From 0c919337a48ac0c7c074c5a55cfa2cf4d2532674 Mon Sep 17 00:00:00 2001 From: Varun Wadekar Date: Fri, 15 Oct 2010 22:42:14 +0530 Subject: [PATCH] ARM: tegra: hardware arbitration semaphore support add apis to use the hardware arbitration semaphores in order to share hardware modules between kernel drivers and AVP firmware (e.g., the BSEA (audio bitstream) engine and AES block) Change-Id: I500ef0797223bc702151ad14e0e2156f50644a2a Signed-off-by: Varun Wadekar --- arch/arm/mach-tegra/Kconfig | 3 + arch/arm/mach-tegra/Makefile | 1 + arch/arm/mach-tegra/arb_sema.c | 242 ++++++++++++++++++++ arch/arm/mach-tegra/include/mach/arb_sema.h | 34 +++ 4 files changed, 280 insertions(+) create mode 100644 arch/arm/mach-tegra/arb_sema.c create mode 100644 arch/arm/mach-tegra/include/mach/arb_sema.h diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig index cfd34566ef12..d351811d9551 100644 --- a/arch/arm/mach-tegra/Kconfig +++ b/arch/arm/mach-tegra/Kconfig @@ -93,3 +93,6 @@ config TEGRA_IOVMM_GART config TEGRA_IOVMM bool + +config TEGRA_ARB_SEMAPHORE + bool diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile index b963d4e509db..2223fee1aa92 100644 --- a/arch/arm/mach-tegra/Makefile +++ b/arch/arm/mach-tegra/Makefile @@ -17,6 +17,7 @@ obj-y += mc.o obj-$(CONFIG_USB_SUPPORT) += usb_phy.o obj-$(CONFIG_FIQ) += fiq.o obj-$(CONFIG_TEGRA_PWM) += pwm.o +obj-$(CONFIG_TEGRA_ARB_SEMAPHORE) += arb_sema.o obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += clock.o obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_clocks.o diff --git a/arch/arm/mach-tegra/arb_sema.c b/arch/arm/mach-tegra/arb_sema.c new file mode 100644 index 000000000000..55af15e935f2 --- /dev/null +++ b/arch/arm/mach-tegra/arb_sema.c @@ -0,0 +1,242 @@ +/* + * Copyright (C) 2010, NVIDIA Corporation + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#define TEGRA_RPC_MAX_SEM 32 + +/* arb_gnt ictrl */ +#define ARB_CPU_INT_EN 0x4 + +/* arb_sema */ +#define ARB_GRANT_STATUS 0x0 +#define ARB_GRANT_REQUEST 0x4 +#define ARB_GRANT_RELEASE 0x8 + +struct tegra_arb_dev { + void __iomem *sema_base; + void __iomem *gnt_base; + spinlock_t lock; + struct completion arb_gnt_complete[TEGRA_RPC_MAX_SEM]; + struct mutex mutexes[TEGRA_RPC_MAX_SEM]; + int irq; + int status; + bool suspended; +}; + +static struct tegra_arb_dev *arb; + +static inline u32 arb_sema_read(u32 offset) +{ + return readl(arb->sema_base + offset); +} + +static inline void arb_sema_write(u32 value, u32 offset) +{ + writel(value, arb->sema_base + offset); +} + +static inline u32 arb_gnt_read(u32 offset) +{ + return readl(arb->gnt_base + offset); +} + +static inline void arb_gnt_write(u32 value, u32 offset) +{ + writel(value, arb->gnt_base + offset); +} + +static void request_arb_sem(enum tegra_arb_module lock) +{ + unsigned long flags; + u32 value; + + spin_lock_irqsave(&arb->lock, flags); + + arb_sema_write(1 << lock, ARB_GRANT_REQUEST); + value = arb_gnt_read(ARB_CPU_INT_EN); + value |= (1 << lock); + arb_gnt_write(value, ARB_CPU_INT_EN); + + spin_unlock_irqrestore(&arb->lock, flags); +} + +static void cancel_arb_sem(enum tegra_arb_module lock) +{ + unsigned long flags; + u32 value; + + spin_lock_irqsave(&arb->lock, flags); + + arb_sema_write(1 << lock, ARB_GRANT_RELEASE); + value = arb_gnt_read(ARB_CPU_INT_EN); + value &= ~(1 << lock); + arb_gnt_write(value, ARB_CPU_INT_EN); + + spin_unlock_irqrestore(&arb->lock, flags); +} + +int tegra_arb_mutex_lock_timeout(enum tegra_arb_module lock, int msecs) +{ + int ret; + + if (!arb) + return -ENODEV; + + if (arb->suspended) { + pr_err("device in suspend\n"); + return -ETIMEDOUT; + } + + mutex_lock(&arb->mutexes[lock]); + INIT_COMPLETION(arb->arb_gnt_complete[lock]); + request_arb_sem(lock); + ret = wait_for_completion_timeout(&arb->arb_gnt_complete[lock], msecs_to_jiffies(msecs)); + if (ret == 0) { + pr_err("timed out.