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204 lines
4.3 KiB
204 lines
4.3 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/errno.h> |
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#include <linux/gfp.h> |
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#include <linux/kernel.h> |
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#include <linux/mm.h> |
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#include <linux/memremap.h> |
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#include <linux/slab.h> |
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#include <asm/page.h> |
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#include <xen/page.h> |
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#include <xen/xen.h> |
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static DEFINE_MUTEX(list_lock); |
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static struct page *page_list; |
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static unsigned int list_count; |
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static int fill_list(unsigned int nr_pages) |
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{ |
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struct dev_pagemap *pgmap; |
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struct resource *res; |
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void *vaddr; |
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unsigned int i, alloc_pages = round_up(nr_pages, PAGES_PER_SECTION); |
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int ret = -ENOMEM; |
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res = kzalloc(sizeof(*res), GFP_KERNEL); |
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if (!res) |
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return -ENOMEM; |
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res->name = "Xen scratch"; |
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res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
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ret = allocate_resource(&iomem_resource, res, |
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alloc_pages * PAGE_SIZE, 0, -1, |
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PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL); |
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if (ret < 0) { |
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pr_err("Cannot allocate new IOMEM resource\n"); |
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goto err_resource; |
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} |
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pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL); |
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if (!pgmap) { |
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ret = -ENOMEM; |
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goto err_pgmap; |
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} |
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pgmap->type = MEMORY_DEVICE_GENERIC; |
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pgmap->range = (struct range) { |
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.start = res->start, |
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.end = res->end, |
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}; |
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pgmap->nr_range = 1; |
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pgmap->owner = res; |
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#ifdef CONFIG_XEN_HAVE_PVMMU |
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/* |
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* memremap will build page tables for the new memory so |
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* the p2m must contain invalid entries so the correct |
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* non-present PTEs will be written. |
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* |
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* If a failure occurs, the original (identity) p2m entries |
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* are not restored since this region is now known not to |
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* conflict with any devices. |
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*/ |
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if (!xen_feature(XENFEAT_auto_translated_physmap)) { |
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xen_pfn_t pfn = PFN_DOWN(res->start); |
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for (i = 0; i < alloc_pages; i++) { |
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if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) { |
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pr_warn("set_phys_to_machine() failed, no memory added\n"); |
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ret = -ENOMEM; |
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goto err_memremap; |
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} |
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} |
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} |
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#endif |
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vaddr = memremap_pages(pgmap, NUMA_NO_NODE); |
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if (IS_ERR(vaddr)) { |
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pr_err("Cannot remap memory range\n"); |
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ret = PTR_ERR(vaddr); |
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goto err_memremap; |
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} |
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for (i = 0; i < alloc_pages; i++) { |
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struct page *pg = virt_to_page(vaddr + PAGE_SIZE * i); |
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BUG_ON(!virt_addr_valid(vaddr + PAGE_SIZE * i)); |
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pg->zone_device_data = page_list; |
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page_list = pg; |
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list_count++; |
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} |
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return 0; |
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err_memremap: |
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kfree(pgmap); |
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err_pgmap: |
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release_resource(res); |
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err_resource: |
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kfree(res); |
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return ret; |
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} |
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/** |
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* xen_alloc_unpopulated_pages - alloc unpopulated pages |
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* @nr_pages: Number of pages |
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* @pages: pages returned |
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* @return 0 on success, error otherwise |
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*/ |
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int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages) |
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{ |
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unsigned int i; |
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int ret = 0; |
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mutex_lock(&list_lock); |
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if (list_count < nr_pages) { |
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ret = fill_list(nr_pages - list_count); |
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if (ret) |
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goto out; |
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} |
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for (i = 0; i < nr_pages; i++) { |
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struct page *pg = page_list; |
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BUG_ON(!pg); |
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page_list = pg->zone_device_data; |
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list_count--; |
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pages[i] = pg; |
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#ifdef CONFIG_XEN_HAVE_PVMMU |
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if (!xen_feature(XENFEAT_auto_translated_physmap)) { |
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ret = xen_alloc_p2m_entry(page_to_pfn(pg)); |
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if (ret < 0) { |
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unsigned int j; |
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for (j = 0; j <= i; j++) { |
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pages[j]->zone_device_data = page_list; |
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page_list = pages[j]; |
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list_count++; |
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} |
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goto out; |
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} |
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} |
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#endif |
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} |
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out: |
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mutex_unlock(&list_lock); |
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return ret; |
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} |
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EXPORT_SYMBOL(xen_alloc_unpopulated_pages); |
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/** |
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* xen_free_unpopulated_pages - return unpopulated pages |
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* @nr_pages: Number of pages |
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* @pages: pages to return |
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*/ |
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void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages) |
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{ |
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unsigned int i; |
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mutex_lock(&list_lock); |
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for (i = 0; i < nr_pages; i++) { |
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pages[i]->zone_device_data = page_list; |
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page_list = pages[i]; |
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list_count++; |
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} |
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mutex_unlock(&list_lock); |
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} |
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EXPORT_SYMBOL(xen_free_unpopulated_pages); |
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#ifdef CONFIG_XEN_PV |
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static int __init init(void) |
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{ |
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unsigned int i; |
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if (!xen_domain()) |
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return -ENODEV; |
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if (!xen_pv_domain()) |
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return 0; |
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/* |
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* Initialize with pages from the extra memory regions (see |
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* arch/x86/xen/setup.c). |
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*/ |
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for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { |
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unsigned int j; |
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for (j = 0; j < xen_extra_mem[i].n_pfns; j++) { |
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struct page *pg = |
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pfn_to_page(xen_extra_mem[i].start_pfn + j); |
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pg->zone_device_data = page_list; |
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page_list = pg; |
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list_count++; |
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} |
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} |
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return 0; |
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} |
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subsys_initcall(init); |
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#endif
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