[PATCH v5 06/38] mm: Add default definition of set_ptes()

From: Matthew Wilcox (Oracle)
Date: Mon Jul 10 2023 - 16:46:41 EST


Most architectures can just define set_pte() and PFN_PTE_SHIFT to
use this definition. It's also a handy spot to document the guarantees
provided by the MM.

Suggested-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
---
include/linux/pgtable.h | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 5063b482e34f..22f48f9997d5 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -180,6 +180,43 @@ static inline int pmd_young(pmd_t pmd)
}
#endif

+#ifndef set_ptes
+#ifdef PFN_PTE_SHIFT
+/**
+ * set_ptes - Map consecutive pages to a contiguous range of addresses.
+ * @mm: Address space to map the pages into.
+ * @addr: Address to map the first page at.
+ * @ptep: Page table pointer for the first entry.
+ * @pte: Page table entry for the first page.
+ * @nr: Number of pages to map.
+ *
+ * May be overridden by the architecture, or the architecture can define
+ * set_pte() and PFN_PTE_SHIFT.
+ *
+ * Context: The caller holds the page table lock. The pages all belong
+ * to the same folio. The PTEs are all in the same PMD.
+ */
+static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned int nr)
+{
+ page_table_check_ptes_set(mm, addr, ptep, pte, nr);
+
+ for (;;) {
+ set_pte(ptep, pte);
+ if (--nr == 0)
+ break;
+ ptep++;
+ pte = __pte(pte_val(pte) + (1UL << PFN_PTE_SHIFT));
+ }
+}
+#ifndef set_pte_at
+#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
+#endif
+#endif
+#else
+#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
+#endif
+
#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
extern int ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,
--
2.39.2