[PATCH 5/5] drm/amdgpu: replace iova debugfs file with iomem

[Tom St Denis]

On 09/02/18 09:12 AM, Christian König wrote:
> No, there is simply no need to initialize the system domain. What are 
> the values of p->mapping and adev->mman.bdev.dev_mapping when they don't 
> match? Maybe we are allocating memory before initializing 
> adev->mman.bdev.dev_mapping.

In my test setup I'm running test 3 from libdrm (suite 1) with a pause 
before the unmap/free call.  So the IB should still be mapped.  Indeed 
the VM PTE decoding has the V bit set.

> Or do you have more than one GPU in the system? E.g. APU+dGPU? Could it 
> be that you read through the wrong device?

I found the issue:

	while (size) {
		phys_addr_t addr = *pos & PAGE_MASK;
		loff_t off = *pos & ~PAGE_MASK;
		size_t bytes = PAGE_SIZE - off;

"bytes" should be limited by the 'size' parameter passed in.  What is 
happening instead is it's reading the entire PTB until it hits a V=0 
page and then returns an error and in the process is doing "fun things" 
to the user mode application (by copying more data than I asked for).


Tom