From patchwork Thu Oct 14 02:44:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Ellerman X-Patchwork-Id: 1540756 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=UPWUMDS1; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4HVDJm1gbRz9sXS for ; Thu, 14 Oct 2021 13:44:56 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4HVDJl3rW4z307l for ; Thu, 14 Oct 2021 13:44:55 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=UPWUMDS1; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4HVDJT06HHz2xtT for ; Thu, 14 Oct 2021 13:44:41 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=UPWUMDS1; dkim-atps=neutral Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4HVDJS4kJrz4xb9; Thu, 14 Oct 2021 13:44:40 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1634179480; bh=PJyjoGNcjS93x8RYvVywazb6un3RK0YsMmizeepswDY=; h=From:To:Cc:Subject:Date:From; b=UPWUMDS1GCxIexe+jVNpYFsLBDqcNppe0vTFclInfZRuWbooJM4JYQrNULQVLd7iD 8FX2FN1GD6AMU0jWrOA1cdTknPuLYHh3zjZtqPff/pYfJfA3mvcaCRdVP9fTRxUnOs AuNsO5/2Tu9YsX7WMJjo52nR1oLP//r31ThGW9PY4OPdrpHHF9Cg4hKcaDIzc1K2Qx LzU4khzgyRaKl+pltybdcZcD2STsCcwvRxejePjvuDWEDqt4SnYkbZwZp6cSZ3X+sA Ni82gfXxAZunlncc7fjW8RNam5sqaTthzlD7gsQtrfHmikM3vUDacyLKRvAkdTfHED M2QOgPBWPaxkg== From: Michael Ellerman To: Subject: [PATCH] powerpc/dcr: Use cmplwi instead of 3-argument cmpli Date: Thu, 14 Oct 2021 13:44:24 +1100 Message-Id: <20211014024424.528848-1-mpe@ellerman.id.au> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ndesaulniers@google.com Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" In dcr-low.S we use cmpli with three arguments, instead of four arguments as defined in the ISA: cmpli cr0,r3,1024 This appears to be a PPC440-ism, looking at the "PPC440x5 CPU Core User’s Manual" it shows cmpli having no L field, but implied to be 0 due to the core being 32-bit. It mentions that the ISA defines four arguments and recommends using cmplwi. dcr-low.S is only built 32-bit, because it is only built when DCR_NATIVE=y, which is only selected by 40x and 44x. Looking at the generated code (with gcc/gas) we see cmplwi as expected. Although gas is happy with the 3-argument version when building for 32-bit, the LLVM assembler is not and errors out with: arch/powerpc/sysdev/dcr-low.S:27:10: error: invalid operand for instruction cmpli 0,%r3,1024; ... ^ Switching to the four argument version avoids any confusion when reading the ISA, fixes the issue with the LLVM assembler, and also means the code could be built 64-bit in future (though that's very unlikely). Reported-by: Nick Desaulniers Signed-off-by: Michael Ellerman Reviewed-by: Nick Desaulniers --- arch/powerpc/sysdev/dcr-low.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/sysdev/dcr-low.S b/arch/powerpc/sysdev/dcr-low.S index efeeb1b885a1..329b9c4ae542 100644 --- a/arch/powerpc/sysdev/dcr-low.S +++ b/arch/powerpc/sysdev/dcr-low.S @@ -11,7 +11,7 @@ #include #define DCR_ACCESS_PROLOG(table) \ - cmpli cr0,r3,1024; \ + cmplwi cr0,r3,1024; \ rlwinm r3,r3,4,18,27; \ lis r5,table@h; \ ori r5,r5,table@l; \