Hi Michael,
> How does access to descriptors work in this setup?
When the ring is setup by remoteproc the descriptors are
also allocated using dma_alloc_coherent().
>> -static void free_buf(struct port_buffer *buf)
>> +/* Allcoate data buffer from DMA memory if requested */
>
> typo
Thanks.
>> +static inline void *
>> +alloc_databuf(struct virtio_device *vdev, size_t size, dma_addr_t *dma_handle,
>> + gfp_t flag)
>> {
>> - kfree(buf->buf);
>> +#ifdef CONFIG_HAS_DMA
>> + if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_DMA_MEM)) {
>> + struct device *dev = &vdev->dev;
>> + /*
>> + * Allocate DMA memory from ancestors. Finding the ancestor
>> + * is a bit quirky when DMA_MEMORY_INCLUDES_CHILDREN is not
>> + * implemented.
>> + */
>> + dev = dev->parent ? dev->parent : dev;
>> + dev = dev->parent ? dev->parent : dev;
>> + return dma_alloc_coherent(dev, size, dma_handle, flag);
>> + }
>> +#endif
>
> Are these ifdefs really needed? If DMA_MEM is set,
> can't we use dma_alloc_coherent
> unconditionally?
If an architecture do not support DMA you will get
a link error: "unknown symbol" for dma_alloc_coherent.
Regards,
Sjur
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