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authorMike Rapoport <rppt@linux.ibm.com>2020-08-06 23:22:39 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-07 11:33:26 -0700
commit1355c31eeb7ea61a7f2f2937d17cd4e343a6b5af (patch)
treed4fb6613355844ad2f28283178f511c5b1e3d35e /include/asm-generic
parent7278914ca1fdb54ba101c8617fb86953b31348cd (diff)
asm-generic: pgalloc: provide generic pmd_alloc_one() and pmd_free_one()
For most architectures that support >2 levels of page tables, pmd_alloc_one() is a wrapper for __get_free_pages(), sometimes with __GFP_ZERO and sometimes followed by memset(0) instead. More elaborate versions on arm64 and x86 account memory for the user page tables and call to pgtable_pmd_page_ctor() as the part of PMD page initialization. Move the arm64 version to include/asm-generic/pgalloc.h and use the generic version on several architectures. The pgtable_pmd_page_ctor() is a NOP when ARCH_ENABLE_SPLIT_PMD_PTLOCK is not enabled, so there is no functional change for most architectures except of the addition of __GFP_ACCOUNT for allocation of user page tables. The pmd_free() is a wrapper for free_page() in all the cases, so no functional change here. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Joerg Roedel <joro@8bytes.org> Cc: Joerg Roedel <jroedel@suse.de> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/20200627143453.31835-5-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/pgalloc.h43
1 files changed, 43 insertions, 0 deletions
diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
index 73f7421413cb..1bc027891a00 100644
--- a/include/asm-generic/pgalloc.h
+++ b/include/asm-generic/pgalloc.h
@@ -102,6 +102,49 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
__free_page(pte_page);
}
+
+#if CONFIG_PGTABLE_LEVELS > 2
+
+#ifndef __HAVE_ARCH_PMD_ALLOC_ONE
+/**
+ * pmd_alloc_one - allocate a page for PMD-level page table
+ * @mm: the mm_struct of the current context
+ *
+ * Allocates a page and runs the pgtable_pmd_page_ctor().
+ * Allocations use %GFP_PGTABLE_USER in user context and
+ * %GFP_PGTABLE_KERNEL in kernel context.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
+{
+ struct page *page;
+ gfp_t gfp = GFP_PGTABLE_USER;
+
+ if (mm == &init_mm)
+ gfp = GFP_PGTABLE_KERNEL;
+ page = alloc_pages(gfp, 0);
+ if (!page)
+ return NULL;
+ if (!pgtable_pmd_page_ctor(page)) {
+ __free_pages(page, 0);
+ return NULL;
+ }
+ return (pmd_t *)page_address(page);
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMD_FREE
+static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
+{
+ BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
+ pgtable_pmd_page_dtor(virt_to_page(pmd));
+ free_page((unsigned long)pmd);
+}
+#endif
+
+#endif /* CONFIG_PGTABLE_LEVELS > 2 */
+
#endif /* CONFIG_MMU */
#endif /* __ASM_GENERIC_PGALLOC_H */