[PATCH] implement flush_cache_vmap for RISC-V

From: Jiuyang Liu <liu@jiuyang.me>
To: Alex Ghiti <alex@ghiti.fr>, Palmer Dabbelt <palmer@dabbelt.com>
Cc: Jiuyang Liu <liu@jiuyang.me>,
	Andrew Waterman <waterman@eecs.berkeley.edu>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] implement flush_cache_vmap for RISC-V
Date: Mon, 12 Apr 2021 00:05:30 +0000	[thread overview]
Message-ID: <20210412000531.12249-1-liu@jiuyang.me> (raw)

This patch implements flush_cache_vmap for RISC-V, since it modifies PTE.
Without this patch, SFENCE.VMA won't be added to related codes, which
might introduce a bug in the out-of-order micro-architecture
implementations.

Signed-off-by: Jiuyang Liu <liu@jiuyang.me>
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/riscv/include/asm/cacheflush.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h
index 23ff70350992..3fd528badc35 100644
--- a/arch/riscv/include/asm/cacheflush.h
+++ b/arch/riscv/include/asm/cacheflush.h
@@ -30,6 +30,12 @@ static inline void flush_dcache_page(struct page *page)
 #define flush_icache_user_page(vma, pg, addr, len) \
 	flush_icache_mm(vma->vm_mm, 0)
 
+/*
+ * flush_cache_vmap is invoked after map_kernel_range() has installed the page
+ * table entries, which modifies PTE, SFENCE.VMA should be inserted.
+ */
+#define flush_cache_vmap(start, end) flush_tlb_all()
+
 #ifndef CONFIG_SMP
 
 #define flush_icache_all() local_flush_icache_all()
-- 
2.31.1


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