From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Hugh Dickins <hughd@google.com>,
John Hubbard <jhubbard@nvidia.com>,
Jason Gunthorpe <jgg@nvidia.com>,
Mike Rapoport <rppt@linux.ibm.com>,
Yang Shi <shy828301@gmail.com>, Vlastimil Babka <vbabka@suse.cz>,
Nadav Amit <namit@vmware.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Peter Xu <peterx@redhat.com>,
linux-mm@kvack.org, x86@kernel.org, linux-alpha@vger.kernel.org,
linux-snps-arc@lists.infradead.org,
linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org,
linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org,
loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org,
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linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org,
David Hildenbrand <david@redhat.com>
Subject: [PATCH mm-unstable RFC 07/26] ia64/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
Date: Tue, 6 Dec 2022 15:47:11 +0100 [thread overview]
Message-ID: <20221206144730.163732-8-david@redhat.com> (raw)
In-Reply-To: <20221206144730.163732-1-david@redhat.com>
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit
from the type. Generic MM currently only uses 5 bits for the type
(MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused.
While at it, also mask the type in __swp_entry().
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/ia64/include/asm/pgtable.h | 32 +++++++++++++++++++++++++++++---
1 file changed, 29 insertions(+), 3 deletions(-)
diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h
index 01517a5e6778..d666eb229d4b 100644
--- a/arch/ia64/include/asm/pgtable.h
+++ b/arch/ia64/include/asm/pgtable.h
@@ -58,6 +58,9 @@
#define _PAGE_ED (__IA64_UL(1) << 52) /* exception deferral */
#define _PAGE_PROTNONE (__IA64_UL(1) << 63)
+/* We borrow bit 7 to store the exclusive marker in swap PTEs. */
+#define _PAGE_SWP_EXCLUSIVE (1 << 7)
+
#define _PFN_MASK _PAGE_PPN_MASK
/* Mask of bits which may be changed by pte_modify(); the odd bits are there for _PAGE_PROTNONE */
#define _PAGE_CHG_MASK (_PAGE_P | _PAGE_PROTNONE | _PAGE_PL_MASK | _PAGE_AR_MASK | _PAGE_ED)
@@ -399,6 +402,9 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern void paging_init (void);
/*
+ * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
+ * are !pte_none() && !pte_present().
+ *
* Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
* bits in the swap-type field of the swap pte. It would be nice to
* enforce that, but we can't easily include <linux/swap.h> here.
@@ -406,16 +412,36 @@ extern void paging_init (void);
*
* Format of swap pte:
* bit 0 : present bit (must be zero)
- * bits 1- 7: swap-type
+ * bits 1- 6: swap type
+ * bit 7 : exclusive marker
* bits 8-62: swap offset
* bit 63 : _PAGE_PROTNONE bit
*/
-#define __swp_type(entry) (((entry).val >> 1) & 0x7f)
+#define __swp_type(entry) (((entry).val >> 1) & 0x3f)
#define __swp_offset(entry) (((entry).val << 1) >> 9)
-#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 1) | ((long) (offset) << 8) })
+#define __swp_entry(type,offset) ((swp_entry_t) { ((type & 0x3f) << 1) | \
+ ((long) (offset) << 8) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
+#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE
+static inline int pte_swp_exclusive(pte_t pte)
+{
+ return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
+}
+
+static inline pte_t pte_swp_mkexclusive(pte_t pte)
+{
+ pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
+ return pte;
+}
+
+static inline pte_t pte_swp_clear_exclusive(pte_t pte)
+{
+ pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
+ return pte;
+}
+
/*
* ZERO_PAGE is a global shared page that is always zero: used
* for zero-mapped memory areas etc..
--
2.38.1
next prev parent reply other threads:[~2022-12-06 14:52 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-06 14:47 [PATCH mm-unstable RFC 00/26] mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 01/26] mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 02/26] alpha/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 03/26] arc/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 04/26] arm/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 05/26] csky/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 06/26] hexagon/mm: " David Hildenbrand
2022-12-06 14:47 ` David Hildenbrand [this message]
2022-12-06 14:47 ` [PATCH mm-unstable RFC 08/26] loongarch/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 09/26] m68k/mm: remove dummy __swp definitions for nommu David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 10/26] m68k/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 11/26] microblaze/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 12/26] mips/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 13/26] nios2/mm: refactor swap PTE layout David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 14/26] nios2/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 15/26] openrisc/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 16/26] parisc/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 17/26] powerpc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit book3s David Hildenbrand
2022-12-07 13:55 ` Christophe Leroy
2022-12-08 8:52 ` David Hildenbrand
2022-12-08 8:55 ` David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 18/26] powerpc/nohash/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 19/26] riscv/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 20/26] sh/mm: " David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 21/26] sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 22/26] sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 64bit David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 23/26] um/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 24/26] x86/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE also on 32bit David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 25/26] xtensa/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-12-06 14:47 ` [PATCH mm-unstable RFC 26/26] mm: remove __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2022-12-14 11:22 ` [PATCH mm-unstable RFC 00/26] mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs David Hildenbrand
2022-12-18 3:32 ` Huacai Chen
2022-12-18 9:59 ` David Hildenbrand
2022-12-19 1:40 ` Huacai Chen
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