On 18/11/15 04:32, Shannon Zhao wrote:
> On 2015/11/18 0:02, David Vrabel wrote:
>> On 17/11/15 09:57, shannon.zhao@xxxxxxxxxx wrote:
>>> From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
>>>
>>> Move xlated_setup_gnttab_pages to common place, so it can be reused by
>>> ARM to setup grant table when booting with ACPI.
>> [...]
>>> --- a/drivers/xen/grant-table.c
>>> +++ b/drivers/xen/grant-table.c
>>> @@ -664,6 +664,55 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr)
>>> }
>>> EXPORT_SYMBOL_GPL(gnttab_setup_auto_xlat_frames);
>>>
>>> +int __init xlated_setup_gnttab_pages(void)
>>> +{
>>> + struct page **pages;
>>> + xen_pfn_t *pfns;
>>> + void *vaddr;
>>> + int rc;
>>> + unsigned int i;
>>> + unsigned long nr_grant_frames = gnttab_max_grant_frames();
>>> +
>>> + BUG_ON(nr_grant_frames == 0);
>>> + pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL);
>>> + if (!pages)
>>> + return -ENOMEM;
>>> +
>>> + pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
>>> + if (!pfns) {
>>> + kfree(pages);
>>> + return -ENOMEM;
>>> + }
>>> + rc = alloc_xenballooned_pages(nr_grant_frames, pages, 0 /* lowmem */);
>>> + if (rc) {
>>> + pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__,
>>> + nr_grant_frames, rc);
>>> + kfree(pages);
>>> + kfree(pfns);
>>> + return rc;
>>> + }
>>> + for (i = 0; i < nr_grant_frames; i++)
>>> + pfns[i] = page_to_pfn(pages[i]);
>>> +
>>> + vaddr = vmap(pages, nr_grant_frames, 0, PAGE_KERNEL);
>>> + if (!vaddr) {
>>> + pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
>>> + nr_grant_frames, rc);
>>> + free_xenballooned_pages(nr_grant_frames, pages);
>>> + kfree(pages);
>>> + kfree(pfns);
>>> + return -ENOMEM;
>>> + }
>>> + kfree(pages);
>>
>> Can you move most of this function into drivers/xen/xlate_mmu.c in a
>> function like:
>>
>> /**
>> * xen_xlate_map_ballooned_pages - map a new set of ballooned pages
>> * count: number of GFNs.
>> * pages: returns the array of (now) ballooned pages.
>> * gfns: returns the array of corresponding GFNs.
>> * virt: returns the virtual address of the mapped region.
>> *
>> * This allocate a set of ballooned pages and maps them into the
>> * kernel's address space.
>> */
>> void *xen_xlate_map_ballooned_pages(
>> unsigned int count,
>> struct page **pages,
>> xen_pfn_t **gfns);
>>
> Sure, but the parameter "pages" is not necessary I think, since the
> pages has been freed in the function and it doesn't need in
> xen_auto_xlat_grant_frames either. Right?
Yes.
David
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