[PATCH v2 05/10] irqchip/gic-v5: Use linear DT and ITT when L2 covers all IDs

[Sascha Bischoff <sascha.bischoff@arm.com>]

The DT and ITT level selector incorrectly chooses a two-level table
when the selected L2 table has exactly enough entries to cover the
full ID space. There are no L1 index bits in this case. ITT allocation
correctly rejects the layout and device registration fails; the DT
path instead allocates an unnecessary one-entry L1 table.

Select a linear DT or ITT when the L2 width equals the ID width.

Fixes: 57d72196dfc85 ("irqchip/gic-v5: Add GICv5 ITS support")
Cc: stable@vger.kernel.org
Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 drivers/irqchip/irq-gic-v5-its.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v5-its.c b/drivers/irqchip/irq-gic-v5-its.c
index 6d98f3dbe34b6..866c238f08dfe 100644
--- a/drivers/irqchip/irq-gic-v5-its.c
+++ b/drivers/irqchip/irq-gic-v5-its.c
@@ -337,7 +337,7 @@ static bool gicv5_its_l2sz_two_level(bool devtab, u32 its_idr1, u8 id_bits, u8 *
 
 	l2_bits = gicv5_its_l2sz_to_l2_bits(l2_sz);
 
-	if (l2_bits > id_bits)
+	if (l2_bits >= id_bits)
 		return false;
 
 	*sz = l2_sz;

-- 
2.34.1