On Fri, Nov 20, 2020 at 10:01:04PM -0600, Bjorn Andersson wrote: > On Thu 19 Nov 00:44 CST 2020, fuyao@xxxxxxxxxxxxxxxxx wrote: > > > From: fuyao <fuyao@xxxxxxxxxxxxxxxxx> > > > > Add hwspinlock support for the SUNXI Hardware Spinlock device. > > > > The Hardware Spinlock device on SUNXI provides hardware assistance > > for synchronization between the multiple processors in the system > > (Cortex-A7, or1k, Xtensa DSP, Cortex-A53) > > > > Signed-off-by: fuyao <fuyao@xxxxxxxxxxxxxxxxx> > > --- > > MAINTAINERS | 6 + > > drivers/hwspinlock/Kconfig | 10 ++ > > drivers/hwspinlock/Makefile | 1 + > > drivers/hwspinlock/sunxi_hwspinlock.c | 205 ++++++++++++++++++++++++++ > > 4 files changed, 222 insertions(+) > > create mode 100644 drivers/hwspinlock/sunxi_hwspinlock.c > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index e451dcce054f0..68d25574432d0 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -737,6 +737,12 @@ L: linux-media@xxxxxxxxxxxxxxx > > S: Maintained > > F: drivers/staging/media/sunxi/cedrus/ > > > > +ALLWINNER HWSPINLOCK DRIVER > > +M: fuyao <fuyao@xxxxxxxxxxxxxxxxx> > > +S: Maintained > > +F: drivers/hwspinlock/sunxi_hwspinlock.c > > +F: Documentation/devicetree/bindings/hwlock/sunxi,hwspinlock.yaml > > + > > ALPHA PORT > > M: Richard Henderson <rth@xxxxxxxxxxx> > > M: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx> > > diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig > > index 32cd26352f381..4d0d516dcb544 100644 > > --- a/drivers/hwspinlock/Kconfig > > +++ b/drivers/hwspinlock/Kconfig > > @@ -55,6 +55,16 @@ config HWSPINLOCK_STM32 > > > > If unsure, say N. > > > > +config HWSPINLOCK_SUNXI > > + tristate "SUNXI Hardware Spinlock device" > > + depends on ARCH_SUNXI || COMPILE_TEST > > + help > > + Say y here to support the SUNXI Hardware Semaphore functionality, which > > + provides a synchronisation mechanism for the various processor on the > > + SoC. > > + > > + If unsure, say N. > > + > > config HSEM_U8500 > > tristate "STE Hardware Semaphore functionality" > > depends on ARCH_U8500 || COMPILE_TEST > > diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile > > index ed053e3f02be4..839a053205f73 100644 > > --- a/drivers/hwspinlock/Makefile > > +++ b/drivers/hwspinlock/Makefile > > @@ -10,3 +10,4 @@ obj-$(CONFIG_HWSPINLOCK_SIRF) += sirf_hwspinlock.o > > obj-$(CONFIG_HWSPINLOCK_SPRD) += sprd_hwspinlock.o > > obj-$(CONFIG_HWSPINLOCK_STM32) += stm32_hwspinlock.o > > obj-$(CONFIG_HSEM_U8500) += u8500_hsem.o > > +obj-$(CONFIG_HWSPINLOCK_SUNXI) += sunxi_hwspinlock.o > > diff --git a/drivers/hwspinlock/sunxi_hwspinlock.c b/drivers/hwspinlock/sunxi_hwspinlock.c > > new file mode 100644 > > index 0000000000000..2c3dc148c9b72 > > --- /dev/null > > +++ b/drivers/hwspinlock/sunxi_hwspinlock.c > > @@ -0,0 +1,205 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * SUNXI hardware spinlock driver > > + * > > + * Copyright (C) 2020 Allwinnertech - http://www.allwinnertech.com > > + * > > Please remove the remainder of this comment, it's already covered by the > SPDX header above. > > > + * This program is free software; you can redistribute it and/or > > + * modify it under the terms of the GNU General Public License > > + * version 2 as published by the Free Software Foundation. > > + * > > + * 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/kernel.h> > > +#include <linux/platform_device.h> > > +#include <linux/module.h> > > +#include <linux/device.h> > > +#include <linux/delay.h> > > +#include <linux/io.h> > > +#include <linux/bitops.h> > > +#include <linux/pm_runtime.h> > > +#include <linux/slab.h> > > +#include <linux/spinlock.h> > > +#include <linux/hwspinlock.h> > > +#include <linux/clk.h> > > +#include <linux/of.h> > > +#include <linux/of_address.h> > > +#include <linux/of_device.h> > > +#include <linux/err.h> > > +#include <linux/reset.h> > > You don't need all of these. > > > + > > +#include "hwspinlock_internal.h" > > + > > +/* hardware spinlock register list */ > > +#define LOCK_SYS_STATUS_REG (0x0000) > > +#define LOCK_STATUS_REG (0x0010) > > +#define LOCK_BASE_OFFSET (0x0100) > > +#define LOCK_BASE_ID (0) > > No need for the parenthesis on these, please drop them. > > > + > > +/* Possible values of SPINLOCK_LOCK_REG */ > > +#define SPINLOCK_NOTTAKEN (0) /* free */ > > +#define SPINLOCK_TAKEN (1) /* locked */ > > + > > +struct sunxi_spinlock_config { > > + int nspin; > > +}; > > + > > +static int sunxi_hwspinlock_trylock(struct hwspinlock *lock) > > +{ > > + void __iomem *lock_addr = lock->priv; > > + > > + /* attempt to acquire the lock by reading its value */ > > + return (readl(lock_addr) == SPINLOCK_NOTTAKEN); > > Please drop the outer (). > > > +} > > + > > +static void sunxi_hwspinlock_unlock(struct hwspinlock *lock) > > +{ > > + void __iomem *lock_addr = lock->priv; > > + > > + /* release the lock by writing 0 to it */ > > + writel(SPINLOCK_NOTTAKEN, lock_addr); > > +} > > + > > +/* > > + * relax the SUNXI interconnect while spinning on it. > > + * > > + * The specs recommended that the retry delay time will be > > + * just over half of the time that a requester would be > > + * expected to hold the lock. > > + * > > + * in sunxi spinlock time less then 200 cycles > > + * > > + * The number below is taken from an hardware specs example, > > + * obviously it is somewhat arbitrary. > > Thank you for the good explanation. > > > + */ > > +static void sunxi_hwspinlock_relax(struct hwspinlock *lock) > > +{ > > + ndelay(50); > > +} > > + > > +static const struct hwspinlock_ops sunxi_hwspinlock_ops = { > > + .trylock = sunxi_hwspinlock_trylock, > > + .unlock = sunxi_hwspinlock_unlock, > > + .relax = sunxi_hwspinlock_relax, > > +}; > > + > > +struct sunxi_hwspinlock_device { > > + struct hwspinlock_device *bank; > > + struct clk *bus_clk; > > + struct reset_control *reset; > > +}; > > + > > +static void sunxi_hwspinlock_clk_init(struct platform_device *pdev, > > + struct sunxi_hwspinlock_device *private) > > +{ > > + private->bus_clk = devm_clk_get(&pdev->dev, NULL); > > + private->reset = devm_reset_control_get(&pdev->dev, NULL); > > You should check the return value of these, e.g. for EPROBE_DEFER and if > so return appropriately from sunxi_hwspinlock_probe(). > > So please move them to the probe function to make this easier and > cleaner. > > > + > > + if (private->reset) > > + reset_control_deassert(private->reset); > > + if (private->bus_clk) > > + clk_prepare_enable(private->bus_clk); > > Both of these apis start with > > if (!argument) > return; > > So there's no need for you to check for NULL before calling them. Also > to make it clear that you want these to be deassered and prepare_enabled > between probe and remvoe, move them into probe (and next function into > remove). > > > +} > > + > > +static void sunxi_hwspinlock_clk_dinit(struct sunxi_hwspinlock_device *private) > > +{ > > + if (private->reset) > > + reset_control_assert(private->reset); > > + if (private->bus_clk) > > + clk_disable(private->bus_clk); > > +} > > + > > +static