = <0x80000000 0x1b000000>; /* (512 - 32) MiB */ + }; + + reserved-memory { + #address-cells = <1>; + #size-cells = <1>; + ranges; + /* + * We just move frame buffer area to the very end of + * available DDR. And even though in case of ARC770 there's + * no strict requirement for a frame-buffer to be in any + * particular location it allows us to use the same + * base board's DT node for ARC PGU as for ARc HS38. + */ + frame_buffer: frame_buffer@9e000000 { + compatible = "shared-dma-pool"; + reg = <0x9e000000 0x2000000>; + no-map; + }; }; }; diff --git a/arch/arc/boot/dts/axc003.dtsi b/arch/arc/boot/dts/axc003.dtsi index f90fadf7f94e5..35ece04d8353d 100644 --- a/arch/arc/boot/dts/axc003.dtsi +++ b/arch/arc/boot/dts/axc003.dtsi @@ -100,4 +100,18 @@ device_type = "memory"; reg = <0x80000000 0x20000000>; /* 512MiB */ }; + + reserved-memory { + #address-cells = <1>; + #size-cells = <1>; + ranges; + /* + * Move frame buffer out of IOC aperture (0x8z-0xAz). + */ + frame_buffer: frame_buffer@be000000 { + compatible = "shared-dma-pool"; + reg = <0xbe000000 0x2000000>; + no-map; + }; + }; }; diff --git a/arch/arc/boot/dts/axc003_idu.dtsi b/arch/arc/boot/dts/axc003_idu.dtsi index 06a9f294a2e60..df9ddb623bfe5 100644 --- a/arch/arc/boot/dts/axc003_idu.dtsi +++ b/arch/arc/boot/dts/axc003_idu.dtsi @@ -123,4 +123,18 @@ device_type = "memory"; reg = <0x80000000 0x20000000>; /* 512MiB */ }; + + reserved-memory { + #address-cells = <1>; + #size-cells = <1>; + ranges; + /* + * Move frame buffer out of IOC aperture (0x8z-0xAz). + */ + frame_buffer: frame_buffer@be000000 { + compatible = "shared-dma-pool"; + reg = <0xbe000000 0x2000000>; + no-map; + }; + }; }; diff --git a/arch/arc/boot/dts/axs10x_mb.dtsi b/arch/arc/boot/dts/axs10x_mb.dtsi index 823f15ca68df0..64b063d4e9969 100644 --- a/arch/arc/boot/dts/axs10x_mb.dtsi +++ b/arch/arc/boot/dts/axs10x_mb.dtsi @@ -283,7 +283,7 @@ encoder-slave = <&adv7511>; clocks = <&pguclk>; clock-names = "pxlclk"; - + memory-region = <&frame_buffer>; port { pgu_output: endpoint { remote-endpoint = <&adv7511_input>;