On Fri, 8 Nov 2019 16:25:05 +0100
Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> wrote:
> 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 <jean-philippe@xxxxxxxxxx>
Looks good to me.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> 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;
