Re: [loongson-PATCH-v1 23/27] Alsa memory maps fixup on mips systems

[David Daney <ddaney@caviumnetworks.com>]

wuzhangjin@gmail.com wrote:
[...]
> @@ -3099,7 +3099,11 @@ static int snd_pcm_mmap_data_fault(struct vm_area_struct *area,
>  			return VM_FAULT_SIGBUS;
>  	} else {
>  		vaddr = runtime->dma_area + offset;
> +#if defined(__mips__) && defined(CONFIG_DMA_NONCOHERENT)
> +		page = virt_to_page(CAC_ADDR(vaddr));
> +#else
>  		page = virt_to_page(vaddr);
> +#endif

That is a bit ugly.  It would be better to either  wrap the fix up in 
mips specific code so there don't have to be #ifdef __mips__ through out 
the generic driver code, or fix the driver in some other way if it is 
making x86 specific assumptions that don't hold in the general case.

The same applies for the remaining #ifdef __mips__ in the patch.




>  	}
>  	get_page(page);
>  	vmf->page = page;
> @@ -3214,6 +3218,11 @@ static int snd_pcm_mmap(struct file *file, struct vm_area_struct *area)
>  	if (PCM_RUNTIME_CHECK(substream))
>  		return -ENXIO;
>  
> +#if defined(__mips__) && defined(CONFIG_DMA_NONCOHERENT)
> +	/* all mmap using uncached mode */
> +	area->vm_page_prot = pgprot_noncached(area->vm_page_prot);
> +	area->vm_flags |= (VM_RESERVED | VM_IO);
> +#endif
>  	offset = area->vm_pgoff << PAGE_SHIFT;
>  	switch (offset) {
>  	case SNDRV_PCM_MMAP_OFFSET_STATUS:
> diff --git a/sound/core/sgbuf.c b/sound/core/sgbuf.c
> index 4e7ec2b..c0fcf0d 100644
> --- a/sound/core/sgbuf.c
> +++ b/sound/core/sgbuf.c
> @@ -114,7 +114,11 @@ void *snd_malloc_sgbuf_pages(struct device *device,
>  			if (!i)
>  				table->addr |= chunk; /* mark head */
>  			table++;
> +#if defined(__mips__) && defined(CONFIG_DMA_NONCOHERENT)
> +			*pgtable++ = virt_to_page(CAC_ADDR(tmpb.area));
> +#else
>  			*pgtable++ = virt_to_page(tmpb.area);
> +#endif
>  			tmpb.area += PAGE_SIZE;
>  			tmpb.addr += PAGE_SIZE;
>  		}
> @@ -125,7 +129,12 @@ void *snd_malloc_sgbuf_pages(struct device *device,
>  	}
>  
>  	sgbuf->size = size;
> +#if defined(__mips__) && defined(CONFIG_DMA_NONCOHERENT)
> +	dmab->area = vmap(sgbuf->page_table, sgbuf->pages, \
> +			VM_MAP | VM_IO, pgprot_noncached(PAGE_KERNEL));
> +#else
>  	dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, PAGE_KERNEL);
> +#endif
>  	if (! dmab->area)
>  		goto _failed;
>  	if (res_size)
> diff --git a/sound/pci/Kconfig b/sound/pci/Kconfig
> index 82b9bdd..4ccfae0 100644
> --- a/sound/pci/Kconfig
> +++ b/sound/pci/Kconfig
> @@ -259,7 +259,6 @@ config SND_CS5530
>  
>  config SND_CS5535AUDIO
>  	tristate "CS5535/CS5536 Audio"
> -	depends on X86 && !X86_64
>  	select SND_PCM
>  	select SND_AC97_CODEC
>  	help