[PATCH] dm: Respect dma-ranges size

Marek Vasut
2026-03-15T23:58:07Z

Rework dev_phys_to_bus() and dev_bus_to_phys() to respect the size
of the area specified in dma-ranges DT property. The area outside
of ranges is remapped 1:1, while the area in the ranges is remapped
according to the description in the dma-ranges property.

Adjust the test to test the area within the remapped range, not area
outside the remapped range, which was incorrect.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: "Markus Schneider-Pargmann (TI.com)" <msp@baylibre.com>
Cc: Andrew Goodbody <andrew.goodbody@linaro.org>
Cc: Casey Connolly <casey.connolly@linaro.org>
Cc: Mattijs Korpershoek <mkorpershoek@kernel.org>
Cc: Michal Simek <michal.simek@amd.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: u-boot@lists.denx.de
---
drivers/core/device.c | 6 +++++-
include/dm/device.h | 17 ++++++-----------
include/phys2bus.h | 12 +++++++++---
test/dm/core.c | 6 +++---
test/dm/phys2bus.c | 4 ++--
5 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/drivers/core/device.c b/drivers/core/device.c
index 779f371b9d5..d365204ba11 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -473,7 +473,11 @@ static int device_get_dma_constraints(struct udevice *dev)
return ret;
}

- dev_set_dma_offset(dev, cpu - bus);
+#if CONFIG_IS_ENABLED(DM_DMA)
+ dev->dma_cpu = cpu;
+ dev->dma_bus = bus;
+ dev->dma_size = size;
+#endif

return 0;
}
diff --git a/include/dm/device.h b/include/dm/device.h
index 678cd83c271..7bcf6df2892 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -166,8 +166,9 @@ enum {
* When CONFIG_DEVRES is enabled, devm_kmalloc() and friends will
* add to this list. Memory so-allocated will be freed
* automatically when the device is removed / unbound
- * @dma_offset: Offset between the physical address space (CPU's) and the
- * device's bus address space
+ * @dma_cpu: DMA physical address space (CPU's)
+ * @dma_bus: DMA device's bus address space
+ * @dma_size: DMA window size
* @iommu: IOMMU device associated with this device
*/
struct udevice {
@@ -196,7 +197,9 @@ struct udevice {
struct list_head devres_head;
#endif
#if CONFIG_IS_ENABLED(DM_DMA)
- ulong dma_offset;
+ phys_addr_t dma_cpu;
+ dma_addr_t dma_bus;
+ u64 dma_size;
#endif
#if CONFIG_IS_ENABLED(IOMMU)
struct udevice *iommu;
@@ -272,14 +275,6 @@ static inline __attribute_const__ ofnode dev_ofnode(const struct udevice *dev)
/* Returns non-zero if the device is active (probed and not removed) */
#define device_active(dev) (dev_get_flags(dev) & DM_FLAG_ACTIVATED)

-#if CONFIG_IS_ENABLED(DM_DMA)
-#define dev_set_dma_offset(_dev, _offset) _dev->dma_offset = _offset
-#define dev_get_dma_offset(_dev) _dev->dma_offset
-#else
-#define dev_set_dma_offset(_dev, _offset)
-#define dev_get_dma_offset(_dev) 0
-#endif
-
static inline __attribute_const__ int dev_of_offset(const struct udevice *dev)
{
#if CONFIG_IS_ENABLED(OF_REAL)
diff --git a/include/phys2bus.h b/include/phys2bus.h
index 866b8b51a8c..80fa88adae1 100644
--- a/include/phys2bus.h
+++ b/include/phys2bus.h
@@ -21,17 +21,23 @@ static inline unsigned long bus_to_phys(unsigned long bus)
}
#endif

-#if CONFIG_IS_ENABLED(DM)
+#if CONFIG_IS_ENABLED(DM_DMA)
#include <dm/device.h>

static inline dma_addr_t dev_phys_to_bus(struct udevice *dev, phys_addr_t phys)
{
- return phys - dev_get_dma_offset(dev);
+ /* If the PA is in the remap range, apply remap. */
+ if (phys >= dev->dma_cpu && phys < dev->dma_cpu + dev->dma_size)
+ phys -= dev->dma_cpu - dev->dma_bus;
+ return phys;
}

static inline phys_addr_t dev_bus_to_phys(struct udevice *dev, dma_addr_t bus)
{
- return bus + dev_get_dma_offset(dev);
+ /* If the DA is in the remap range, apply remap. */
+ if (bus >= dev->dma_bus && bus < dev->dma_bus + dev->dma_size)
+ bus += dev->dma_cpu - dev->dma_bus;
+ return bus;
}
#else
#define dev_phys_to_bus(_, _addr) _addr
diff --git a/test/dm/core.c b/test/dm/core.c
index 78ee14af228..bb9f526b064 100644
--- a/test/dm/core.c
+++ b/test/dm/core.c
@@ -1248,13 +1248,13 @@ static int dm_test_dma_offset(struct unit_test_state *uts)
node = ofnode_path("/mmio-bus@0");
ut_assert(ofnode_valid(node));
ut_assertok(uclass_get_device_by_ofnode(UCLASS_TEST_BUS, node, &dev));
- ut_asserteq_64(0, dev->dma_offset);
+ ut_asserteq_64(0, dev->dma_cpu - dev->dma_bus);

/* Device behind a bus with dma-ranges */
node = ofnode_path("/mmio-bus@0/subnode@0");
ut_assert(ofnode_valid(node));
ut_assertok(uclass_get_device_by_ofnode(UCLASS_TEST_FDT, node, &dev));
- ut_asserteq_64(-0x10000000ULL, dev->dma_offset);
+ ut_asserteq_64(-0x10000000ULL, dev->dma_cpu - dev->dma_bus);

/* This one has no dma-ranges */
node = ofnode_path("/mmio-bus@1");
@@ -1263,7 +1263,7 @@ static int dm_test_dma_offset(struct unit_test_state *uts)
node = ofnode_path("/mmio-bus@1/subnode@0");
ut_assert(ofnode_valid(node));
ut_assertok(uclass_get_device_by_ofnode(UCLASS_TEST_FDT, node, &dev));
- ut_asserteq_64(0, dev->dma_offset);
+ ut_asserteq_64(0, dev->dma_cpu - dev->dma_bus);

return 0;
}
diff --git a/test/dm/phys2bus.c b/test/dm/phys2bus.c
index 0f30c7e37fd..67f33904943 100644
--- a/test/dm/phys2bus.c
+++ b/test/dm/phys2bus.c
@@ -28,8 +28,8 @@ static int dm_test_phys_to_bus(struct unit_test_state *uts)
node = ofnode_path("/mmio-bus@0/subnode@0");
ut_assert(ofnode_valid(node));
ut_assertok(uclass_get_device_by_ofnode(UCLASS_TEST_FDT, node, &dev));
- ut_asserteq_addr((void*)0x100fffffULL, (void*)dev_phys_to_bus(dev, 0xfffff));
- ut_asserteq_addr((void*)0xfffffULL, (void*)(ulong)dev_bus_to_phys(dev, 0x100fffff));
+ ut_asserteq_addr((void*)0x1003ffffULL, (void*)dev_phys_to_bus(dev, 0x3ffff));
+ ut_asserteq_addr((void*)0x3ffffULL, (void*)(ulong)dev_bus_to_phys(dev, 0x1003ffff));

return 0;
}
--
2.51.0