On Sun, Jul 28, 2024 at 10:22:53AM +0100, Marc Zyngier wrote:
On Sun, 28 Jul 2024 01:47:31 +0100,
Sasha Levin <sashal@xxxxxxxxxx> wrote:
From: James Morse <james.morse@xxxxxxx>
[ Upstream commit fa2dabe57220e6af78ed7a2f7016bf250a618204 ]
gic_acpi_match_gicc() is only called via gic_acpi_count_gicr_regions().
It should only count the number of enabled redistributors, but it
also tries to sanity check the GICC entry, currently returning an
error if the Enabled bit is set, but the gicr_base_address is zero.
Adding support for the online-capable bit to the sanity check will
complicate it, for no benefit. The existing check implicitly depends on
gic_acpi_count_gicr_regions() previous failing to find any GICR regions
(as it is valid to have gicr_base_address of zero if the redistributors
are described via a GICR entry).
Instead of complicating the check, remove it. Failures that happen at
this point cause the irqchip not to register, meaning no irqs can be
requested. The kernel grinds to a panic() pretty quickly.
Without the check, MADT tables that exhibit this problem are still
caught by gic_populate_rdist(), which helpfully also prints what went
wrong:
| CPU4: mpidr 100 has no re-distributor!
Signed-off-by: James Morse <james.morse@xxxxxxx>
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
Tested-by: Miguel Luis <miguel.luis@xxxxxxxxxx>
Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Reviewed-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240529133446.28446-14-Jonathan.Cameron@xxxxxxxxxx
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Please drop this. It has no purpose being backported to stable.
Ack, thanks!
--
Thanks,
Sasha
