scsi: ufs: exynos: Fix programming of HCI_UTRL_NEXUS_TYPE

On Google gs101, the number of UTP transfer request slots (nutrs) is 32,
and in this case the driver ends up programming the UTRL_NEXUS_TYPE
incorrectly as 0.

This is because the left hand side of the shift is 1, which is of type
int, i.e. 31 bits wide. Shifting by more than that width results in
undefined behaviour.

Fix this by switching to the BIT() macro, which applies correct type
casting as required. This ensures the correct value is written to
UTRL_NEXUS_TYPE (0xffffffff on gs101), and it also fixes a UBSAN shift
warning:

    UBSAN: shift-out-of-bounds in drivers/ufs/host/ufs-exynos.c:1113:21
    shift exponent 32 is too large for 32-bit type 'int'

For consistency, apply the same change to the nutmrs / UTMRL_NEXUS_TYPE
write.

Fixes: 55f4b1f73631 ("scsi: ufs: ufs-exynos: Add UFS host support for Exynos SoCs")
Cc: stable@vger.kernel.org
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250707-ufs-exynos-shift-v1-1-1418e161ae40@linaro.org
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/ufs/host/ufs-exynos.c b/drivers/ufs/host/ufs-exynos.c
index 3e545af536e53e06b66c624ed0dc6dc7de13549f..f0adcd9dd553d2e630c75e8c3220e21bc5f7c8d8 100644 (file)
--- a/drivers/ufs/host/ufs-exynos.c
+++ b/drivers/ufs/host/ufs-exynos.c
@@ -1110,8 +1110,8 @@ static int exynos_ufs_post_link(struct ufs_hba *hba)
        hci_writel(ufs, val, HCI_TXPRDT_ENTRY_SIZE);
 
        hci_writel(ufs, ilog2(DATA_UNIT_SIZE), HCI_RXPRDT_ENTRY_SIZE);
-       hci_writel(ufs, (1 << hba->nutrs) - 1, HCI_UTRL_NEXUS_TYPE);
-       hci_writel(ufs, (1 << hba->nutmrs) - 1, HCI_UTMRL_NEXUS_TYPE);
+       hci_writel(ufs, BIT(hba->nutrs) - 1, HCI_UTRL_NEXUS_TYPE);
+       hci_writel(ufs, BIT(hba->nutmrs) - 1, HCI_UTMRL_NEXUS_TYPE);
        hci_writel(ufs, 0xf, HCI_AXIDMA_RWDATA_BURST_LEN);
 
        if (ufs->opts & EXYNOS_UFS_OPT_SKIP_CONNECTION_ESTAB)