[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/arch/s390/mm/gup.c b/src/kernel/linux/v4.14/arch/s390/mm/gup.c
new file mode 100644
index 0000000..9bce54e
--- /dev/null
+++ b/src/kernel/linux/v4.14/arch/s390/mm/gup.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Lockless get_user_pages_fast for s390
+ *
+ * Copyright IBM Corp. 2010
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/vmstat.h>
+#include <linux/pagemap.h>
+#include <linux/rwsem.h>
+#include <asm/pgtable.h>
+
+/*
+ * The performance critical leaf functions are made noinline otherwise gcc
+ * inlines everything into a single function which results in too much
+ * register pressure.
+ */
+static inline int gup_pte_range(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
+ unsigned long end, int write, struct page **pages, int *nr)
+{
+ struct page *head, *page;
+ unsigned long mask;
+ pte_t *ptep, pte;
+
+ mask = (write ? _PAGE_PROTECT : 0) | _PAGE_INVALID | _PAGE_SPECIAL;
+
+ ptep = ((pte_t *) pmd_deref(pmd)) + pte_index(addr);
+ do {
+ pte = *ptep;
+ barrier();
+ /* Similar to the PMD case, NUMA hinting must take slow path */
+ if (pte_protnone(pte))
+ return 0;
+ if ((pte_val(pte) & mask) != 0)
+ return 0;
+ VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
+ page = pte_page(pte);
+ head = compound_head(page);
+ if (unlikely(WARN_ON_ONCE(page_ref_count(head) < 0)
+ || !page_cache_get_speculative(head)))
+ return 0;
+ if (unlikely(pte_val(pte) != pte_val(*ptep))) {
+ put_page(head);
+ return 0;
+ }
+ VM_BUG_ON_PAGE(compound_head(page) != head, page);
+ pages[*nr] = page;
+ (*nr)++;
+
+ } while (ptep++, addr += PAGE_SIZE, addr != end);
+
+ return 1;
+}
+
+static inline int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
+ unsigned long end, int write, struct page **pages, int *nr)
+{
+ struct page *head, *page;
+ unsigned long mask;
+ int refs;
+
+ mask = (write ? _SEGMENT_ENTRY_PROTECT : 0) | _SEGMENT_ENTRY_INVALID;
+ if ((pmd_val(pmd) & mask) != 0)
+ return 0;
+ VM_BUG_ON(!pfn_valid(pmd_val(pmd) >> PAGE_SHIFT));
+
+ refs = 0;
+ head = pmd_page(pmd);
+ page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
+ do {
+ VM_BUG_ON(compound_head(page) != head);
+ pages[*nr] = page;
+ (*nr)++;
+ page++;
+ refs++;
+ } while (addr += PAGE_SIZE, addr != end);
+
+ if (unlikely(WARN_ON_ONCE(page_ref_count(head) < 0)
+ || !page_cache_add_speculative(head, refs))) {
+ *nr -= refs;
+ return 0;
+ }
+
+ if (unlikely(pmd_val(pmd) != pmd_val(*pmdp))) {
+ *nr -= refs;
+ while (refs--)
+ put_page(head);
+ return 0;
+ }
+
+ return 1;
+}
+
+
+static inline int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr,
+ unsigned long end, int write, struct page **pages, int *nr)
+{
+ unsigned long next;
+ pmd_t *pmdp, pmd;
+
+ pmdp = (pmd_t *) pudp;
+ if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
+ pmdp = (pmd_t *) pud_deref(pud);
+ pmdp += pmd_index(addr);
+ do {
+ pmd = *pmdp;
+ barrier();
+ next = pmd_addr_end(addr, end);
+ if (pmd_none(pmd))
+ return 0;
+ if (unlikely(pmd_large(pmd))) {
+ /*
+ * NUMA hinting faults need to be handled in the GUP
+ * slowpath for accounting purposes and so that they
+ * can be serialised against THP migration.
