Messages in this thread | | | Date | Tue, 13 Aug 2013 09:54:54 -0600 | From | Jeffrey Hugo <> | Subject | Re: [PATCH v2] hwspinlock/msm: Add support for Qualcomm MSM HW Mutex block |
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On 8/12/2013 10:35 AM, Stephen Boyd wrote: > On 07/29/13 15:00, Kumar Gala wrote: >> diff --git a/drivers/hwspinlock/msm_hwspinlock.c b/drivers/hwspinlock/msm_hwspinlock.c >> new file mode 100644 >> index 0000000..dbd9a69 >> --- /dev/null >> +++ b/drivers/hwspinlock/msm_hwspinlock.c >> @@ -0,0 +1,150 @@ >> +/* >> + * Copyright (c) 2013, The Linux Foundation. All rights reserved. >> + * >> + * This software is licensed under the terms of the GNU General Public >> + * License version 2, as published by the Free Software Foundation, and >> + * may be copied, distributed, and modified under those terms. >> + * >> + * This program is distributed in the hope that it will be useful, >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >> + * GNU General Public License for more details. >> + */ >> + >> +#include <linux/err.h> >> +#include <linux/kernel.h> >> +#include <linux/slab.h> >> +#include <linux/device.h> >> +#include <linux/module.h> >> +#include <linux/platform_device.h> >> +#include <linux/of.h> >> +#include <linux/of_address.h> >> +#include <linux/of_device.h> >> +#include <linux/hwspinlock.h> >> +#include <linux/io.h> >> + >> +#include "hwspinlock_internal.h" >> + >> +#define SPINLOCK_ID_APPS_PROC 1 > > Is this id only for the apps processor? What about hexagon? Does it need > a different number?
Yes, hexagon would need a different id based on what job that particular hexagon processor is doing. I'm not currently aware of a hexagon usecase, but I believe modifying the DT binding in the future would cover the usecase if it comes up.
> >> +#define BASE_ID 0 >> + >> +static int msm_hwspinlock_trylock(struct hwspinlock *lock) >> +{ >> + void __iomem *lock_addr = lock->priv; >> + >> + writel_relaxed(SPINLOCK_ID_APPS_PROC, lock_addr); >> + smp_mb(); >> + return readl_relaxed(lock_addr) == SPINLOCK_ID_APPS_PROC; >> +} >> + >> +static void msm_hwspinlock_unlock(struct hwspinlock *lock) >> +{ >> + int lock_owner; > > This should probably be u32 to be explicit about the size of the register. > >> + void __iomem *lock_addr = lock->priv; >> + >> + lock_owner = readl_relaxed(lock_addr); >> + if (lock_owner != SPINLOCK_ID_APPS_PROC) { >> + pr_err("%s: spinlock not owned by Apps (actual owner is %d)\n", > > Maybe you should just say "spinlock not owned by us (actual owner is > %d)" so that this driver is agnostic to the processor it runs on? > >> + __func__, lock_owner); >> + } >> + >> + writel_relaxed(0, lock_addr); >> + smp_mb(); >> +} >> >
Jeffrey Hugo -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation.
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