Commit 7278914c authored Aug 06, 2020 by Mike Rapoport Committed by Linus Torvalds Aug 07, 2020

xtensa: switch to generic version of pte allocation

xtensa clears PTEs during allocation of the page tables and pte_clear()
sets the PTE to a non-zero value.  Splitting ptes_clear() helper out of
pte_alloc_one() and pte_alloc_one_kernel() allows reuse of base generic
allocation methods (__pte_alloc_one() and __pte_alloc_one_kernel()) and
the common GFP mask for page table allocations.

The pte_free() and pte_free_kernel() implementations on xtensa are
identical to the generic ones and can be dropped.

[jcmvbkbc@gmail.com: xtensa: fix closing endif comment]
  Link: http://lkml.kernel.org/r/20200721024751.1257-1-jcmvbkbc@gmail.com



Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.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>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-4-rppt@kernel.org


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent fc2a6b83

arch/xtensa/include/asm/pgalloc.h

+19 −22

Original line number	Diff line number	Diff line
		@@ -8,9 +8,14 @@
		#ifndef _XTENSA_PGALLOC_H
		#define _XTENSA_PGALLOC_H

		#ifdef CONFIG_MMU
		#include <linux/highmem.h>
		#include <linux/slab.h>

		#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
		#define __HAVE_ARCH_PTE_ALLOC_ONE
		#include <asm-generic/pgalloc.h>

		/*
		* Allocating and freeing a pmd is trivial: the 1-entry pmd is
		* inside the pgd, so has no extra memory associated with it.
		@@ -33,45 +38,37 @@ static inline void pgd_free(struct mm_struct mm, pgd_t pgd)
		free_page((unsigned long)pgd);
		}

		static inline void ptes_clear(pte_t *ptep)
		{
		int i;

		for (i = 0; i < PTRS_PER_PTE; i++)
		pte_clear(NULL, 0, ptep + i);
		}

		static inline pte_t pte_alloc_one_kernel(struct mm_struct mm)
		{
		pte_t *ptep;
		int i;

		ptep = (pte_t *)__get_free_page(GFP_KERNEL);
		ptep = (pte_t *)__pte_alloc_one_kernel(mm);
		if (!ptep)
		return NULL;
		for (i = 0; i < 1024; i++)
		pte_clear(NULL, 0, ptep + i);
		ptes_clear(ptep);
		return ptep;
		}

		static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
		{
		pte_t *pte;
		struct page *page;

		pte = pte_alloc_one_kernel(mm);
		if (!pte)
		return NULL;
		page = virt_to_page(pte);
		if (!pgtable_pte_page_ctor(page)) {
		__free_page(page);
		page = __pte_alloc_one(mm, GFP_PGTABLE_USER);
		if (!page)
		return NULL;
		}
		ptes_clear(page_address(page));
		return page;
		}

		static inline void pte_free_kernel(struct mm_struct mm, pte_t pte)
		{
		free_page((unsigned long)pte);
		}

		static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
		{
		pgtable_pte_page_dtor(pte);
		__free_page(pte);
		}
		#define pmd_pgtable(pmd) pmd_page(pmd)
		#endif /* CONFIG_MMU */

		#endif /* _XTENSA_PGALLOC_H */

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