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iommu/arm-smmu-v3: Move the CD generation for S1 domains into a function
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Introduce arm_smmu_make_s1_cd() to build the CD from the paging S1 domain,
and reorganize all the places programming S1 domain CD table entries to
call it.

Split arm_smmu_update_s1_domain_cd_entry() from
arm_smmu_update_ctx_desc_devices() so that the S1 path has its own call
chain separate from the unrelated SVA path.

arm_smmu_update_s1_domain_cd_entry() only works on S1 domains attached to
RIDs and refreshes all their CDs. Remove case (3) from
arm_smmu_write_ctx_desc() as it is now handled by directly calling
arm_smmu_write_cd_entry().

Remove the forced clear of the CD during S1 domain attach,
arm_smmu_write_cd_entry() will do this automatically if necessary.

Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Michael Shavit <mshavit@google.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v9-5040dc602008+177d7-smmuv3_newapi_p2_jgg@nvidia.com
[will: Drop unused arm_smmu_clean_cd_entry() function]
Signed-off-by: Will Deacon <will@kernel.org>
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Jason Gunthorpe authored and Will Deacon committed May 1, 2024
1 parent 78a5fbe commit e9d1e4f
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Showing 3 changed files with 76 additions and 29 deletions.
25 changes: 24 additions & 1 deletion drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -53,6 +53,29 @@ static void arm_smmu_update_ctx_desc_devices(struct arm_smmu_domain *smmu_domain
spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
}

static void
arm_smmu_update_s1_domain_cd_entry(struct arm_smmu_domain *smmu_domain)
{
struct arm_smmu_master *master;
struct arm_smmu_cd target_cd;
unsigned long flags;

spin_lock_irqsave(&smmu_domain->devices_lock, flags);
list_for_each_entry(master, &smmu_domain->devices, domain_head) {
struct arm_smmu_cd *cdptr;

/* S1 domains only support RID attachment right now */
cdptr = arm_smmu_get_cd_ptr(master, IOMMU_NO_PASID);
if (WARN_ON(!cdptr))
continue;

arm_smmu_make_s1_cd(&target_cd, master, smmu_domain);
arm_smmu_write_cd_entry(master, IOMMU_NO_PASID, cdptr,
&target_cd);
}
spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
}

/*
* Check if the CPU ASID is available on the SMMU side. If a private context
* descriptor is using it, try to replace it.
Expand Down Expand Up @@ -96,7 +119,7 @@ arm_smmu_share_asid(struct mm_struct *mm, u16 asid)
* be some overlap between use of both ASIDs, until we invalidate the
* TLB.
*/
arm_smmu_update_ctx_desc_devices(smmu_domain, IOMMU_NO_PASID, cd);
arm_smmu_update_s1_domain_cd_entry(smmu_domain);

/* Invalidate TLB entries previously associated with that context */
arm_smmu_tlb_inv_asid(smmu, asid);
Expand Down
71 changes: 43 additions & 28 deletions drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1203,8 +1203,8 @@ static void arm_smmu_write_cd_l1_desc(__le64 *dst,
WRITE_ONCE(*dst, cpu_to_le64(val));
}

static struct arm_smmu_cd *arm_smmu_get_cd_ptr(struct arm_smmu_master *master,
u32 ssid)
struct arm_smmu_cd *arm_smmu_get_cd_ptr(struct arm_smmu_master *master,
u32 ssid)
{
__le64 *l1ptr;
unsigned int idx;
Expand Down Expand Up @@ -1269,9 +1269,9 @@ static const struct arm_smmu_entry_writer_ops arm_smmu_cd_writer_ops = {
.get_used = arm_smmu_get_cd_used,
};

static void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
struct arm_smmu_cd *cdptr,
const struct arm_smmu_cd *target)
void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
struct arm_smmu_cd *cdptr,
const struct arm_smmu_cd *target)
{
struct arm_smmu_cd_writer cd_writer = {
.writer = {
Expand All @@ -1284,6 +1284,32 @@ static void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
arm_smmu_write_entry(&cd_writer.writer, cdptr->data, target->data);
}

void arm_smmu_make_s1_cd(struct arm_smmu_cd *target,
struct arm_smmu_master *master,
struct arm_smmu_domain *smmu_domain)
{
struct arm_smmu_ctx_desc *cd = &smmu_domain->cd;

memset(target, 0, sizeof(*target));

