On Tue, 2018-09-25 at 10:22 -0600, Logan Gunthorpe wrote:
> +int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
> + enum dma_data_direction dir)
> +{
> + struct dev_pagemap *pgmap;
> + struct scatterlist *s;
> + phys_addr_t paddr;
> + int i;
> +
> + /*
> + * p2pdma mappings are not compatible with devices that use
> + * dma_virt_ops. If the upper layers do the right thing
> + * this should never happen because it will be prevented
> + * by the check in pci_p2pdma_add_client()
> + */
> + if (WARN_ON_ONCE(IS_ENABLED(CONFIG_DMA_VIRT_OPS) &&
> + dev->dma_ops == &dma_virt_ops))
> + return 0;
Are you assuming that the compiler will optimize out the dev->dma_ops
== &dma_virt_ops test if CONFIG_DMA_VIRT_OPS=n such that no reference to the
dma_virt_ops symbol appears in the object file? Are you sure all compilers
and compiler versions that are used to build the Linux kernel will do that?
Thanks,
Bart.
_______________________________________________
Linux-nvdimm mailing list
[email protected]
https://lists.01.org/mailman/listinfo/linux-nvdimm
