Re: [PATCH] dm: Respect dma-ranges size

Markus Schneider-Pargmann
2026-03-31T07:00:39Z

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On Mon Mar 30, 2026 at 7:24 PM CEST, Marek Vasut wrote:
> On 3/30/26 3:34 PM, Markus Schneider-Pargmann wrote:
>
> Hello Markus,
>
>> On Mon Mar 16, 2026 at 12:57 AM CET, Marek Vasut wrote:
>>> 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.
>>>
>>
>> Should this have a Fixes tag?
>>
>>> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
>>
>> Not a big expert, but this looks good to me:
>>
>> Reviewed-by: Markus Schneider-Pargmann <msp@baylibre.com>
>
> This was broken long enough, so this should go into next so it would get
> sufficient testing before the next release.
>
> [...]
>
>>> +++ 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
>
> [...]
>
>>> +++ 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)
>>
>> This is not related to the code changes right?
>
> It is, see the matching hunk above and below why this is guarded by DM_DMA .

Ah thanks, yes, the macro had the check for DM_DMA, I missed that.

Best
Markus

>
>>> #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;
> [...]

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