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94171b19c3
Add newer helpers to make the function usage simpler. It is always recommended to use find_current_mm_pte() for walking the page table. If we cannot use find_current_mm_pte(), it should be documented why the said usage of __find_linux_pte() is safe against a parallel THP split. For now we have KVM code using __find_linux_pte(). This is because kvm code ends up calling __find_linux_pte() in real mode with MSR_EE=0 but with PACA soft_enabled = 1. We may want to fix that later and make sure we keep the MSR_EE and PACA soft_enabled in sync. When we do that we can switch kvm to use find_linux_pte(). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
35 lines
1.1 KiB
C
35 lines
1.1 KiB
C
#ifndef _ASM_POWERPC_PTE_WALK_H
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#define _ASM_POWERPC_PTE_WALK_H
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#include <linux/sched.h>
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/* Don't use this directly */
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extern pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
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bool *is_thp, unsigned *hshift);
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static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea,
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bool *is_thp, unsigned *hshift)
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{
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VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
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return __find_linux_pte(pgdir, ea, is_thp, hshift);
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}
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static inline pte_t *find_init_mm_pte(unsigned long ea, unsigned *hshift)
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{
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pgd_t *pgdir = init_mm.pgd;
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return __find_linux_pte(pgdir, ea, NULL, hshift);
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}
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/*
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* This is what we should always use. Any other lockless page table lookup needs
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* careful audit against THP split.
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*/
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static inline pte_t *find_current_mm_pte(pgd_t *pgdir, unsigned long ea,
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bool *is_thp, unsigned *hshift)
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{
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VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
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VM_WARN(pgdir != current->mm->pgd,
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"%s lock less page table lookup called on wrong mm\n", __func__);
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return __find_linux_pte(pgdir, ea, is_thp, hshift);
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}
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#endif /* _ASM_POWERPC_PTE_WALK_H */
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