The SMMU can support up to 20 bits of SSID. Add a second level of page
tables to accommodate this. Devices that support more than 1024 SSIDs now
have a table of 1024 L1 entries (8kB), pointing to tables of 1024 context
descriptors (64kB), allocated on demand.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
---
drivers/iommu/arm-smmu-v3.c | 142 ++++++++++++++++++++++++++++++++++--
1 file changed, 134 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index c35863073ab3..04144b39c4ce 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -224,6 +224,7 @@
#define STRTAB_STE_0_S1FMT GENMASK_ULL(5, 4)
#define STRTAB_STE_0_S1FMT_LINEAR 0
+#define STRTAB_STE_0_S1FMT_64K_L2 2
#define STRTAB_STE_0_S1CTXPTR_MASK GENMASK_ULL(51, 6)
#define STRTAB_STE_0_S1CDMAX GENMASK_ULL(63, 59)
@@ -263,7 +264,20 @@
#define STRTAB_STE_3_S2TTB_MASK GENMASK_ULL(51, 4)
-/* Context descriptor (stage-1 only) */
+/*
+ * Context descriptors.
+ *
+ * Linear: when less than 1024 SSIDs are supported
+ * 2lvl: at most 1024 L1 entries,
+ * 1024 lazy entries per table.
+ */
+#define CTXDESC_SPLIT 10
+#define CTXDESC_L2_ENTRIES (1 << CTXDESC_SPLIT)
+
+#define CTXDESC_L1_DESC_DWORDS 1
+#define CTXDESC_L1_DESC_V (1UL << 0)
+#define CTXDESC_L1_DESC_L2PTR_MASK GENMASK_ULL(51, 12)
+
#define CTXDESC_CD_DWORDS 8
#define CTXDESC_CD_0_TCR_T0SZ GENMASK_ULL(5, 0)
#define ARM64_TCR_T0SZ GENMASK_ULL(5, 0)
@@ -569,9 +583,15 @@ struct arm_smmu_ctx_desc {
u64 mair;
};
+struct arm_smmu_l1_ctx_desc {
+ __le64 *l2ptr;
+ dma_addr_t l2ptr_dma;
+};
+
struct arm_smmu_ctx_desc_cfg {
__le64 *cdtab;
dma_addr_t cdtab_dma;
+ struct arm_smmu_l1_ctx_desc *l1_desc;
unsigned int num_l1_ents;
};
@@ -1500,6 +1520,57 @@ static void arm_smmu_sync_cd(struct arm_smmu_domain *smmu_domain,
arm_smmu_cmdq_issue_sync(smmu);
}
+static int arm_smmu_alloc_cd_leaf_table(struct arm_smmu_device *smmu,
+ struct arm_smmu_l1_ctx_desc *l1_desc)
+{
+ size_t size = CTXDESC_L2_ENTRIES * (CTXDESC_CD_DWORDS << 3);
+
+ l1_desc->l2ptr = dmam_alloc_coherent(smmu->dev, size,
+ &l1_desc->l2ptr_dma, GFP_KERNEL);
+ if (!l1_desc->l2ptr) {
+ dev_warn(smmu->dev,
+ "failed to allocate context descriptor table\n");
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+static void arm_smmu_write_cd_l1_desc(__le64 *dst,
+ struct arm_smmu_l1_ctx_desc *l1_desc)
+{
+ u64 val = (l1_desc->l2ptr_dma & CTXDESC_L1_DESC_L2PTR_MASK) |
+ CTXDESC_L1_DESC_V;
+
+ WRITE_ONCE(*dst, cpu_to_le64(val));
+}
+
+static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain,
+ u32 ssid)
+{
+ __le64 *l1ptr;
+ unsigned int idx;
+ struct arm_smmu_l1_ctx_desc *l1_desc;
+ struct arm_smmu_device *smmu = smmu_domain->smmu;
+ struct arm_smmu_ctx_desc_cfg *cdcfg = &smmu_domain->s1_cfg.cdcfg;
+
+ if (smmu_domain->s1_cfg.s1fmt == STRTAB_STE_0_S1FMT_LINEAR)
+ return cdcfg->cdtab + ssid * CTXDESC_CD_DWORDS;
+
+ idx = ssid >> CTXDESC_SPLIT;
+ l1_desc = &cdcfg->l1_desc[idx];
+ if (!l1_desc->l2ptr) {
+ if (arm_smmu_alloc_cd_leaf_table(smmu, l1_desc))
+ return NULL;
+
+ l1ptr = cdcfg->cdtab + idx * CTXDESC_L1_DESC_DWORDS;
+ arm_smmu_write_cd_l1_desc(l1ptr, l1_desc);
