1*9e2369c0SRoger Pau Monne // SPDX-License-Identifier: GPL-2.0 2*9e2369c0SRoger Pau Monne #include <linux/errno.h> 3*9e2369c0SRoger Pau Monne #include <linux/gfp.h> 4*9e2369c0SRoger Pau Monne #include <linux/kernel.h> 5*9e2369c0SRoger Pau Monne #include <linux/mm.h> 6*9e2369c0SRoger Pau Monne #include <linux/memremap.h> 7*9e2369c0SRoger Pau Monne #include <linux/slab.h> 8*9e2369c0SRoger Pau Monne 9*9e2369c0SRoger Pau Monne #include <asm/page.h> 10*9e2369c0SRoger Pau Monne 11*9e2369c0SRoger Pau Monne #include <xen/page.h> 12*9e2369c0SRoger Pau Monne #include <xen/xen.h> 13*9e2369c0SRoger Pau Monne 14*9e2369c0SRoger Pau Monne static DEFINE_MUTEX(list_lock); 15*9e2369c0SRoger Pau Monne static LIST_HEAD(page_list); 16*9e2369c0SRoger Pau Monne static unsigned int list_count; 17*9e2369c0SRoger Pau Monne 18*9e2369c0SRoger Pau Monne static int fill_list(unsigned int nr_pages) 19*9e2369c0SRoger Pau Monne { 20*9e2369c0SRoger Pau Monne struct dev_pagemap *pgmap; 21*9e2369c0SRoger Pau Monne void *vaddr; 22*9e2369c0SRoger Pau Monne unsigned int i, alloc_pages = round_up(nr_pages, PAGES_PER_SECTION); 23*9e2369c0SRoger Pau Monne int ret; 24*9e2369c0SRoger Pau Monne 25*9e2369c0SRoger Pau Monne pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL); 26*9e2369c0SRoger Pau Monne if (!pgmap) 27*9e2369c0SRoger Pau Monne return -ENOMEM; 28*9e2369c0SRoger Pau Monne 29*9e2369c0SRoger Pau Monne pgmap->type = MEMORY_DEVICE_GENERIC; 30*9e2369c0SRoger Pau Monne pgmap->res.name = "Xen scratch"; 31*9e2369c0SRoger Pau Monne pgmap->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; 32*9e2369c0SRoger Pau Monne 33*9e2369c0SRoger Pau Monne ret = allocate_resource(&iomem_resource, &pgmap->res, 34*9e2369c0SRoger Pau Monne alloc_pages * PAGE_SIZE, 0, -1, 35*9e2369c0SRoger Pau Monne PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL); 36*9e2369c0SRoger Pau Monne if (ret < 0) { 37*9e2369c0SRoger Pau Monne pr_err("Cannot allocate new IOMEM resource\n"); 38*9e2369c0SRoger Pau Monne kfree(pgmap); 39*9e2369c0SRoger Pau Monne return ret; 40*9e2369c0SRoger Pau Monne } 41*9e2369c0SRoger Pau Monne 42*9e2369c0SRoger Pau Monne #ifdef CONFIG_XEN_HAVE_PVMMU 43*9e2369c0SRoger Pau Monne /* 44*9e2369c0SRoger Pau Monne * memremap will build page tables for the new memory so 45*9e2369c0SRoger Pau Monne * the p2m must contain invalid entries so the correct 46*9e2369c0SRoger Pau Monne * non-present PTEs will be written. 47*9e2369c0SRoger Pau Monne * 48*9e2369c0SRoger Pau Monne * If a failure occurs, the original (identity) p2m entries 49*9e2369c0SRoger Pau Monne * are not restored since this region is now known not to 50*9e2369c0SRoger Pau Monne * conflict with any devices. 