Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37;
From:   Alexandru Elisei <alexandru.elisei@arm.com>
To:     catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev,
        maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com,
        yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org,
        mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
        vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
        rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
        bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org,
        rppt@kernel.org, hughd@google.com
Cc:     pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com,
        vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com,
        kcc@google.com, hyesoo.yu@samsung.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org,
        linux-arch@vger.kernel.org, linux-mm@kvack.org,
        linux-trace-kernel@vger.kernel.org
Subject: [PATCH RFC v2 06/27] mm: page_alloc: Allow an arch to hook early into free_pages_prepare()
Date:   Sun, 19 Nov 2023 16:57:00 +0000
Message-Id: <20231119165721.9849-7-alexandru.elisei@arm.com>
In-Reply-To: <20231119165721.9849-1-alexandru.elisei@arm.com>
References: <20231119165721.9849-1-alexandru.elisei@arm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Add arch_free_pages_prepare() hook that is called before that page flags
are cleared. This will be used by arm64 when explicit management of tag
storage pages is enabled.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
 include/linux/pgtable.h | 4 ++++
 mm/page_alloc.c         | 4 +++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index b31f53e9ab1d..3f34f00ced62 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -880,6 +880,10 @@ static inline int arch_prep_new_page(struct page *page, int order, gfp_t gfp)
 }
 #endif
 
+#ifndef __HAVE_ARCH_FREE_PAGES_PREPARE
+static inline void arch_free_pages_prepare(struct page *page, int order) { }
+#endif
+
 #ifndef __HAVE_ARCH_UNMAP_ONE
 /*
  * Some architectures support metadata associated with a page. When a
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b2782b778e78..86e4b1dac538 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1086,6 +1086,8 @@ static __always_inline bool free_pages_prepare(struct page *page,
 	trace_mm_page_free(page, order);
 	kmsan_free_page(page, order);
 
+	arch_free_pages_prepare(page, order);
+
 	if (unlikely(PageHWPoison(page)) && !order) {
 		/*
 		 * Do not let hwpoison pages hit pcplists/buddy
@@ -3171,7 +3173,7 @@ static inline unsigned int gfp_to_alloc_flags_cma(gfp_t gfp_mask,
 	return alloc_flags;
 }
 
-#ifdef HAVE_ARCH_ALLOC_PAGE
+#ifdef HAVE_ARCH_PREP_NEW_PAGE
 static void return_page_to_buddy(struct page *page, int order)
 {
 	int migratetype = get_pfnblock_migratetype(page, pfn);
-- 
2.42.1