![Ard Biesheuvel](/assets/img/avatar_default.png)
In order to make the static inline function is_zero_pfn() callable by modules, export its symbol dependencies 'zero_pfn' and (for s390 and mips) 'zero_page_mask'. We need this for KVM, as CONFIG_KVM is a tristate for all supported architectures except ARM and arm64, and testing a pfn whether it refers to the zero page is required to correctly distinguish the zero page from other special RAM ranges that may also have the PG_reserved bit set, but need to be treated as MMIO memory. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
233 lines
5.8 KiB
C
233 lines
5.8 KiB
C
/*
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* S390 version
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* Copyright IBM Corp. 1999
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* Author(s): Hartmut Penner (hp@de.ibm.com)
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*
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* Derived from "arch/i386/mm/init.c"
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* Copyright (C) 1995 Linus Torvalds
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*/
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/ptrace.h>
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#include <linux/mman.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/smp.h>
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#include <linux/init.h>
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#include <linux/pagemap.h>
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#include <linux/bootmem.h>
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#include <linux/memory.h>
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#include <linux/pfn.h>
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#include <linux/poison.h>
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#include <linux/initrd.h>
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#include <linux/export.h>
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#include <linux/gfp.h>
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#include <asm/processor.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/dma.h>
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#include <asm/lowcore.h>
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#include <asm/tlb.h>
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#include <asm/tlbflush.h>
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#include <asm/sections.h>
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#include <asm/ctl_reg.h>
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#include <asm/sclp.h>
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pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
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unsigned long empty_zero_page, zero_page_mask;
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EXPORT_SYMBOL(empty_zero_page);
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EXPORT_SYMBOL(zero_page_mask);
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static void __init setup_zero_pages(void)
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{
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struct cpuid cpu_id;
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unsigned int order;
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struct page *page;
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int i;
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get_cpu_id(&cpu_id);
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switch (cpu_id.machine) {
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case 0x9672: /* g5 */
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case 0x2064: /* z900 */
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case 0x2066: /* z900 */
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case 0x2084: /* z990 */
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case 0x2086: /* z990 */
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case 0x2094: /* z9-109 */
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case 0x2096: /* z9-109 */
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order = 0;
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break;
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case 0x2097: /* z10 */
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case 0x2098: /* z10 */
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case 0x2817: /* z196 */
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case 0x2818: /* z196 */
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order = 2;
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break;
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case 0x2827: /* zEC12 */
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case 0x2828: /* zEC12 */
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default:
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order = 5;
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break;
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}
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/* Limit number of empty zero pages for small memory sizes */
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if (order > 2 && totalram_pages <= 16384)
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order = 2;
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empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
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if (!empty_zero_page)
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panic("Out of memory in setup_zero_pages");
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page = virt_to_page((void *) empty_zero_page);
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split_page(page, order);
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for (i = 1 << order; i > 0; i--) {
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mark_page_reserved(page);
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page++;
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}
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zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
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}
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/*
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* paging_init() sets up the page tables
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*/
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void __init paging_init(void)
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{
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unsigned long max_zone_pfns[MAX_NR_ZONES];
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unsigned long pgd_type, asce_bits;
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init_mm.pgd = swapper_pg_dir;
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#ifdef CONFIG_64BIT
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if (VMALLOC_END > (1UL << 42)) {
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asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
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pgd_type = _REGION2_ENTRY_EMPTY;
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} else {
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asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
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pgd_type = _REGION3_ENTRY_EMPTY;
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}
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#else
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asce_bits = _ASCE_TABLE_LENGTH;
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pgd_type = _SEGMENT_ENTRY_EMPTY;
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#endif
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S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
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clear_table((unsigned long *) init_mm.pgd, pgd_type,
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sizeof(unsigned long)*2048);
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vmem_map_init();
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/* enable virtual mapping in kernel mode */
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__ctl_load(S390_lowcore.kernel_asce, 1, 1);
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__ctl_load(S390_lowcore.kernel_asce, 7, 7);
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__ctl_load(S390_lowcore.kernel_asce, 13, 13);
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arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
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sparse_memory_present_with_active_regions(MAX_NUMNODES);
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sparse_init();
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memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
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max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
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max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
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free_area_init_nodes(max_zone_pfns);
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}
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void __init mem_init(void)
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{
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if (MACHINE_HAS_TLB_LC)
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cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
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cpumask_set_cpu(0, mm_cpumask(&init_mm));
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atomic_set(&init_mm.context.attach_count, 1);
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max_mapnr = max_low_pfn;
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high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
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/* Setup guest page hinting */
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cmma_init();
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/* this will put all low memory onto the freelists */
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free_all_bootmem();
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setup_zero_pages(); /* Setup zeroed pages. */
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mem_init_print_info(NULL);
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printk("Write protected kernel read-only data: %#lx - %#lx\n",
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(unsigned long)&_stext,
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PFN_ALIGN((unsigned long)&_eshared) - 1);
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}
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void free_initmem(void)
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{
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free_initmem_default(POISON_FREE_INITMEM);
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}
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#ifdef CONFIG_BLK_DEV_INITRD
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void __init free_initrd_mem(unsigned long start, unsigned long end)
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{
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free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
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"initrd");
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}
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#endif
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#ifdef CONFIG_MEMORY_HOTPLUG
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int arch_add_memory(int nid, u64 start, u64 size)
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{
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unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
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unsigned long start_pfn = PFN_DOWN(start);
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unsigned long size_pages = PFN_DOWN(size);
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struct zone *zone;
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int rc;
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rc = vmem_add_mapping(start, size);
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if (rc)
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return rc;
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for_each_zone(zone) {
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if (zone_idx(zone) != ZONE_MOVABLE) {
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/* Add range within existing zone limits */
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zone_start_pfn = zone->zone_start_pfn;
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zone_end_pfn = zone->zone_start_pfn +
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zone->spanned_pages;
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} else {
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/* Add remaining range to ZONE_MOVABLE */
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zone_start_pfn = start_pfn;
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zone_end_pfn = start_pfn + size_pages;
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}
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if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn)
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continue;
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nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
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zone_end_pfn - start_pfn : size_pages;
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rc = __add_pages(nid, zone, start_pfn, nr_pages);
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if (rc)
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break;
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start_pfn += nr_pages;
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size_pages -= nr_pages;
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if (!size_pages)
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break;
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}
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if (rc)
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vmem_remove_mapping(start, size);
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return rc;
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}
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unsigned long memory_block_size_bytes(void)
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{
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/*
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* Make sure the memory block size is always greater
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* or equal than the memory increment size.
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*/
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return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp_get_rzm());
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}
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#ifdef CONFIG_MEMORY_HOTREMOVE
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int arch_remove_memory(u64 start, u64 size)
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{
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/*
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* There is no hardware or firmware interface which could trigger a
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* hot memory remove on s390. So there is nothing that needs to be
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* implemented.
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*/
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return -EBUSY;
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}
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#endif
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#endif /* CONFIG_MEMORY_HOTPLUG */
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