[RFC][PATCH 2/2] DSPBRIDGE: Distinguish between read or write buffers

[Omar Ramirez Luna <omar.ramirez@ti.com>]

This patch introduces the check to differentiate the buffers
coming to the dsp through bridgedriver. So far they can be
input (read) or output (write) or rw (which are treated the
same way as an output buffer), this distinctions are made from
dsp perspective.

Since this needs to be checked on map function, unused
bits (16, 15) of flags were used to check for this argument.

As 128 byte alignment limitation doesn't affect input buffers
only writable buffers are checked. Default value for read buffers
is set to be 1, this will enforce that users of bridge will fill
the flags with significant values otherwise (if enabled) check
will reject buffers not aligned to 128 bytes (even if they fall in
the input category).

Signed-off-by: Omar Ramirez Luna <omar.ramirez@ti.com>
---
 drivers/dsp/bridge/rmgr/proc.c |   16 ++++++++++++----
 1 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/dsp/bridge/rmgr/proc.c b/drivers/dsp/bridge/rmgr/proc.c
index 78a31ef..4fe20ed 100644
--- a/drivers/dsp/bridge/rmgr/proc.c
+++ b/drivers/dsp/bridge/rmgr/proc.c
@@ -71,6 +71,12 @@
 
 #define DSP_CACHE_LINE 128
 
+#define BUFMODE_MASK	(3 << 14)
+
+/* Buffer modes from DSP perspective */
+#define RBUF		0x1	/* Input buffer */
+#define WBUF		0x2	/* Output Buffer */
+
 extern char *iva_img;
 
 /*  ----------------------------------- Globals */
@@ -1297,11 +1303,13 @@ DSP_STATUS PROC_Map(DSP_HPROCESSOR hProcessor, void *pMpuAddr, u32 ulSize,
 		 pReqAddr, ulMapAttr, ppMapAddr);
 
 #ifdef CONFIG_BRIDGE_CACHE_LINE_CHECK
-	if (!IS_ALIGNED((u32)pMpuAddr, DSP_CACHE_LINE) ||
-	    !IS_ALIGNED(size, DSP_CACHE_LINE)) {
-		pr_err("%s: not aligned: 0x%x (%d)\n", __func__,
+	if ((ulMapAttr & BUFMODE_MASK) != RBUF) {
+		if (!IS_ALIGNED((u32)pMpuAddr, DSP_CACHE_LINE) ||
+		    !IS_ALIGNED(ulSize, DSP_CACHE_LINE)) {
+			pr_err("%s: not aligned: 0x%x (%d)\n", __func__,
 						(u32)pMpuAddr, ulSize);
-		return -EFAULT;
+			return -EFAULT;
+		}
 	}
 #endif
 
-- 
1.6.2.4