diff options
Diffstat (limited to 'arch/s390/mm/page-states.c')
| -rw-r--r-- | arch/s390/mm/page-states.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c new file mode 100644 index 0000000000..79a037f49f --- /dev/null +++ b/arch/s390/mm/page-states.c @@ -0,0 +1,226 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 2008 + * + * Guest page hinting for unused pages. + * + * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/memblock.h> +#include <linux/gfp.h> +#include <linux/init.h> +#include <asm/asm-extable.h> +#include <asm/facility.h> +#include <asm/page-states.h> + +static int cmma_flag = 1; + +static int __init cmma(char *str) +{ + bool enabled; + + if (!kstrtobool(str, &enabled)) + cmma_flag = enabled; + return 1; +} +__setup("cmma=", cmma); + +static inline int cmma_test_essa(void) +{ + unsigned long tmp = 0; + int rc = -EOPNOTSUPP; + + /* test ESSA_GET_STATE */ + asm volatile( + " .insn rrf,0xb9ab0000,%[tmp],%[tmp],%[cmd],0\n" + "0: la %[rc],0\n" + "1:\n" + EX_TABLE(0b,1b) + : [rc] "+&d" (rc), [tmp] "+&d" (tmp) + : [cmd] "i" (ESSA_GET_STATE)); + return rc; +} + +void __init cmma_init(void) +{ + if (!cmma_flag) + return; + if (cmma_test_essa()) { + cmma_flag = 0; + return; + } + if (test_facility(147)) + cmma_flag = 2; +} + +static inline void set_page_unused(struct page *page, int order) +{ + int i, rc; + + for (i = 0; i < (1 << order); i++) + asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" + : "=&d" (rc) + : "a" (page_to_phys(page + i)), + "i" (ESSA_SET_UNUSED)); +} + +static inline void set_page_stable_dat(struct page *page, int order) +{ + int i, rc; + + for (i = 0; i < (1 << order); i++) + asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" + : "=&d" (rc) + : "a" (page_to_phys(page + i)), + "i" (ESSA_SET_STABLE)); +} + +static inline void set_page_stable_nodat(struct page *page, int order) +{ + int i, rc; + + for (i = 0; i < (1 << order); i++) + asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" + : "=&d" (rc) + : "a" (page_to_phys(page + i)), + "i" (ESSA_SET_STABLE_NODAT)); +} + +static void mark_kernel_pmd(pud_t *pud, unsigned long addr, unsigned long end) +{ + unsigned long next; + struct page *page; + pmd_t *pmd; + + pmd = pmd_offset(pud, addr); + do { + next = pmd_addr_end(addr, end); + if (pmd_none(*pmd) || pmd_large(*pmd)) + continue; + page = phys_to_page(pmd_val(*pmd)); + set_bit(PG_arch_1, &page->flags); + } while (pmd++, addr = next, addr != end); +} + +static void mark_kernel_pud(p4d_t *p4d, unsigned long addr, unsigned long end) +{ + unsigned long next; + struct page *page; + pud_t *pud; + int i; + + pud = pud_offset(p4d, addr); + do { + next = pud_addr_end(addr, end); + if (pud_none(*pud) || pud_large(*pud)) + continue; + if (!pud_folded(*pud)) { + page = phys_to_page(pud_val(*pud)); + for (i = 0; i < 4; i++) + set_bit(PG_arch_1, &page[i].flags); + } + mark_kernel_pmd(pud, addr, next); + } while (pud++, addr = next, addr != end); +} + +static void mark_kernel_p4d(pgd_t *pgd, unsigned long addr, unsigned long end) +{ + unsigned long next; + struct page *page; + p4d_t *p4d; + int i; + + p4d = p4d_offset(pgd, addr); + do { + next = p4d_addr_end(addr, end); + if (p4d_none(*p4d)) + continue; + if (!p4d_folded(*p4d)) { + page = phys_to_page(p4d_val(*p4d)); + for (i = 0; i < 4; i++) + set_bit(PG_arch_1, &page[i].flags); + } + mark_kernel_pud(p4d, addr, next); + } while (p4d++, addr = next, addr != end); +} + +static void mark_kernel_pgd(void) +{ + unsigned long addr, next; + struct page *page; + pgd_t *pgd; + int i; + + addr = 0; + pgd = pgd_offset_k(addr); + do { + next = pgd_addr_end(addr, MODULES_END); + if (pgd_none(*pgd)) + continue; + if (!pgd_folded(*pgd)) { + page = phys_to_page(pgd_val(*pgd)); + for (i = 0; i < 4; i++) + set_bit(PG_arch_1, &page[i].flags); + } + mark_kernel_p4d(pgd, addr, next); + } while (pgd++, addr = next, addr != MODULES_END); +} + +void __init cmma_init_nodat(void) +{ + struct page *page; + unsigned long start, end, ix; + int i; + + if (cmma_flag < 2) + return; + /* Mark pages used in kernel page tables */ + mark_kernel_pgd(); + page = virt_to_page(&swapper_pg_dir); + for (i = 0; i < 4; i++) + set_bit(PG_arch_1, &page[i].flags); + page = virt_to_page(&invalid_pg_dir); + for (i = 0; i < 4; i++) + set_bit(PG_arch_1, &page[i].flags); + + /* Set all kernel pages not used for page tables to stable/no-dat */ + for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) { + page = pfn_to_page(start); + for (ix = start; ix < end; ix++, page++) { + if (__test_and_clear_bit(PG_arch_1, &page->flags)) + continue; /* skip page table pages */ + if (!list_empty(&page->lru)) + continue; /* skip free pages */ + set_page_stable_nodat(page, 0); + } + } +} + +void arch_free_page(struct page *page, int order) +{ + if (!cmma_flag) + return; + set_page_unused(page, order); +} + +void arch_alloc_page(struct page *page, int order) +{ + if (!cmma_flag) + return; + if (cmma_flag < 2) + set_page_stable_dat(page, order); + else + set_page_stable_nodat(page, order); +} + +void arch_set_page_dat(struct page *page, int order) +{ + if (!cmma_flag) + return; + set_page_stable_dat(page, order); +} |