[PATCH v1 4/5] iommu/arm-smmu-v3: Keep track of attached ssids

Michael Shavit
2023-05-10T20:53:24Z

The arm-smmu-v3 driver keeps track of all masters that a domain is
attached so that it can re-write their STEs when the domain's ASID is
upated by SVA. This tracking is also used to invalidate ATCs on all
masters that a domain is attached.

This change introduces a new data structures to track all the CD entries
that a domain is attached to. This change is a pre-requisite to allow
domain attachment on non 0 SSIDs.

Signed-off-by: Michael Shavit <mshavit@google.com>
---
.../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 31 ++++---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 90 ++++++++++++-------
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 17 ++--
3 files changed, 89 insertions(+), 49 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index a721461b355c6..2eb066c0f3f99 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -53,7 +53,7 @@ arm_smmu_share_asid(struct mm_struct *mm, u16 asid)
struct arm_smmu_ctx_desc *cd;
struct arm_smmu_device *smmu;
struct arm_smmu_domain *smmu_domain;
- struct arm_smmu_master *master;
+ struct arm_smmu_attached_domain *attached_domain;

cd = xa_load(&arm_smmu_asid_xa, asid);
if (!cd)
@@ -85,11 +85,11 @@ arm_smmu_share_asid(struct mm_struct *mm, u16 asid)
* be some overlap between use of both ASIDs, until we invalidate the
* TLB.
*/
- spin_lock_irqsave(&smmu_domain->devices_lock, flags);
- list_for_each_entry(master, &smmu_domain->devices, domain_head) {
- arm_smmu_write_ctx_desc(master, 0, cd);
+ spin_lock_irqsave(&smmu_domain->attached_domains_lock, flags);
+ list_for_each_entry(attached_domain, &smmu_domain->attached_domains, domain_head) {
+ arm_smmu_write_ctx_desc(attached_domain->master, attached_domain->ssid, cd);
}
- spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
+ spin_unlock_irqrestore(&smmu_domain->attached_domains_lock, flags);

/* Invalidate TLB entries previously associated with that context */
arm_smmu_tlb_inv_asid(smmu, asid);
@@ -213,14 +213,14 @@ static void arm_smmu_mm_invalidate_range(struct mmu_notifier *mn,
if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_BTM))
arm_smmu_tlb_inv_range_asid(start, size, smmu_mn->cd->asid,
PAGE_SIZE, false, smmu_domain);
- arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, start, size);
+ arm_smmu_atc_inv_domain_ssid(smmu_domain, mm->pasid, start, size);
}

static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
{
struct arm_smmu_mmu_notifier *smmu_mn = mn_to_smmu(mn);
struct arm_smmu_domain *smmu_domain = smmu_mn->domain;
- struct arm_smmu_master *master;
+ struct arm_smmu_attached_domain *attached_domain;
unsigned long flags;

mutex_lock(&sva_lock);
@@ -233,14 +233,19 @@ static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
* DMA may still be running. Keep the cd valid to avoid C_BAD_CD events,
* but disable translation.
*/
- spin_lock_irqsave(&smmu_domain->devices_lock, flags);
- list_for_each_entry(master, &smmu_domain->devices, domain_head) {
- arm_smmu_write_ctx_desc(master, mm->pasid, &quiet_cd);
+ spin_lock_irqsave(&smmu_domain->attached_domains_lock, flags);
+ list_for_each_entry(attached_domain, &smmu_domain->attached_domains, domain_head) {
+ /*
+ * SVA domains piggyback on the attached_domain with SSID 0.
+ */
+ if (attached_domain->ssid == 0)
+ arm_smmu_write_ctx_desc(attached_domain->master,
+ mm->pasid, &quiet_cd);
}
- spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
+ spin_unlock_irqrestore(&smmu_domain->attached_domains_lock, flags);

arm_smmu_tlb_inv_asid(smmu_domain->smmu, smmu_mn->cd->asid);
- arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, 0, 0);
+ arm_smmu_atc_inv_domain_ssid(smmu_domain, mm->pasid, 0, 0);

smmu_mn->cleared = true;
mutex_unlock(&sva_lock);
@@ -329,7 +334,7 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_master *master,
*/
if (!smmu_mn->cleared) {
arm_smmu_tlb_inv_asid(smmu_domain->smmu, cd->asid);
- arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, 0, 0);
+ arm_smmu_atc_inv_domain_ssid(smmu_domain, mm->pasid, 0, 0);
}

