At the moment, the SMMUv3 driver implements only one stage-1 or stage-2
page directory per device. However SMMUv3 allows more than one address
space for some devices, by providing multiple stage-1 page directories. In
addition to the Stream ID (SID), that identifies a device, we can now have
Substream IDs (SSID) identifying an address space. In PCIe, SID is called
Requester ID (RID) and SSID is called Process Address-Space ID (PASID).
Prepare the driver for SSID support, by adding context descriptor tables
in STEs (previously a single static context descriptor). A complete
stage-1 walk is now performed like this by the SMMU:
Stream tables Ctx. tables Page tables
+--------+ ,------->+-------+ ,------->+-------+
: : | : : | : :
+--------+ | +-------+ | +-------+
SID->| STE |---' SSID->| CD |---' IOVA->| PTE |--> IPA
+--------+ +-------+ +-------+
: : : : : :
+--------+ +-------+ +-------+
Implement a single level of context descriptor table for now, but as with
stream and page tables, an SSID can be split to index multiple levels of
tables.
Signed-off-by: Jean-Philippe Brucker <[email protected]>
---
drivers/iommu/arm-smmu-v3.c | 132 ++++++++++++++++++++++++++++++------
1 file changed, 111 insertions(+), 21 deletions(-)
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 122bed0168a3..df7d45503c65 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -227,6 +227,11 @@
#define STRTAB_STE_0_S1CTXPTR_MASK GENMASK_ULL(51, 6)
#define STRTAB_STE_0_S1CDMAX GENMASK_ULL(63, 59)
+#define STRTAB_STE_1_S1DSS GENMASK_ULL(1, 0)
+#define STRTAB_STE_1_S1DSS_TERMINATE 0x0
+#define STRTAB_STE_1_S1DSS_BYPASS 0x1
+#define STRTAB_STE_1_S1DSS_SSID0 0x2
+
#define STRTAB_STE_1_S1C_CACHE_NC 0UL
#define STRTAB_STE_1_S1C_CACHE_WBRA 1UL
#define STRTAB_STE_1_S1C_CACHE_WT 2UL
@@ -329,6 +334,7 @@
#define CMDQ_PREFETCH_1_SIZE GENMASK_ULL(4, 0)
#define CMDQ_PREFETCH_1_ADDR_MASK GENMASK_ULL(63, 12)
+#define CMDQ_CFGI_0_SSID GENMASK_ULL(31, 12)
#define CMDQ_CFGI_0_SID GENMASK_ULL(63, 32)
#define CMDQ_CFGI_1_LEAF (1UL << 0)
#define CMDQ_CFGI_1_RANGE GENMASK_ULL(4, 0)
@@ -446,8 +452,11 @@ struct arm_smmu_cmdq_ent {
#define CMDQ_OP_CFGI_STE 0x3
#define CMDQ_OP_CFGI_ALL 0x4
+ #define CMDQ_OP_CFGI_CD 0x5
+ #define CMDQ_OP_CFGI_CD_ALL 0x6
struct {
u32 sid;
+ u32 ssid;
union {
bool leaf;
u8 span;
@@ -566,6 +575,7 @@ struct arm_smmu_cd_table {
};
struct arm_smmu_s1_cfg {
+ u8 s1fmt;
u8 s1cdmax;
struct arm_smmu_cd_table table;
struct arm_smmu_ctx_desc cd;
@@ -860,10 +870,16 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct
arm_smmu_cmdq_ent *ent)
cmd[1] |= FIELD_PREP(CMDQ_PREFETCH_1_SIZE, ent->prefetch.size);
cmd[1] |= ent->prefetch.addr & CMDQ_PREFETCH_1_ADDR_MASK;
break;
+ case CMDQ_OP_CFGI_CD:
+ cmd[0] |= FIELD_PREP(CMDQ_CFGI_0_SSID, ent->cfgi.ssid);
+ /* Fallthrough */
case CMDQ_OP_CFGI_STE:
cmd[0] |= FIELD_PREP(CMDQ_CFGI_0_SID, ent->cfgi.sid);
cmd[1] |= FIELD_PREP(CMDQ_CFGI_1_LEAF, ent->cfgi.leaf);
break;
+ case CMDQ_OP_CFGI_CD_ALL:
+ cmd[0] |= FIELD_PREP(CMDQ_CFGI_0_SID, ent->cfgi.sid);
+ break;
case CMDQ_OP_CFGI_ALL:
/* Cover the entire SID range */
cmd[1] |= FIELD_PREP(CMDQ_CFGI_1_RANGE, 31);
@@ -1456,6 +1472,33 @@ static int arm_smmu_cmdq_issue_sync(struct
arm_smmu_device *smmu)
}
/* Context descriptor manipulation functions */
