lkml.org 
[lkml]   [2019]   [Nov]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] ARM: mvebu: Enable MBUS error propagation
Date
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
\
 
 \ /
  Last update: 2019-11-24 10:36    [W:0.109 / U:0.348 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site