+ */
+ if (pmd_protnone(pmd))
+ return 0;
+ if (!gup_huge_pmd(pmdp, pmd, addr, next,
+ write, pages, nr))
+ return 0;
+ } else if (!gup_pte_range(pmdp, pmd, addr, next,
+ write, pages, nr))
+ return 0;
+ } while (pmdp++, addr = next, addr != end);
+
+ return 1;
+}
+
+static int gup_huge_pud(pud_t *pudp, pud_t pud, unsigned long addr,
+ unsigned long end, int write, struct page **pages, int *nr)
+{
+ struct page *head, *page;
+ unsigned long mask;
+ int refs;
+
+ mask = (write ? _REGION_ENTRY_PROTECT : 0) | _REGION_ENTRY_INVALID;
+ if ((pud_val(pud) & mask) != 0)
+ return 0;
+ VM_BUG_ON(!pfn_valid(pud_pfn(pud)));
+
+ refs = 0;
+ head = pud_page(pud);
+ page = head + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
+ do {
+ VM_BUG_ON_PAGE(compound_head(page) != head, page);
+ pages[*nr] = page;
+ (*nr)++;
+ page++;
+ refs++;
+ } while (addr += PAGE_SIZE, addr != end);
+
+ if (unlikely(WARN_ON_ONCE(page_ref_count(head) < 0)
+ || !page_cache_add_speculative(head, refs))) {
+ *nr -= refs;
+ return 0;
+ }
+
+ if (unlikely(pud_val(pud) != pud_val(*pudp))) {
+ *nr -= refs;
+ while (refs--)
+ put_page(head);
+ return 0;
+ }
+
+ return 1;
+}
+
+static inline int gup_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr,
+ unsigned long end, int write, struct page **pages, int *nr)
+{
+ unsigned long next;
+ pud_t *pudp, pud;
+
+ pudp = (pud_t *) p4dp;
+ if ((p4d_val(p4d) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
+ pudp = (pud_t *) p4d_deref(p4d);
+ pudp += pud_index(addr);
+ do {
+ pud = *pudp;
+ barrier();
+ next = pud_addr_end(addr, end);
+ if (pud_none(pud))
+ return 0;
+ if (unlikely(pud_large(pud))) {
+ if (!gup_huge_pud(pudp, pud, addr, next, write, pages,
+ nr))
+ return 0;
+ } else if (!gup_pmd_range(pudp, pud, addr, next, write, pages,
+ nr))
+ return 0;
+ } while (pudp++, addr = next, addr != end);
+
+ return 1;
+}
+
+static inline int gup_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr,
+ unsigned long end, int write, struct page **pages, int *nr)
+{
+ unsigned long next;
+ p4d_t *p4dp, p4d;
+
+ p4dp = (p4d_t *) pgdp;
+ if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R1)
+ p4dp = (p4d_t *) pgd_deref(pgd);
+ p4dp += p4d_index(addr);
+ do {
+ p4d = *p4dp;
+ barrier();
+ next = p4d_addr_end(addr, end);
+ if (p4d_none(p4d))
+ return 0;
+ if (!gup_pud_range(p4dp, p4d, addr, next, write, pages, nr))
+ return 0;
+ } while (p4dp++, addr = next, addr != end);
+
+ return 1;
+}
+
+/*
+ * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
+ * back to the regular GUP.
+ */
+int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
+ struct page **pages)
+{
+ struct mm_struct *mm = current->mm;
+ unsigned long addr, len, end;
+ unsigned long next, flags;
+ pgd_t *pgdp, pgd;
+ int nr = 0;
+
+ start &= PAGE_MASK;
+ addr = start;
+ len = (unsigned long) nr_pages << PAGE_SHIFT;
+ end = start + len;
+ if ((end <= start) || (end > mm->context.asce_limit))
+ return 0;
+ /*
+ * local_irq_save() doesn't prevent pagetable teardown, but does
+ * prevent the pagetables from being freed on s390.
+ *
+ * So long as we atomically load page table pointers versus teardown,
+ * we can follow the address down to the the page and take a ref on it.
+ */
+ local_irq_save(flags);
+ pgdp = pgd_offset(mm, addr);
+ do {
+ pgd = *pgdp;
+ barrier();
+ next = pgd_addr_end(addr, end);
+ if (pgd_none(pgd))
+ break;
+ if (!gup_p4d_range(pgdp, pgd, addr, next, write, pages, &nr))
+ break;
+ } while (pgdp++, addr = next, addr != end);
+ local_irq_restore(flags);
+
+ return nr;
+}
+
+/**
+ * get_user_pages_fast() - pin user pages in memory
+ * @start: starting user address
+ * @nr_pages: number of pages from start to pin
+ * @write: whether pages will be written to
+ * @pages: array that receives pointers to the pages pinned.
+ * Should be at least nr_pages long.
+ *
+ * Attempt to pin user pages in memory without taking mm->mmap_sem.
+ * If not successful, it will fall back to taking the lock and
+ * calling get_user_pages().
+ *
+ * Returns number of pages pinned. This may be fewer than the number
+ * requested. If nr_pages is 0 or negative, returns 0. If no pages
+ * were pinned, returns -errno.
+ */
+int get_user_pages_fast(unsigned long start, int nr_pages, int write,
+ struct page **pages)
+{
+ int nr, ret;
+
+ might_sleep();
+ start &= PAGE_MASK;
+ nr = __get_user_pages_fast(start, nr_pages, write, pages);
+ if (nr == nr_pages)
+ return nr;
+
+ /* Try to get the remaining pages with get_user_pages */
+ start += nr << PAGE_SHIFT;
+ pages += nr;
+ ret = get_user_pages_unlocked(start, nr_pages - nr, pages,
+ write ? FOLL_WRITE : 0);
+ /* Have to be a bit careful with return values */
+ if (nr > 0)
+ ret = (ret < 0) ? nr : ret + nr;
+ return ret;
+}