[PATCH 03/14] iommu: Create a base struct for io_mm

On Fri, Mar 02, 2018 at 12:25:48PM +0000, Jean-Philippe Brucker wrote:

Hi Jordan,

Thank you for this, SMMUv3 and virtio-iommu need these SVA patches as well.

On 21/02/18 22:59, Jordan Crouse wrote:
[...]> diff --git a/include/linux/iommu.h b/include/linux/iommu.h

quoted

index e2c49e583d8d..e998389cf195 100644

--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h

@@ -110,8 +110,17 @@ struct iommu_domain {
 	struct list_head mm_list;
 };
 
+enum iommu_io_type {
+	IO_TYPE_MM,
+};
+
+struct io_base {
+	int type;
+	int pasid;
+};

"io_base" is a bit vague. I'm bad at naming so my opinion doesn't hold
much water, but I'd rather this be something like "io_mm_base". When I
initially toyed with the idea I intended to keep io_mm as parent structure
and have "private" and "shared" sub-structures. Even if private PASIDs
don't rely on the kernel mm subsystem, this structure would still
represent an I/O mm of sorts, with a pgd and pgtable info.

I'm also bad at naming but I don't mind changing it. io_mm_base seems okay to me
unless somebody has a better idea. I also like the terms "private" and
"shared". I'm going to start adopting those where it makes sense.

Jordan

quoted

+
 struct io_mm {
-	int			pasid;
+	struct io_base		base;
 	struct list_head	devices;
 	struct kref		kref;
 #if defined(CONFIG_MMU_NOTIFIER)

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