+ /* An invalid L1CD can be cached */
+ arm_smmu_sync_cd(smmu_domain, ssid, false);
+ }
+ idx = ssid & (CTXDESC_L2_ENTRIES - 1);
+ return l1_desc->l2ptr + idx * CTXDESC_CD_DWORDS;
+}
+
static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
{
u64 val = 0;
@@ -1531,9 +1602,15 @@ static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
*/
u64 val;
bool cd_live;
+ __le64 *cdptr;
struct arm_smmu_device *smmu = smmu_domain->smmu;
- __le64 *cdptr = smmu_domain->s1_cfg.cdcfg.cdtab + ssid *
- CTXDESC_CD_DWORDS;
+
+ if (WARN_ON(ssid >= (1 << smmu_domain->s1_cfg.s1cdmax)))
+ return -E2BIG;
+
+ cdptr = arm_smmu_get_cd_ptr(smmu_domain, ssid);
+ if (!cdptr)
+ return -ENOMEM;
val = le64_to_cpu(cdptr[0]);
cd_live = !!(val & CTXDESC_CD_0_V);
@@ -1589,29 +1666,78 @@ static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
static int arm_smmu_alloc_cd_tables(struct arm_smmu_domain *smmu_domain)
{
+ int ret;
size_t l1size;
+ size_t max_contexts;
struct arm_smmu_device *smmu = smmu_domain->smmu;
struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
struct arm_smmu_ctx_desc_cfg *cdcfg = &cfg->cdcfg;
- cfg->s1fmt = STRTAB_STE_0_S1FMT_LINEAR;
+ max_contexts = 1 << cfg->s1cdmax;
+
+ if (!(smmu->features & ARM_SMMU_FEAT_2_LVL_CDTAB) ||
+ max_contexts <= CTXDESC_L2_ENTRIES) {
+ cfg->s1fmt = STRTAB_STE_0_S1FMT_LINEAR;
+ cdcfg->num_l1_ents = max_contexts;
+
+ l1size = max_contexts * (CTXDESC_CD_DWORDS << 3);
+ } else {
+ cfg->s1fmt = STRTAB_STE_0_S1FMT_64K_L2;
+ cdcfg->num_l1_ents = DIV_ROUND_UP(max_contexts,
+ CTXDESC_L2_ENTRIES);
+
+ cdcfg->l1_desc = devm_kcalloc(smmu->dev, cdcfg->num_l1_ents,
+ sizeof(*cdcfg->l1_desc),
+ GFP_KERNEL);
+ if (!cdcfg->l1_desc)
+ return -ENOMEM;
+
+ l1size = cdcfg->num_l1_ents * (CTXDESC_L1_DESC_DWORDS << 3);
+ }
- cdcfg->num_l1_ents = 1UL << cfg->s1cdmax;
- l1size = cdcfg->num_l1_ents * (CTXDESC_CD_DWORDS << 3);
cdcfg->cdtab = dmam_alloc_coherent(smmu->dev, l1size, &cdcfg->cdtab_dma,
GFP_KERNEL);
if (!cdcfg->cdtab) {
dev_warn(smmu->dev, "failed to allocate context descriptor\n");
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto err_free_l1;
}
+
return 0;
+
+err_free_l1:
+ if (cdcfg->l1_desc) {
+ devm_kfree(smmu->dev, cdcfg->l1_desc);
+ cdcfg->l1_desc = NULL;
+ }
+ return ret;
}
static void arm_smmu_free_cd_tables(struct arm_smmu_domain *smmu_domain)
{
+ int i;
+ size_t size, l1size;
struct arm_smmu_device *smmu = smmu_domain->smmu;
struct arm_smmu_ctx_desc_cfg *cdcfg = &smmu_domain->s1_cfg.cdcfg;
- size_t l1size = cdcfg->num_l1_ents * (CTXDESC_CD_DWORDS << 3);
+
+ if (cdcfg->l1_desc) {
+ size = CTXDESC_L2_ENTRIES * (CTXDESC_CD_DWORDS << 3);
+
+ for (i = 0; i < cdcfg->num_l1_ents; i++) {
+ if (!cdcfg->l1_desc[i].l2ptr)
+ continue;
+
+ dmam_free_coherent(smmu->dev, size,
+ cdcfg->l1_desc[i].l2ptr,
+ cdcfg->l1_desc[i].l2ptr_dma);
+ }
+ devm_kfree(smmu->dev, cdcfg->l1_desc);
+ cdcfg->l1_desc = NULL;
+
+ l1size = cdcfg->num_l1_ents * (CTXDESC_L1_DESC_DWORDS << 3);
+ } else {
+ l1size = cdcfg->num_l1_ents * (CTXDESC_CD_DWORDS << 3);
+ }
dmam_free_coherent(smmu->dev, l1size, cdcfg->cdtab, cdcfg->cdtab_dma);
cdcfg->cdtab_dma = 0;
--
2.24.1
