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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2017-03-09 17:24:06 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-09 22:48:47 +0300
commit048456dcf2c56ad6f6248e2899dda92fb6a613f6 (patch)
tree5a36b42c6ec1d44ce29becbf7ace2b8c4bebd61f /include/asm-generic/pgtable-nop4d.h
parent9849a5697d3defb2087cb6b9be5573a142697889 (diff)
downloadlinux-048456dcf2c56ad6f6248e2899dda92fb6a613f6.tar.xz
asm-generic: introduce <asm-generic/pgtable-nop4d.h>
Like with pgtable-nopud.h for 4-level paging, this new header is base for converting an architectures to properly folded p4d_t level. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-generic/pgtable-nop4d.h')
-rw-r--r--include/asm-generic/pgtable-nop4d.h56
1 files changed, 56 insertions, 0 deletions
diff --git a/include/asm-generic/pgtable-nop4d.h b/include/asm-generic/pgtable-nop4d.h
new file mode 100644
index 000000000000..de364ecb8df6
--- /dev/null
+++ b/include/asm-generic/pgtable-nop4d.h
@@ -0,0 +1,56 @@
+#ifndef _PGTABLE_NOP4D_H
+#define _PGTABLE_NOP4D_H
+
+#ifndef __ASSEMBLY__
+
+#define __PAGETABLE_P4D_FOLDED
+
+typedef struct { pgd_t pgd; } p4d_t;
+
+#define P4D_SHIFT PGDIR_SHIFT
+#define PTRS_PER_P4D 1
+#define P4D_SIZE (1UL << P4D_SHIFT)
+#define P4D_MASK (~(P4D_SIZE-1))
+
+/*
+ * The "pgd_xxx()" functions here are trivial for a folded two-level
+ * setup: the p4d is never bad, and a p4d always exists (as it's folded
+ * into the pgd entry)
+ */
+static inline int pgd_none(pgd_t pgd) { return 0; }
+static inline int pgd_bad(pgd_t pgd) { return 0; }
+static inline int pgd_present(pgd_t pgd) { return 1; }
+static inline void pgd_clear(pgd_t *pgd) { }
+#define p4d_ERROR(p4d) (pgd_ERROR((p4d).pgd))
+
+#define pgd_populate(mm, pgd, p4d) do { } while (0)
+/*
+ * (p4ds are folded into pgds so this doesn't get actually called,
+ * but the define is needed for a generic inline function.)
+ */
+#define set_pgd(pgdptr, pgdval) set_p4d((p4d_t *)(pgdptr), (p4d_t) { pgdval })
+
+static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
+{
+ return (p4d_t *)pgd;
+}
+
+#define p4d_val(x) (pgd_val((x).pgd))
+#define __p4d(x) ((p4d_t) { __pgd(x) })
+
+#define pgd_page(pgd) (p4d_page((p4d_t){ pgd }))
+#define pgd_page_vaddr(pgd) (p4d_page_vaddr((p4d_t){ pgd }))
+
+/*
+ * allocating and freeing a p4d is trivial: the 1-entry p4d is
+ * inside the pgd, so has no extra memory associated with it.
+ */
+#define p4d_alloc_one(mm, address) NULL
+#define p4d_free(mm, x) do { } while (0)
+#define __p4d_free_tlb(tlb, x, a) do { } while (0)
+
+#undef p4d_addr_end
+#define p4d_addr_end(addr, end) (end)
+
+#endif /* __ASSEMBLY__ */
+#endif /* _PGTABLE_NOP4D_H */