/* Frees smmu_mn */
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 47dda287a4736..81f49a86c1266 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1703,7 +1703,16 @@ static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
}

static void
-arm_smmu_atc_inv_to_cmd(int ssid, unsigned long iova, size_t size,
+arm_smmu_atc_inv_cmd_set_ssid(int ssid, struct arm_smmu_cmdq_ent *cmd)
+{
+ *cmd = (struct arm_smmu_cmdq_ent) {
+ .substream_valid = !!ssid,
+ .atc.ssid = ssid,
+ };
+}
+
+static void
+arm_smmu_atc_inv_to_cmd(unsigned long iova, size_t size,
struct arm_smmu_cmdq_ent *cmd)
{
size_t log2_span;
@@ -1728,8 +1737,8 @@ arm_smmu_atc_inv_to_cmd(int ssid, unsigned long iova, size_t size,
*/
*cmd = (struct arm_smmu_cmdq_ent) {
.opcode = CMDQ_OP_ATC_INV,
- .substream_valid = !!ssid,
- .atc.ssid = ssid,
+ .substream_valid = false,
+ .atc.ssid = 0,
};

if (!size) {
@@ -1775,8 +1784,7 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master)
struct arm_smmu_cmdq_ent cmd;
struct arm_smmu_cmdq_batch cmds;

- arm_smmu_atc_inv_to_cmd(0, 0, 0, &cmd);
-
+ arm_smmu_atc_inv_to_cmd(0, 0, &cmd);
cmds.num = 0;
for (i = 0; i < master->num_streams; i++) {
cmd.atc.sid = master->streams[i].id;
@@ -1786,13 +1794,21 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master)
return arm_smmu_cmdq_batch_submit(master->smmu, &cmds);
}

-int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
- unsigned long iova, size_t size)
+/*
+ * If ssid is 0, the domain is invalidated on all SSIDs that it is attached to.
+ * Otherwise, the domain is specifically invalidated on the provided SSID only.
+ * This second functionality is provided specifically for SVA which wants to
+ * invalidate domains on SSIDs that aren't recorded in the master's
+ * attached_domains list.
+ */
+int arm_smmu_atc_inv_domain_ssid(struct arm_smmu_domain *smmu_domain, int ssid,
+ unsigned long iova, size_t size)
{
int i;
unsigned long flags;
struct arm_smmu_cmdq_ent cmd;
struct arm_smmu_master *master;
+ struct arm_smmu_attached_domain *attached_domain;
struct arm_smmu_cmdq_batch cmds;

if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_ATS))
@@ -1815,25 +1831,35 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
if (!atomic_read(&smmu_domain->nr_ats_masters))
return 0;

- arm_smmu_atc_inv_to_cmd(ssid, iova, size, &cmd);
+ arm_smmu_atc_inv_to_cmd(iova, size, &cmd);
+ if (ssid != 0)
+ arm_smmu_atc_inv_cmd_set_ssid(ssid, &cmd);

cmds.num = 0;

- spin_lock_irqsave(&smmu_domain->devices_lock, flags);
- list_for_each_entry(master, &smmu_domain->devices, domain_head) {
+ spin_lock_irqsave(&smmu_domain->attached_domains_lock, flags);
+ list_for_each_entry(attached_domain, &smmu_domain->attached_domains, domain_head) {
+ master = attached_domain->master;
if (!master->ats_enabled)
continue;
-
+ if (ssid == 0)
+ arm_smmu_atc_inv_cmd_set_ssid(attached_domain->ssid, &cmd);
for (i = 0; i < master->num_streams; i++) {
cmd.atc.sid = master->streams[i].id;
arm_smmu_cmdq_batch_add(smmu_domain->smmu, &cmds, &cmd);
}
}
- spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
+ spin_unlock_irqrestore(&smmu_domain->attached_domains_lock, flags);

return arm_smmu_cmdq_batch_submit(smmu_domain->smmu, &cmds);
}

+int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
+ unsigned long iova, size_t size)
+{
+ return arm_smmu_atc_inv_domain_ssid(smmu_domain, 0, iova, size);
+}
+
/* IO_PGTABLE API */
static void arm_smmu_tlb_inv_context(void *cookie)
{
@@ -1855,7 +1881,7 @@ static void arm_smmu_tlb_inv_context(void *cookie)
cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid;
arm_smmu_cmdq_issue_cmd_with_sync(smmu, &cmd);
}
- arm_smmu_atc_inv_domain(smmu_domain, 0, 0, 0);
+ arm_smmu_atc_inv_domain(smmu_domain, 0, 0);
}

static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
@@ -1943,7 +1969,7 @@ static void arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
* Unfortunately, this can't be leaf-only since we may have
* zapped an entire table.
*/
- arm_smmu_atc_inv_domain(smmu_domain, 0, iova, size);
+ arm_smmu_atc_inv_domain(smmu_domain, iova, size);
}

void arm_smmu_tlb_inv_range_asid(unsigned long iova, size_t size, int asid,
@@ -2023,8 +2049,8 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
return NULL;

mutex_init(&smmu_domain->init_mutex);
- INIT_LIST_HEAD(&smmu_domain->devices);
- spin_lock_init(&smmu_domain->devices_lock);
+ INIT_LIST_HEAD(&smmu_domain->attached_domains);
+ spin_lock_init(&smmu_domain->attached_domains_lock);
INIT_LIST_HEAD(&smmu_domain->mmu_notifiers);

return &smmu_domain->domain;
@@ -2259,12 +2285,12 @@ static bool arm_smmu_ats_supported(struct arm_smmu_master *master)
return dev_is_pci(dev) && pci_ats_supported(to_pci_dev(dev));
}

