[PATCH v5 2/9] iommu/arm-smmu-v3: Replace s1_cfg with cdtab_cfg

From: Michael Shavit
Date: Tue Aug 08 2023 - 14:12:13 EST


Remove struct arm_smmu_s1_cfg. This is really just a CD table with a
bit of extra information. Enhance the existing CD table structure,
struct arm_smmu_ctx_desc_cfg, with max_cds_bits and replace all usages
of arm_smmu_s1_cfg with arm_smmu_ctx_desc_cfg.

Compute the other values that were stored in s1cfg directly from
existing arm_smmu_ctx_desc_cfg.

For clarity, use the name "cd_table" for the variables pointing to
arm_smmu_ctx_desc_cfg in the new code instead of cdcfg. A later patch
will make this fully consistent.

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Reviewed-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Signed-off-by: Michael Shavit <mshavit@xxxxxxxxxx>
---

(no changes since v3)

Changes in v3:
- Updated commit messages again
- Replace more usages of cdcfg with cdtable (lines that were already
touched by this commit anyways).

Changes in v2:
- Updated commit message

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 45 +++++++++++----------
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 10 ++---
2 files changed, 26 insertions(+), 29 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index bb277ff86f65f..ded613aedbb04 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1033,9 +1033,9 @@ static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain,
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;
+ struct arm_smmu_ctx_desc_cfg *cdcfg = &smmu_domain->cd_table;

- if (smmu_domain->s1_cfg.s1fmt == STRTAB_STE_0_S1FMT_LINEAR)
+ if (!cdcfg->l1_desc)
return cdcfg->cdtab + ssid * CTXDESC_CD_DWORDS;

idx = ssid >> CTXDESC_SPLIT;
@@ -1071,7 +1071,7 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain, int ssid,
bool cd_live;
__le64 *cdptr;

- if (WARN_ON(ssid >= (1 << smmu_domain->s1_cfg.s1cdmax)))
+ if (WARN_ON(ssid >= (1 << smmu_domain->cd_table.max_cds_bits)))
return -E2BIG;

cdptr = arm_smmu_get_cd_ptr(smmu_domain, ssid);
@@ -1138,19 +1138,16 @@ static int arm_smmu_alloc_cd_tables(struct arm_smmu_domain *smmu_domain)
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;
+ struct arm_smmu_ctx_desc_cfg *cdcfg = &smmu_domain->cd_table;

- max_contexts = 1 << cfg->s1cdmax;
+ max_contexts = 1 << cdcfg->max_cds_bits;

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);

@@ -1186,7 +1183,7 @@ 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;
+ struct arm_smmu_ctx_desc_cfg *cdcfg = &smmu_domain->cd_table;

if (cdcfg->l1_desc) {
size = CTXDESC_L2_ENTRIES * (CTXDESC_CD_DWORDS << 3);
@@ -1276,7 +1273,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
u64 val = le64_to_cpu(dst[0]);
bool ste_live = false;
struct arm_smmu_device *smmu = NULL;
- struct arm_smmu_s1_cfg *s1_cfg = NULL;
+ struct arm_smmu_ctx_desc_cfg *cd_table = NULL;
struct arm_smmu_s2_cfg *s2_cfg = NULL;
struct arm_smmu_domain *smmu_domain = NULL;
struct arm_smmu_cmdq_ent prefetch_cmd = {
@@ -1294,7 +1291,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
if (smmu_domain) {
switch (smmu_domain->stage) {
case ARM_SMMU_DOMAIN_S1:
- s1_cfg = &smmu_domain->s1_cfg;
+ cd_table = &smmu_domain->cd_table;
break;
case ARM_SMMU_DOMAIN_S2:
case ARM_SMMU_DOMAIN_NESTED:
@@ -1325,7 +1322,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
val = STRTAB_STE_0_V;

