include/asm/pte-walk.h

0001 #ifndef _ASM_POWERPC_PTE_WALK_H
0002 #define _ASM_POWERPC_PTE_WALK_H
0003
0004 #include <linux/sched.h>
0005
0006 /* Don't use this directly */
0007 extern pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
0008                    bool *is_thp, unsigned *hshift);
0009
0010 static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea,
0011                     bool *is_thp, unsigned *hshift)
0012 {
0013     pte_t *pte;
0014
0015     VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
0016     pte = __find_linux_pte(pgdir, ea, is_thp, hshift);
0017
0018 #if defined(CONFIG_DEBUG_VM) &&                     \
0019     !(defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE))
0020     /*
0021      * We should not find huge page if these configs are not enabled.
0022      */
0023     if (hshift)
0024         WARN_ON(*hshift);
0025 #endif
0026     return pte;
0027 }
0028
0029 static inline pte_t *find_init_mm_pte(unsigned long ea, unsigned *hshift)
0030 {
0031     pgd_t *pgdir = init_mm.pgd;
0032     return __find_linux_pte(pgdir, ea, NULL, hshift);
0033 }
0034
0035 /*
0036  * Convert a kernel vmap virtual address (vmalloc or ioremap space) to a
0037  * physical address, without taking locks. This can be used in real-mode.
0038  */
0039 static inline phys_addr_t ppc_find_vmap_phys(unsigned long addr)
0040 {
0041     pte_t *ptep;
0042     phys_addr_t pa;
0043     int hugepage_shift;
0044
0045     /*
0046      * init_mm does not free page tables, and does not do THP. It may
0047      * have huge pages from huge vmalloc / ioremap etc.
0048      */
0049     ptep = find_init_mm_pte(addr, &hugepage_shift);
0050     if (WARN_ON(!ptep))
0051         return 0;
0052
0053     pa = PFN_PHYS(pte_pfn(*ptep));
0054
0055     if (!hugepage_shift)
0056         hugepage_shift = PAGE_SHIFT;
0057
0058     pa |= addr & ((1ul << hugepage_shift) - 1);
0059
0060     return pa;
0061 }
0062
0063 /*
0064  * This is what we should always use. Any other lockless page table lookup needs
0065  * careful audit against THP split.
0066  */
0067 static inline pte_t *find_current_mm_pte(pgd_t *pgdir, unsigned long ea,
0068                      bool *is_thp, unsigned *hshift)
0069 {
0070     pte_t *pte;
0071
0072     VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
0073     VM_WARN(pgdir != current->mm->pgd,
0074         "%s lock less page table lookup called on wrong mm\n", __func__);
0075     pte = __find_linux_pte(pgdir, ea, is_thp, hshift);
0076
0077 #if defined(CONFIG_DEBUG_VM) &&                     \
0078     !(defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE))
0079     /*
0080      * We should not find huge page if these configs are not enabled.
0081      */
0082     if (hshift)
0083         WARN_ON(*hshift);
0084 #endif
0085     return pte;
0086 }
0087
0088 #endif /* _ASM_POWERPC_PTE_WALK_H */