From mboxrd@z Thu Jan 1 00:00:00 1970 From: gregory.clement@free-electrons.com (Gregory CLEMENT) Date: Wed, 24 Oct 2012 13:50:12 +0200 Subject: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support In-Reply-To: <20121024082529.GZ11837@lunn.ch> References: <1351065841-18654-1-git-send-email-gregory.clement@free-electrons.com> <1351065841-18654-3-git-send-email-gregory.clement@free-electrons.com> <20121024082529.GZ11837@lunn.ch> Message-ID: <5087D5F4.9060104@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/24/2012 10:25 AM, Andrew Lunn wrote: > On Wed, Oct 24, 2012 at 10:04:01AM +0200, Gregory CLEMENT wrote: >> 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 >> Reviewed-by: Yehuda Yitschak >> --- >> 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>; >> }; > > ... > >> 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