51*9e2369c0SRoger Pau Monne */ 52*9e2369c0SRoger Pau Monne if (!xen_feature(XENFEAT_auto_translated_physmap)) { 53*9e2369c0SRoger Pau Monne xen_pfn_t pfn = PFN_DOWN(pgmap->res.start); 54*9e2369c0SRoger Pau Monne 55*9e2369c0SRoger Pau Monne for (i = 0; i < alloc_pages; i++) { 56*9e2369c0SRoger Pau Monne if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) { 57*9e2369c0SRoger Pau Monne pr_warn("set_phys_to_machine() failed, no memory added\n"); 58*9e2369c0SRoger Pau Monne release_resource(&pgmap->res); 59*9e2369c0SRoger Pau Monne kfree(pgmap); 60*9e2369c0SRoger Pau Monne return -ENOMEM; 61*9e2369c0SRoger Pau Monne } 62*9e2369c0SRoger Pau Monne } 63*9e2369c0SRoger Pau Monne } 64*9e2369c0SRoger Pau Monne #endif 65*9e2369c0SRoger Pau Monne 66*9e2369c0SRoger Pau Monne vaddr = memremap_pages(pgmap, NUMA_NO_NODE); 67*9e2369c0SRoger Pau Monne if (IS_ERR(vaddr)) { 68*9e2369c0SRoger Pau Monne pr_err("Cannot remap memory range\n"); 69*9e2369c0SRoger Pau Monne release_resource(&pgmap->res); 70*9e2369c0SRoger Pau Monne kfree(pgmap); 71*9e2369c0SRoger Pau Monne return PTR_ERR(vaddr); 72*9e2369c0SRoger Pau Monne } 73*9e2369c0SRoger Pau Monne 74*9e2369c0SRoger Pau Monne for (i = 0; i < alloc_pages; i++) { 75*9e2369c0SRoger Pau Monne struct page *pg = virt_to_page(vaddr + PAGE_SIZE * i); 76*9e2369c0SRoger Pau Monne 77*9e2369c0SRoger Pau Monne BUG_ON(!virt_addr_valid(vaddr + PAGE_SIZE * i)); 78*9e2369c0SRoger Pau Monne list_add(&pg->lru, &page_list); 79*9e2369c0SRoger Pau Monne list_count++; 80*9e2369c0SRoger Pau Monne } 81*9e2369c0SRoger Pau Monne 82*9e2369c0SRoger Pau Monne return 0; 83*9e2369c0SRoger Pau Monne } 84*9e2369c0SRoger Pau Monne 85*9e2369c0SRoger Pau Monne /** 86*9e2369c0SRoger Pau Monne * xen_alloc_unpopulated_pages - alloc unpopulated pages 87*9e2369c0SRoger Pau Monne * @nr_pages: Number of pages 88*9e2369c0SRoger Pau Monne * @pages: pages returned 89*9e2369c0SRoger Pau Monne * @return 0 on success, error otherwise 90*9e2369c0SRoger Pau Monne */ 91*9e2369c0SRoger Pau Monne int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages) 92*9e2369c0SRoger Pau Monne { 93*9e2369c0SRoger Pau Monne unsigned int i; 94*9e2369c0SRoger Pau Monne int ret = 0; 95*9e2369c0SRoger Pau Monne 96*9e2369c0SRoger Pau Monne mutex_lock(&list_lock); 97*9e2369c0SRoger Pau Monne if (list_count < nr_pages) { 98*9e2369c0SRoger Pau Monne ret = fill_list(nr_pages - list_count); 99*9e2369c0SRoger Pau Monne if (ret) 100*9e2369c0SRoger Pau Monne goto out; 101*9e2369c0SRoger Pau Monne } 102*9e2369c0SRoger Pau Monne 103*9e2369c0SRoger Pau Monne for (i = 0; i < nr_pages; i++) { 104*9e2369c0SRoger Pau Monne struct page *pg = list_first_entry_or_null(&page_list, 105*9e2369c0SRoger Pau Monne struct page, 106*9e2369c0SRoger Pau Monne lru); 107*9e2369c0SRoger Pau Monne 108*9e2369c0SRoger Pau Monne BUG_ON(!pg); 109*9e2369c0SRoger Pau Monne list_del(&pg->lru); 110*9e2369c0SRoger Pau Monne list_count--; 111*9e2369c0SRoger Pau Monne pages[i] = pg; 112*9e2369c0SRoger Pau Monne 113*9e2369c0SRoger Pau Monne #ifdef CONFIG_XEN_HAVE_PVMMU 114*9e2369c0SRoger Pau Monne if (!xen_feature(XENFEAT_auto_translated_physmap)) { 115*9e2369c0SRoger Pau Monne ret = xen_alloc_p2m_entry(page_to_pfn(pg)); 116*9e2369c0SRoger Pau Monne if (ret < 0) { 117*9e2369c0SRoger Pau Monne unsigned int j; 