+static void arm_smmu_sync_cd(struct arm_smmu_domain *smmu_domain,
+ int ssid, bool leaf)
+{
+ size_t i;
+ unsigned long flags;
+ struct arm_smmu_master *master;
+ struct arm_smmu_device *smmu = smmu_domain->smmu;
+ struct arm_smmu_cmdq_ent cmd = {
+ .opcode = CMDQ_OP_CFGI_CD,
+ .cfgi = {
+ .ssid = ssid,
+ .leaf = leaf,
+ },
+ };
+
+ spin_lock_irqsave(&smmu_domain->devices_lock, flags);
+ list_for_each_entry(master, &smmu_domain->devices, domain_head) {
+ for (i = 0; i < master->num_sids; i++) {
+ cmd.cfgi.sid = master->sids[i];
+ arm_smmu_cmdq_issue_cmd(smmu, &cmd);
+ }
+ }
+ spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
+
+ arm_smmu_cmdq_issue_sync(smmu);
+}
+
static int arm_smmu_alloc_cd_leaf_table(struct arm_smmu_device *smmu,
struct arm_smmu_cd_table *table,
size_t num_entries)
@@ -1481,6 +1524,11 @@ static void arm_smmu_free_cd_leaf_table(struct
arm_smmu_device *smmu,
dmam_free_coherent(smmu->dev, size, table->ptr, table->ptr_dma);
}
+static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_s1_cfg *cfg, u32 ssid)
+{
+ return cfg->table.ptr + ssid * CTXDESC_CD_DWORDS;
+}
+
static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
{
u64 val = 0;
@@ -1498,34 +1546,68 @@ static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
return val;
}
-static void arm_smmu_write_ctx_desc(struct arm_smmu_device *smmu,
- struct arm_smmu_s1_cfg *cfg)
+static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
+ int ssid, struct arm_smmu_ctx_desc *cd)
{
u64 val;
- __le64 *cdptr = cfg->table.ptr;
+ bool cd_live;
+ struct arm_smmu_device *smmu = smmu_domain->smmu;
+ __le64 *cdptr = arm_smmu_get_cd_ptr(&smmu_domain->s1_cfg, ssid);
/*
- * We don't need to issue any invalidation here, as we'll invalidate
- * the STE when installing the new entry anyway.
+ * This function handles the following cases:
+ *
+ * (1) Install primary CD, for normal DMA traffic (SSID = 0).
+ * (2) Install a secondary CD, for SID+SSID traffic.
+ * (3) Update ASID of a CD. Atomically write the first 64 bits of the
+ * CD, then invalidate the old entry and mappings.
+ * (4) Remove a secondary CD.
*/
- val = arm_smmu_cpu_tcr_to_cd(cfg->cd.tcr) |
-#ifdef __BIG_ENDIAN
- CTXDESC_CD_0_ENDI |
-#endif
- CTXDESC_CD_0_R | CTXDESC_CD_0_A | CTXDESC_CD_0_ASET |
- CTXDESC_CD_0_AA64 | FIELD_PREP(CTXDESC_CD_0_ASID, cfg->cd.asid) |
- CTXDESC_CD_0_V;
- /* STALL_MODEL==0b10 && CD.S==0 is ILLEGAL */
- if (smmu->features & ARM_SMMU_FEAT_STALL_FORCE)
- val |= CTXDESC_CD_0_S;
+ if (!cdptr)
+ return -ENOMEM;
- cdptr[0] = cpu_to_le64(val);
+ val = le64_to_cpu(cdptr[0]);
+ cd_live = !!(val & CTXDESC_CD_0_V);
- val = cfg->cd.ttbr & CTXDESC_CD_1_TTB0_MASK;
- cdptr[1] = cpu_to_le64(val);
+ if (!cd) { /* (4) */
+ val = 0;
+ } else if (cd_live) { /* (3) */
+ val &= ~CTXDESC_CD_0_ASID;
+ val |= FIELD_PREP(CTXDESC_CD_0_ASID, cd->asid);
+ /*
+ * Until CD+TLB invalidation, both ASIDs may be used for tagging
+ * this substream's traffic
+ */
+ } else { /* (1) and (2) */
+ cdptr[1] = cpu_to_le64(cd->ttbr & CTXDESC_CD_1_TTB0_MASK);
+ cdptr[2] = 0;
+ cdptr[3] = cpu_to_le64(cd->mair);
- cdptr[3] = cpu_to_le64(cfg->cd.mair);
+ /*
+ * STE is live, and the SMMU might fetch this CD at any
+ * time. Ensure that it observes the rest of the CD before we
+ * enable it.
