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-rw-r--r--arch/powerpc/include/asm/pte-walk.h29
1 files changed, 29 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pte-walk.h b/arch/powerpc/include/asm/pte-walk.h
index 33fa5dd8ee6a..714a35f0d425 100644
--- a/arch/powerpc/include/asm/pte-walk.h
+++ b/arch/powerpc/include/asm/pte-walk.h
@@ -31,6 +31,35 @@ 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);
}
+
+/*
+ * Convert a kernel vmap virtual address (vmalloc or ioremap space) to a
+ * physical address, without taking locks. This can be used in real-mode.
+ */
+static inline phys_addr_t ppc_find_vmap_phys(unsigned long addr)
+{
+ pte_t *ptep;
+ phys_addr_t pa;
+ int hugepage_shift;
+
+ /*
+ * init_mm does not free page tables, and does not do THP. It may
+ * have huge pages from huge vmalloc / ioremap etc.
+ */
+ ptep = find_init_mm_pte(addr, &hugepage_shift);
+ if (WARN_ON(!ptep))
+ return 0;
+
+ pa = PFN_PHYS(pte_pfn(*ptep));
+
+ if (!hugepage_shift)
+ hugepage_shift = PAGE_SHIFT;
+
+ pa |= addr & ((1ul << hugepage_shift) - 1);
+
+ return pa;
+}
+
/*
* This is what we should always use. Any other lockless page table lookup needs
* careful audit against THP split.