118*9e2369c0SRoger Pau Monne 119*9e2369c0SRoger Pau Monne for (j = 0; j <= i; j++) { 120*9e2369c0SRoger Pau Monne list_add(&pages[j]->lru, &page_list); 121*9e2369c0SRoger Pau Monne list_count++; 122*9e2369c0SRoger Pau Monne } 123*9e2369c0SRoger Pau Monne goto out; 124*9e2369c0SRoger Pau Monne } 125*9e2369c0SRoger Pau Monne } 126*9e2369c0SRoger Pau Monne #endif 127*9e2369c0SRoger Pau Monne } 128*9e2369c0SRoger Pau Monne 129*9e2369c0SRoger Pau Monne out: 130*9e2369c0SRoger Pau Monne mutex_unlock(&list_lock); 131*9e2369c0SRoger Pau Monne return ret; 132*9e2369c0SRoger Pau Monne } 133*9e2369c0SRoger Pau Monne EXPORT_SYMBOL(xen_alloc_unpopulated_pages); 134*9e2369c0SRoger Pau Monne 135*9e2369c0SRoger Pau Monne /** 136*9e2369c0SRoger Pau Monne * xen_free_unpopulated_pages - return unpopulated pages 137*9e2369c0SRoger Pau Monne * @nr_pages: Number of pages 138*9e2369c0SRoger Pau Monne * @pages: pages to return 139*9e2369c0SRoger Pau Monne */ 140*9e2369c0SRoger Pau Monne void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages) 141*9e2369c0SRoger Pau Monne { 142*9e2369c0SRoger Pau Monne unsigned int i; 143*9e2369c0SRoger Pau Monne 144*9e2369c0SRoger Pau Monne mutex_lock(&list_lock); 145*9e2369c0SRoger Pau Monne for (i = 0; i < nr_pages; i++) { 146*9e2369c0SRoger Pau Monne list_add(&pages[i]->lru, &page_list); 147*9e2369c0SRoger Pau Monne list_count++; 148*9e2369c0SRoger Pau Monne } 149*9e2369c0SRoger Pau Monne mutex_unlock(&list_lock); 150*9e2369c0SRoger Pau Monne } 151*9e2369c0SRoger Pau Monne EXPORT_SYMBOL(xen_free_unpopulated_pages); 152*9e2369c0SRoger Pau Monne 153*9e2369c0SRoger Pau Monne #ifdef CONFIG_XEN_PV 154*9e2369c0SRoger Pau Monne static int __init init(void) 155*9e2369c0SRoger Pau Monne { 156*9e2369c0SRoger Pau Monne unsigned int i; 157*9e2369c0SRoger Pau Monne 158*9e2369c0SRoger Pau Monne if (!xen_domain()) 159*9e2369c0SRoger Pau Monne return -ENODEV; 160*9e2369c0SRoger Pau Monne 161*9e2369c0SRoger Pau Monne if (!xen_pv_domain()) 162*9e2369c0SRoger Pau Monne return 0; 163*9e2369c0SRoger Pau Monne 164*9e2369c0SRoger Pau Monne /* 165*9e2369c0SRoger Pau Monne * Initialize with pages from the extra memory regions (see 166*9e2369c0SRoger Pau Monne * arch/x86/xen/setup.c). 167*9e2369c0SRoger Pau Monne */ 168*9e2369c0SRoger Pau Monne for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 169*9e2369c0SRoger Pau Monne unsigned int j; 170*9e2369c0SRoger Pau Monne 171*9e2369c0SRoger Pau Monne for (j = 0; j < xen_extra_mem[i].n_pfns; j++) { 172*9e2369c0SRoger Pau Monne struct page *pg = 173*9e2369c0SRoger Pau Monne pfn_to_page(xen_extra_mem[i].start_pfn + j); 174*9e2369c0SRoger Pau Monne 175*9e2369c0SRoger Pau Monne list_add(&pg->lru, &page_list); 176*9e2369c0SRoger Pau Monne list_count++; 177*9e2369c0SRoger Pau Monne } 178*9e2369c0SRoger Pau Monne } 179*9e2369c0SRoger Pau Monne 180*9e2369c0SRoger Pau Monne return 0; 181*9e2369c0SRoger Pau Monne } 182*9e2369c0SRoger Pau Monne subsys_initcall(init); 183*9e2369c0SRoger Pau Monne #endif 184