> +#ifdef CONFIG_DMA_RESTRICTED_POOL
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_fdt.h>
> +#include <linux/of_reserved_mem.h>
> +#include <linux/slab.h>
> +#endif
I don't think any of this belongs into swiotlb.c. Marking
swiotlb_init_io_tlb_mem non-static and having all this code in a separate
file is probably a better idea.
> +#ifdef CONFIG_DMA_RESTRICTED_POOL
> +static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
> + struct device *dev)
> +{
> + struct io_tlb_mem *mem = rmem->priv;
> + unsigned long nslabs = rmem->size >> IO_TLB_SHIFT;
> +
> + if (dev->dma_io_tlb_mem)
> + return 0;
> +
> + /* Since multiple devices can share the same pool, the private data,
> + * io_tlb_mem struct, will be initialized by the first device attached
> + * to it.
> + */
This is not the normal kernel comment style.
> +#ifdef CONFIG_ARM
> + if (!PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) {
> + kfree(mem);
> + return -EINVAL;
> + }
> +#endif /* CONFIG_ARM */
And this is weird. Why would ARM have such a restriction? And if we have
such rstrictions it absolutely belongs into an arch helper.
> + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false);
> +
> + rmem->priv = mem;
> +
> +#ifdef CONFIG_DEBUG_FS
> + if (!debugfs_dir)
> + debugfs_dir = debugfs_create_dir("swiotlb", NULL);
> +
> + swiotlb_create_debugfs(mem, rmem->name, debugfs_dir);
Doesn't the debugfs_create_dir belong into swiotlb_create_debugfs? Also
please use IS_ENABLEd or a stub to avoid ifdefs like this.
