diff options
author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2017-07-27 11:54:53 +0530 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-08-17 23:13:46 +1000 |
commit | 94171b19c3f1f4d9d4c0e3aaa1aa161def1ec7ea (patch) | |
tree | 92f29a416e19671ac8fce9a84ed138c115396704 /arch/powerpc/include/asm | |
parent | 520eccdfe187591a51ea9ab4c1a024ae4d0f68d9 (diff) | |
download | op-kernel-dev-94171b19c3f1f4d9d4c0e3aaa1aa161def1ec7ea.zip op-kernel-dev-94171b19c3f1f4d9d4c0e3aaa1aa161def1ec7ea.tar.gz |
powerpc/mm: Rename find_linux_pte_or_hugepte()
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>
Diffstat (limited to 'arch/powerpc/include/asm')
-rw-r--r-- | arch/powerpc/include/asm/pgtable.h | 10 | ||||
-rw-r--r-- | arch/powerpc/include/asm/pte-walk.h | 35 |
2 files changed, 36 insertions, 9 deletions
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index afae9a3..eb9d57d 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -66,16 +66,8 @@ extern int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr, #ifndef CONFIG_TRANSPARENT_HUGEPAGE #define pmd_large(pmd) 0 #endif -pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, - bool *is_thp, unsigned *shift); -static inline pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, - bool *is_thp, unsigned *shift) -{ - VM_WARN(!arch_irqs_disabled(), - "%s called with irq enabled\n", __func__); - return __find_linux_pte_or_hugepte(pgdir, ea, is_thp, shift); -} +/* can we use this in kvm */ unsigned long vmalloc_to_phys(void *vmalloc_addr); void pgtable_cache_add(unsigned shift, void (*ctor)(void *)); diff --git a/arch/powerpc/include/asm/pte-walk.h b/arch/powerpc/include/asm/pte-walk.h new file mode 100644 index 0000000..2d633e9 --- /dev/null +++ b/arch/powerpc/include/asm/pte-walk.h @@ -0,0 +1,35 @@ +#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 */ |