From: Shanker Donthineni shankerd@codeaurora.org
[ Upstream commit ebe2f8718007d5a1238bb3cb8141b5bb2b4d5773 ]
The ACPI specification says OS shouldn't attempt to use GICC configuration parameters if the flag ACPI_MADT_ENABLED is cleared. The ARM64-SMP code skips the disabled GICC entries but not causing any issue. However the current GICv3 driver probe bails out causing kernel panic() instead of skipping the disabled GICC interfaces. This issue happens on systems where redistributor regions are not in the always-on power domain and one of GICC interface marked with ACPI_MADT_ENABLED=0.
This patch does the two things to fix the panic. - Don't return an error in gic_acpi_match_gicc() for disabled GICC entry. - No need to keep GICR region information for disabled GICC entry.
Observed kernel crash on QDF2400 platform GICC entry is disabled. Kernel crash traces: Kernel panic - not syncing: No interrupt controller found. CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.13.5 #26 [<ffff000008087770>] dump_backtrace+0x0/0x218 [<ffff0000080879dc>] show_stack+0x14/0x20 [<ffff00000883b078>] dump_stack+0x98/0xb8 [<ffff0000080c5c14>] panic+0x118/0x26c [<ffff000008b62348>] init_IRQ+0x24/0x2c [<ffff000008b609fc>] start_kernel+0x230/0x394 [<ffff000008b601e4>] __primary_switched+0x64/0x6c ---[ end Kernel panic - not syncing: No interrupt controller found.
Disabled GICC subtable example: Subtable Type : 0B [Generic Interrupt Controller] Length : 50 Reserved : 0000 CPU Interface Number : 0000003D Processor UID : 0000003D Flags (decoded below) : 00000000 Processor Enabled : 0 Performance Interrupt Trig Mode : 0 Virtual GIC Interrupt Trig Mode : 0 Parking Protocol Version : 00000000 Performance Interrupt : 00000017 Parked Address : 0000000000000000 Base Address : 0000000000000000 Virtual GIC Base Address : 0000000000000000 Hypervisor GIC Base Address : 0000000000000000 Virtual GIC Interrupt : 00000019 Redistributor Base Address : 0000FFFF88F40000 ARM MPIDR : 000000000000000D Efficiency Class : 00 Reserved : 000000 Signed-off-by: Shanker Donthineni shankerd@codeaurora.org Signed-off-by: Marc Zyngier marc.zyngier@arm.com
Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- drivers/irqchip/irq-gic-v3.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index fd4a78296b48..100c80e48190 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -1250,6 +1250,10 @@ gic_acpi_parse_madt_gicc(struct acpi_subtable_header *header, u32 size = reg == GIC_PIDR2_ARCH_GICv4 ? SZ_64K * 4 : SZ_64K * 2; void __iomem *redist_base;
+ /* GICC entry which has !ACPI_MADT_ENABLED is not unusable so skip */ + if (!(gicc->flags & ACPI_MADT_ENABLED)) + return 0; + redist_base = ioremap(gicc->gicr_base_address, size); if (!redist_base) return -ENOMEM; @@ -1299,6 +1303,13 @@ static int __init gic_acpi_match_gicc(struct acpi_subtable_header *header, if ((gicc->flags & ACPI_MADT_ENABLED) && gicc->gicr_base_address) return 0;
+ /* + * It's perfectly valid firmware can pass disabled GICC entry, driver + * should not treat as errors, skip the entry instead of probe fail. + */ + if (!(gicc->flags & ACPI_MADT_ENABLED)) + return 0; + return -ENODEV; }