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f9cb654cb5
Most architectures define pgd_free() as a wrapper for free_page(). Provide a generic version in asm-generic/pgalloc.h and enable its use for most architectures. 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> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] 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: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200627143453.31835-7-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
109 lines
3.1 KiB
C
109 lines
3.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_PGALLOC_H
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#define _ASM_PGALLOC_H
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#include <linux/gfp.h>
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#include <linux/mm.h>
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#include <linux/threads.h>
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#include <asm/processor.h>
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#include <asm/fixmap.h>
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#include <asm/cache.h>
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#define __HAVE_ARCH_PMD_FREE
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#define __HAVE_ARCH_PGD_FREE
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#include <asm-generic/pgalloc.h>
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/* Allocate the top level pgd (page directory)
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*
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* Here (for 64 bit kernels) we implement a Hybrid L2/L3 scheme: we
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* allocate the first pmd adjacent to the pgd. This means that we can
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* subtract a constant offset to get to it. The pmd and pgd sizes are
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* arranged so that a single pmd covers 4GB (giving a full 64-bit
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* process access to 8TB) so our lookups are effectively L2 for the
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* first 4GB of the kernel (i.e. for all ILP32 processes and all the
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* kernel for machines with under 4GB of memory) */
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static inline pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *pgd = (pgd_t *)__get_free_pages(GFP_KERNEL,
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PGD_ALLOC_ORDER);
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pgd_t *actual_pgd = pgd;
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if (likely(pgd != NULL)) {
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memset(pgd, 0, PAGE_SIZE<<PGD_ALLOC_ORDER);
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#if CONFIG_PGTABLE_LEVELS == 3
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actual_pgd += PTRS_PER_PGD;
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/* Populate first pmd with allocated memory. We mark it
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* with PxD_FLAG_ATTACHED as a signal to the system that this
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* pmd entry may not be cleared. */
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set_pgd(actual_pgd, __pgd((PxD_FLAG_PRESENT |
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PxD_FLAG_VALID |
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PxD_FLAG_ATTACHED)
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+ (__u32)(__pa((unsigned long)pgd) >> PxD_VALUE_SHIFT)));
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/* The first pmd entry also is marked with PxD_FLAG_ATTACHED as
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* a signal that this pmd may not be freed */
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set_pgd(pgd, __pgd(PxD_FLAG_ATTACHED));
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#endif
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}
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spin_lock_init(pgd_spinlock(actual_pgd));
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return actual_pgd;
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}
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static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
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{
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#if CONFIG_PGTABLE_LEVELS == 3
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pgd -= PTRS_PER_PGD;
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#endif
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free_pages((unsigned long)pgd, PGD_ALLOC_ORDER);
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}
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#if CONFIG_PGTABLE_LEVELS == 3
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/* Three Level Page Table Support for pmd's */
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static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
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{
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set_pud(pud, __pud((PxD_FLAG_PRESENT | PxD_FLAG_VALID) +
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(__u32)(__pa((unsigned long)pmd) >> PxD_VALUE_SHIFT)));
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}
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static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
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{
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if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED) {
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/*
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* This is the permanent pmd attached to the pgd;
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* cannot free it.
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* Increment the counter to compensate for the decrement
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* done by generic mm code.
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*/
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mm_inc_nr_pmds(mm);
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return;
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}
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free_pages((unsigned long)pmd, PMD_ORDER);
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}
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#endif
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static inline void
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pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
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{
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#if CONFIG_PGTABLE_LEVELS == 3
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/* preserve the gateway marker if this is the beginning of
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* the permanent pmd */
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if(pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
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set_pmd(pmd, __pmd((PxD_FLAG_PRESENT |
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PxD_FLAG_VALID |
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PxD_FLAG_ATTACHED)
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+ (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT)));
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else
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#endif
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set_pmd(pmd, __pmd((PxD_FLAG_PRESENT | PxD_FLAG_VALID)
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+ (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT)));
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}
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#define pmd_populate(mm, pmd, pte_page) \
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pmd_populate_kernel(mm, pmd, page_address(pte_page))
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#define pmd_pgtable(pmd) pmd_page(pmd)
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#endif
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