From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Li, ZhenHua" <zhen-hual-VXdhtT5mjnY@public.gmane.org>
Subject: Re: [PATCH v11 06/10] iommu/vt-d: datatypes and functions used for
	kdump
Date: Wed, 13 May 2015 16:58:25 +0800
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To: Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: tom.vaden-VXdhtT5mjnY@public.gmane.org, rwright-VXdhtT5mjnY@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lisa.mitchell-VXdhtT5mjnY@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, "Li,
	ZhenHua" <zhen-hual-VXdhtT5mjnY@public.gmane.org>, doug.hatch-VXdhtT5mjnY@public.gmane.org, ishii.hironobu-+CUm20s59erQFUHtdCDX3A@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, billsumnerlinux-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, li.zhang6-VXdhtT5mjnY@public.gmane.org, dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
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Hi Dave,

iommu->root_entry_old_virt is used to store the mapped old rta.
iommu->root_entry_old_phys is used to store the physical address stored 
in registers.
So we must not free/unmap iommu->root_entry_old_phys .

Zhenhua
On 05/13/2015 04:56 PM, Baoquan He wrote:
>> +
>> +	iommu->root_entry_old_phys = q & VTD_PAGE_MASK;
>> +	if (!iommu->root_entry_old_phys) {
>> +		pr_err("Could not read old root entry address.");
>> +		return -1;
>> +	}
>> +
>
> I didn't find where you call iounmap to free mapping of
> iommu->root_entry_old_phys. Am I missing anything?
>
>> +	iommu->root_entry_old_virt = ioremap_cache(iommu->root_entry_old_phys,
>> +						VTD_PAGE_SIZE);
>> +	if (!iommu->root_entry_old_virt) {
>> +		pr_err("Could not map the old root entry.");
>> +		return -ENOMEM;
>> +	}