+ */
+ arm_smmu_sync_cd(smmu_domain, ssid, true);
+
+ val = arm_smmu_cpu_tcr_to_cd(cd->tcr) |
+#ifdef __BIG_ENDIAN
+ CTXDESC_CD_0_ENDI |
+#endif
+ CTXDESC_CD_0_R | CTXDESC_CD_0_A | CTXDESC_CD_0_ASET |
+ CTXDESC_CD_0_AA64 |
+ FIELD_PREP(CTXDESC_CD_0_ASID, cd->asid) |
+ CTXDESC_CD_0_V;
+
+ /* STALL_MODEL==0b10 && CD.S==0 is ILLEGAL */
+ if (smmu->features & ARM_SMMU_FEAT_STALL_FORCE)
+ val |= CTXDESC_CD_0_S;
+ }
+
+ WRITE_ONCE(cdptr[0], cpu_to_le64(val));
+ arm_smmu_sync_cd(smmu_domain, ssid, true);
+ return 0;
}
static int arm_smmu_alloc_cd_tables(struct arm_smmu_domain *smmu_domain)
@@ -1533,6 +1615,7 @@ static int arm_smmu_alloc_cd_tables(struct
arm_smmu_domain *smmu_domain)
struct arm_smmu_device *smmu = smmu_domain->smmu;
struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
+ cfg->s1fmt = STRTAB_STE_0_S1FMT_LINEAR;
return arm_smmu_alloc_cd_leaf_table(smmu, &cfg->table,
1 << cfg->s1cdmax);
}
@@ -1664,6 +1747,7 @@ static void arm_smmu_write_strtab_ent(struct
arm_smmu_master *master, u32 sid,
if (s1_cfg) {
BUG_ON(ste_live);
dst[1] = cpu_to_le64(
+ FIELD_PREP(STRTAB_STE_1_S1DSS,
STRTAB_STE_1_S1DSS_SSID0) |
FIELD_PREP(STRTAB_STE_1_S1CIR,
STRTAB_STE_1_S1C_CACHE_WBRA) |
FIELD_PREP(STRTAB_STE_1_S1COR,
STRTAB_STE_1_S1C_CACHE_WBRA) |
FIELD_PREP(STRTAB_STE_1_S1CSH, ARM_SMMU_SH_ISH) |
@@ -1674,7 +1758,9 @@ static void arm_smmu_write_strtab_ent(struct
arm_smmu_master *master, u32 sid,
dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
val |= (s1_cfg->table.ptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
- FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_S1_TRANS);
+ FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_S1_TRANS)
|
+ FIELD_PREP(STRTAB_STE_0_S1CDMAX, s1_cfg->s1cdmax) |
+ FIELD_PREP(STRTAB_STE_0_S1FMT, s1_cfg->s1fmt);
}
if (s2_cfg) {
@@ -2224,10 +2310,14 @@ static int arm_smmu_domain_finalise_s1(struct
arm_smmu_domain *smmu_domain,
cfg->cd.tcr = pgtbl_cfg->arm_lpae_s1_cfg.tcr;
cfg->cd.mair = pgtbl_cfg->arm_lpae_s1_cfg.mair[0];
- arm_smmu_write_ctx_desc(smmu, cfg);
+ ret = arm_smmu_write_ctx_desc(smmu_domain, 0, &cfg->cd);
+ if (ret)
+ goto out_free_tables;
return 0;
+out_free_tables:
+ arm_smmu_free_cd_tables(smmu_domain);
out_free_asid:
arm_smmu_bitmap_free(smmu->asid_map, asid);
return ret;
--
2.23.0
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