cxl: Add set and get private data to context struct

This provides AFU drivers a means to associate private data with a cxl
context. This is particularly intended for make the new callbacks for
driver specific events easier for AFU drivers to use, as they can easily
get back to any private data structures they may use.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

drivers/misc/cxl/api.c

@@ -94,6 +94,27 @@ static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num)
 	return 0;
 }
 
+
+int cxl_set_priv(struct cxl_context *ctx, void *priv)
+{
+	if (!ctx)
+		return -EINVAL;
+
+	ctx->priv = priv;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cxl_set_priv);
+
+void *cxl_get_priv(struct cxl_context *ctx)
+{
+	if (!ctx)
+		return ERR_PTR(-EINVAL);
+
+	return ctx->priv;
+}
+EXPORT_SYMBOL_GPL(cxl_get_priv);
+
 int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num)
 {
 	int res;

drivers/misc/cxl/cxl.h

@@ -484,6 +484,9 @@ struct cxl_context {
 	/* Only used in PR mode */
 	u64 process_token;
 
+	/* driver private data */
+	void *priv;
+
 	unsigned long *irq_bitmap; /* Accessed from IRQ context */
 	struct cxl_irq_ranges irqs;
 	struct list_head irq_names;

include/misc/cxl.h

@@ -85,6 +85,13 @@ struct cxl_context *cxl_dev_context_init(struct pci_dev *dev);
  */
 int cxl_release_context(struct cxl_context *ctx);
 
+/*
+ * Set and get private data associated with a context. Allows drivers to have a
+ * back pointer to some useful structure.
+ */
+int cxl_set_priv(struct cxl_context *ctx, void *priv);
+void *cxl_get_priv(struct cxl_context *ctx);
+
 /*
  * Allocate AFU interrupts for this context. num=0 will allocate the default
  * for this AFU as given in the AFU descriptor. This number doesn't include the