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| author | Oliver Upton <oliver.upton@linux.dev> | 2024-02-19 21:58:06 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-01 15:35:01 +0300 |
| commit | 4332f54153de06d75a8d122ead32bc0b43049be8 (patch) | |
| tree | eac6fd7de95593365f74f27245a536f2298b5bea /drivers/irqchip | |
| parent | a9ab338683a243f93ff467ead1c02cf0c57600f3 (diff) | |
| download | linux-4332f54153de06d75a8d122ead32bc0b43049be8.tar.xz | |
irqchip/gic-v3-its: Do not assume vPE tables are preallocated
commit ec4308ecfc887128a468f03fb66b767559c57c23 upstream.
The GIC/ITS code is designed to ensure to pick up any preallocated LPI
tables on the redistributors, as enabling LPIs is a one-way switch. There
is no such restriction for vLPIs, and for GICv4.1 it is expected to
allocate a new vPE table at boot.
This works as intended when initializing an ITS, however when setting up a
redistributor in cpu_init_lpis() the early return for preallocated RD
tables skips straight past the GICv4 setup. This all comes to a head when
trying to kexec() into a new kernel, as the new kernel silently fails to
set up GICv4, leading to a complete loss of SGIs and LPIs for KVM VMs.
Slap a band-aid on the problem by ensuring its_cpu_init_lpis() always
initializes GICv4 on the way out, even if the other RD tables were
preallocated.
Fixes: 6479450f72c1 ("irqchip/gic-v4: Fix occasional VLPI drop")
Reported-by: George Cherian <gcherian@marvell.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240219185809.286724-2-oliver.upton@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/irqchip')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3-its.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 3632c92cd183..676c9250d3f2 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -3181,6 +3181,7 @@ static void its_cpu_init_lpis(void) val |= GICR_CTLR_ENABLE_LPIS; writel_relaxed(val, rbase + GICR_CTLR); +out: if (gic_rdists->has_vlpis && !gic_rdists->has_rvpeid) { void __iomem *vlpi_base = gic_data_rdist_vlpi_base(); @@ -3216,7 +3217,6 @@ static void its_cpu_init_lpis(void) /* Make sure the GIC has seen the above */ dsb(sy); -out: gic_data_rdist()->flags |= RD_LOCAL_LPI_ENABLED; pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n", smp_processor_id(), |