[PATCH 3/3] irqchip/gic-v3-its: Clean a non-shareable vPE table to PoC

[Fuad Tabba <fuad.tabba@linux.dev>]

On a GICv4.1 redistributor that doesn't support shareability,
allocate_vpe_l1_table() points GICR_VPROPBASER at a freshly zeroed
vPE table with Z and Valid set, but leaves the zeroes in the CPU's
cache. The redistributor reads the table from memory, where it may
not be zero, and the spec makes that UNPREDICTABLE (GICR_VPROPBASER.Z,
IHI 0069H.b 12.11).

Clean the table to PoC when the redistributor is non-shareable, as the
driver does for its other tables.

Fixes: 846297e11e8ae ("irqchip/gic-v3-its: Handle non-coherent GICv4 redistributors")
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
---
 drivers/irqchip/irq-gic-v3-its.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index badc3843d90ca..5b3273e0dfc79 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3012,6 +3012,8 @@ static int allocate_vpe_l1_table(void)
 	if (rdists_support_shareable()) {
 		val |= GICR_VPROPBASER_RaWb;
 		val |= GICR_VPROPBASER_InnerShareable;
+	} else {
+		gic_flush_dcache_to_poc(page_address(page), np * PAGE_SIZE);
 	}
 	val |= GICR_VPROPBASER_4_1_Z;
 	val |= GICR_VPROPBASER_4_1_VALID;
-- 
2.47.3