On 6/20/21 7:32 AM, Neel Chauhan wrote:
On 2021-06-18 20:03, Neel Chauhan wrote:
Apparently, the vm_start values is for some reason coming as 0 when it
is passed into vm_fault_cpu(). That's why it's giving these errors: of
course the address at 0 is mapped, it is (probably) used by the
kernel.
An update: The vm_start 0 seems to be expected. I checked the values
with printf()s.
I have posted this on Twitter, and am considering hiring a kernel
consultant to help if I am unable to do this on my own.
So I am guessing this line (Line 231) is incorrect:
pa = sg_dma_address(sgl);
Source:
https://github.com/neelchauhan/drm-kmod/blob/d0eee96973ee0772e977b813678f92c5becf0507/drivers/gpu/drm/i915/intel_freebsd.c#L231
Hi Neel,
sg_dma_address() is zero, because the memory hasn't been loaded.
You need to handle two cases there:
When r->iobase is -1 and when it is not.
I suspect you should add r->iobase to the sg_dma_address() only and only
when it is non -1.
Also, there is a superfluous "pa = " in the beginning of the function.
--HPS
