From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: linux-mm@kvack.org
Cc: linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org,
linux-arch@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Will Deacon <will@kernel.org>,
"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Nick Piggin <npiggin@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [PATCH v3 1/5] ARC: mm: remove __ARCH_USE_5LEVEL_HACK
Date: Wed, 16 Oct 2019 09:23:56 -0700 [thread overview]
Message-ID: <20191016162400.14796-2-vgupta@synopsys.com> (raw)
In-Reply-To: <20191016162400.14796-1-vgupta@synopsys.com>
With paging code made 5-level compliant, this is no longer needed.
ARC has software page walker with 2 lookup levels (pgd -> pte)
This was expected to be non functional change but ended with slight
code bloat due to needless inclusions of p*d_free_tlb() macros which
will be addressed in further patches.
| bloat-o-meter2 vmlinux-[AB]*
| add/remove: 0/0 grow/shrink: 2/0 up/down: 128/0 (128)
| function old new delta
| free_pgd_range 546 656 +110
| p4d_clear_bad 2 20 +18
| Total: Before=4137148, After=4137276, chg 0.000000%
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/include/asm/pgtable.h | 1 -
arch/arc/mm/fault.c | 10 ++++++++--
arch/arc/mm/highmem.c | 4 +++-
3 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 7addd0301c51..b917b596f7fb 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -33,7 +33,6 @@
#define _ASM_ARC_PGTABLE_H
#include <linux/bits.h>
-#define __ARCH_USE_5LEVEL_HACK
#include <asm-generic/pgtable-nopmd.h>
#include <asm/page.h>
#include <asm/mmu.h> /* to propagate CONFIG_ARC_MMU_VER <n> */
diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index 3861543b66a0..fb86bc3e9b35 100644
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -30,6 +30,7 @@ noinline static int handle_kernel_vaddr_fault(unsigned long address)
* with the 'reference' page table.
*/
pgd_t *pgd, *pgd_k;
+ p4d_t *p4d, *p4d_k;
pud_t *pud, *pud_k;
pmd_t *pmd, *pmd_k;
@@ -39,8 +40,13 @@ noinline static int handle_kernel_vaddr_fault(unsigned long address)
if (!pgd_present(*pgd_k))
goto bad_area;
- pud = pud_offset(pgd, address);
- pud_k = pud_offset(pgd_k, address);
+ p4d = p4d_offset(pgd, address);
+ p4d_k = p4d_offset(pgd_k, address);
+ if (!p4d_present(*p4d_k))
+ goto bad_area;
+
+ pud = pud_offset(p4d, address);
+ pud_k = pud_offset(p4d_k, address);
if (!pud_present(*pud_k))
goto bad_area;
diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index a4856bfaedf3..fc8849e4f72e 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -111,12 +111,14 @@ EXPORT_SYMBOL(__kunmap_atomic);
static noinline pte_t * __init alloc_kmap_pgtable(unsigned long kvaddr)
{
pgd_t *pgd_k;
+ p4d_t *p4d_k;
pud_t *pud_k;
pmd_t *pmd_k;
pte_t *pte_k;
pgd_k = pgd_offset_k(kvaddr);
- pud_k = pud_offset(pgd_k, kvaddr);
+ p4d_k = p4d_offset(pgd_k, kvaddr);
+ pud_k = pud_offset(p4d_k, kvaddr);
pmd_k = pmd_offset(pud_k, kvaddr);
pte_k = (pte_t *)memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
--
2.20.1
next prev parent reply other threads:[~2019-10-16 16:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-16 16:23 [PATCH v3 0/5] elide extraneous generated code for folded p4d/pud/pmd Vineet Gupta
2019-10-16 16:23 ` Vineet Gupta [this message]
2019-10-16 16:23 ` [PATCH v3 2/5] asm-generic/tlb: stub out pud_free_tlb() if nopud Vineet Gupta
2019-10-16 16:23 ` [PATCH v3 3/5] asm-generic/tlb: stub out p4d_free_tlb() if nop4d Vineet Gupta
2019-10-16 16:23 ` [PATCH v3 4/5] asm-generic/tlb: stub out pmd_free_tlb() if nopmd Vineet Gupta
2019-10-16 16:24 ` [PATCH v3 5/5] asm-generic/mm: stub out p{4,u}d_clear_bad() if __PAGETABLE_P{4,U}D_FOLDED Vineet Gupta
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