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

[Alexandre Torgue <alexandre.torgue@st.com>]

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.

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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