[PATCH 01/10] powerpc/vas: Define vas_win_paste_addr()

[Haren Myneni <haren@linux.ibm.com>]

Define an interface that the NX drivers can use to find the physical
paste address of a send window. This interface is expected to be used
with the mmap() operation of the NX driver's device. i.e the user space
process can use driver's mmap() operation to map the send window's paste
address into their address space and then use copy and paste instructions
to submit the CRBs to the NX engine.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Haren Myneni <haren@us.ibm.com>
---
 arch/powerpc/include/asm/vas.h              |  5 +++++
 arch/powerpc/platforms/powernv/vas-window.c | 10 ++++++++++
 2 files changed, 15 insertions(+)

diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index f93e6b0..6d9e692 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -163,4 +163,9 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
  */
 int vas_paste_crb(struct vas_window *win, int offset, bool re);
 
+/*
+ * Return the power bus paste address associated with @win so the caller
+ * can map that address into their address space.
+ */
+extern u64 vas_win_paste_addr(struct vas_window *win);
 #endif /* __ASM_POWERPC_VAS_H */
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 5322d1c..b51eac5 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -42,6 +42,16 @@ static void compute_paste_address(struct vas_window *window, u64 *addr, int *len
 	pr_debug("Txwin #%d: Paste addr 0x%llx\n", winid, *addr);
 }
 
+u64 vas_win_paste_addr(struct vas_window *win)
+{
+	u64 addr;
+
+	compute_paste_address(win, &addr, NULL);
+
+	return addr;
+}
+EXPORT_SYMBOL(vas_win_paste_addr);
+
 static inline void get_hvwc_mmio_bar(struct vas_window *window,
 			u64 *start, int *len)
 {
-- 
1.8.3.1