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231 lines
4.8 KiB
231 lines
4.8 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright IBM Corp. 2008 |
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* |
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* Guest page hinting for unused pages. |
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* |
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* Author(s): Martin Schwidefsky <[email protected]> |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/errno.h> |
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#include <linux/types.h> |
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#include <linux/mm.h> |
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#include <linux/memblock.h> |
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#include <linux/gfp.h> |
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#include <linux/init.h> |
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#include <asm/asm-extable.h> |
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#include <asm/facility.h> |
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#include <asm/page-states.h> |
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static int cmma_flag = 1; |
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static int __init cmma(char *str) |
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{ |
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bool enabled; |
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if (!kstrtobool(str, &enabled)) |
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cmma_flag = enabled; |
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return 1; |
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} |
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__setup("cmma=", cmma); |
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static inline int cmma_test_essa(void) |
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{ |
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unsigned long tmp = 0; |
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int rc = -EOPNOTSUPP; |
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/* test ESSA_GET_STATE */ |
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asm volatile( |
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" .insn rrf,0xb9ab0000,%[tmp],%[tmp],%[cmd],0\n" |
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"0: la %[rc],0\n" |
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"1:\n" |
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EX_TABLE(0b,1b) |
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: [rc] "+&d" (rc), [tmp] "+&d" (tmp) |
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: [cmd] "i" (ESSA_GET_STATE)); |
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return rc; |
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} |
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void __init cmma_init(void) |
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{ |
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if (!cmma_flag) |
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return; |
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if (cmma_test_essa()) { |
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cmma_flag = 0; |
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return; |
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} |
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if (test_facility(147)) |
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cmma_flag = 2; |
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} |
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static inline unsigned char get_page_state(struct page *page) |
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{ |
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unsigned char state; |
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asm volatile(" .insn rrf,0xb9ab0000,%0,%1,%2,0" |
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: "=&d" (state) |
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: "a" (page_to_phys(page)), |
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"i" (ESSA_GET_STATE)); |
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return state & 0x3f; |
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} |
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static inline void set_page_unused(struct page *page, int order) |
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{ |
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int i, rc; |
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for (i = 0; i < (1 << order); i++) |
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asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" |
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: "=&d" (rc) |
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: "a" (page_to_phys(page + i)), |
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"i" (ESSA_SET_UNUSED)); |
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} |
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static inline void set_page_stable_dat(struct page *page, int order) |
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{ |
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int i, rc; |
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for (i = 0; i < (1 << order); i++) |
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asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" |
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: "=&d" (rc) |
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: "a" (page_to_phys(page + i)), |
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"i" (ESSA_SET_STABLE)); |
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} |
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static inline void set_page_stable_nodat(struct page *page, int order) |
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{ |
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int i, rc; |
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for (i = 0; i < (1 << order); i++) |
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asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" |
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: "=&d" (rc) |
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: "a" (page_to_phys(page + i)), |
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"i" (ESSA_SET_STABLE_NODAT)); |
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} |
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static void mark_kernel_pmd(pud_t *pud, unsigned long addr, unsigned long end) |
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{ |
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unsigned long next; |
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struct page *page; |
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pmd_t *pmd; |
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pmd = pmd_offset(pud, addr); |
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do { |
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next = pmd_addr_end(addr, end); |
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if (pmd_none(*pmd) || pmd_large(*pmd)) |
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continue; |
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page = phys_to_page(pmd_val(*pmd)); |
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set_bit(PG_arch_1, &page->flags); |
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} while (pmd++, addr = next, addr != end); |
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} |
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static void mark_kernel_pud(p4d_t *p4d, unsigned long addr, unsigned long end) |
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{ |
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unsigned long next; |
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struct page *page; |
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pud_t *pud; |
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int i; |
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pud = pud_offset(p4d, addr); |
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do { |
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next = pud_addr_end(addr, end); |
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if (pud_none(*pud) || pud_large(*pud)) |
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continue; |
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if (!pud_folded(*pud)) { |
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page = phys_to_page(pud_val(*pud)); |
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for (i = 0; i < 3; i++) |
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set_bit(PG_arch_1, &page[i].flags); |
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} |
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mark_kernel_pmd(pud, addr, next); |
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} while (pud++, addr = next, addr != end); |
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} |
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static void mark_kernel_p4d(pgd_t *pgd, unsigned long addr, unsigned long end) |
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{ |
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unsigned long next; |
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struct page *page; |
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p4d_t *p4d; |
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int i; |
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p4d = p4d_offset(pgd, addr); |
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do { |
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next = p4d_addr_end(addr, end); |
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if (p4d_none(*p4d)) |
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continue; |
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if (!p4d_folded(*p4d)) { |
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page = phys_to_page(p4d_val(*p4d)); |
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for (i = 0; i < 3; i++) |
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set_bit(PG_arch_1, &page[i].flags); |
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} |
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mark_kernel_pud(p4d, addr, next); |
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} while (p4d++, addr = next, addr != end); |
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} |
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static void mark_kernel_pgd(void) |
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{ |
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unsigned long addr, next; |
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struct page *page; |
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pgd_t *pgd; |
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int i; |
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addr = 0; |
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pgd = pgd_offset_k(addr); |
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do { |
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next = pgd_addr_end(addr, MODULES_END); |
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if (pgd_none(*pgd)) |
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continue; |
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if (!pgd_folded(*pgd)) { |
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page = phys_to_page(pgd_val(*pgd)); |
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for (i = 0; i < 3; i++) |
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set_bit(PG_arch_1, &page[i].flags); |
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} |
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mark_kernel_p4d(pgd, addr, next); |
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} while (pgd++, addr = next, addr != MODULES_END); |
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} |
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void __init cmma_init_nodat(void) |
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{ |
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struct page *page; |
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unsigned long start, end, ix; |
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int i; |
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if (cmma_flag < 2) |
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return; |
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/* Mark pages used in kernel page tables */ |
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mark_kernel_pgd(); |
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/* Set all kernel pages not used for page tables to stable/no-dat */ |
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for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) { |
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page = pfn_to_page(start); |
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for (ix = start; ix < end; ix++, page++) { |
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if (__test_and_clear_bit(PG_arch_1, &page->flags)) |
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continue; /* skip page table pages */ |
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if (!list_empty(&page->lru)) |
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continue; /* skip free pages */ |
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set_page_stable_nodat(page, 0); |
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} |
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} |
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} |
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void arch_free_page(struct page *page, int order) |
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{ |
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if (!cmma_flag) |
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return; |
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set_page_unused(page, order); |
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} |
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void arch_alloc_page(struct page *page, int order) |
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{ |
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if (!cmma_flag) |
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return; |
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if (cmma_flag < 2) |
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set_page_stable_dat(page, order); |
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else |
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set_page_stable_nodat(page, order); |
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} |
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void arch_set_page_dat(struct page *page, int order) |
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{ |
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if (!cmma_flag) |
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return; |
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set_page_stable_dat(page, order); |
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}
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