[PATCH 2/3] irqchip/gic-v3-its: Don't clamp nvecs to zero when id_bits is 32

[Fuad Tabba]

GITS_TYPER_IDBITS is five bits, so id_bits reaches 32 and
min_t(unsigned int, ...) truncates BIT(32) to 0. nvecs becomes 0,
its_lpi_alloc() rejects that, and its_msi_prepare() returns -ENOMEM.
On 32-bit ARM the shift is undefined instead.

The clamp is correct for every value below the maximum, so only that
one value is affected.

Fixes: ce9e40a9a5e5c ("irqchip/gic-v3-its: Limit number of per-device MSIs to the range the ITS supports")
Cc: stable at vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba at linux.dev>
---
 drivers/irqchip/irq-gic-v3-its.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index e9807af235373..81a96149f9154 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3484,7 +3484,7 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
 	 * Also honor the ITS's own EID limit.
 	 */
 	id_bits = FIELD_GET(GITS_TYPER_IDBITS, its->typer) + 1;
-	nvecs = min_t(unsigned int, nvecs, BIT(id_bits));
+	nvecs = min_t(u64, nvecs, BIT_ULL(id_bits));
 	nr_ites = max(2, nvecs);
 	sz = nr_ites * (FIELD_GET(GITS_TYPER_ITT_ENTRY_SIZE, its->typer) + 1);
 	sz = max(sz, ITS_ITT_ALIGN);
-- 
2.39.5