Re: [BUG] dma-ranges, reserved memory regions, dma_alloc_coherent: possible bug?

[Vladimir Murzin <vladimir.murzin@arm.com>]

Hi Alex,

On 10/24/19 4:20 PM, Alexandre Torgue wrote:
> Hi Vlad,
> 
> On 10/24/19 2:43 PM, Vladimir Murzin wrote:
>> On 10/17/19 10:46 AM, Vladimir Murzin wrote:
>>> I'm wondering if I've missed something with diff bellow (it was a long time ago when I touched DMA)?
>>
>> Any comments on that? I can only build test it, so lack of testing stopping me from sending it as a
>> proper patch :(
> 
> I can make some tests tomorrow. Which particular setup I need to test: cortex M7 + cache + dma + xip ? Let me know.

I assume xip implies dma-ranges in dt, then yes it looks like what we need.

Great thanks!

Vladimir

> 
> regards
> alex
> 
>>
>>>
>>> diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c
>>> index db92478..287ef89 100644
>>> --- a/arch/arm/mm/dma-mapping-nommu.c
>>> +++ b/arch/arm/mm/dma-mapping-nommu.c
>>> @@ -35,7 +35,7 @@ static void *arm_nommu_dma_alloc(struct device *dev, size_t size,
>>>                    unsigned long attrs)
>>>     {
>>> -    void *ret = dma_alloc_from_global_coherent(size, dma_handle);
>>> +    void *ret = dma_alloc_from_global_coherent(dev, size, dma_handle);
>>>         /*
>>>        * dma_alloc_from_global_coherent() may fail because:
>>> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
>>> index 4a1c4fc..10918c5 100644
>>> --- a/include/linux/dma-mapping.h
>>> +++ b/include/linux/dma-mapping.h
>>> @@ -162,7 +162,7 @@ int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr);
>>>   int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,
>>>                   void *cpu_addr, size_t size, int *ret);
>>>   -void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle);
>>> +void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, dma_addr_t *dma_handle);
>>>   int dma_release_from_global_coherent(int order, void *vaddr);
>>>   int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr,
>>>                     size_t size, int *ret);
>>> @@ -172,7 +172,7 @@ int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr,
>>>   #define dma_release_from_dev_coherent(dev, order, vaddr) (0)
>>>   #define dma_mmap_from_dev_coherent(dev, vma, vaddr, order, ret) (0)
>>>   -static inline void *dma_alloc_from_global_coherent(ssize_t size,
>>> +static inline void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size,
>>>                              dma_addr_t *dma_handle)
>>>   {
>>>       return NULL;
>>> diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
>>> index 545e386..551b0eb 100644
>>> --- a/kernel/dma/coherent.c
>>> +++ b/kernel/dma/coherent.c
>>> @@ -123,8 +123,9 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
>>>       return ret;
>>>   }
>>>   -static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem,
>>> -        ssize_t size, dma_addr_t *dma_handle)
>>> +static void *__dma_alloc_from_coherent(struct device *dev,
>>> +                       struct dma_coherent_mem *mem,
>>> +                       ssize_t size, dma_addr_t *dma_handle)
>>>   {
>>>       int order = get_order(size);
>>>       unsigned long flags;
>>> @@ -143,7 +144,7 @@ static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem,
>>>       /*
>>>        * Memory was found in the coherent area.
>>>        */
>>> -    *dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
>>> +    *dma_handle = dma_get_device_base(dev, mem) + (pageno << PAGE_SHIFT);
>>>       ret = mem->virt_base + (pageno << PAGE_SHIFT);
>>>       spin_unlock_irqrestore(&mem->spinlock, flags);
>>>       memset(ret, 0, size);
>>> @@ -175,17 +176,18 @@ int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
>>>       if (!mem)
>>>           return 0;
>>>   -    *ret = __dma_alloc_from_coherent(mem, size, dma_handle);
>>> +    *ret = __dma_alloc_from_coherent(dev, mem, size, dma_handle);
>>>       return 1;
>>>   }
>>>   -void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle)
>>> +void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size,
>>> +                     dma_addr_t *dma_handle)
>>>   {
>>>       if (!dma_coherent_default_memory)
>>>           return NULL;
>>>   -    return __dma_alloc_from_coherent(dma_coherent_default_memory, size,
>>> -            dma_handle);
>>> +    return __dma_alloc_from_coherent(dev, dma_coherent_default_memory, size,
>>> +                     dma_handle);
>>>   }
>>>     static int __dma_release_from_coherent(struct dma_coherent_mem *mem,
>>
>>
>> Thanks
>> Vladimir
>>

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