[PATCH] fsldma: Support 40 bit DMA addresses where capable
Ben Collins
bcollins at kernel.org
Tue Apr 22 12:49:49 AEST 2025
On 64-bit QorIQ platforms like T4240, the CPU supports 40-bit addressing
and memory configurations > 64GiB. The fsldma driver is limiting itself
to only 64GiB in all Elo configurations.
Setup fsldma driver to make use of the full 40-bit addressing space,
specifically on the e5500 and e6500 CPUs.
Signed-off-by: Ben Collins <bcollins at kernel.org>
Cc: Zhang Wei <zw at zh-kernel.org>
Cc: Vinod Koul <vkoul at kernel.org>
Cc: linuxppc-dev at lists.ozlabs.org
Cc: dmaengine at vger.kernel.org
Cc: linux-kernel at vger.kernel.org
---
drivers/dma/fsldma.c | 2 +-
drivers/dma/fsldma.h | 7 +++++++
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index b5e7d18b97669..8c01963ad47d8 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -1254,7 +1254,7 @@ static int fsldma_of_probe(struct platform_device *op)
fdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
fdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
- dma_set_mask(&(op->dev), DMA_BIT_MASK(36));
+ dma_set_mask(&(op->dev), DMA_BIT_MASK(ELO_MAX_PHYS_BITS));
platform_set_drvdata(op, fdev);
diff --git a/drivers/dma/fsldma.h b/drivers/dma/fsldma.h
index 308bed0a560ac..1e7bd37208412 100644
--- a/drivers/dma/fsldma.h
+++ b/drivers/dma/fsldma.h
@@ -13,6 +13,13 @@
#include <linux/dmapool.h>
#include <linux/dmaengine.h>
+/* Physical addressing capability */
+#if defined(CONFIG_E6500_CPU) || defined(CONFIG_E5500_CPU)
+#define ELO_MAX_PHYS_BITS 40
+#else
+#define ELO_MAX_PHYS_BITS 36
+#endif
+
/* Define data structures needed by Freescale
* MPC8540 and MPC8349 DMA controller.
*/
--
2.49.0
--
Ben Collins
https://libjwt.io
https://github.com/benmcollins
--
3EC9 7598 1672 961A 1139 173A 5D5A 57C7 242B 22CF
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