cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

pte-walk.h (2281B)

      1#ifndef _ASM_POWERPC_PTE_WALK_H
      2#define _ASM_POWERPC_PTE_WALK_H
      3
      4#include <linux/sched.h>
      5
      6/* Don't use this directly */
      7extern pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
      8			       bool *is_thp, unsigned *hshift);
      9
     10static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea,
     11				    bool *is_thp, unsigned *hshift)
     12{
     13	pte_t *pte;
     14
     15	VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
     16	pte = __find_linux_pte(pgdir, ea, is_thp, hshift);
     17
     18#if defined(CONFIG_DEBUG_VM) &&						\
     19	!(defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE))
     20	/*
     21	 * We should not find huge page if these configs are not enabled.
     22	 */
     23	if (hshift)
     24		WARN_ON(*hshift);
     25#endif
     26	return pte;
     27}
     28
     29static inline pte_t *find_init_mm_pte(unsigned long ea, unsigned *hshift)
     30{
     31	pgd_t *pgdir = init_mm.pgd;
     32	return __find_linux_pte(pgdir, ea, NULL, hshift);
     33}
     34
     35/*
     36 * Convert a kernel vmap virtual address (vmalloc or ioremap space) to a
     37 * physical address, without taking locks. This can be used in real-mode.
     38 */
     39static inline phys_addr_t ppc_find_vmap_phys(unsigned long addr)
     40{
     41	pte_t *ptep;
     42	phys_addr_t pa;
     43	int hugepage_shift;
     44
     45	/*
     46	 * init_mm does not free page tables, and does not do THP. It may
     47	 * have huge pages from huge vmalloc / ioremap etc.
     48	 */
     49	ptep = find_init_mm_pte(addr, &hugepage_shift);
     50	if (WARN_ON(!ptep))
     51		return 0;
     52
     53	pa = PFN_PHYS(pte_pfn(*ptep));
     54
     55	if (!hugepage_shift)
     56		hugepage_shift = PAGE_SHIFT;
     57
     58	pa |= addr & ((1ul << hugepage_shift) - 1);
     59
     60	return pa;
     61}
     62
     63/*
     64 * This is what we should always use. Any other lockless page table lookup needs
     65 * careful audit against THP split.
     66 */
     67static inline pte_t *find_current_mm_pte(pgd_t *pgdir, unsigned long ea,
     68					 bool *is_thp, unsigned *hshift)
     69{
     70	pte_t *pte;
     71
     72	VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
     73	VM_WARN(pgdir != current->mm->pgd,
     74		"%s lock less page table lookup called on wrong mm\n", __func__);
     75	pte = __find_linux_pte(pgdir, ea, is_thp, hshift);
     76
     77#if defined(CONFIG_DEBUG_VM) &&						\
     78	!(defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE))
     79	/*
     80	 * We should not find huge page if these configs are not enabled.
     81	 */
     82	if (hshift)
     83		WARN_ON(*hshift);
     84#endif
     85	return pte;
     86}
     87
     88#endif /* _ASM_POWERPC_PTE_WALK_H */