From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x242.google.com (mail-pg0-x242.google.com [IPv6:2607:f8b0:400e:c05::242]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xLLgF6Lm2zDr0Y for ; Mon, 31 Jul 2017 10:58:49 +1000 (AEST) Received: by mail-pg0-x242.google.com with SMTP id k190so13283307pgk.4 for ; Sun, 30 Jul 2017 17:58:49 -0700 (PDT) Received: from matt.ozlabs.ibm.com ([122.99.82.10]) by smtp.gmail.com with ESMTPSA id d127sm46851127pfa.171.2017.07.30.17.58.46 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 30 Jul 2017 17:58:47 -0700 (PDT) From: Matt Brown To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v4 1/5] powerpc/lib/sstep: Add cmpb instruction emulation Date: Mon, 31 Jul 2017 10:58:22 +1000 Message-Id: <20170731005826.32044-1-matthew.brown.dev@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This patch adds emulation of the cmpb instruction, enabling xmon to emulate this instruction. Tested for correctness against the cmpb asm instruction on ppc64le. Signed-off-by: Matt Brown --- v2: - fixed opcode - fixed mask typecasting --- arch/powerpc/lib/sstep.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 33117f8..87d277f 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -596,6 +596,22 @@ static nokprobe_inline void do_cmp_unsigned(struct pt_regs *regs, unsigned long regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift); } +static nokprobe_inline void do_cmpb(struct pt_regs *regs, unsigned long v1, + unsigned long v2, int rd) +{ + unsigned long long out_val, mask; + int i; + + out_val = 0; + for (i = 0; i < 8; i++) { + mask = 0xffUL << (i * 8); + if ((v1 & mask) == (v2 & mask)) + out_val |= mask; + } + + regs->gpr[rd] = out_val; +} + static nokprobe_inline int trap_compare(long v1, long v2) { int ret = 0; @@ -1049,6 +1065,10 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, do_cmp_unsigned(regs, val, val2, rd >> 2); goto instr_done; + case 508: /* cmpb */ + do_cmpb(regs, regs->gpr[rd], regs->gpr[rb], ra); + goto instr_done; + /* * Arithmetic instructions */ -- 2.9.3