[PATCH v4 10/10] dmaengine: Drop legacy bus width fields from dma_slave_caps

[Nuno Sá]

All users of dma_get_slave_caps() that inspect bus width capabilities now
use the bitmap helpers.

Hence, remove the legacy u32 src_addr_widths and dst_addr_widths fields
from struct dma_slave_caps and stop copying the dma_device masks into
them.

Note the legacy u32 src_addr_widths and dst_addr_widths fields in struct
dma_device are kept for now as every DMA controller driver setting them
still has to be converted to the new helpers. dma_get_slave_caps() keeps
folding those masks into the bitmaps it returns so unconverted producers
continue to work during the transition.

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
---
 drivers/dma/dmaengine.c   | 31 +------------------------------
 include/linux/dmaengine.h | 13 ++-----------
 2 files changed, 3 insertions(+), 41 deletions(-)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 8e68921cf01d..945079c677b1 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -596,8 +596,6 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
 
 	dma_bus_width_copy(caps->src_bus_widths, device->src_bus_widths);
 	dma_bus_width_copy(caps->dst_bus_widths, device->dst_bus_widths);
-	caps->src_addr_widths = device->src_addr_widths;
-	caps->dst_addr_widths = device->dst_addr_widths;
 
 	caps->directions = device->directions;
 	caps->min_burst = device->min_burst;
@@ -616,31 +614,9 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
 	 * callback to override the generic capabilities with
 	 * channel-specific ones.
 	 */
-	if (device->device_caps) {
+	if (device->device_caps)
 		device->device_caps(chan, caps);
 
-		/*
-		 * A driver already converted to the bus width interface
-		 * adjusts the masks, so derive the legacy capabilities from
-		 * them for the consumers not converted yet. Drivers not
-		 * converted adjust the legacy capabilities directly, in which
-		 * case there is nothing to do.
-		 *
-		 * Goes away with the legacy dma_slave_caps fields.
-		 */
-		if (!bitmap_equal(caps->src_bus_widths.bits,
-				  device->src_bus_widths.bits,
-				  DMA_SLAVE_BUSWIDTH_MAX))
-			caps->src_addr_widths = bitmap_read(caps->src_bus_widths.bits,
-							    0, 32);
-
-		if (!bitmap_equal(caps->dst_bus_widths.bits,
-				  device->dst_bus_widths.bits,
-				  DMA_SLAVE_BUSWIDTH_MAX))
-			caps->dst_addr_widths = bitmap_read(caps->dst_bus_widths.bits,
-							    0, 32);
-	}
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(dma_get_slave_caps);
@@ -1208,14 +1184,9 @@ static void dma_device_fold_legacy_bus_widths(struct dma_device *device)
 {
 	if (bitmap_empty(device->src_bus_widths.bits, DMA_SLAVE_BUSWIDTH_MAX))
 		bitmap_from_arr32(device->src_bus_widths.bits, &device->src_addr_widths, 32);
-	/* consumers not converted yet still read the legacy caps */
-	else if (!device->src_addr_widths)
-		device->src_addr_widths = bitmap_read(device->src_bus_widths.bits, 0, 32);
 
 	if (bitmap_empty(device->dst_bus_widths.bits, DMA_SLAVE_BUSWIDTH_MAX))
 		bitmap_from_arr32(device->dst_bus_widths.bits, &device->dst_addr_widths, 32);
-	else if (!device->dst_addr_widths)
-		device->dst_addr_widths = bitmap_read(device->dst_bus_widths.bits, 0, 32);
 }
 
 /**
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 8236a1b274fb..657d3a1ee976 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -483,10 +483,7 @@ enum dma_residue_granularity {
 /**
  * struct dma_slave_caps - expose capabilities of a slave channel only
  * @src_bus_widths: mask of source bus widths the channel supports.
- * @src_addr_widths: legacy bit mask of source bus widths the channel supports.
  * @dst_bus_widths: mask of destination bus widths the channel supports.
- * @dst_addr_widths: legacy bit mask of destination bus widths the channel
- *	supports.
  * @directions: bit mask of slave directions the channel supports.
  *	Since the enum dma_transfer_direction is not defined as bit flag for
  *	each type, the dma controller should set BIT(<TYPE>) and same
@@ -505,14 +502,8 @@ enum dma_residue_granularity {
  * resubmitted multiple times
  */
 struct dma_slave_caps {
-	struct {
-		dma_buswidth_mask_t src_bus_widths;
-		u32 src_addr_widths;
-	};
-	struct {
-		dma_buswidth_mask_t dst_bus_widths;
-		u32 dst_addr_widths;
-	};
+	dma_buswidth_mask_t src_bus_widths;
+	dma_buswidth_mask_t dst_bus_widths;
 	u32 directions;
 	u32 min_burst;
 	u32 max_burst;

-- 
2.55.0