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From:   Tong Tiangen <tongtiangen@huawei.com>
To:     Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>
CC:     <linux-riscv@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        "Tong Tiangen" <tongtiangen@huawei.com>,
        <wangkefeng.wang@huawei.com>, Guohanjun <guohanjun@huawei.com>
Subject: [PATCH -next 2/2] riscv/mm: add arch hook arch_clear_hugepage_flags
Date:   Mon, 24 Oct 2022 09:47:25 +0000
Message-ID: <20221024094725.3054311-3-tongtiangen@huawei.com>
In-Reply-To: <20221024094725.3054311-1-tongtiangen@huawei.com>
References: <20221024094725.3054311-1-tongtiangen@huawei.com>
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With the PG_arch_1 we keep track if the page's data cache is clean,
architecture rely on this property to treat new pages as dirty with
respect to the data cache and perform the flushing before mapping the pages
into userspace.

This patch adds a new architecture hook, arch_clear_hugepage_flags,so that
architectures which rely on the page flags being in a particular state for
fresh allocations can adjust the flags accordingly when a page is freed
into the pool.

Fixes: 9e953cda5cdf ("riscv: Introduce huge page support for 32/64bit kernel")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 arch/riscv/include/asm/hugetlb.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
index a5c2ca1d1cd8..ec19d6afc896 100644
--- a/arch/riscv/include/asm/hugetlb.h
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -5,4 +5,10 @@
 #include <asm-generic/hugetlb.h>
 #include <asm/page.h>
 
+static inline void arch_clear_hugepage_flags(struct page *page)
+{
+	clear_bit(PG_dcache_clean, &page->flags);
+}
+#define arch_clear_hugepage_flags arch_clear_hugepage_flags
+
 #endif /* _ASM_RISCV_HUGETLB_H */
-- 
2.25.1