[PATCH v2 28/40] iommu/arm-smmu-v3: Implement mm operations

Jean-Philippe Brucker
2018-05-11T19:06:29Z

Hook mm operations to support PASID and page table sharing with the
SMMUv3:

* mm_alloc allocates a context descriptor.
* mm_free releases the context descriptor.
* mm_attach checks device capabilities and writes the context descriptor.
* mm_detach clears the context descriptor and sends required
invalidations.
* mm_invalidate sends required invalidations.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker-5wv7dgnIgG8@public.gmane.org>
---
drivers/iommu/Kconfig | 1 +
drivers/iommu/arm-smmu-v3.c | 126 ++++++++++++++++++++++++++++++++++++
2 files changed, 127 insertions(+)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 11c8492b3763..70900670a9fa 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -343,6 +343,7 @@ config ARM_SMMU_V3
bool "ARM Ltd. System MMU Version 3 (SMMUv3) Support"
depends on ARM64
select IOMMU_API
+ select IOMMU_SVA
select IOMMU_IO_PGTABLE_LPAE
select ARM_SMMU_V3_CONTEXT
select GENERIC_MSI_IRQ_DOMAIN
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 2716e4a4d3f7..c2c96025ac3b 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -31,6 +31,7 @@
#include <linux/interrupt.h>
#include <linux/iommu.h>
#include <linux/iopoll.h>
+#include <linux/mmu_context.h>
#include <linux/module.h>
#include <linux/msi.h>
#include <linux/of.h>
@@ -39,6 +40,7 @@
#include <linux/of_platform.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
+#include <linux/sched/mm.h>

#include <linux/amba/bus.h>

@@ -599,6 +601,11 @@ struct arm_smmu_domain {
spinlock_t devices_lock;
};

+struct arm_smmu_mm {
+ struct io_mm io_mm;
+ struct iommu_pasid_entry *cd;
+};
+
struct arm_smmu_option_prop {
u32 opt;
const char *prop;
@@ -625,6 +632,11 @@ static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
return container_of(dom, struct arm_smmu_domain, domain);
}

+static struct arm_smmu_mm *to_smmu_mm(struct io_mm *io_mm)
+{
+ return container_of(io_mm, struct arm_smmu_mm, io_mm);
+}
+
static void parse_driver_options(struct arm_smmu_device *smmu)
{
int i = 0;
@@ -1725,6 +1737,8 @@ static void arm_smmu_detach_dev(struct device *dev)
struct arm_smmu_domain *smmu_domain = master->domain;

if (smmu_domain) {
+ __iommu_sva_unbind_dev_all(dev);
+
spin_lock_irqsave(&smmu_domain->devices_lock, flags);
list_del(&master->list);
spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
@@ -1842,6 +1856,111 @@ arm_smmu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)
return ops->iova_to_phys(ops, iova);
}

+static int arm_smmu_sva_init(struct device *dev, struct iommu_sva_param *param)
+{
+ struct arm_smmu_master_data *master = dev->iommu_fwspec->iommu_priv;
+
+ /* SSID support is mandatory for the moment */
+ if (!master->ssid_bits)
+ return -EINVAL;
+
+ if (param->features)
+ return -EINVAL;
+
+ if (!param->max_pasid)
+ param->max_pasid = 0xfffffU;
+
+ /* SSID support in the SMMU requires at least one SSID bit */
+ param->min_pasid = max(param->min_pasid, 1U);
+ param->max_pasid = min(param->max_pasid, (1U << master->ssid_bits) - 1);
+
+ return 0;
+}
+
+static void arm_smmu_sva_shutdown(struct device *dev,
+ struct iommu_sva_param *param)
+{
+}
+
+static struct io_mm *arm_smmu_mm_alloc(struct iommu_domain *domain,
+ struct mm_struct *mm,
+ unsigned long flags)
+{
+ struct arm_smmu_mm *smmu_mm;
+ struct iommu_pasid_entry *cd;
+ struct iommu_pasid_table_ops *ops;
+ struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+
+ if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1)
+ return NULL;
+
+ smmu_mm = kzalloc(sizeof(*smmu_mm), GFP_KERNEL);
+ if (!smmu_mm)
+ return NULL;
+
+ ops = smmu_domain->s1_cfg.ops;
+ cd = ops->alloc_shared_entry(ops, mm);
+ if (IS_ERR(cd)) {
+ kfree(smmu_mm);
+ return ERR_CAST(cd);
+ }
+
+ smmu_mm->cd = cd;
+ return &smmu_mm->io_mm;
+}
+
+static void arm_smmu_mm_free(struct io_mm *io_mm)
+{
+ struct arm_smmu_mm *smmu_mm = to_smmu_mm(io_mm);
+
+ iommu_free_pasid_entry(smmu_mm->cd);
+ kfree(smmu_mm);
+}
+
+static int arm_smmu_mm_attach(struct iommu_domain *domain, struct device *dev,
+ struct io_mm *io_mm, bool attach_domain)
+{
+ struct arm_smmu_mm *smmu_mm = to_smmu_mm(io_mm);
+ struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+ struct iommu_pasid_table_ops *ops = smmu_domain->s1_cfg.ops;
+ struct arm_smmu_master_data *master = dev->iommu_fwspec->iommu_priv;
+
+ if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1)
+ return -EINVAL;
+
+ if (!(master->smmu->features & ARM_SMMU_FEAT_SVA))
+ return -ENODEV;
+
+ if (!attach_domain)
+ return 0;
+
+ return ops->set_entry(ops, io_mm->pasid, smmu_mm->cd);
+}
+
+static void arm_smmu_mm_detach(struct iommu_domain *domain, struct device *dev,
+ struct io_mm *io_mm, bool detach_domain)
+{
+ struct arm_smmu_mm *smmu_mm = to_smmu_mm(io_mm);
+ struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+ struct iommu_pasid_table_ops *ops = smmu_domain->s1_cfg.ops;
+
+ if (detach_domain)
+ ops->clear_entry(ops, io_mm->pasid, smmu_mm->cd);
+
+ /* TODO: Invalidate ATC. */
+ /* TODO: Invalidate all mappings if last and not DVM. */
+}
+
+static void arm_smmu_mm_invalidate(struct iommu_domain *domain,
+ struct device *dev, struct io_mm *io_mm,
+ unsigned long iova, size_t size)
+{
+ /*
+ * TODO: Invalidate ATC.
+ * TODO: Invalidate mapping if not DVM
+ */
+}
+
static struct platform_driver arm_smmu_driver;

static int arm_smmu_match_node(struct device *dev, void *data)
@@ -2048,6 +2167,13 @@ static struct iommu_ops arm_smmu_ops = {
.domain_alloc = arm_smmu_domain_alloc,
.domain_free = arm_smmu_domain_free,
.attach_dev = arm_smmu_attach_dev,
+ .sva_device_init = arm_smmu_sva_init,
+ .sva_device_shutdown = arm_smmu_sva_shutdown,
+ .mm_alloc = arm_smmu_mm_alloc,
+ .mm_free = arm_smmu_mm_free,
+ .mm_attach = arm_smmu_mm_attach,
+ .mm_detach = arm_smmu_mm_detach,
+ .mm_invalidate = arm_smmu_mm_invalidate,
.map = arm_smmu_map,
.unmap = arm_smmu_unmap,
.map_sg = default_iommu_map_sg,
--
2.17.0