Messages in this thread Patch in this message | | | From | Chris Packham <> | Subject | [PATCH] ARM: mvebu: Enable MBUS error propagation | Date | Sun, 24 Nov 2019 22:35:29 +1300 |
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U-boot disables MBUS error propagation for Armada-385. The effect of this on the kernel is that any access to a mapped but inaccessible address causes the system to hang.
By enabling MBUS error propagation the kernel can raise a Bus Error and panic to restart the system.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> ---
Notes: We've encountered an issue where rogue accesses to PCI-e space cause an Armada-385 system to lockup. We've found that enabling MBUS error propagation lets us get a bus error which at least gives us a panic to help identify what was accessed. U-boot clears the IO Err Prop Enable Bit[1] but so far no-one seems to know why. I wasn't sure where to put this code. There is similar code for kirwood in the equivalent dt_init function. On Armada-XP the register is part of the Core Coherency Fabric block (for A385 it's documented as part of the CCF block). -- [1] - https://gitlab.denx.de/u-boot/u-boot/blob/master/arch/arm/mach-mvebu/cpu.c#L489
arch/arm/boot/dts/armada-38x.dtsi | 5 +++++ arch/arm/mach-mvebu/board-v7.c | 27 +++++++++++++++++++++++++++ 2 files changed, 32 insertions(+)
diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi index 3f4bb44d85f0..3214c67433eb 100644 --- a/arch/arm/boot/dts/armada-38x.dtsi +++ b/arch/arm/boot/dts/armada-38x.dtsi @@ -386,6 +386,11 @@ <0x20250 0x8>; }; + ioerrc: io-err-control@20200 { + compatible = "marvell,io-err-control"; + reg = <0x20200 0x4>; + }; + mpic: interrupt-controller@20a00 { compatible = "marvell,mpic"; reg = <0x20a00 0x2d0>, <0x21070 0x58>; diff --git a/arch/arm/mach-mvebu/board-v7.c b/arch/arm/mach-mvebu/board-v7.c index d2df5ef9382b..fb7718386ef9 100644 --- a/arch/arm/mach-mvebu/board-v7.c +++ b/arch/arm/mach-mvebu/board-v7.c @@ -138,10 +138,36 @@ static void __init i2c_quirk(void) } } +#define MBUS_ERR_PROP_EN BIT(8) + +/* + * U-boot disables MBUS error propagation. Re-enable it so we + * can handle them as Bus Errors. + */ +static void __init enable_mbus_error_propagation(void) +{ + struct device_node *np = + of_find_compatible_node(NULL, NULL, "marvell,io-err-control"); + + if (np) { + void __iomem *reg; + + reg = of_iomap(np, 0); + if (reg) { + u32 val; + + val = readl_relaxed(reg); + writel_relaxed(val | MBUS_ERR_PROP_EN, reg); + } + of_node_put(np); + } +} + static void __init mvebu_dt_init(void) { if (of_machine_is_compatible("marvell,armadaxp")) i2c_quirk(); + enable_mbus_error_propagation(); } static void __init armada_370_xp_dt_fixup(void) @@ -191,6 +217,7 @@ DT_MACHINE_START(ARMADA_38X_DT, "Marvell Armada 380/385 (Device Tree)") .l2c_aux_val = 0, .l2c_aux_mask = ~0, .init_irq = mvebu_init_irq, + .init_machine = mvebu_dt_init, .restart = mvebu_restart, .dt_compat = armada_38x_dt_compat, MACHINE_END -- 2.24.0
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