From: Chris Packham <chris.packham@alliedtelesis.co.nz>
To: jason@lakedaemon.net, andrew@lunn.ch,
gregory.clement@bootlin.com, sebastian.hesselbarth@gmail.com,
Joshua Scott <joshua.scott@alliedtelesis.co.nz>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Chris Packham <chris.packham@alliedtelesis.co.nz>
Subject: [PATCH] ARM: mvebu: Enable MBUS error propagation
Date: Sun, 24 Nov 2019 22:35:29 +1300 [thread overview]
Message-ID: <20191124093529.32399-1-chris.packham@alliedtelesis.co.nz> (raw)
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
next reply other threads:[~2019-11-24 9:35 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-24 9:35 Chris Packham [this message]
2020-01-08 10:22 ` [PATCH] ARM: mvebu: Enable MBUS error propagation Gregory CLEMENT
2020-01-08 19:42 ` Chris Packham
2021-06-03 12:55 ` Pali Rohár
2021-06-03 21:03 ` Chris Packham
2022-04-22 9:27 ` Pali Rohár
2022-04-26 1:17 ` Chris Packham
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