iommu/rockchip: Fix "is stall active" check

Since commit cd6438c5 ("iommu/rockchip: Reconstruct to support multi
slaves") rk_iommu_is_stall_active() always returns false because the
bitwise AND operates on the boolean flag promoted to an integer and a
value that is either zero or BIT(2).

Explicitly convert the right-hand value to a boolean so that both sides
are guaranteed to be either zero or one.

rk_iommu_is_paging_enabled() does not suffer from the same problem since
RK_MMU_STATUS_PAGING_ENABLED is BIT(0), but let's apply the same change
for consistency and to make it clear that it's correct without needing
to lookup the value.

Fixes: cd6438c5 ("iommu/rockchip: Reconstruct to support multi slaves")
Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/rockchip-iommu.c

@@ -315,8 +315,8 @@ static bool rk_iommu_is_stall_active(struct rk_iommu *iommu)
 	int i;
 
 	for (i = 0; i < iommu->num_mmu; i++)
-		active &= rk_iommu_read(iommu->bases[i], RK_MMU_STATUS) &
-					RK_MMU_STATUS_STALL_ACTIVE;
+		active &= !!(rk_iommu_read(iommu->bases[i], RK_MMU_STATUS) &
+					   RK_MMU_STATUS_STALL_ACTIVE);
 
 	return active;
 }
@@ -327,8 +327,8 @@ static bool rk_iommu_is_paging_enabled(struct rk_iommu *iommu)
 	int i;
 
 	for (i = 0; i < iommu->num_mmu; i++)
-		enable &= rk_iommu_read(iommu->bases[i], RK_MMU_STATUS) &
-					RK_MMU_STATUS_PAGING_ENABLED;
+		enable &= !!(rk_iommu_read(iommu->bases[i], RK_MMU_STATUS) &
+					   RK_MMU_STATUS_PAGING_ENABLED);
 
 	return enable;
 }