irqchip/gic-v4: Disable redistributors' view of the VPE table at boot time

[ Upstream commit 79a7f77b9b154d572bd9d2f1eecf58c4d018d8e2 ]

Jay Chen reported that using a kdump kernel on a GICv4.1 system
results in a RAS error being delivered when the secondary kernel
configures the ITS's view of the new VPE table.

As it turns out, that's because each RD still has a pointer to
the previous instance of the VPE table, and that particular
implementation is very upset by seeing two bits of the HW that
should point to the same table with different values.

To solve this, let's invalidate any reference that any RD has to
the VPE table when discovering the RDs. The ITS can then be
programmed as expected.

Reported-by: Jay Chen <jkchen@linux.alibaba.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Link: https://lore.kernel.org/r/20211214064716.21407-1-jkchen@linux.alibaba.com
Link: https://lore.kernel.org/r/20211216144804.1578566-1-maz@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index fd4e9a37fea679e4a6e06de7975632462d43fedb..7bbccb13b896b60845def364335c87c887c3baf6 100644 (file)
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -920,6 +920,22 @@ static int __gic_update_rdist_properties(struct redist_region *region,
 {
        u64 typer = gic_read_typer(ptr + GICR_TYPER);
 
+       /* Boot-time cleanip */
+       if ((typer & GICR_TYPER_VLPIS) && (typer & GICR_TYPER_RVPEID)) {
+               u64 val;
+
+               /* Deactivate any present vPE */
+               val = gicr_read_vpendbaser(ptr + SZ_128K + GICR_VPENDBASER);
+               if (val & GICR_VPENDBASER_Valid)
+                       gicr_write_vpendbaser(GICR_VPENDBASER_PendingLast,
+                                             ptr + SZ_128K + GICR_VPENDBASER);
+
+               /* Mark the VPE table as invalid */
+               val = gicr_read_vpropbaser(ptr + SZ_128K + GICR_VPROPBASER);
+               val &= ~GICR_VPROPBASER_4_1_VALID;
+               gicr_write_vpropbaser(val, ptr + SZ_128K + GICR_VPROPBASER);
+       }
+
        gic_data.rdists.has_vlpis &= !!(typer & GICR_TYPER_VLPIS);
 
        /* RVPEID implies some form of DirectLPI, no matter what the doc says... :-/ */