linux/include/asm-generic/pgtable-nop4d.h
Vineet Gupta bffd972347 asm-generic/tlb: stub out p4d_free_tlb() if nop4d ...
... independent of __ARCH_HAS_5LEVEL_HACK

This came up when removing __ARCH_HAS_5LEVEL_HACK for ARC as code bloat.
With this patch we see the following code reduction

| bloat-o-meter2 vmlinux-C-elide-pud_free_tlb vmlinux-D-elide-p4d_free_tlb
| add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-104 (-104)
| function                                     old     new   delta
| free_pgd_range                               552     422    -130
| Total: Before=4137172, After=4137042, chg -1.000000%

Link: http://lkml.kernel.org/r/20191016162400.14796-4-vgupta@synopsys.com
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01 06:29:19 -08:00

60 lines
1.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _PGTABLE_NOP4D_H
#define _PGTABLE_NOP4D_H
#ifndef __ASSEMBLY__
#define __PAGETABLE_P4D_FOLDED 1
typedef struct { pgd_t pgd; } p4d_t;
#define P4D_SHIFT PGDIR_SHIFT
#define MAX_PTRS_PER_P4D 1
#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)
#define pgd_populate_safe(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 */