dmaengine: pl330: Simplify marking a request as unused

Instead of storing a special instruction in the command buffer to mark a request
as currently unused just set the descriptor field to NULL.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 13 insertions, 38 deletions

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index b31c6c380158..105e33e3bb33 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -245,9 +245,6 @@ enum pl330_byteswap {
  */
 #define MCODE_BUFF_PER_REQ      256
 
-/* If the _pl330_req is available to the client */
-#define IS_FREE(req)    (*((u8 *)((req)->mc_cpu)) == CMD_DMAEND)
-
 /* Use this _only_ to wait on transient states */
 #define UNTIL(t, s)     while (!(_state(t) & (s))) cpu_relax();
 
@@ -529,14 +526,12 @@ struct _xfer_spec {
 
 static inline bool _queue_empty(struct pl330_thread *thrd)
 {
-        return (IS_FREE(&thrd->req[0]) && IS_FREE(&thrd->req[1]))
-                ? true : false;
+        return thrd->req[0].desc == NULL && thrd->req[1].desc == NULL;
 }
 
 static inline bool _queue_full(struct pl330_thread *thrd)
 {
-        return (IS_FREE(&thrd->req[0]) || IS_FREE(&thrd->req[1]))
-                ? false : true;
+        return thrd->req[0].desc != NULL && thrd->req[1].desc != NULL;
 }
 
 static inline bool is_manager(struct pl330_thread *thrd)
@@ -948,21 +943,6 @@ static inline void _execute_DBGINSN(struct pl330_thread *thrd,
         writel(0, regs + DBGCMD);
 }
 
-/*
- * Mark a _pl330_req as free.
- * We do it by writing DMAEND as the first instruction
- * because no valid request is going to have DMAEND as
- * its first instruction to execute.
- */
-static void mark_free(struct pl330_thread *thrd, int idx)
-{
-        struct _pl330_req *req = &thrd->req[idx];
-
-        _emit_END(0, req->mc_cpu);
-
-        thrd->req_running = -1;
-}
-
 static inline u32 _state(struct pl330_thread *thrd)
 {
         void __iomem *regs = thrd->dmac->base;
@@ -1059,18 +1039,18 @@ static bool _trigger(struct pl330_thread *thrd)
                 return true;
 
         idx = 1 - thrd->lstenq;
-        if (!IS_FREE(&thrd->req[idx]))
+        if (thrd->req[idx].desc != NULL) {
                 req = &thrd->req[idx];
-        else {
+        } else {
                 idx = thrd->lstenq;
-                if (!IS_FREE(&thrd->req[idx]))
+                if (thrd->req[idx].desc != NULL)
                         req = &thrd->req[idx];
                 else
                         req = NULL;
         }
 
         /* Return if no request */
-        if (!req || !req->desc)
+        if (!req)
                 return true;
 
         desc = req->desc;
@@ -1438,7 +1418,7 @@ static int pl330_submit_req(struct pl330_thread *thrd,
 
         ccr = _prepare_ccr(&desc->rqcfg);
 
-        idx = IS_FREE(&thrd->req[0]) ? 0 : 1;
+        idx = thrd->req[0].desc == NULL ? 0 : 1;
 
         xs.ccr = ccr;
         xs.desc = desc;
@@ -1532,8 +1512,7 @@ static void pl330_dotask(unsigned long data)
 
                         thrd->req[0].desc = NULL;
                         thrd->req[1].desc = NULL;
-                        mark_free(thrd, 0);
-                        mark_free(thrd, 1);
+                        thrd->req_running = -1;
 
                         /* Clear the reset flag */
                         pl330->dmac_tbd.reset_chan &= ~(1 << i);
@@ -1615,8 +1594,6 @@ static int pl330_update(struct pl330_dmac *pl330)
                         descdone = thrd->req[active].desc;
                         thrd->req[active].desc = NULL;
 
-                        mark_free(thrd, active);
-
                         /* Get going again ASAP */
                         _start(thrd);
 
@@ -1667,8 +1644,7 @@ static int pl330_chan_ctrl(struct pl330_thread *thrd, enum pl330_chan_op op)
 
                 thrd->req[0].desc = NULL;
                 thrd->req[1].desc = NULL;
-                mark_free(thrd, 0);
-                mark_free(thrd, 1);
+                thrd->req_running = -1;
                 break;
 
         case PL330_OP_ABORT:
@@ -1680,7 +1656,7 @@ static int pl330_chan_ctrl(struct pl330_thread *thrd, enum pl330_chan_op op)
                         break;
 
                 thrd->req[active].desc = NULL;
-                mark_free(thrd, active);
+                thrd->req_running = -1;
 
                 /* Start the next */
         case PL330_OP_START:
@@ -1741,9 +1717,8 @@ static struct pl330_thread *pl330_request_channel(struct pl330_dmac *pl330)
                                 thrd->free = false;
                                 thrd->lstenq = 1;
                                 thrd->req[0].desc = NULL;
-                                mark_free(thrd, 0);
                                 thrd->req[1].desc = NULL;
-                                mark_free(thrd, 1);
+                                thrd->req_running = -1;
                                 break;
                         }
                 }
@@ -1841,14 +1816,14 @@ static inline void _reset_thread(struct pl330_thread *thrd)
         thrd->req[0].mc_bus = pl330->mcode_bus
                                 + (thrd->id * pl330->mcbufsz);
         thrd->req[0].desc = NULL;
-        mark_free(thrd, 0);
 
         thrd->req[1].mc_cpu = thrd->req[0].mc_cpu
                                 + pl330->mcbufsz / 2;
         thrd->req[1].mc_bus = thrd->req[0].mc_bus
                                 + pl330->mcbufsz / 2;
         thrd->req[1].desc = NULL;
-        mark_free(thrd, 1);
+
+        thrd->req_running = -1;
 }
 
 static int dmac_alloc_threads(struct pl330_dmac *pl330)