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[199.106.103.254]) by mx.google.com with ESMTPSA id fs16sm6095565pdb.12.2015.06.09.09.23.58 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 09 Jun 2015 09:23:59 -0700 (PDT) From: Lina Iyer To: ohad@wizery.com Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Lina Iyer , Jeffrey Hugo , Bjorn Andersson , Andy Gross Subject: [PATCH RFC v2 2/2] hwspinlock: qcom: Lock #7 is special lock, uses dynamic proc_id Date: Tue, 9 Jun 2015 10:23:40 -0600 Message-Id: <1433867020-7746-3-git-send-email-lina.iyer@linaro.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1433867020-7746-1-git-send-email-lina.iyer@linaro.org> References: <1433867020-7746-1-git-send-email-lina.iyer@linaro.org> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hwspinlocks are widely used between processors in an SoC, and also between elevation levels within in the same processor. QCOM SoC's use hwspinlock to serialize entry into a low power mode when the context switches from Linux to secure monitor. Lock #7 has been assigned for this purpose. In order to differentiate between one cpu core holding a lock while another cpu is contending for the same lock, the proc id written into the lock is (128 + cpu id). This makes it unique value among the cpu cores and therefore when a core locks the hwspinlock, other cores would wait for the lock to be released since they would have a different proc id. This value is specific for the lock #7 only. Declare lock #7 as raw capable, so the hwspinlock framework would not enfore acquiring a s/w spinlock before acquiring the hwspinlock. Cc: Jeffrey Hugo Cc: Bjorn Andersson Cc: Andy Gross Signed-off-by: Lina Iyer --- drivers/hwspinlock/qcom_hwspinlock.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/hwspinlock/qcom_hwspinlock.c b/drivers/hwspinlock/qcom_hwspinlock.c index 93b62e0..59278b0 100644 --- a/drivers/hwspinlock/qcom_hwspinlock.c +++ b/drivers/hwspinlock/qcom_hwspinlock.c @@ -25,16 +25,26 @@ #include "hwspinlock_internal.h" -#define QCOM_MUTEX_APPS_PROC_ID 1 -#define QCOM_MUTEX_NUM_LOCKS 32 +#define QCOM_MUTEX_APPS_PROC_ID 1 +#define QCOM_MUTEX_CPUIDLE_OFFSET 128 +#define QCOM_CPUIDLE_LOCK 7 +#define QCOM_MUTEX_NUM_LOCKS 32 + +static inline u32 __qcom_get_proc_id(struct hwspinlock *lock) +{ + return hwspin_lock_get_id(lock) == QCOM_CPUIDLE_LOCK ? + (QCOM_MUTEX_CPUIDLE_OFFSET + smp_processor_id()) : + QCOM_MUTEX_APPS_PROC_ID; +} static int qcom_hwspinlock_trylock(struct hwspinlock *lock) { struct regmap_field *field = lock->priv; u32 lock_owner; int ret; + u32 proc_id = __qcom_get_proc_id(lock); - ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID); + ret = regmap_field_write(field, proc_id); if (ret) return ret; @@ -42,7 +52,7 @@ static int qcom_hwspinlock_trylock(struct hwspinlock *lock) if (ret) return ret; - return lock_owner == QCOM_MUTEX_APPS_PROC_ID; + return lock_owner == proc_id; } static void qcom_hwspinlock_unlock(struct hwspinlock *lock) @@ -57,7 +67,7 @@ static void qcom_hwspinlock_unlock(struct hwspinlock *lock) return; } - if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) { + if (lock_owner != __qcom_get_proc_id(lock)) { pr_err("%s: spinlock not owned by us (actual owner is %d)\n", __func__, lock_owner); } @@ -129,6 +139,8 @@ static int qcom_hwspinlock_probe(struct platform_device *pdev) regmap, field); } + bank->lock[QCOM_CPUIDLE_LOCK].hwcaps = HWL_CAP_ALLOW_RAW; + pm_runtime_enable(&pdev->dev); ret = hwspin_lock_register(bank, &pdev->dev, &qcom_hwspinlock_ops,