Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934897AbcJGB5t (ORCPT ); Thu, 6 Oct 2016 21:57:49 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:37960 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751233AbcJGB5m (ORCPT ); Thu, 6 Oct 2016 21:57:42 -0400 DMARC-Filter: OpenDMARC Filter v1.3.1 smtp.codeaurora.org 05B4361A06 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=pass smtp.mailfrom=subhashj@codeaurora.org From: Subhash Jadavani To: vinholikatti@gmail.com, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com Cc: Subhash Jadavani , linux-scsi@vger.kernel.org (open list:UNIVERSAL FLASH STORAGE HOST CONTROLLER DRIVER), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v3] scsi: ufshcd: fix possible unclocked register access Date: Thu, 6 Oct 2016 18:57:30 -0700 Message-Id: <1475805450-14039-1-git-send-email-subhashj@codeaurora.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: 4993 Lines: 148 Vendor specific setup_clocks callback may require the clocks managed by ufshcd driver to be ON. So if the vendor specific setup_clocks callback is called while the required clocks are turned off, it could result into unclocked register access. To prevent possible unclock register access, this change adds one more argument to setup_clocks callback to let it know whether it is called pre/post the clock changes by core driver. Signed-off-by: Subhash Jadavani --- drivers/scsi/ufs/ufs-qcom.c | 10 ++++++---- drivers/scsi/ufs/ufshcd.c | 17 ++++++++--------- drivers/scsi/ufs/ufshcd.h | 8 +++++--- 3 files changed, 19 insertions(+), 16 deletions(-) diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c index 3aedf73..3c4f602 100644 --- a/drivers/scsi/ufs/ufs-qcom.c +++ b/drivers/scsi/ufs/ufs-qcom.c @@ -1094,10 +1094,12 @@ static void ufs_qcom_set_caps(struct ufs_hba *hba) * ufs_qcom_setup_clocks - enables/disable clocks * @hba: host controller instance * @on: If true, enable clocks else disable them. + * @status: PRE_CHANGE or POST_CHANGE notify * * Returns 0 on success, non-zero on failure. */ -static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on) +static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on, + enum ufs_notify_change_status status) { struct ufs_qcom_host *host = ufshcd_get_variant(hba); int err; @@ -1111,7 +1113,7 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on) if (!host) return 0; - if (on) { + if (on && (status == POST_CHANGE)) { err = ufs_qcom_phy_enable_iface_clk(host->generic_phy); if (err) goto out; @@ -1130,7 +1132,7 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on) if (vote == host->bus_vote.min_bw_vote) ufs_qcom_update_bus_bw_vote(host); - } else { + } else if (!on && (status == PRE_CHANGE)) { /* M-PHY RMMI interface clocks can be turned off */ ufs_qcom_phy_disable_iface_clk(host->generic_phy); @@ -1254,7 +1256,7 @@ static int ufs_qcom_init(struct ufs_hba *hba) ufs_qcom_set_caps(hba); ufs_qcom_advertise_quirks(hba); - ufs_qcom_setup_clocks(hba, true); + ufs_qcom_setup_clocks(hba, true, POST_CHANGE); if (hba->dev->id < MAX_UFS_QCOM_HOSTS) ufs_qcom_hosts[hba->dev->id] = host; diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 05c7456..571a2f6 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5389,6 +5389,10 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on, if (!head || list_empty(head)) goto out; + ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE); + if (ret) + return ret; + list_for_each_entry(clki, head, list) { if (!IS_ERR_OR_NULL(clki->clk)) { if (skip_ref_clk && !strcmp(clki->name, "ref_clk")) @@ -5410,7 +5414,10 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on, } } - ret = ufshcd_vops_setup_clocks(hba, on); + ret = ufshcd_vops_setup_clocks(hba, on, POST_CHANGE); + if (ret) + return ret; + out: if (ret) { list_for_each_entry(clki, head, list) { @@ -5500,8 +5507,6 @@ static void ufshcd_variant_hba_exit(struct ufs_hba *hba) if (!hba->vops) return; - ufshcd_vops_setup_clocks(hba, false); - ufshcd_vops_setup_regulators(hba, false); ufshcd_vops_exit(hba); @@ -5905,10 +5910,6 @@ disable_clks: if (ret) goto set_link_active; - ret = ufshcd_vops_setup_clocks(hba, false); - if (ret) - goto vops_resume; - if (!ufshcd_is_link_active(hba)) ufshcd_setup_clocks(hba, false); else @@ -5925,8 +5926,6 @@ disable_clks: ufshcd_hba_vreg_set_lpm(hba); goto out; -vops_resume: - ufshcd_vops_resume(hba, pm_op); set_link_active: ufshcd_vreg_set_hpm(hba); if (ufshcd_is_link_hibern8(hba) && !ufshcd_uic_hibern8_exit(hba)) diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 430bef1..afff7f4 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -273,7 +273,8 @@ struct ufs_hba_variant_ops { u32 (*get_ufs_hci_version)(struct ufs_hba *); int (*clk_scale_notify)(struct ufs_hba *, bool, enum ufs_notify_change_status); - int (*setup_clocks)(struct ufs_hba *, bool); + int (*setup_clocks)(struct ufs_hba *, bool, + enum ufs_notify_change_status); int (*setup_regulators)(struct ufs_hba *, bool); int (*hce_enable_notify)(struct ufs_hba *, enum ufs_notify_change_status); @@ -755,10 +756,11 @@ static inline int ufshcd_vops_clk_scale_notify(struct ufs_hba *hba, return 0; } -static inline int ufshcd_vops_setup_clocks(struct ufs_hba *hba, bool on) +static inline int ufshcd_vops_setup_clocks(struct ufs_hba *hba, bool on, + enum ufs_notify_change_status status) { if (hba->vops && hba->vops->setup_clocks) - return hba->vops->setup_clocks(hba, on); + return hba->vops->setup_clocks(hba, on, status); return 0; } -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project