forked from Minki/linux
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>
36 lines
1.1 KiB
C
36 lines
1.1 KiB
C
#ifndef _ASM_POWERPC_PTE_WALK_H
|
|
#define _ASM_POWERPC_PTE_WALK_H
|
|
|
|
#include <linux/sched.h>
|
|
|
|
/* Don't use this directly */
|
|
extern pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
|
|
bool *is_thp, unsigned *hshift);
|
|
|
|
static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea,
|
|
bool *is_thp, unsigned *hshift)
|
|
{
|
|
VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
|
|
return __find_linux_pte(pgdir, ea, is_thp, hshift);
|
|
}
|
|
|
|
static inline pte_t *find_init_mm_pte(unsigned long ea, unsigned *hshift)
|
|
{
|
|
pgd_t *pgdir = init_mm.pgd;
|
|
return __find_linux_pte(pgdir, ea, NULL, hshift);
|
|
}
|
|
/*
|
|
* This is what we should always use. Any other lockless page table lookup needs
|
|
* careful audit against THP split.
|
|
*/
|
|
static inline pte_t *find_current_mm_pte(pgd_t *pgdir, unsigned long ea,
|
|
bool *is_thp, unsigned *hshift)
|
|
{
|
|
VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
|
|
VM_WARN(pgdir != current->mm->pgd,
|
|
"%s lock less page table lookup called on wrong mm\n", __func__);
|
|
return __find_linux_pte(pgdir, ea, is_thp, hshift);
|
|
}
|
|
|
|
#endif /* _ASM_POWERPC_PTE_WALK_H */
|