On Mon, May 10, 2021 at 11:03 PM Christoph Hellwig hch@lst.de wrote:
+#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.
Will do in the next version.
+#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.
Will fix this in the next version.
+#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.
Now I think the CONFIG_ARM can just be removed? The goal here is to make sure we're using linear map and can safely use phys_to_dma/dma_to_phys.
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.
Will move it into swiotlb_create_debugfs and use IS_ENABLED in the next version.