powerpc/powernv/vas: Define vas_tx_win_open()

Define an interface to open a VAS send window. This interface is
intended to be used the Nest Accelerator (NX) driver(s) to open
a send window and use it to submit compression/encryption requests
to a VAS receive window.

The receive window, identified by the [vasid, cop] parameters, must
already be open in VAS (i.e connected to an NX engine).

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 42 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index 96bc24d61625..033461c17637 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -81,6 +81,29 @@ struct vas_rx_win_attr {
 };
 
 /*
+ * Window attributes specified by the in-kernel owner of a send window.
+ */
+struct vas_tx_win_attr {
+	enum vas_cop_type cop;
+	int wcreds_max;
+	int lpid;
+	int pidr;		/* hardware PID (from SPRN_PID) */
+	int pid;		/* linux process id */
+	int pswid;
+	int rsvd_txbuf_count;
+	int tc_mode;
+
+	bool user_win;
+	bool pin_win;
+	bool rej_no_credit;
+	bool rsvd_txbuf_enable;
+	bool tx_wcred_mode;
+	bool rx_wcred_mode;
+	bool tx_win_ord_mode;
+	bool rx_win_ord_mode;
+};
+
+/*
  * Helper to initialize receive window attributes to defaults for an
  * NX window.
  */
@@ -96,6 +119,25 @@ struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop,
 				   struct vas_rx_win_attr *attr);
 
 /*
+ * Helper to initialize send window attributes to defaults for an NX window.
+ */
+extern void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr,
+			enum vas_cop_type cop);
+
+/*
+ * Open a VAS send window for the instance of VAS identified by @vasid
+ * and the co-processor type @cop. Use @attr to initialize attributes
+ * of the window.
+ *
+ * Note: The instance of VAS must already have an open receive window for
+ * the coprocessor type @cop.
+ *
+ * Return a handle to the send window or ERR_PTR() on error.
+ */
+struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
+			struct vas_tx_win_attr *attr);
+
+/*
  * Close the send or receive window identified by @win. For receive windows
  * return -EAGAIN if there are active send windows attached to this receive
  * window.