target->data[0] = cpu_to_le64(
cd->tcr |
#ifdef __BIG_ENDIAN
CTXDESC_CD_0_ENDI |
#endif
CTXDESC_CD_0_V |
CTXDESC_CD_0_AA64 |
(master->stall_enabled ? CTXDESC_CD_0_S : 0) |
CTXDESC_CD_0_R |
CTXDESC_CD_0_A |
CTXDESC_CD_0_ASET |
FIELD_PREP(CTXDESC_CD_0_ASID, cd->asid)
);

target->data[1] = cpu_to_le64(cd->ttbr & CTXDESC_CD_1_TTB0_MASK);
target->data[3] = cpu_to_le64(cd->mair);
}

int arm_smmu_write_ctx_desc(struct arm_smmu_master *master, int ssid,
struct arm_smmu_ctx_desc *cd)
{
Expand All @@ -1292,14 +1318,11 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_master *master, int ssid,
*
* (1) Install primary CD, for normal DMA traffic (SSID = IOMMU_NO_PASID = 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) Quiesce the context without clearing the valid bit. Disable
* translation, and ignore any translation fault.
* (5) Remove a secondary CD.
*/
u64 val;
bool cd_live;
struct arm_smmu_cd target;
struct arm_smmu_cd *cdptr = &target;
struct arm_smmu_cd *cd_table_entry;
Expand All @@ -1315,7 +1338,6 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_master *master, int ssid,

target = *cd_table_entry;
val = le64_to_cpu(cdptr->data[0]);
cd_live = !!(val & CTXDESC_CD_0_V);

if (!cd) { /* (5) */
memset(cdptr, 0, sizeof(*cdptr));
Expand All @@ -1328,13 +1350,6 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_master *master, int ssid,
val &= ~(CTXDESC_CD_0_S | CTXDESC_CD_0_R);
val |= CTXDESC_CD_0_TCR_EPD0;
cdptr->data[1] &= ~cpu_to_le64(CTXDESC_CD_1_TTB0_MASK);
} 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->data[1] = cpu_to_le64(cd->ttbr & CTXDESC_CD_1_TTB0_MASK);
cdptr->data[2] = 0;
Expand Down Expand Up @@ -2633,29 +2648,29 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);

switch (smmu_domain->stage) {
case ARM_SMMU_DOMAIN_S1:
case ARM_SMMU_DOMAIN_S1: {
struct arm_smmu_cd target_cd;
struct arm_smmu_cd *cdptr;

if (!master->cd_table.cdtab) {
ret = arm_smmu_alloc_cd_tables(master);
if (ret)
goto out_list_del;
} else {
/*
* arm_smmu_write_ctx_desc() relies on the entry being
* invalid to work, clear any existing entry.
*/
ret = arm_smmu_write_ctx_desc(master, IOMMU_NO_PASID,
NULL);
if (ret)
goto out_list_del;
}

ret = arm_smmu_write_ctx_desc(master, IOMMU_NO_PASID, &smmu_domain->cd);
if (ret)
cdptr = arm_smmu_get_cd_ptr(master, IOMMU_NO_PASID);
if (!cdptr) {
ret = -ENOMEM;
goto out_list_del;
}

arm_smmu_make_s1_cd(&target_cd, master, smmu_domain);
arm_smmu_write_cd_entry(master, IOMMU_NO_PASID, cdptr,
&target_cd);
arm_smmu_make_cdtable_ste(&target, master);
arm_smmu_install_ste_for_dev(master, &target);
break;
}
case ARM_SMMU_DOMAIN_S2:
arm_smmu_make_s2_domain_ste(&target, master, smmu_domain);
arm_smmu_install_ste_for_dev(master, &target);
Expand Down
9 changes: 9 additions & 0 deletions drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -751,6 +751,15 @@ extern struct xarray arm_smmu_asid_xa;
extern struct mutex arm_smmu_asid_lock;
extern struct arm_smmu_ctx_desc quiet_cd;

struct arm_smmu_cd *arm_smmu_get_cd_ptr(struct arm_smmu_master *master,
u32 ssid);
void arm_smmu_make_s1_cd(struct arm_smmu_cd *target,
struct arm_smmu_master *master,
struct arm_smmu_domain *smmu_domain);
void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
struct arm_smmu_cd *cdptr,
const struct arm_smmu_cd *target);

int arm_smmu_write_ctx_desc(struct arm_smmu_master *smmu_master, int ssid,
struct arm_smmu_ctx_desc *cd);
void arm_smmu_tlb_inv_asid(struct arm_smmu_device *smmu, u16 asid);
Expand Down

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