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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-28 09:58:46 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-28 09:58:46 -0700
commit14bc84ce0b41787acc08aefabe718479c5dde60e (patch)
tree865d39bf0c4682e11c9c7bef0712872b2a5eca55 /arch/s390/mm/pgtable.c
parent2decb2682f80759f631c8332f9a2a34a02150a03 (diff)
parent57127645d79d2e83e801f141f7d03f64accf28aa (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky: "One additional new feature for 4.1, a new PRNG based on SHA-512 for the zcrypt driver. Two memory management related changes, the page table reallocation for KVM is removed, and with file ptes gone the encoding of page table entries is improved. And three bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/zcrypt: Introduce new SHA-512 based Pseudo Random Generator. s390/mm: change swap pte encoding and pgtable cleanup s390/mm: correct transfer of dirty & young bits in __pmd_to_pte s390/bpf: add dependency to z196 features s390/3215: free memory in error path s390/kvm: remove delayed reallocation of page tables for KVM kexec: allocate the kexec control page with KEXEC_CONTROL_MEMORY_GFP
Diffstat (limited to 'arch/s390/mm/pgtable.c')
-rw-r--r--arch/s390/mm/pgtable.c142
1 files changed, 43 insertions, 99 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 33f589459113..b33f66110ca9 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -18,6 +18,7 @@
#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/swapops.h>
+#include <linux/sysctl.h>
#include <linux/ksm.h>
#include <linux/mman.h>
@@ -920,6 +921,40 @@ unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr)
}
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)
@@ -963,7 +998,7 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
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);
@@ -1165,116 +1200,25 @@ static inline void thp_split_mm(struct mm_struct *mm)
}
#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);

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