[PATCH v3 4/7] ocxl: Allow external drivers to use OpenCAPI contexts

[Alastair D'Silva]

From: Alastair D'Silva <alastair at d-silva.org>

Most OpenCAPI operations require a valid context, so
exposing these functions to external drivers is necessary.

Signed-off-by: Alastair D'Silva <alastair at d-silva.org>
Reviewed-by: Greg Kurz <groug at kaod.org>
---
 drivers/misc/ocxl/context.c       |  9 +++++--
 drivers/misc/ocxl/file.c          |  2 +-
 drivers/misc/ocxl/ocxl_internal.h |  6 -----
 include/misc/ocxl.h               | 45 +++++++++++++++++++++++++++++++
 4 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c
index c73a859d2224..8b97b0f19db8 100644
--- a/drivers/misc/ocxl/context.c
+++ b/drivers/misc/ocxl/context.c
@@ -8,6 +8,7 @@ struct ocxl_context *ocxl_context_alloc(void)
 {
 	return kzalloc(sizeof(struct ocxl_context), GFP_KERNEL);
 }
+EXPORT_SYMBOL_GPL(ocxl_context_alloc);
 
 int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
 		struct address_space *mapping)
@@ -43,6 +44,7 @@ int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
 	ocxl_afu_get(afu);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(ocxl_context_init);
 
 /*
  * Callback for when a translation fault triggers an error
@@ -63,7 +65,7 @@ static void xsl_fault_error(void *data, u64 addr, u64 dsisr)
 	wake_up_all(&ctx->events_wq);
 }
 
-int ocxl_context_attach(struct ocxl_context *ctx, u64 amr)
+int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm)
 {
 	int rc;
 
@@ -75,7 +77,7 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr)
 	}
 
 	rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid,
-			current->mm->context.id, ctx->tidr, amr, current->mm,
+			mm->context.id, ctx->tidr, amr, mm,
 			xsl_fault_error, ctx);
 	if (rc)
 		goto out;
@@ -85,6 +87,7 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr)
 	mutex_unlock(&ctx->status_mutex);
 	return rc;
 }
+EXPORT_SYMBOL_GPL(ocxl_context_attach);
 
 static vm_fault_t map_afu_irq(struct vm_area_struct *vma, unsigned long address,
 		u64 offset, struct ocxl_context *ctx)
@@ -243,6 +246,7 @@ int ocxl_context_detach(struct ocxl_context *ctx)
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(ocxl_context_detach);
 
 void ocxl_context_detach_all(struct ocxl_afu *afu)
 {
@@ -280,3 +284,4 @@ void ocxl_context_free(struct ocxl_context *ctx)
 	ocxl_afu_put(ctx->afu);
 	kfree(ctx);
 }
+EXPORT_SYMBOL_GPL(ocxl_context_free);
diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c
index e6e6121cd9a3..e51578186fd4 100644
--- a/drivers/misc/ocxl/file.c
+++ b/drivers/misc/ocxl/file.c
@@ -94,7 +94,7 @@ static long afu_ioctl_attach(struct ocxl_context *ctx,
 		return -EINVAL;
 
 	amr = arg.amr & mfspr(SPRN_UAMOR);
-	rc = ocxl_context_attach(ctx, amr);
+	rc = ocxl_context_attach(ctx, amr, current->mm);
 	return rc;
 }
 
diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h
index e04e547df29e..cda1e7667fc8 100644
--- a/drivers/misc/ocxl/ocxl_internal.h
+++ b/drivers/misc/ocxl/ocxl_internal.h
@@ -130,15 +130,9 @@ int ocxl_config_check_afu_index(struct pci_dev *dev,
  */
 int ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid);
 
-struct ocxl_context *ocxl_context_alloc(void);
-int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
-			struct address_space *mapping);
-int ocxl_context_attach(struct ocxl_context *ctx, u64 amr);
 int ocxl_context_mmap(struct ocxl_context *ctx,
 			struct vm_area_struct *vma);
-int ocxl_context_detach(struct ocxl_context *ctx);
 void ocxl_context_detach_all(struct ocxl_afu *afu);
-void ocxl_context_free(struct ocxl_context *ctx);
 
 int ocxl_sysfs_register_afu(struct ocxl_afu *afu);
 void ocxl_sysfs_unregister_afu(struct ocxl_afu *afu);
diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
index 8bafd748e380..a8fe0ce4ea67 100644
--- a/include/misc/ocxl.h
+++ b/include/misc/ocxl.h
@@ -116,6 +116,51 @@ const struct ocxl_fn_config *ocxl_function_config(struct ocxl_fn *fn);
  */
 void ocxl_function_close(struct ocxl_fn *fn);
 
+// Context allocation
+
+/**
+ * Allocate space for a new OpenCAPI context
+ *
+ * Returns NULL on failure
+ */
+struct ocxl_context *ocxl_context_alloc(void);
+
+/**
+ * Initialize an OpenCAPI context
+ *
+ * @ctx: The OpenCAPI context to initialize
+ * @afu: The AFU the context belongs to
+ * @mapping: The mapping to unmap when the context is closed (may be NULL)
+ */
+int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu,
+			struct address_space *mapping);
+
+/**
+ * Free an OpenCAPI context
+ *
+ * @ctx: The OpenCAPI context to free
+ */
+void ocxl_context_free(struct ocxl_context *ctx);
+
+/**
+ * Grant access to an MM to an OpenCAPI context
+ * @ctx: The OpenCAPI context to attach
+ * @amr: The value of the AMR register to restrict access
+ * @mm: The mm to attach to the context
+ *
+ * Returns 0 on success, negative on failure
+ */
+int ocxl_context_attach(struct ocxl_context *ctx, u64 amr,
+				struct mm_struct *mm);
+
+/**
+ * Detach an MM from an OpenCAPI context
+ * @ctx: The OpenCAPI context to attach
+ *
+ * Returns 0 on success, negative on failure
+ */
+int ocxl_context_detach(struct ocxl_context *ctx);
+
 // AFU Metadata
 
 /**
-- 
2.20.1