-static void arm_smmu_enable_ats(struct arm_smmu_master *master)
+static void arm_smmu_enable_ats(struct arm_smmu_master *master,
+ struct arm_smmu_domain *smmu_domain)
{
size_t stu;
struct pci_dev *pdev;
struct arm_smmu_device *smmu = master->smmu;
- struct arm_smmu_domain *smmu_domain = master->domain;

/* Don't enable ATS at the endpoint if it's not enabled in the STE */
if (!master->ats_enabled)
@@ -2280,10 +2306,9 @@ static void arm_smmu_enable_ats(struct arm_smmu_master *master)
dev_err(master->dev, "Failed to enable ATS (STU %zu)\n", stu);
}

-static void arm_smmu_disable_ats(struct arm_smmu_master *master)
+static void arm_smmu_disable_ats(struct arm_smmu_master *master,
+ struct arm_smmu_domain *smmu_domain)
{
- struct arm_smmu_domain *smmu_domain = master->domain;
-
if (!master->ats_enabled)
return;

@@ -2347,20 +2372,21 @@ static void arm_smmu_disable_pasid(struct arm_smmu_master *master)
static void arm_smmu_detach_dev(struct arm_smmu_master *master)
{
unsigned long flags;
- struct arm_smmu_domain *smmu_domain = master->domain;
+ struct arm_smmu_domain *smmu_domain = master->attached_domain.domain;

if (!smmu_domain)
return;

- arm_smmu_disable_ats(master);
+ arm_smmu_disable_ats(master, smmu_domain);

- spin_lock_irqsave(&smmu_domain->devices_lock, flags);
- list_del(&master->domain_head);
- spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
+ spin_lock_irqsave(&smmu_domain->attached_domains_lock, flags);
+ list_del(&master->attached_domain.domain_head);
+ spin_unlock_irqrestore(&smmu_domain->attached_domains_lock, flags);

master->ats_enabled = false;
master->s2_cfg = NULL;
master->has_stage1 = false;
+ master->attached_domain.domain = NULL;
/*
* Note that this will end up calling arm_smmu_sync_cd() even though
* we're about to destroy the entire STE anyways. This is ok because
@@ -2436,14 +2462,16 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
if (smmu_domain->stage != ARM_SMMU_DOMAIN_BYPASS)
master->ats_enabled = arm_smmu_ats_supported(master);

- master->domain = smmu_domain;
+ master->attached_domain.master = master;
+ master->attached_domain.domain = smmu_domain;
+ master->attached_domain.ssid = 0;
arm_smmu_install_ste_for_dev(master);

- spin_lock_irqsave(&smmu_domain->devices_lock, flags);
- list_add(&master->domain_head, &smmu_domain->devices);
- spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
+ spin_lock_irqsave(&smmu_domain->attached_domains_lock, flags);
+ list_add(&master->attached_domain.domain_head, &smmu_domain->attached_domains);
+ spin_unlock_irqrestore(&smmu_domain->attached_domains_lock, flags);

- arm_smmu_enable_ats(master);
+ arm_smmu_enable_ats(master, smmu_domain);

out_unlock:
mutex_unlock(&smmu_domain->init_mutex);
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 d715794572b13..35700534a0b4a 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -681,11 +681,18 @@ struct arm_smmu_stream {
struct rb_node node;
};

+struct arm_smmu_attached_domain {
+ struct list_head domain_head;
+ struct arm_smmu_master *master;
+ int ssid;
+ struct arm_smmu_domain *domain;
+};
+
/* SMMU private data for each master */
struct arm_smmu_master {
struct arm_smmu_device *smmu;
struct device *dev;
- struct arm_smmu_domain *domain;
+ struct arm_smmu_attached_domain attached_domain;
struct list_head domain_head;
struct arm_smmu_stream *streams;
struct arm_smmu_s1_cfg s1_cfg;
@@ -724,8 +731,8 @@ struct arm_smmu_domain {

struct iommu_domain domain;

- struct list_head devices;
- spinlock_t devices_lock;
+ struct list_head attached_domains;
+ spinlock_t attached_domains_lock;

struct list_head mmu_notifiers;
};
@@ -746,8 +753,8 @@ void arm_smmu_tlb_inv_range_asid(unsigned long iova, size_t size, int asid,
size_t granule, bool leaf,
struct arm_smmu_domain *smmu_domain);
bool arm_smmu_free_asid(struct arm_smmu_ctx_desc *cd);
-int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
- unsigned long iova, size_t size);
+int arm_smmu_atc_inv_domain_ssid(struct arm_smmu_domain *smmu_domain, int ssid,
+ unsigned long iova, size_t size);

#ifdef CONFIG_ARM_SMMU_V3_SVA
bool arm_smmu_sva_supported(struct arm_smmu_device *smmu);
--
2.40.1.521.gf1e218fcd8-goog