From: David Hildenbrand <david@redhat•com>
To: linux-kernel@vger•kernel.org
Cc: x86@kernel•org, Jan Kara <jack@suse•cz>,
David Hildenbrand <david@redhat•com>,
Catalin Marinas <catalin.marinas@arm•com>,
Yang Shi <shy828301@gmail•com>,
Dave Hansen <dave.hansen@linux•intel.com>,
Peter Xu <peterx@redhat•com>, Michal Hocko <mhocko@kernel•org>,
linux-mm@kvack•org, Donald Dutile <ddutile@redhat•com>,
Liang Zhang <zhangliang5@huawei•com>,
Borislav Petkov <bp@alien8•de>,
Alexander Gordeev <agordeev@linux•ibm.com>,
Will Deacon <will@kernel•org>, Christoph Hellwig <hch@lst•de>,
Paul Mackerras <paulus@samba•org>,
Andrea Arcangeli <aarcange@redhat•com>,
linux-s390@vger•kernel.org, Vasily Gorbik <gor@linux•ibm.com>,
Rik van Riel <riel@surriel•com>, Hugh Dickins <hughd@google•com>,
Matthew Wilcox <willy@infradead•org>,
Mike Rapoport <rppt@linux•ibm.com>,
Ingo Molnar <mingo@redhat•com>,
linux-arm-kernel@lists•infradead.org,
Jason Gunthorpe <jgg@nvidia•com>,
David Rientjes <rientjes@google•com>,
Gerald Schaefer <gerald.schaefer@linux•ibm.com>,
Pedro Gomes <pedrodemargomes@gmail•com>,
Jann Horn <jannh@google•com>, John Hubbard <jhubbard@nvidia•com>,
Heiko Carstens <hca@linux•ibm.com>,
Shakeel Butt <shakeelb@google•com>,
Thomas Gleixner <tglx@linutronix•de>,
Vlastimil Babka <vbabka@suse•cz>,
Oded Gabbay <oded.gabbay@gmail•com>,
linuxppc-dev@lists•ozlabs.org, Oleg Nesterov <oleg@redhat•com>,
Nadav Amit <namit@vmware•com>,
Andrew Morton <akpm@linux-foundation•org>,
Linus Torvalds <torvalds@linux-foundation•org>,
Roman Gushchin <guro@fb•com>,
"Kirill A . Shutemov" <kirill.shutemov@linux•intel.com>,
Mike Kravetz <mike.kravetz@oracle•com>
Subject: [PATCH v2 4/8] arm64/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
Date: Tue, 29 Mar 2022 18:43:25 +0200 [thread overview]
Message-ID: <20220329164329.208407-5-david@redhat.com> (raw)
In-Reply-To: <20220329164329.208407-1-david@redhat.com>
Let's use one of the type bits: core-mm only supports 5, so there is no
need to consume 6.
Note that we might be able to reuse bit 1, but reusing bit 1 turned out
problematic in the past for PROT_NONE handling; so let's play safe and
use another bit.
Reviewed-by: Catalin Marinas <catalin.marinas@arm•com>
Signed-off-by: David Hildenbrand <david@redhat•com>
---
arch/arm64/include/asm/pgtable-prot.h | 1 +
arch/arm64/include/asm/pgtable.h | 23 ++++++++++++++++++++---
2 files changed, 21 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index b1e1b74d993c..62e0ebeed720 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -14,6 +14,7 @@
* Software defined PTE bits definition.
*/
#define PTE_WRITE (PTE_DBM) /* same as DBM (51) */
+#define PTE_SWP_EXCLUSIVE (_AT(pteval_t, 1) << 2) /* only for swp ptes */
#define PTE_DIRTY (_AT(pteval_t, 1) << 55)
#define PTE_SPECIAL (_AT(pteval_t, 1) << 56)
#define PTE_DEVMAP (_AT(pteval_t, 1) << 57)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 94e147e5456c..ad9b221963d4 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -402,6 +402,22 @@ static inline pgprot_t mk_pmd_sect_prot(pgprot_t prot)
return __pgprot((pgprot_val(prot) & ~PMD_TABLE_BIT) | PMD_TYPE_SECT);
}
+#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE
+static inline pte_t pte_swp_mkexclusive(pte_t pte)
+{
+ return set_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
+}
+
+static inline int pte_swp_exclusive(pte_t pte)
+{
+ return pte_val(pte) & PTE_SWP_EXCLUSIVE;
+}
+
+static inline pte_t pte_swp_clear_exclusive(pte_t pte)
+{
+ return clear_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
+}
+
#ifdef CONFIG_NUMA_BALANCING
/*
* See the comment in include/linux/pgtable.h
@@ -909,12 +925,13 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
/*
* Encode and decode a swap entry:
* bits 0-1: present (must be zero)
- * bits 2-7: swap type
+ * bits 2: remember PG_anon_exclusive
+ * bits 3-7: swap type
* bits 8-57: swap offset
* bit 58: PTE_PROT_NONE (must be zero)
*/
-#define __SWP_TYPE_SHIFT 2
-#define __SWP_TYPE_BITS 6
+#define __SWP_TYPE_SHIFT 3
+#define __SWP_TYPE_BITS 5
#define __SWP_OFFSET_BITS 50
#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
--
2.35.1
next prev parent reply other threads:[~2022-03-29 16:49 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-29 16:43 [PATCH v2 0/8] mm: COW fixes part 3: reliable GUP R/W FOLL_GET of anonymous pages David Hildenbrand
2022-03-29 16:43 ` [PATCH v2 1/8] mm/swap: remember PG_anon_exclusive via a swp pte bit David Hildenbrand
2022-04-20 17:10 ` Vlastimil Babka
2022-04-20 17:13 ` David Hildenbrand
2022-03-29 16:43 ` [PATCH v2 2/8] mm/debug_vm_pgtable: add tests for __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-04-20 17:14 ` Vlastimil Babka
2022-03-29 16:43 ` [PATCH v2 3/8] x86/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-04-19 12:46 ` David Hildenbrand
2022-03-29 16:43 ` David Hildenbrand [this message]
2022-03-29 16:43 ` [PATCH v2 5/8] s390/pgtable: cleanup description of swp pte layout David Hildenbrand
2022-03-30 16:48 ` Gerald Schaefer
2022-03-29 16:43 ` [PATCH v2 6/8] s390/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-03-30 16:48 ` Gerald Schaefer
2022-03-29 16:43 ` [PATCH v2 7/8] powerpc/pgtable: remove _PAGE_BIT_SWAP_TYPE for book3s David Hildenbrand
2022-03-30 6:07 ` Christophe Leroy
2022-03-30 6:58 ` David Hildenbrand
2022-03-29 16:43 ` [PATCH v2 8/8] powerpc/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE " David Hildenbrand
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