Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   David Hildenbrand <david@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Hugh Dickins <hughd@google.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        David Rientjes <rientjes@google.com>,
        Shakeel Butt <shakeelb@google.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Yang Shi <shy828301@gmail.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Matthew Wilcox <willy@infradead.org>,
        Vlastimil Babka <vbabka@suse.cz>, Jann Horn <jannh@google.com>,
        Michal Hocko <mhocko@kernel.org>,
        Nadav Amit <namit@vmware.com>, Rik van Riel <riel@surriel.com>,
        Roman Gushchin <guro@fb.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Peter Xu <peterx@redhat.com>,
        Donald Dutile <ddutile@redhat.com>,
        Christoph Hellwig <hch@lst.de>,
        Oleg Nesterov <oleg@redhat.com>, Jan Kara <jack@suse.cz>,
        Liang Zhang <zhangliang5@huawei.com>,
        Pedro Gomes <pedrodemargomes@gmail.com>,
        Oded Gabbay <oded.gabbay@gmail.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Gerald Schaefer <gerald.schaefer@linux.ibm.com>,
        linux-mm@kvack.org, x86@kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org,
        David Hildenbrand <david@redhat.com>
Subject: [PATCH v2 8/8] powerpc/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE for book3s
Date:   Tue, 29 Mar 2022 18:43:29 +0200
Message-Id: <20220329164329.208407-9-david@redhat.com>
In-Reply-To: <20220329164329.208407-1-david@redhat.com>
References: <20220329164329.208407-1-david@redhat.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Right now, the last 5 bits (0x1f) of the swap entry are used for the
type and the bit before that (0x20) is used for _PAGE_SWP_SOFT_DIRTY. We
cannot use 0x40, as that collides with _RPAGE_RSV1 -- contained in
_PAGE_HPTEFLAGS. The next candidate would be _RPAGE_SW3 (0x200) -- which is
used for _PAGE_SOFT_DIRTY for !swp ptes.

So let's just use _PAGE_SOFT_DIRTY for _PAGE_SWP_SOFT_DIRTY (to make it
easier to grasp) and use 0x20 now for _PAGE_SWP_EXCLUSIVE.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/powerpc/include/asm/book3s/64/pgtable.h | 21 +++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 8e98375d5c4a..eecff2036869 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -752,6 +752,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 	 */							\
 	BUILD_BUG_ON(_PAGE_HPTEFLAGS & SWP_TYPE_MASK); \
 	BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_SOFT_DIRTY);	\
+	BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_EXCLUSIVE);	\
 	} while (0)
 
 #define SWP_TYPE_BITS 5
@@ -772,11 +773,13 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 #define __swp_entry_to_pmd(x)	(pte_pmd(__swp_entry_to_pte(x)))
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
-#define _PAGE_SWP_SOFT_DIRTY	_PAGE_NON_IDEMPOTENT
+#define _PAGE_SWP_SOFT_DIRTY	_PAGE_SOFT_DIRTY
 #else
 #define _PAGE_SWP_SOFT_DIRTY	0UL
 #endif /* CONFIG_MEM_SOFT_DIRTY */
 
+#define _PAGE_SWP_EXCLUSIVE	_PAGE_NON_IDEMPOTENT
+
 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
 static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
 {
@@ -794,6 +797,22 @@ static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
 }
 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
 
+#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE
+static inline pte_t pte_swp_mkexclusive(pte_t pte)
+{
+	return __pte_raw(pte_raw(pte) | cpu_to_be64(_PAGE_SWP_EXCLUSIVE));
+}
+
+static inline int pte_swp_exclusive(pte_t pte)
+{
+	return !!(pte_raw(pte) & cpu_to_be64(_PAGE_SWP_EXCLUSIVE));
+}
+
+static inline pte_t pte_swp_clear_exclusive(pte_t pte)
+{
+	return __pte_raw(pte_raw(pte) & cpu_to_be64(~_PAGE_SWP_EXCLUSIVE));
+}
+
 static inline bool check_pte_access(unsigned long access, unsigned long ptev)
 {
 	/*
-- 
2.35.1