ARM: bL_switcher: add a simple /dev user interface for debugging purposes (b22537c6) · Commits · 戴 / test

arch/arm/Kconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -1556,6 +1556,14 @@ config BL_SWITCHER
		transparently handle transition between a cluster of A15's
		and a cluster of A7's in a big.LITTLE system.

		config BL_SWITCHER_DUMMY_IF
		tristate "Simple big.LITTLE switcher user interface"
		depends on BL_SWITCHER && DEBUG_KERNEL
		help
		This is a simple and dummy char dev interface to control
		the big.LITTLE switcher core code. It is meant for
		debugging purposes only.

		choice
		prompt "Memory split"
		default VMSPLIT_3G

arch/arm/common/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -18,3 +18,4 @@ AFLAGS_mcpm_head.o := -march=armv7-a
		AFLAGS_vlock.o := -march=armv7-a
		obj-$(CONFIG_TI_PRIV_EDMA) += edma.o
		obj-$(CONFIG_BL_SWITCHER) += bL_switcher.o
		obj-$(CONFIG_BL_SWITCHER_DUMMY_IF) += bL_switcher_dummy_if.o

arch/arm/common/bL_switcher_dummy_if.c

0 → 100644

+71 −0

Original line number	Diff line number	Diff line
		/*
		* arch/arm/common/bL_switcher_dummy_if.c -- b.L switcher dummy interface
		*
		* Created by: Nicolas Pitre, November 2012
		* Copyright: (C) 2012-2013 Linaro Limited
		*
		* Dummy interface to user space for debugging purpose only.
		*
		* 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.
		*/

		#include <linux/init.h>
		#include <linux/module.h>
		#include <linux/fs.h>
		#include <linux/miscdevice.h>
		#include <asm/uaccess.h>
		#include <asm/bL_switcher.h>

		static ssize_t bL_switcher_write(struct file file, const char __user buf,
		size_t len, loff_t *pos)
		{
		unsigned char val[3];
		unsigned int cpu, cluster;
		int ret;

		pr_debug("%s\n", __func__);

		if (len < 3)
		return -EINVAL;

		if (copy_from_user(val, buf, 3))
		return -EFAULT;

		/* format: <cpu#>,<cluster#> */
		if (val[0] < '0' \|\| val[0] > '9' \|\|
		val[1] != ',' \|\|
		val[2] < '0' \|\| val[2] > '1')
		return -EINVAL;

		cpu = val[0] - '0';
		cluster = val[2] - '0';
		ret = bL_switch_request(cpu, cluster);

		return ret ? : len;
		}

		static const struct file_operations bL_switcher_fops = {
		.write = bL_switcher_write,
		.owner = THIS_MODULE,
		};

		static struct miscdevice bL_switcher_device = {
		MISC_DYNAMIC_MINOR,
		"b.L_switcher",
		&bL_switcher_fops
		};

		static int __init bL_switcher_dummy_if_init(void)
		{
		return misc_register(&bL_switcher_device);
		}

		static void __exit bL_switcher_dummy_if_exit(void)
		{
		misc_deregister(&bL_switcher_device);
		}

		module_init(bL_switcher_dummy_if_init);
		module_exit(bL_switcher_dummy_if_exit);

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