ARM: PL08x: use min() to calculate target_len

[mv-sheeva.git] / drivers / dma / amba-pl08x.c

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 986c12775b0b8c8127236f198a119f895764aa50..91dd6bfcc30f566ce65761da52f0c2aca58083d6 100644 (file)
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -521,9 +521,8 @@ static void pl08x_choose_master_bus(struct pl08x_bus_data *src_bus,
  * Fills in one LLI for a certain transfer descriptor
  * and advance the counter
  */
-static int pl08x_fill_lli_for_desc(struct pl08x_driver_data *pl08x,
-                           struct pl08x_txd *txd, int num_llis, int len,
-                           u32 cctl, u32 *remainder)
+static void pl08x_fill_lli_for_desc(struct pl08x_driver_data *pl08x,
+       struct pl08x_txd *txd, int num_llis, int len, u32 cctl, u32 *remainder)
 {
        struct pl08x_lli *llis_va = txd->llis_va;
        dma_addr_t llis_bus = txd->llis_bus;
@@ -545,24 +544,18 @@ static int pl08x_fill_lli_for_desc(struct pl08x_driver_data *pl08x,
        BUG_ON(*remainder < len);
 
        *remainder -= len;
-
-       return num_llis + 1;
 }
 
 /*
- * Return number of bytes to fill to boundary, or len
+ * Return number of bytes to fill to boundary, or len.
+ * This calculation works for any value of addr.
  */
 static inline size_t pl08x_pre_boundary(u32 addr, size_t len)
 {
-       u32 boundary;
-
-       boundary = ((addr >> PL08X_BOUNDARY_SHIFT) + 1)
-               << PL08X_BOUNDARY_SHIFT;
+       size_t boundary_len = PL08X_BOUNDARY_SIZE -
+                       (addr & (PL08X_BOUNDARY_SIZE - 1));
 
-       if (boundary < addr + len)
-               return boundary - addr;
-       else
-               return len;
+       return min(boundary_len, len);
 }
 
 /*
@@ -646,8 +639,7 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
                                 "less than a bus width (remain 0x%08x)\n",
                                 __func__, remainder);
                        cctl = pl08x_cctl_bits(cctl, 1, 1, 1);
-                       num_llis =
-                               pl08x_fill_lli_for_desc(pl08x, txd, num_llis, 1,
+                       pl08x_fill_lli_for_desc(pl08x, txd, num_llis++, 1,
                                        cctl, &remainder);
                        total_bytes++;
                }
@@ -662,8 +654,8 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
                                 "(remain 0x%08x)\n",
                                 __func__, remainder);
                        cctl = pl08x_cctl_bits(cctl, 1, 1, 1);
-                       num_llis = pl08x_fill_lli_for_desc
-                               (pl08x, txd, num_llis, 1, cctl, &remainder);
+                       pl08x_fill_lli_for_desc(pl08x, txd, num_llis++, 1,
+                                       cctl, &remainder);
                        total_bytes++;
                }
 
@@ -690,9 +682,7 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
                         * If enough left try to send max possible,
                         * otherwise try to send the remainder
                         */
-                       target_len = remainder;
-                       if (remainder > max_bytes_per_lli)
-                               target_len = max_bytes_per_lli;
+                       target_len = min(remainder, max_bytes_per_lli);
 
                        /*
                         * Set bus lengths for incrementing buses
@@ -787,9 +777,8 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
                                dev_vdbg(&pl08x->adev->dev,
                                        "%s fill lli with single lli chunk of size 0x%08zx (remainder 0x%08zx)\n",
                                        __func__, lli_len, remainder);
-                               num_llis = pl08x_fill_lli_for_desc(pl08x, txd,
-                                               num_llis, lli_len, cctl,
-                                               &remainder);
+                               pl08x_fill_lli_for_desc(pl08x, txd, num_llis++,
+                                               lli_len, cctl, &remainder);
                                total_bytes += lli_len;
                        }
 
@@ -806,10 +795,9 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
                                        dev_vdbg(&pl08x->adev->dev,
                                                "%s align with boundary, single byte (remain 0x%08zx)\n",
                                                __func__, remainder);
-                                       num_llis =
-                                               pl08x_fill_lli_for_desc(pl08x,
-                                                       txd, num_llis, 1,
-                                                       cctl, &remainder);
+                                       pl08x_fill_lli_for_desc(pl08x, txd,
+                                                       num_llis++, 1, cctl,
+                                                       &remainder);
                                        total_bytes++;
                                }
                        }
@@ -823,8 +811,8 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
                        dev_vdbg(&pl08x->adev->dev,
                                "%s align with boundary, single odd byte (remain %zu)\n",
                                __func__, remainder);
-                       num_llis = pl08x_fill_lli_for_desc(pl08x, txd, num_llis,
-                                       1, cctl, &remainder);
+                       pl08x_fill_lli_for_desc(pl08x, txd, num_llis++, 1,
+                                       cctl, &remainder);
                        total_bytes++;
                }
        }
@@ -1540,32 +1528,29 @@ static void pl08x_tasklet(unsigned long data)
 {
        struct pl08x_dma_chan *plchan = (struct pl08x_dma_chan *) data;
        struct pl08x_driver_data *pl08x = plchan->host;
+       struct pl08x_txd *txd;
+       dma_async_tx_callback callback = NULL;
+       void *callback_param = NULL;
        unsigned long flags;
 
        spin_lock_irqsave(&plchan->lock, flags);
 
-       if (plchan->at) {
-               dma_async_tx_callback callback =
-                       plchan->at->tx.callback;
-               void *callback_param =
-                       plchan->at->tx.callback_param;
+       txd = plchan->at;
+       plchan->at = NULL;
+
+       if (txd) {
+               callback = txd->tx.callback;
+               callback_param = txd->tx.callback_param;
 
                /*
                 * Update last completed
                 */
-               plchan->lc = plchan->at->tx.cookie;
-
-               /*
-                * Callback to signal completion
-                */
-               if (callback)
-                       callback(callback_param);
+               plchan->lc = txd->tx.cookie;
 
                /*
                 * Free the descriptor
                 */
-               pl08x_free_txd(pl08x, plchan->at);
-               plchan->at = NULL;
+               pl08x_free_txd(pl08x, txd);
        }
        /*
         * If a new descriptor is queued, set it up
@@ -1616,6 +1601,10 @@ static void pl08x_tasklet(unsigned long data)
        }
 
        spin_unlock_irqrestore(&plchan->lock, flags);
+
+       /* Callback to signal completion */
+       if (callback)
+               callback(callback_param);
 }
 
 static irqreturn_t pl08x_irq(int irq, void *dev)