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Message-ID: <20150115032858.GA2461@dhcp-16-105.nay.redhat.com>
Date: Thu, 15 Jan 2015 11:28:58 +0800
From: Baoquan He <bhe@...hat.com>
To: "Li, Zhen-Hua" <zhen-hual@...com>
Cc: dwmw2@...radead.org, indou.takao@...fujitsu.com, joro@...tes.org,
vgoyal@...hat.com, dyoung@...hat.com, jerry.hoemann@...com,
tom.vaden@...com, rwright@...com, linux-pci@...r.kernel.org,
kexec@...ts.infradead.org, iommu@...ts.linux-foundation.org,
lisa.mitchell@...com, linux-kernel@...r.kernel.org,
alex.williamson@...hat.com, ddutile@...hat.com, doug.hatch@...com,
ishii.hironobu@...fujitsu.com, bhelgaas@...gle.com,
billsumnerlinux@...il.com, li.zhang6@...com
Subject: Re: [PATCH v8 06/10] iommu/vt-d: datatypes and functions used for
kdump
On 01/12/15 at 03:06pm, Li, Zhen-Hua wrote:
> +/*
> + * Interface to the "copy translation tables" set of functions
> + * from mainline code.
> + */
> +static int intel_iommu_load_translation_tables(struct dmar_drhd_unit *drhd,
> + int g_num_of_iommus)
The argument g_num_of_iommus is the same as the global variable, it's better
to rename it as num_of_iommus. And even it can be removed since you can
just use the global variable g_num_of_iommus in this function.
Argument drhd can be intel_iommu because no other member variable in
drhd is needed.
> +{
> + struct intel_iommu *iommu; /* Virt(iommu hardware registers) */
> + unsigned long long q; /* quadword scratch */
> + int ret = 0; /* Integer return code */
> + int i = 0; /* Loop index */
> + unsigned long flags;
> +
> + /* Structure so copy_page_addr() can accumulate things
> + * over multiple calls and returns
> + */
> + struct copy_page_addr_parms ppa_parms = copy_page_addr_parms_init;
> + struct copy_page_addr_parms *ppap = &ppa_parms;
> +
> +
> + iommu = drhd->iommu;
> + q = dmar_readq(iommu->reg + DMAR_RTADDR_REG);
> + if (!q)
> + return -1;
> +
> + /* If (list needs initializing) do it here */
This initializing should not be here, because it's not only for this
drhd. It should be done in init_dmars().
> + if (!domain_values_list) {
> + domain_values_list =
> + kcalloc(g_num_of_iommus, sizeof(struct list_head),
> + GFP_KERNEL);
> +
> + if (!domain_values_list) {
> + pr_err("Allocation failed for domain_values_list array\n");
> + return -ENOMEM;
> + }
> + for (i = 0; i < g_num_of_iommus; i++)
> + INIT_LIST_HEAD(&domain_values_list[i]);
> + }
> +
> + spin_lock_irqsave(&iommu->lock, flags);
> +
> + /* Load the root-entry table from the old kernel
> + * foreach context_entry_table in root_entry
> + * foreach context_entry in context_entry_table
> + * foreach level-1 page_table_entry in context_entry
> + * foreach level-2 page_table_entry in level 1 page_table_entry
> + * Above pattern continues up to 6 levels of page tables
> + * Sanity-check the entry
> + * Process the bus, devfn, page_address, page_size
> + */
> + if (!iommu->root_entry) {
> + iommu->root_entry =
> + (struct root_entry *)alloc_pgtable_page(iommu->node);
> + if (!iommu->root_entry) {
> + spin_unlock_irqrestore(&iommu->lock, flags);
> + return -ENOMEM;
> + }
> + }
> +
> + 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;
> + }
> +
> + 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;
> + }
> +
> + __iommu_load_old_root_entry(iommu);
> + ret = copy_root_entry_table(iommu, ppap);
> + __iommu_flush_cache(iommu, iommu->root_entry, PAGE_SIZE);
> + __iommu_update_old_root_entry(iommu, -1);
> +
> + spin_unlock_irqrestore(&iommu->lock, flags);
> +
> + __iommu_free_mapped_mem();
> +
> + if (ret)
> + return ret;
> +
> + ppa_parms.last = 1;
> + copy_page_addr(0, 0, 0, 0, 0, NULL, ppap);
> +
> + return 0;
> +}
> +
> #endif /* CONFIG_CRASH_DUMP */
> --
> 2.0.0-rc0
>
>
> _______________________________________________
> kexec mailing list
> kexec@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
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