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.brucker@xxxxxxx> --- drivers/iommu/arm-smmu-v3-context.c | 137 ++++++++++++++++++++++++++-- 1 file changed, 130 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/arm-smmu-v3-context.c b/drivers/iommu/arm-smmu-v3-context.c index 0969a3626110..d68da99aa472 100644 --- a/drivers/iommu/arm-smmu-v3-context.c +++ b/drivers/iommu/arm-smmu-v3-context.c @@ -14,6 +14,18 @@ #include "iommu-pasid-table.h" +/* + * Linear: when less than 1024 SSIDs are supported + * 2lvl: at most 1024 L1 entrie, + * 1024 lazy entries per table. + */ +#define CTXDESC_SPLIT 10 +#define CTXDESC_NUM_L2_ENTRIES (1 << CTXDESC_SPLIT) + +#define CTXDESC_L1_DESC_DWORD 1 +#define CTXDESC_L1_DESC_VALID 1 +#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) @@ -69,7 +81,17 @@ struct arm_smmu_cd_table { struct arm_smmu_cd_tables { struct iommu_pasid_table pasid; - struct arm_smmu_cd_table table; + bool linear; + union { + struct arm_smmu_cd_table table; + struct { + __le64 *ptr; + dma_addr_t ptr_dma; + size_t num_entries; + + struct arm_smmu_cd_table *tables; + } l1; + }; }; #define pasid_to_cd_tables(pasid_table) \ @@ -105,9 +127,44 @@ static void arm_smmu_free_cd_leaf_table(struct device *dev, dmam_free_coherent(dev, size, desc->ptr, desc->ptr_dma); } +static void arm_smmu_write_cd_l1_desc(__le64 *dst, + struct arm_smmu_cd_table *desc) +{ + u64 val = (desc->ptr_dma & CTXDESC_L1_DESC_L2PTR_MASK) | + CTXDESC_L1_DESC_VALID; + + *dst = cpu_to_le64(val); +} + static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_cd_tables *tbl, u32 ssid) { - return tbl->table.ptr + ssid * CTXDESC_CD_DWORDS; + unsigned long idx; + struct arm_smmu_cd_table *l1_desc; + struct iommu_pasid_table_cfg *cfg = &tbl->pasid.cfg; + + if (tbl->linear) + return tbl->table.ptr + ssid * CTXDESC_CD_DWORDS; + + idx = ssid >> CTXDESC_SPLIT; + if (idx >= tbl->l1.num_entries) + return NULL; + + l1_desc = &tbl->l1.tables[idx]; + if (!l1_desc->ptr) { + __le64 *l1ptr = tbl->l1.ptr + idx * CTXDESC_L1_DESC_DWORD; + + if (arm_smmu_alloc_cd_leaf_table(cfg->iommu_dev, l1_desc, + CTXDESC_NUM_L2_ENTRIES)) + return NULL; + + arm_smmu_write_cd_l1_desc(l1ptr, l1_desc); + /* An invalid L1 entry is allowed to be cached */ + iommu_pasid_flush(&tbl->pasid, idx << CTXDESC_SPLIT, false); + } + + idx = ssid & (CTXDESC_NUM_L2_ENTRIES - 1); + + return l1_desc->ptr + idx * CTXDESC_CD_DWORDS; } static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr) @@ -284,16 +341,51 @@ static struct iommu_pasid_table * arm_smmu_alloc_cd_tables(struct iommu_pasid_table_cfg *cfg, void *cookie) { int ret; + size_t size = 0; struct arm_smmu_cd_tables *tbl; struct device *dev = cfg->iommu_dev; + struct arm_smmu_cd_table *leaf_table; + size_t num_contexts, num_leaf_entries; tbl = devm_kzalloc(dev, sizeof(*tbl), GFP_KERNEL); if (!tbl) return NULL; - ret = arm_smmu_alloc_cd_leaf_table(dev, &tbl->table, 1 << cfg->order); + num_contexts = 1 << cfg->order; + if (num_contexts <= CTXDESC_NUM_L2_ENTRIES) { + /* Fits in a single table */ + tbl->linear = true; + num_leaf_entries = num_contexts; + leaf_table = &tbl->table; + } else { + /* + * SSID[S1CDmax-1:10] indexes 1st-level table, SSID[9:0] indexes + * 2nd-level + */ + tbl->l1.num_entries = num_contexts / CTXDESC_NUM_L2_ENTRIES; + + tbl->l1.tables = devm_kzalloc(dev, + sizeof(struct arm_smmu_cd_table) * + tbl->l1.num_entries, GFP_KERNEL); + if (!tbl->l1.tables) + goto err_free_tbl; + + size = tbl->l1.num_entries * (CTXDESC_L1_DESC_DWORD << 3); + tbl->l1.ptr = dmam_alloc_coherent(dev, size, &tbl->l1.ptr_dma, + GFP_KERNEL | __GFP_ZERO); + if (!tbl->l1.ptr) { + dev_warn(dev, "failed to allocate L1 context table\n"); + devm_kfree(dev, tbl->l1.tables); + goto err_free_tbl; + } + + num_leaf_entries = CTXDESC_NUM_L2_ENTRIES; + leaf_table = tbl->l1.tables; + } + + ret = arm_smmu_alloc_cd_leaf_table(dev, leaf_table, num_leaf_entries); if (ret) - goto err_free_tbl; + goto err_free_l1; tbl->pasid.ops = (struct iommu_pasid_table_ops) { .alloc_priv_entry = arm_smmu_alloc_priv_cd, @@ -301,11 +393,23 @@ arm_smmu_alloc_cd_tables(struct iommu_pasid_table_cfg *cfg, void *cookie) .set_entry = arm_smmu_set_cd, .clear_entry = arm_smmu_clear_cd, }; - cfg->base = tbl->table.ptr_dma; - cfg->arm_smmu.s1fmt = ARM_SMMU_S1FMT_LINEAR; + + if (tbl->linear) { + cfg->base = leaf_table->ptr_dma; + cfg->arm_smmu.s1fmt = ARM_SMMU_S1FMT_LINEAR; + } else { + cfg->base = tbl->l1.ptr_dma; + cfg->arm_smmu.s1fmt = ARM_SMMU_S1FMT_64K_L2; + arm_smmu_write_cd_l1_desc(tbl->l1.ptr, leaf_table); + } return &tbl->pasid; +err_free_l1: + if (!tbl->linear) { + dmam_free_coherent(dev, size, tbl->l1.ptr, tbl->l1.ptr_dma); + devm_kfree(dev, tbl->l1.tables); + } err_free_tbl: devm_kfree(dev, tbl); @@ -318,7 +422,26 @@ static void arm_smmu_free_cd_tables(struct iommu_pasid_table *pasid_table) struct device *dev = cfg->iommu_dev; struct arm_smmu_cd_tables *tbl = pasid_to_cd_tables(pasid_table); - arm_smmu_free_cd_leaf_table(dev, &tbl->table, 1 << cfg->order); + if (tbl->linear) { + arm_smmu_free_cd_leaf_table(dev, &tbl->table, 1 << cfg->order); + } else { + size_t i, size; + + for (i = 0; i < tbl->l1.num_entries; i++) { + struct arm_smmu_cd_table *table = &tbl->l1.tables[i]; + + if (!table->ptr) + continue; + + arm_smmu_free_cd_leaf_table(dev, table, + CTXDESC_NUM_L2_ENTRIES); + } + + size = tbl->l1.num_entries * (CTXDESC_L1_DESC_DWORD << 3); + dmam_free_coherent(dev, size, tbl->l1.ptr, tbl->l1.ptr_dma); + devm_kfree(dev, tbl->l1.tables); + } + devm_kfree(dev, tbl); } -- 2.17.0 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html