lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Sun, 15 Aug 2021 11:10:00 +0200
From:   Christoph Hellwig <>
To:     Alex Sierra <>
Subject: Re: [PATCH v6 04/13] drm/amdkfd: add SPM support for SVM

> @@ -880,17 +881,22 @@ int svm_migrate_init(struct amdgpu_device *adev)
>  	 * should remove reserved size
>  	 */
>  	size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
> -	res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
> +	if (xgmi_connected_to_cpu)
> +		res = lookup_resource(&iomem_resource, adev->gmc.aper_base);
> +	else
> +		res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
> +

Can you explain what the point of the lookup_resource is here? res->start
is obviously identical to the start value you pass in.  So this is used
as a way to query the length, but I'm pretty sure the driver must
already know that as it inserted the resource itself, right?

On a slightly higher level comment svm_migrate_init is a bit of a mess
with all the if/else already, and with the above addressed will become
a bit more.  I think splitting it into a device private and device
generic case would probably help people finding it to understand the code
much better later on.  Even more so with a useful comment.

Powered by blists - more mailing lists