[PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
From: Gregory CLEMENT <hidden>
Date: 2012-10-24 11:50:33
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On 10/24/2012 10:25 AM, Andrew Lunn wrote:
On Wed, Oct 24, 2012 at 10:04:01AM +0200, Gregory CLEMENT wrote:quoted
Armada 370 and XP come with an unit called coherency fabric. This unit allows to use the Armada XP as a nearly coherent architecture. The coherency mechanism uses snoop filters to ensure the coherency between caches, DRAM and devices. This mechanism needs a synchronization barrier which guarantees that all memory write initiated by the devices has reached their target and do not reside in intermediate write buffers. That's why the architecture is not totally coherent and we need to provide our own functions for some DMA operations. Beside the use of the coherency fabric, the device units will have to set the attribute flag to select the accurate coherency process for the memory transaction. This is done each device driver programs the DRAM address windows. The value of the attribute set by the driver is retrieved through the orion_addr_map_cfg struct filled during the early initialization of the platform. Signed-off-by: Gregory CLEMENT <redacted> Reviewed-by: Yehuda Yitschak <redacted> --- arch/arm/boot/dts/armada-370-xp.dtsi | 3 +- arch/arm/mach-mvebu/addr-map.c | 3 ++ arch/arm/mach-mvebu/armada-370-xp.c | 1 + arch/arm/mach-mvebu/coherency.c | 87 ++++++++++++++++++++++++++++++++++ arch/arm/mach-mvebu/common.h | 2 + 5 files changed, 95 insertions(+), 1 deletion(-)diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi b/arch/arm/boot/dts/armada-370-xp.dtsi index 18ba60b..af22e53 100644 --- a/arch/arm/boot/dts/armada-370-xp.dtsi +++ b/arch/arm/boot/dts/armada-370-xp.dtsi@@ -38,7 +38,8 @@ coherency-fabric at d0020200 { compatible = "marvell,coherency-fabric"; - reg = <0xd0020200 0xb0>; + reg = <0xd0020200 0xb0>, + <0xd0021010 0x1c>; };...quoted
int __init armada_370_xp_coherency_init(void) { struct device_node *np;@@ -82,7 +159,17 @@ int __init armada_370_xp_coherency_init(void) if (np) { pr_info("Initializing Coherency fabric\n"); coherency_base = of_iomap(np, 0); + coherency_cpu_base = of_iomap(np, 1);Is this already in the binding documentation?
No indeed, the documentation should be completed. I will do it the V2
Thanks Andrew _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
-- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com