dmaengine: ti-dma-crossbar: dra7: Use bitops instead of idr
The use of idr was nice, but it was a bit heavy and we did not need the
features it provides. Using simple bitmap to track allocated DMA channels
is adequate here and it will be easier to add support for reserving
channels later on.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/ti-dma-crossbar.c b/drivers/dma/ti-dma-crossbar.c
index fccf65f..7b1e3ea 100644
--- a/drivers/dma/ti-dma-crossbar.c
+++ b/drivers/dma/ti-dma-crossbar.c
@@ -12,7 +12,6 @@
#include <linux/init.h>
#include <linux/list.h>
#include <linux/io.h>
-#include <linux/idr.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
@@ -198,7 +197,8 @@
void __iomem *iomem;
struct dma_router dmarouter;
- struct idr map_idr;
+ struct mutex mutex;
+ unsigned long *dma_inuse;
u16 safe_val; /* Value to rest the crossbar lines */
u32 xbar_requests; /* number of DMA requests connected to XBAR */
@@ -225,7 +225,9 @@
map->xbar_in, map->xbar_out);
ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
- idr_remove(&xbar->map_idr, map->xbar_out);
+ mutex_lock(&xbar->mutex);
+ clear_bit(map->xbar_out, xbar->dma_inuse);
+ mutex_unlock(&xbar->mutex);
kfree(map);
}
@@ -255,8 +257,17 @@
return ERR_PTR(-ENOMEM);
}
- map->xbar_out = idr_alloc(&xbar->map_idr, NULL, 0, xbar->dma_requests,
- GFP_KERNEL);
+ mutex_lock(&xbar->mutex);
+ map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
+ xbar->dma_requests);
+ mutex_unlock(&xbar->mutex);
+ if (map->xbar_out == xbar->dma_requests) {
+ dev_err(&pdev->dev, "Run out of free DMA requests\n");
+ kfree(map);
+ return ERR_PTR(-ENOMEM);
+ }
+ set_bit(map->xbar_out, xbar->dma_inuse);
+
map->xbar_in = (u16)dma_spec->args[0];
dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
@@ -303,8 +314,6 @@
if (!xbar)
return -ENOMEM;
- idr_init(&xbar->map_idr);
-
dma_node = of_parse_phandle(node, "dma-masters", 0);
if (!dma_node) {
dev_err(&pdev->dev, "Can't get DMA master node\n");
@@ -326,6 +335,12 @@
}
of_node_put(dma_node);
+ xbar->dma_inuse = devm_kcalloc(&pdev->dev,
+ BITS_TO_LONGS(xbar->dma_requests),
+ sizeof(unsigned long), GFP_KERNEL);
+ if (!xbar->dma_inuse)
+ return -ENOMEM;
+
if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
dev_info(&pdev->dev,
"Missing XBAR input information, using %u.\n",
@@ -347,6 +362,7 @@
xbar->dmarouter.route_free = ti_dra7_xbar_free;
xbar->dma_offset = (u32)match->data;
+ mutex_init(&xbar->mutex);
platform_set_drvdata(pdev, xbar);
/* Reset the crossbar */