/* Bypass/fault */
- if (!smmu_domain || !(s1_cfg || s2_cfg)) {
+ if (!smmu_domain || !(cd_table || s2_cfg)) {
if (!smmu_domain && disable_bypass)
val |= FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_ABORT);
else
@@ -1344,7 +1341,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
return;
}

- if (s1_cfg) {
+ if (cd_table) {
u64 strw = smmu->features & ARM_SMMU_FEAT_E2H ?
STRTAB_STE_1_STRW_EL2 : STRTAB_STE_1_STRW_NSEL1;

@@ -1360,10 +1357,14 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
!master->stall_enabled)
dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);

- val |= (s1_cfg->cdcfg.cdtab_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
- 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);
+ val |= (cd_table->cdtab_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
+ FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_S1_TRANS) |
+ FIELD_PREP(STRTAB_STE_0_S1CDMAX,
+ cd_table->max_cds_bits) |
+ FIELD_PREP(STRTAB_STE_0_S1FMT,
+ cd_table->l1_desc ?
+ STRTAB_STE_0_S1FMT_64K_L2 :
+ STRTAB_STE_0_S1FMT_LINEAR);
}

if (s2_cfg) {
@@ -2082,11 +2083,11 @@ static void arm_smmu_domain_free(struct iommu_domain *domain)

/* Free the CD and ASID, if we allocated them */
if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
- struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
+ struct arm_smmu_ctx_desc_cfg *cd_table = &smmu_domain->cd_table;

/* Prevent SVA from touching the CD while we're freeing it */
mutex_lock(&arm_smmu_asid_lock);
- if (cfg->cdcfg.cdtab)
+ if (cd_table->cdtab)
arm_smmu_free_cd_tables(smmu_domain);
arm_smmu_free_asid(&smmu_domain->cd);
mutex_unlock(&arm_smmu_asid_lock);
@@ -2106,7 +2107,7 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
int ret;
u32 asid;
struct arm_smmu_device *smmu = smmu_domain->smmu;
- struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
+ struct arm_smmu_ctx_desc_cfg *cd_table = &smmu_domain->cd_table;
struct arm_smmu_ctx_desc *cd = &smmu_domain->cd;
typeof(&pgtbl_cfg->arm_lpae_s1_cfg.tcr) tcr = &pgtbl_cfg->arm_lpae_s1_cfg.tcr;

@@ -2119,7 +2120,7 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
if (ret)
goto out_unlock;

- cfg->s1cdmax = master->ssid_bits;
+ cd_table->max_cds_bits = master->ssid_bits;

smmu_domain->stall_enabled = master->stall_enabled;

@@ -2457,7 +2458,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
ret = -EINVAL;
goto out_unlock;
} else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1 &&
- master->ssid_bits != smmu_domain->s1_cfg.s1cdmax) {
+ master->ssid_bits != smmu_domain->cd_table.max_cds_bits) {
ret = -EINVAL;
goto out_unlock;
} else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1 &&
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index f841383a55a35..35a93e8858872 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -595,12 +595,8 @@ struct arm_smmu_ctx_desc_cfg {
dma_addr_t cdtab_dma;
struct arm_smmu_l1_ctx_desc *l1_desc;
unsigned int num_l1_ents;
-};
-
-struct arm_smmu_s1_cfg {
- struct arm_smmu_ctx_desc_cfg cdcfg;
- u8 s1fmt;
- u8 s1cdmax;
+ /* log2 of the maximum number of CDs supported by this table */
+ u8 max_cds_bits;
};

struct arm_smmu_s2_cfg {
@@ -725,7 +721,7 @@ struct arm_smmu_domain {
union {
struct {
struct arm_smmu_ctx_desc cd;
- struct arm_smmu_s1_cfg s1_cfg;
+ struct arm_smmu_ctx_desc_cfg cd_table;
};
struct arm_smmu_s2_cfg s2_cfg;
};
--
2.41.0.640.ga95def55d0-goog