Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752664AbbH0EJF (ORCPT ); Thu, 27 Aug 2015 00:09:05 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:33169 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751530AbbH0EJE (ORCPT ); Thu, 27 Aug 2015 00:09:04 -0400 From: Chunyan Zhang To: gregkh@linuxfoundation.org, mathieu.poirier@linaro.org Cc: broonie@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] Coresight: ETMv4: Prevent TRCRSCTLR0&1 from being accessed Date: Thu, 27 Aug 2015 12:06:09 +0800 Message-Id: <1440648369-4614-1-git-send-email-zhang.chunyan@linaro.org> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2626 Lines: 69 1. TRCRSCTLRn - Resource Selection Control Registers n=0~1 are reserved, we shouldn't access them. 2. The max number of 'n' here is defined in TRCIDR4.NUMRSPAIR whoes value indicates the number of resource selection *pairs*, and 0 indicates one resource selection pair, 1 indicates two pairs, and so on ... So, the total number of resource selection control registers which we can access is (TRCIDR4.NUMRSPAIR * 2) Signed-off-by: Chunyan Zhang --- drivers/hwtracing/coresight/coresight-etm4x.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 1312e99..9425249 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -136,7 +136,9 @@ static void etm4_enable_hw(void *info) writel_relaxed(drvdata->cntr_val[i], drvdata->base + TRCCNTVRn(i)); } - for (i = 0; i < drvdata->nr_resource; i++) + + /* Resource selector pair 0 is always implemented and reserved */ + for (i = 2; i < (drvdata->nr_resource + 1) * 2; i++) writel_relaxed(drvdata->res_ctrl[i], drvdata->base + TRCRSCTLRn(i)); @@ -489,8 +491,9 @@ static ssize_t reset_store(struct device *dev, drvdata->cntr_val[i] = 0x0; } - drvdata->res_idx = 0x0; - for (i = 0; i < drvdata->nr_resource; i++) + /* Resource selector pair 0 is always implemented and reserved */ + drvdata->res_idx = 0x2; + for (i = 2; i < (drvdata->nr_resource + 1) * 2; i++) drvdata->res_ctrl[i] = 0x0; for (i = 0; i < drvdata->nr_ss_cmp; i++) { @@ -1729,7 +1732,7 @@ static ssize_t res_idx_store(struct device *dev, if (kstrtoul(buf, 16, &val)) return -EINVAL; /* Resource selector pair 0 is always implemented and reserved */ - if ((val == 0) || (val >= drvdata->nr_resource)) + if (val < 2 || val > (drvdata->nr_resource + 1) * 2) return -EINVAL; /* @@ -2498,7 +2501,9 @@ static void etm4_init_default_data(struct etmv4_drvdata *drvdata) drvdata->cntr_val[i] = 0x0; } - for (i = 2; i < drvdata->nr_resource * 2; i++) + /* Resource selector pair 0 is always implemented and reserved */ + drvdata->res_idx = 0x2; + for (i = 2; i < (drvdata->nr_resource + 1) * 2; i++) drvdata->res_ctrl[i] = 0x0; for (i = 0; i < drvdata->nr_ss_cmp; i++) { -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/