#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/swapops.h>
+#include <linux/sysctl.h>
#include <linux/ksm.h>
#include <linux/mman.h>
#define ALLOC_ORDER 2
#define FRAG_MASK 0x03
+int HPAGE_SHIFT;
+
unsigned long *crst_table_alloc(struct mm_struct *mm)
{
struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
}
EXPORT_SYMBOL(get_guest_storage_key);
+static int page_table_allocate_pgste_min = 0;
+static int page_table_allocate_pgste_max = 1;
+int page_table_allocate_pgste = 0;
+EXPORT_SYMBOL(page_table_allocate_pgste);
+
+static struct ctl_table page_table_sysctl[] = {
+ {
+ .procname = "allocate_pgste",
+ .data = &page_table_allocate_pgste,
+ .maxlen = sizeof(int),
+ .mode = S_IRUGO | S_IWUSR,
+ .proc_handler = proc_dointvec,
+ .extra1 = &page_table_allocate_pgste_min,
+ .extra2 = &page_table_allocate_pgste_max,
+ },
+ { }
+};
+
+static struct ctl_table page_table_sysctl_dir[] = {
+ {
+ .procname = "vm",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = page_table_sysctl,
+ },
+ { }
+};
+
+static int __init page_table_register_sysctl(void)
+{
+ return register_sysctl_table(page_table_sysctl_dir) ? 0 : -ENOMEM;
+}
+__initcall(page_table_register_sysctl);
+
#else /* CONFIG_PGSTE */
static inline int page_table_with_pgste(struct page *page)
struct page *uninitialized_var(page);
unsigned int mask, bit;
- if (mm_has_pgste(mm))
+ if (mm_alloc_pgste(mm))
return page_table_alloc_pgste(mm);
/* Allocate fragments of a 4K page as 1K/2K page table */
spin_lock_bh(&mm->context.list_lock);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-static unsigned long page_table_realloc_pmd(struct mmu_gather *tlb,
- struct mm_struct *mm, pud_t *pud,
- unsigned long addr, unsigned long end)
-{
- unsigned long next, *table, *new;
- struct page *page;
- spinlock_t *ptl;
- pmd_t *pmd;
-
- pmd = pmd_offset(pud, addr);
- do {
- next = pmd_addr_end(addr, end);
-again:
- if (pmd_none_or_clear_bad(pmd))
- continue;
- table = (unsigned long *) pmd_deref(*pmd);
- page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
- if (page_table_with_pgste(page))
- continue;
- /* Allocate new page table with pgstes */
- new = page_table_alloc_pgste(mm);
- if (!new)
- return -ENOMEM;
-
- ptl = pmd_lock(mm, pmd);
- if (likely((unsigned long *) pmd_deref(*pmd) == table)) {
- /* Nuke pmd entry pointing to the "short" page table */
- pmdp_flush_lazy(mm, addr, pmd);
- pmd_clear(pmd);
- /* Copy ptes from old table to new table */
- memcpy(new, table, PAGE_SIZE/2);
- clear_table(table, _PAGE_INVALID, PAGE_SIZE/2);
- /* Establish new table */
- pmd_populate(mm, pmd, (pte_t *) new);
- /* Free old table with rcu, there might be a walker! */
- page_table_free_rcu(tlb, table, addr);
- new = NULL;
- }
- spin_unlock(ptl);
- if (new) {
- page_table_free_pgste(new);
- goto again;
- }
- } while (pmd++, addr = next, addr != end);
-
- return addr;
-}
-
-static unsigned long page_table_realloc_pud(struct mmu_gather *tlb,
- struct mm_struct *mm, pgd_t *pgd,
- unsigned long addr, unsigned long end)
-{
- unsigned long next;
- pud_t *pud;
-
- pud = pud_offset(pgd, addr);
- do {
- next = pud_addr_end(addr, end);
- if (pud_none_or_clear_bad(pud))
- continue;
- next = page_table_realloc_pmd(tlb, mm, pud, addr, next);
- if (unlikely(IS_ERR_VALUE(next)))
- return next;
- } while (pud++, addr = next, addr != end);
-
- return addr;
-}
-
-static unsigned long page_table_realloc(struct mmu_gather *tlb, struct mm_struct *mm,
- unsigned long addr, unsigned long end)
-{
- unsigned long next;
- pgd_t *pgd;
-
- pgd = pgd_offset(mm, addr);
- do {
- next = pgd_addr_end(addr, end);
- if (pgd_none_or_clear_bad(pgd))
- continue;
- next = page_table_realloc_pud(tlb, mm, pgd, addr, next);
- if (unlikely(IS_ERR_VALUE(next)))
- return next;
- } while (pgd++, addr = next, addr != end);
-
- return 0;
-}
-
/*
* switch on pgstes for its userspace process (for kvm)
*/
int s390_enable_sie(void)
{
- struct task_struct *tsk = current;
- struct mm_struct *mm = tsk->mm;
- struct mmu_gather tlb;
+ struct mm_struct *mm = current->mm;
/* Do we have pgstes? if yes, we are done */
- if (mm_has_pgste(tsk->mm))
+ if (mm_has_pgste(mm))
return 0;
-
+ /* Fail if the page tables are 2K */
+ if (!mm_alloc_pgste(mm))
+ return -EINVAL;
down_write(&mm->mmap_sem);
+ mm->context.has_pgste = 1;
/* split thp mappings and disable thp for future mappings */
thp_split_mm(mm);
- /* Reallocate the page tables with pgstes */
- tlb_gather_mmu(&tlb, mm, 0, TASK_SIZE);
- if (!page_table_realloc(&tlb, mm, 0, TASK_SIZE))
- mm->context.has_pgste = 1;
- tlb_finish_mmu(&tlb, 0, TASK_SIZE);
up_write(&mm->mmap_sem);
- return mm->context.has_pgste ? 0 : -ENOMEM;
+ return 0;
}
EXPORT_SYMBOL_GPL(s390_enable_sie);
projects / linux-drm-fsl-dcu.git / blobdiff