From d01fd161e85904064290435f67f4ed59af5daf74 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 11 Mar 2020 11:56:49 +0000 Subject: irqchip/gic-v3: Workaround Cavium erratum 38539 when reading GICD_TYPER2 Despite the architecture spec requiring that reserved registers in the GIC distributor memory map are RES0 (and thus are not allowed to generate an exception), the Cavium ThunderX (aka TX1) SoC explodes as such: [ 0.000000] GICv3: GIC: Using split EOI/Deactivate mode [ 0.000000] GICv3: 128 SPIs implemented [ 0.000000] GICv3: 0 Extended SPIs implemented [ 0.000000] Internal error: synchronous external abort: 96000210 [#1] SMP [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc4-00035-g3cf6a3d5725f #7956 [ 0.000000] Hardware name: cavium,thunder-88xx (DT) [ 0.000000] pstate: 60000085 (nZCv daIf -PAN -UAO) [ 0.000000] pc : __raw_readl+0x0/0x8 [ 0.000000] lr : gic_init_bases+0x110/0x560 [ 0.000000] sp : ffff800011243d90 [ 0.000000] x29: ffff800011243d90 x28: 0000000000000000 [ 0.000000] x27: 0000000000000018 x26: 0000000000000002 [ 0.000000] x25: ffff8000116f0000 x24: ffff000fbe6a2c80 [ 0.000000] x23: 0000000000000000 x22: ffff010fdc322b68 [ 0.000000] x21: ffff800010a7a208 x20: 00000000009b0404 [ 0.000000] x19: ffff80001124dad0 x18: 0000000000000010 [ 0.000000] x17: 000000004d8d492b x16: 00000000f67eb9af [ 0.000000] x15: ffffffffffffffff x14: ffff800011249908 [ 0.000000] x13: ffff800091243ae7 x12: ffff800011243af4 [ 0.000000] x11: ffff80001126e000 x10: ffff800011243a70 [ 0.000000] x9 : 00000000ffffffd0 x8 : ffff80001069c828 [ 0.000000] x7 : 0000000000000059 x6 : ffff8000113fb4d1 [ 0.000000] x5 : 0000000000000001 x4 : 0000000000000000 [ 0.000000] x3 : 0000000000000000 x2 : 0000000000000000 [ 0.000000] x1 : 0000000000000000 x0 : ffff8000116f000c [ 0.000000] Call trace: [ 0.000000] __raw_readl+0x0/0x8 [ 0.000000] gic_of_init+0x188/0x224 [ 0.000000] of_irq_init+0x200/0x3cc [ 0.000000] irqchip_init+0x1c/0x40 [ 0.000000] init_IRQ+0x160/0x1d0 [ 0.000000] start_kernel+0x2ec/0x4b8 [ 0.000000] Code: a8c47bfd d65f03c0 d538d080 d65f03c0 (b9400000) when reading the GICv4.1 GICD_TYPER2 register, which is unexpected... Work around it by adding a new quirk for the following variants: ThunderX: CN88xx OCTEON TX: CN83xx, CN81xx OCTEON TX2: CN93xx, CN96xx, CN98xx, CNF95xx* and use this flag to avoid accessing GICD_TYPER2. Note that all reserved registers (including redistributors and ITS) are impacted by this erratum, but that only GICD_TYPER2 has to be worked around so far. Signed-off-by: Marc Zyngier Tested-by: Robert Richter Tested-by: Mark Salter Tested-by: Tim Harvey Acked-by: Catalin Marinas Acked-by: Robert Richter Link: https://lore.kernel.org/r/20191027144234.8395-11-maz@kernel.org Link: https://lore.kernel.org/r/20200311115649.26060-1-maz@kernel.org --- Documentation/arm64/silicon-errata.rst | 2 ++ 1 file changed, 2 insertions(+) (limited to 'Documentation') diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index 99b2545455ff..a1563da07b2c 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -108,6 +108,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | Cavium | ThunderX GICv3 | #23154 | CAVIUM_ERRATUM_23154 | +----------------+-----------------+-----------------+-----------------------------+ +| Cavium | ThunderX GICv3 | #38539 | N/A | ++----------------+-----------------+-----------------+-----------------------------+ | Cavium | ThunderX Core | #27456 | CAVIUM_ERRATUM_27456 | +----------------+-----------------+-----------------+-----------------------------+ | Cavium | ThunderX Core | #30115 | CAVIUM_ERRATUM_30115 | -- cgit v1.2.3