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From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org,
	David Hildenbrand <david@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Matthew Wilcox <willy@infradead.org>,
	Ryan Roberts <ryan.roberts@arm.com>,
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	Yin Fengwei <fengwei.yin@intel.com>,
	Michal Hocko <mhocko@suse.com>,
	Will Deacon <will@kernel.org>,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	Nick Piggin <npiggin@gmail.com>,
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	Christophe Leroy <christophe.leroy@csgroup.eu>,
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	Heiko Carstens <hca@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Alexander Gordeev <agordeev@linux.ibm.com>,
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	linux-s390@vger.kernel.org
Subject: [PATCH v3 07/10] mm/mmu_gather: add tlb_remove_tlb_entries()
Date: Wed, 14 Feb 2024 21:44:32 +0100
Message-ID: <20240214204435.167852-8-david@redhat.com>
In-Reply-To: <20240214204435.167852-1-david@redhat.com>
References: <20240214204435.167852-1-david@redhat.com>
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Let's add a helper that lets us batch-process multiple consecutive PTEs.

Note that the loop will get optimized out on all architectures except on
powerpc. We have to add an early define of __tlb_remove_tlb_entry() on
ppc to make the compiler happy (and avoid making tlb_remove_tlb_entries() a
macro).

Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/powerpc/include/asm/tlb.h |  2 ++
 include/asm-generic/tlb.h      | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/arch/powerpc/include/asm/tlb.h b/arch/powerpc/include/asm/tlb.h
index b3de6102a907..1ca7d4c4b90d 100644
--- a/arch/powerpc/include/asm/tlb.h
+++ b/arch/powerpc/include/asm/tlb.h
@@ -19,6 +19,8 @@
 
 #include <linux/pagemap.h>
 
+static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
+					  unsigned long address);
 #define __tlb_remove_tlb_entry	__tlb_remove_tlb_entry
 
 #define tlb_flush tlb_flush
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 2eb7b0d4f5d2..95d60a4f468a 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -608,6 +608,26 @@ static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
 		__tlb_remove_tlb_entry(tlb, ptep, address);	\
 	} while (0)
 
+/**
+ * tlb_remove_tlb_entries - remember unmapping of multiple consecutive ptes for
+ *			    later tlb invalidation.
+ *
+ * Similar to tlb_remove_tlb_entry(), but remember unmapping of multiple
+ * consecutive ptes instead of only a single one.
+ */
+static inline void tlb_remove_tlb_entries(struct mmu_gather *tlb,
+		pte_t *ptep, unsigned int nr, unsigned long address)
+{
+	tlb_flush_pte_range(tlb, address, PAGE_SIZE * nr);
+	for (;;) {
+		__tlb_remove_tlb_entry(tlb, ptep, address);
+		if (--nr == 0)
+			break;
+		ptep++;
+		address += PAGE_SIZE;
+	}
+}
+
 #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address)	\
 	do {							\
 		unsigned long _sz = huge_page_size(h);		\
-- 
2.43.0