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

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

On 10/28/19 10:55 AM, Alexandre Torgue wrote:
> Hi Vlad,
> 
> On 10/24/19 5:27 PM, Vladimir Murzin wrote:
>> 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.
>>
> 
> I tested your patch on stm32h7431-eval board (cortex-M7). No issues reported. I use reserved dma memory pool for dma access ( Dcache disabled) and dma_alloc_coherent is ok. Note there is no "dma-ranges" for this board.
> 
> I also tested it on stm32f469-disco (cortex-M4) which uses dma-ranges. No issues reported too. Note there is no data cache at all in this case.

Happy to hear it doesn't introduce regression for NOMM - thanks got giving it a try!

@Daniele, it'd be handy to know if that fix issue for you...

Cheers
Vladimir

> 
> regards
> 
> Alex
> 
>> 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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