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[66.187.233.206]) by smtp.gmail.com with ESMTPSA id z57sm6538533qta.62.2019.06.11.08.19.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Jun 2019 08:19:33 -0700 (PDT) From: Masayoshi Mizuma To: Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org Subject: [PATCH 0/2] Correct the cache line size warning Date: Tue, 11 Jun 2019 11:17:29 -0400 Message-Id: <20190611151731.6135-1-msys.mizuma@gmail.com> X-Mailer: git-send-email 2.17.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190611_081938_947401_C586CBAD X-CRM114-Status: UNSURE ( 9.67 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Masayoshi Mizuma , Hidetoshi Seto , Masayoshi Mizuma , linux-kernel@vger.kernel.org, Zhang Lei MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Masayoshi Mizuma If the cache line size is greater than ARCH_DMA_MINALIGN (128), the warning shows and it's tainted as TAINT_CPU_OUT_OF_SPEC. However, it's not good about two points. First, as discussed in the thread [1], the cpu cache line size will be problem only on non-coherent devices. Then, it should not be tainted as TAINT_CPU_OUT_OF_SPEC because according to the specification of CTR_EL0.CWG, the maximum cache writeback granule is 2048 byte (CWG == 0b1001). This patch series try to: - Show the warning only if the device is non-coherent device and ARCH_DMA_MINALIGN is smaller than the cpu cache size. - Show the warning and taints as TAINT_CPU_OUT_OF_SPEC if the cache line size is greater than the maximum. [1] https://lore.kernel.org/linux-arm-kernel/20180514145703.celnlobzn3uh5tc2@localhost/ Masayoshi Mizuma (2): arm64/mm: check cpu cache line size with non-coherent device arm64/mm: show TAINT_CPU_OUT_OF_SPEC warning if the cache size is over the spec. arch/arm64/include/asm/cache.h | 2 ++ arch/arm64/mm/dma-mapping.c | 9 +++++---- arch/arm64/mm/init.c | 5 +++++ 3 files changed, 12 insertions(+), 4 deletions(-)