From: Haren Myneni Subject: Crypto/nx842: Ignore invalid XER[S0] return error Date: Fri, 11 Dec 2015 19:30:29 -0800 Message-ID: <1449891029.19568.5.camel@hbabu-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org To: herbert@gondor.apana.org.au, ddstreet@ieee.org, davem@davemloft.net, mpe@ellerman.id.au, pair@us.ibm.com Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org NX842 coprocessor sets 3rd bit in CR register with XER[S0] which is nothing to do with NX request. On powerpc, XER[S0] will be set if overflow in FPU and stays until another floating point operation is executed. Since this bit can be set with other valuable return status, ignore this XER[S0] value. One of other bits (INITIATED, BUSY or REJECTED) will be returned for any given NX request. Signed-off-by: Haren Myneni diff --git a/arch/powerpc/include/asm/icswx.h b/arch/powerpc/include/asm/icswx.h index 9f8402b..27e588f 100644 --- a/arch/powerpc/include/asm/icswx.h +++ b/arch/powerpc/include/asm/icswx.h @@ -164,6 +164,7 @@ struct coprocessor_request_block { #define ICSWX_INITIATED (0x8) #define ICSWX_BUSY (0x4) #define ICSWX_REJECTED (0x2) +#define ICSWX_XERS0 (0x1) /* undefined or set from XERSO. */ static inline int icswx(__be32 ccw, struct coprocessor_request_block *crb) { diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c index 9ef51fa..6bc33ae 100644 --- a/drivers/crypto/nx/nx-842-powernv.c +++ b/drivers/crypto/nx/nx-842-powernv.c @@ -442,6 +442,16 @@ static int nx842_powernv_function(const unsigned char *in, unsigned int inlen, (unsigned int)ccw, (unsigned int)be32_to_cpu(crb->ccw)); + /* + * NX842 coprocessor sets 3rd bit in CR register with XER[S0]. + * Setting XER[S0] happens if overflow in FPU and stays until + * other floating operation is executed. XER[S0] value is nothing + * to NX and no use to user. Since this bit can be set with other + * return values, ignore this error. + */ + if (ret & ICSWX_XERS0) + ret &= ~ICSWX_XERS0; + switch (ret) { case ICSWX_INITIATED: ret = wait_for_csb(wmem, csb); @@ -454,10 +464,6 @@ static int nx842_powernv_function(const unsigned char *in, unsigned int inlen, pr_err_ratelimited("ICSWX rejected\n"); ret = -EPROTO; break; - default: - pr_err_ratelimited("Invalid ICSWX return code %x\n", ret); - ret = -EPROTO; - break; } if (!ret)