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,
linux-mips@vger.kernel.org, openrisc@lists.librecores.org,
linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org,
linux-sh@vger.kernel.org, sparclinux@vger.kernel.org,
linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org,
David Hildenbrand <david@redhat.com>,
Chris Zankel <chris@zankel.net>,
Max Filippov <jcmvbkbc@gmail.com>
Subject: [PATCH mm-unstable v1 25/26] xtensa/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
Date: Fri, 13 Jan 2023 18:10:25 +0100 [thread overview]
Message-ID: <20230113171026.582290-26-david@redhat.com> (raw)
In-Reply-To: <20230113171026.582290-1-david@redhat.com>
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using bit 1. This
bit should be safe to use for our usecase.
Most importantly, we can still distinguish swap PTEs from PAGE_NONE PTEs
(see pte_present()) and don't use one of the two reserved attribute
masks (1101 and 1111). Attribute mask 1100 and 1110 now identify swap PTEs.
While at it, remove SWP_TYPE_BITS (not really helpful as it's not used in
the actual swap macros) and mask the type in __swp_entry().
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/xtensa/include/asm/pgtable.h | 32 ++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
index 5b5484d707b2..1025e2dc292b 100644
--- a/arch/xtensa/include/asm/pgtable.h
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -96,7 +96,7 @@
* +- - - - - - - - - - - - - - - - - - - - -+
* (PAGE_NONE)| PPN | 0 | 00 | ADW | 01 | 11 | 11 |
* +-----------------------------------------+
- * swap | index | type | 01 | 11 | 00 |
+ * swap | index | type | 01 | 11 | e0 |
* +-----------------------------------------+
*
* For T1050 hardware and earlier the layout differs for present and (PAGE_NONE)
@@ -112,6 +112,7 @@
* RI ring (0=privileged, 1=user, 2 and 3 are unused)
* CA cache attribute: 00 bypass, 01 writeback, 10 writethrough
* (11 is invalid and used to mark pages that are not present)
+ * e exclusive marker in swap PTEs
* w page is writable (hw)
* x page is executable (hw)
* index swap offset / PAGE_SIZE (bit 11-31: 21 bits -> 8 GB)
@@ -158,6 +159,9 @@
#define _PAGE_DIRTY (1<<7) /* software: page dirty */
#define _PAGE_ACCESSED (1<<8) /* software: page accessed (read) */
+/* We borrow bit 1 to store the exclusive marker in swap PTEs. */
+#define _PAGE_SWP_EXCLUSIVE (1<<1)
+
#ifdef CONFIG_MMU
#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
@@ -343,19 +347,37 @@ ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
}
/*
- * Encode and decode a swap and file entry.
+ * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
+ * are !pte_none() && !pte_present().
*/
-#define SWP_TYPE_BITS 5
-#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
+#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > 5)
#define __swp_type(entry) (((entry).val >> 6) & 0x1f)
#define __swp_offset(entry) ((entry).val >> 11)
#define __swp_entry(type,offs) \
- ((swp_entry_t){((type) << 6) | ((offs) << 11) | \
+ ((swp_entry_t){(((type) & 0x1f) << 6) | ((offs) << 11) | \
_PAGE_CA_INVALID | _PAGE_USER})
#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;
+}
+
#endif /* !defined (__ASSEMBLY__) */
--
2.39.0
next prev parent reply other threads:[~2023-01-13 17:21 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-13 17:10 [PATCH mm-unstable v1 00/26] mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 01/26] mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks David Hildenbrand
2023-01-14 16:09 ` David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 02/26] alpha/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 03/26] arc/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 04/26] arm/mm: " David Hildenbrand
2023-01-13 17:38 ` Russell King (Oracle)
2023-02-07 0:32 ` Mark Brown
2023-02-08 14:12 ` David Hildenbrand
2023-02-08 16:39 ` Mark Brown
2023-01-13 17:10 ` [PATCH mm-unstable v1 05/26] csky/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 06/26] hexagon/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 07/26] ia64/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 08/26] loongarch/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 09/26] m68k/mm: remove dummy __swp definitions for nommu David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 10/26] m68k/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 11/26] microblaze/mm: " David Hildenbrand
2023-02-26 20:13 ` Geert Uytterhoeven
2023-02-27 13:31 ` David Hildenbrand
2023-02-27 14:43 ` Geert Uytterhoeven
2023-02-27 17:01 ` David Hildenbrand
2023-02-27 19:46 ` Geert Uytterhoeven
2023-02-28 15:55 ` David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 12/26] mips/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 13/26] nios2/mm: refactor swap PTE layout David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 14/26] nios2/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 15/26] openrisc/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 16/26] parisc/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 17/26] powerpc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit book3s David Hildenbrand
2023-02-10 5:08 ` Michael Ellerman
2023-01-13 17:10 ` [PATCH mm-unstable v1 18/26] powerpc/nohash/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 19/26] riscv/mm: " David Hildenbrand
2023-02-28 15:50 ` Palmer Dabbelt
2023-02-28 15:56 ` David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 20/26] sh/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 21/26] sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 22/26] sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 64bit David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 23/26] um/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 24/26] x86/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE also on 32bit David Hildenbrand
2023-01-13 17:10 ` David Hildenbrand [this message]
2023-01-13 17:10 ` [PATCH mm-unstable v1 26/26] mm: remove __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-02-28 21:11 ` [PATCH mm-unstable v1 00/26] mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs patchwork-bot+linux-riscv
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