iommu/arm-smmu: Fix error checking for ASID and VMID allocation

The bitmap allocator returns an int, which is one of the standard
negative values on failure. Rather than assigning this straight to a
u16 (like we do for the ASID and VMID callers), which means that we
won't detect failure correctly, use an int for the purposes of error
checking.

Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 637014ab89654e7549df6e9752e1c975617856ef..970d78dcac53ee2683924f172a0ea981343210e6 100644 (file)
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1419,7 +1419,7 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
                                       struct io_pgtable_cfg *pgtbl_cfg)
 {
        int ret;
-       u16 asid;
+       int asid;
        struct arm_smmu_device *smmu = smmu_domain->smmu;
        struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
 
@@ -1431,10 +1431,11 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
                                         &cfg->cdptr_dma, GFP_KERNEL);
        if (!cfg->cdptr) {
                dev_warn(smmu->dev, "failed to allocate context descriptor\n");
+               ret = -ENOMEM;
                goto out_free_asid;
        }
 
-       cfg->cd.asid    = asid;
+       cfg->cd.asid    = (u16)asid;
        cfg->cd.ttbr    = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0];
        cfg->cd.tcr     = pgtbl_cfg->arm_lpae_s1_cfg.tcr;
        cfg->cd.mair    = pgtbl_cfg->arm_lpae_s1_cfg.mair[0];
@@ -1448,7 +1449,7 @@ out_free_asid:
 static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
                                       struct io_pgtable_cfg *pgtbl_cfg)
 {
-       u16 vmid;
+       int vmid;
        struct arm_smmu_device *smmu = smmu_domain->smmu;
        struct arm_smmu_s2_cfg *cfg = &smmu_domain->s2_cfg;
 
@@ -1456,7 +1457,7 @@ static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
        if (IS_ERR_VALUE(vmid))
                return vmid;
 
-       cfg->vmid       = vmid;
+       cfg->vmid       = (u16)vmid;
        cfg->vttbr      = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
        cfg->vtcr       = pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
        return 0;