\n"); + cancel_arb_sem(lock); + mutex_unlock(&arb->mutexes[lock]); + return -ETIMEDOUT; + } + + return 0; +} +EXPORT_SYMBOL(tegra_arb_mutex_lock_timeout); + +int tegra_arb_mutex_unlock(enum tegra_arb_module lock) +{ + if (!arb) + return -ENODEV; + + if (arb->suspended) { + pr_err("device in suspend\n"); + return -ETIMEDOUT; + } + + cancel_arb_sem(lock); + mutex_unlock(&arb->mutexes[lock]); + return 0; +} +EXPORT_SYMBOL(tegra_arb_mutex_unlock); + +static irqreturn_t arb_gnt_isr(int irq, void *dev_id) +{ + struct tegra_arb_dev *dev = dev_id; + unsigned long status; + u32 cpu_int_en; + unsigned int bit; + unsigned long flags; + + spin_lock_irqsave(&arb->lock, flags); + + status = arb_sema_read(ARB_GRANT_STATUS); + pr_debug("%s: 0x%lx\n", __func__, status); + + /* disable the arb semaphores which were signalled */ + cpu_int_en = arb_gnt_read(ARB_CPU_INT_EN); + arb_gnt_write((cpu_int_en & ~(status & cpu_int_en)), + ARB_CPU_INT_EN); + + status &= cpu_int_en; + for_each_set_bit(bit, &status, BITS_PER_LONG) + complete(&dev->arb_gnt_complete[bit]); + + spin_unlock_irqrestore(&arb->lock, flags); + return IRQ_HANDLED; +} + +int tegra_arb_suspend(void) +{ + unsigned long status = arb_sema_read(ARB_GRANT_STATUS); + + if (WARN_ON(status != 0)) { + pr_err("%s: suspending while holding arbitration " + "semaphore: %08lx\n", __func__, status); + } + arb->suspended = true; + + return status ? -EBUSY : 0; +} + +int tegra_arb_resume(void) +{ + arb->suspended = false; + return 0; +} + +static int __init tegra_arb_init(void) +{ + struct tegra_arb_dev *dev = NULL; + int err, i; + + dev = kzalloc(sizeof(struct tegra_arb_dev), GFP_KERNEL); + if (dev == NULL) { + pr_err("%s: unable to alloc data struct.\n", __func__); + return -ENOMEM; + } + + for (i = 0; i < TEGRA_RPC_MAX_SEM; i++) { + mutex_init(&dev->mutexes[i]); + init_completion(&dev->arb_gnt_complete[i]); + } + + dev->sema_base = IO_ADDRESS(TEGRA_ARB_SEMA_BASE); + if (!dev->sema_base) { + pr_err("%s: can't get arb sema_base\n", __func__); + err = -ENOMEM; + goto out; + } + + dev->gnt_base = IO_ADDRESS(TEGRA_ARBGNT_ICTLR_BASE); + if (!dev->gnt_base) { + pr_err("%s: can't ioremap gnt_base\n", __func__); + err = -ENOMEM; + goto out; + } + + dev->irq = INT_GNT_1; + err = request_irq(dev->irq, arb_gnt_isr, 0, "rpc-arbsema", dev); + if (err) { + pr_err("%s: request_irq(%d) failed(%d)\n", __func__, + dev->irq, err); + goto out; + } + + spin_lock_init(&dev->lock); + arb = dev; + + pr_info("%s: initialized\n", __func__); + return 0; + +out: + kfree(dev); + pr_err("%s: initialization failed.\n", __func__); + return err; +} +subsys_initcall(tegra_arb_init); + +MODULE_LICENSE("GPLv2"); diff --git a/arch/arm/mach-tegra/include/mach/arb_sema.h b/arch/arm/mach-tegra/include/mach/arb_sema.h new file mode 100644 index 000000000000..374c5a913700 --- /dev/null +++ b/arch/arm/mach-tegra/include/mach/arb_sema.h @@ -0,0 +1,34 @@ +/* + * arch/arm/mach-tegra/include/mach/arb_sema.h + * + * Hardware arbitration semaphore interface + * + * Copyright (c) 2010, NVIDIA Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#ifndef __MACH_TEGRA_ARB_SEMA_H +#define __MACH_TEGRA_ARB_SEMA_H + +enum tegra_arb_module { + TEGRA_ARB_AES = 0, +}; + +int tegra_arb_mutex_lock_timeout(enum tegra_arb_module lock, int msecs); + +int tegra_arb_mutex_unlock(enum tegra_arb_module lock); + +#endif -- 2.34.1