[PATCH RFC v1 06/11] iommu/pasid-table: Add pasid table ops for shared context management
Vivek Gautam
vivek.gautam at arm.com
Fri Apr 23 10:51:42 BST 2021
Add pasid table ops to allocate and free shared contexts. These helpers
interact using mmu notifiers, so add a mmu notifier implementation
structure in pasid tables as well. This change can help pull out the
shared pasid (context-descriptor) implementation out of arm-smmu-v3.
Signed-off-by: Vivek Gautam <vivek.gautam at arm.com>
---
.../arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c | 1 +
drivers/iommu/iommu-pasid-table.h | 42 +++++++++++++++++++
2 files changed, 43 insertions(+)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c
index fa1a6a632559..ea94f57ad261 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-cd-lib.c
@@ -299,6 +299,7 @@ arm_smmu_register_cd_table(struct device *dev, void *cookie,
tbl->cookie = cookie;
tbl->ops = &arm_cd_table_ops;
tbl->cfg.sync = sync_ops;
+ INIT_LIST_HEAD(&tbl->mmu_notifiers);
return tbl;
}
diff --git a/drivers/iommu/iommu-pasid-table.h b/drivers/iommu/iommu-pasid-table.h
index 00b1c66e6a9e..4d6590e60f9b 100644
--- a/drivers/iommu/iommu-pasid-table.h
+++ b/drivers/iommu/iommu-pasid-table.h
@@ -8,6 +8,7 @@
#define __IOMMU_PASID_TABLE_H
#include <linux/io-pgtable.h>
+#include <linux/mmu_notifier.h>
#include "arm/arm-smmu-v3/arm-smmu-v3.h"
@@ -52,6 +53,21 @@ struct iommu_vendor_psdtable_cfg {
struct iommu_vendor_psdtable_ops;
+/* In-line with 'struct arm_smmu_mmu_notifier' */
+struct iommu_psdtable_mmu_notifier {
+ struct mmu_notifier mn;
+ bool cleared;
+ refcount_t refs;
+ struct list_head list;
+ /* cookie captures the domain implementation */
+ void *cookie;
+ union {
+ struct arm_smmu_ctx_desc *cd;
+ } vendor;
+};
+#define mn_to_pstiommu(mn) \
+ container_of(mn, struct iommu_psdtable_mmu_notifier, mn)
+
/**
* struct iommu_pasid_table - describes a set of PASID tables
*
@@ -64,6 +80,7 @@ struct iommu_pasid_table {
void *cookie;
struct iommu_vendor_psdtable_cfg cfg;
const struct iommu_vendor_psdtable_ops *ops;
+ struct list_head mmu_notifiers;
};
#define pasid_table_cfg_to_table(pst_cfg) \
@@ -77,6 +94,11 @@ struct iommu_vendor_psdtable_ops {
int (*write)(struct iommu_vendor_psdtable_cfg *cfg, int ssid,
void *cookie);
bool (*free_asid)(struct xarray *xa, void *cookie_cd);
+ struct iommu_psdtable_mmu_notifier *
+ (*alloc_shared)(struct iommu_pasid_table *tbl, struct mm_struct *mm,
+ struct xarray *xa, u32 asid_bits);
+ void (*free_shared)(struct iommu_pasid_table *tbl, struct xarray *xa,
+ void *cookie_cd);
};
/* CD manipulation ops */
@@ -129,6 +151,26 @@ static inline bool iommu_psdtable_free_asid(struct iommu_pasid_table *tbl,
return tbl->ops->free_asid(xa, cookie_cd);
}
+static inline struct iommu_psdtable_mmu_notifier *
+iommu_psdtable_alloc_shared(struct iommu_pasid_table *tbl,
+ struct mm_struct *mm, struct xarray *xa,
+ u32 asid_bits)
+{
+ if (!tbl->ops->alloc_shared)
+ return false;
+
+ return tbl->ops->alloc_shared(tbl, mm, xa, asid_bits);
+}
+
+static inline void iommu_psdtable_free_shared(struct iommu_pasid_table *tbl,
+ struct xarray *xa, void *cookie)
+{
+ if (!tbl->ops->free_shared)
+ return;
+
+ tbl->ops->free_shared(tbl, xa, cookie);
+}
+
/* Sync ops for CD cfg or tlb */
static inline void iommu_psdtable_flush(struct iommu_pasid_table *tbl,
void *cookie, int ssid, bool leaf)
--
2.17.1
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