const struct sunxi_spinlock_config spin_ver_1 = { > > + .nspin = 32, > > +}; > > + > > +static const struct of_device_id sunxi_hwspinlock_of_match[] = { > > + { > > + .compatible = "allwinner,h3-hwspinlock", > > + .data = &spin_ver_1, > > If all cases comes with the same "data", then please just put nspin in a > #define until you're going to support hardware that has some other > number of locks. > > > + }, > > + { > > + .compatible = "allwinner,h6-hwspinlock", > > + .data = &spin_ver_1, > > + }, > > + { /* Sentinel */ }, > > No need to spell out "/* Sentinel */", leave it emtpy and please drop the , at > the end. > > > +}; > > +MODULE_DEVICE_TABLE(of, sunxi_hwspinlock_of_match); > > Please move this down by sunxi_hwspinlock_driver and use > device_get_match_data() instead of of_match_device(). > > > + > > +static int sunxi_hwspinlock_probe(struct platform_device *pdev) > > +{ > > + struct sunxi_hwspinlock_device *private; > > + struct hwspinlock_device *bank; > > + struct hwspinlock *hwlock; > > + const struct sunxi_spinlock_config *config; > > + const struct of_device_id *match; > > + void __iomem *iobase; > > + int num_locks, i, ret; > > + > > + iobase = devm_platform_ioremap_resource(pdev, 0); > > + if (PTR_ERR(iobase)) > > + return PTR_ERR(iobase); > > + > > + match = of_match_device(of_match_ptr(sunxi_hwspinlock_of_match), > > + &pdev->dev); > > + if (!match) > > + return -ENODEV; > > + > > + config = match->data; > > + num_locks = config->nspin; > > + > > + private = devm_kzalloc(&pdev->dev, sizeof(*private), GFP_KERNEL); > > + if (!private) > > + return -ENOMEM; > > + > > + bank = devm_kzalloc(&pdev->dev, > > + sizeof(*bank) + num_locks * sizeof(*hwlock), > > + GFP_KERNEL); > > + if (!bank) > > + return -ENOMEM; > > + > > + private->bank = bank; > > + sunxi_hwspinlock_clk_init(pdev, private); > > + > > + platform_set_drvdata(pdev, private); > > + > > + for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++) > > + hwlock->priv = iobase + LOCK_BASE_OFFSET + sizeof(u32) * i; > > + > > + ret = devm_hwspin_lock_register(&pdev->dev, bank, &sunxi_hwspinlock_ops, > > + LOCK_BASE_ID, num_locks); > > This returns 0 or -errno, so rather than returning ret if ret otherwise > 0, just do: > > return devm_hwspin_lock_register(...) > > > + if (ret) > > + return ret; > > + > > + > > + return 0; > > +} > > + > > +static int sunxi_hwspinlock_remove(struct platform_device *pdev) > > +{ > > + struct sunxi_hwspinlock_device *private = platform_get_drvdata(pdev); > > + > > + sunxi_hwspinlock_clk_dinit(private); > > + > > + return 0; > > +} > > + > > +static struct platform_driver sunxi_hwspinlock_driver = { > > + .probe = sunxi_hwspinlock_probe, > > + .remove = sunxi_hwspinlock_remove, > > + .driver = { > > + .name = "sunxi-hwspinlock", > > + .owner = THIS_MODULE, > > module_platform_driver() fills out .owner for you, so please remove > this. > > > + .of_match_table = of_match_ptr(sunxi_hwspinlock_of_match), > > Please skip of_match_ptr(), it will just cause build warnings when > compile tested without CONFIG_OF. > > Thank you, > Bjorn > > > + }, > > +}; > > + > > +module_platform_driver(sunxi_hwspinlock_driver); > > + > > +MODULE_LICENSE("GPL v2"); > > +MODULE_DESCRIPTION("Hardware spinlock driver for SUNXI"); > > +MODULE_AUTHOR("fuyao <fuyao@xxxxxxxxxxxxxxxxx>"); Thanks for you review, I read it carefully, and learned a lot. Maxim tells that there is already the same submission, so this submission will be abandoned. thanks again. -- fuyao
