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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:message-id:mime-version:subject:from :to:cc; bh=VKloTl371bW+jJpPMsZsEwVhgcWcUjghC6NZx1oQjaE=; b=bqqB4GGYCYcLNcaiybUyHiku3AEU/CFxCUkVsjyk7uxbIra3QJ+5TfhXtAPeIPqxK4 HdK13du528KIJ2lHSw9ZkY3L+O4qaMYIAd8W2eDyp3oDanebZPozX9TR13RgUB7nHAli NxDkQakC4lMf+tiH5gsJWfTwBQ+xTzLIyk0l7K7bQ8DlNFzd5MIYjnTZJFddLKUDLzee TZlSljJN/kZwvOH13CcSEGxy/+iEwNxCIf4/8HgCyjetbFFVrZDNZowVcMhOovx81MKB o8d2Y869hVUdCguUY8g60A/C+EzrnLHbVLfD8daH/jjU4/zHtgRxr+KLVxUF2AOFcCPa xvGg== X-Gm-Message-State: AOAM531kyyaOpC67GN+gZkzb6lm79ucxVre5qlTAzWIrn2poIPpqYV2u DJuCkVBVtOlt1ZcNEFG++azIHIA= X-Google-Smtp-Source: ABdhPJy2UJDCf4xZd+fXi32Ia0ZyLvQX3Vmiu/hW3dsgjPTytW//wA3eK9SNsbGw16MGQanJU16BAKw= X-Received: from pcc-desktop.svl.corp.google.com ([2620:15c:2ce:0:7220:84ff:fe09:385a]) (user=pcc job=sendgmr) by 2002:a25:3252:: with SMTP id y79mr2805287yby.404.1606980909335; Wed, 02 Dec 2020 23:35:09 -0800 (PST) Date: Wed, 2 Dec 2020 23:34:58 -0800 Message-Id: <20201203073458.2675400-1-pcc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.29.2.454.gaff20da3a2-goog Subject: [PATCH] arm64: mte: remove an ISB on kernel exit From: Peter Collingbourne To: Andrey Konovalov , Catalin Marinas X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201203_023517_391516_538F2AF9 X-CRM114-Status: GOOD ( 12.01 ) 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: Peter Collingbourne , Linux ARM Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This ISB is unnecessary because we will soon do an ERET. Signed-off-by: Peter Collingbourne Link: https://linux-review.googlesource.com/id/I69f1ee6bb09b1372dd744a0e01cedaf090c8d448 --- arch/arm64/kernel/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 07646ef4f184..f8ad8d7fb1a2 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -182,7 +182,6 @@ alternative_else_nop_endif mrs_s \tmp2, SYS_GCR_EL1 bfi \tmp2, \tmp, #0, #16 msr_s SYS_GCR_EL1, \tmp2 - isb #endif .endm @@ -194,6 +193,7 @@ alternative_else_nop_endif ldr_l \tmp, gcr_kernel_excl mte_set_gcr \tmp, \tmp2 + isb 1: #endif .endm