arch/mips/kernel/vpe-cmp.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2004, 2005 MIPS Technologies, Inc.  All rights reserved.
 * Copyright (C) 2013 Imagination Technologies Ltd.
 */
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/export.h>

#include <asm/vpe.h>

static int major;

void cleanup_tc(struct tc *tc)
{

}

static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t len)
{
	struct vpe *vpe = get_vpe(aprp_cpu_index());
	struct vpe_notifications *notifier;

	list_for_each_entry(notifier, &vpe->notify, list)
		notifier->stop(aprp_cpu_index());

	release_progmem(vpe->load_addr);
	vpe->state = VPE_STATE_UNUSED;

	return len;
}
static DEVICE_ATTR(kill, S_IWUSR, NULL, store_kill);

static ssize_t ntcs_show(struct device *cd, struct device_attribute *attr,
			 char *buf)
{
	struct vpe *vpe = get_vpe(aprp_cpu_index());

	return sprintf(buf, "%d\n", vpe->ntcs);
}

static ssize_t ntcs_store(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t len)
{
	struct vpe *vpe = get_vpe(aprp_cpu_index());
	unsigned long new;
	int ret;

	ret = kstrtoul(buf, 0, &new);
	if (ret < 0)
		return ret;

	/* APRP can only reserve one TC in a VPE and no more. */
	if (new != 1)
		return -EINVAL;

	vpe->ntcs = new;

	return len;
}
static DEVICE_ATTR_RW(ntcs);

static struct attribute *vpe_attrs[] = {
	&dev_attr_kill.attr,
	&dev_attr_ntcs.attr,
	NULL,
};
ATTRIBUTE_GROUPS(vpe);

static void vpe_device_release(struct device *cd)
{
	kfree(cd);
}

static struct class vpe_class = {
	.name = "vpe",
	.owner = THIS_MODULE,
	.dev_release = vpe_device_release,
	.dev_groups = vpe_groups,
};

static struct device vpe_device;

int __init vpe_module_init(void)
{
	struct vpe *v = NULL;
	struct tc *t;
	int err;

	if (!cpu_has_mipsmt) {
		pr_warn("VPE loader: not a MIPS MT capable processor\n");
		return -ENODEV;
	}

	if (num_possible_cpus() - aprp_cpu_index() < 1) {
		pr_warn("No VPEs reserved for AP/SP, not initialize VPE loader\n"
			"Pass maxcpus=<n> argument as kernel argument\n");
		return -ENODEV;
	}

	major = register_chrdev(0, VPE_MODULE_NAME, &vpe_fops);
	if (major < 0) {
		pr_warn("VPE loader: unable to register character device\n");
		return major;
	}

	err = class_register(&vpe_class);
	if (err) {
		pr_err("vpe_class registration failed\n");
		goto out_chrdev;
	}

	device_initialize(&vpe_device);
	vpe_device.class	= &vpe_class;
	vpe_device.parent	= NULL;
	dev_set_name(&vpe_device, "vpe_sp");
	vpe_device.devt = MKDEV(major, VPE_MODULE_MINOR);
	err = device_add(&vpe_device);
	if (err) {
		pr_err("Adding vpe_device failed\n");
		goto out_class;
	}

	t = alloc_tc(aprp_cpu_index());
	if (!t) {
		pr_warn("VPE: unable to allocate TC\n");
		err = -ENOMEM;
		goto out_dev;
	}

	/* VPE */
	v = alloc_vpe(aprp_cpu_index());
	if (v == NULL) {
		pr_warn("VPE: unable to allocate VPE\n");
		kfree(t);
		err = -ENOMEM;
		goto out_dev;
	}

	v->ntcs = 1;

	/* add the tc to the list of this vpe's tc's. */
	list_add(&t->tc, &v->tc);

	/* TC */
	t->pvpe = v;	/* set the parent vpe */

	return 0;

out_dev:
	device_del(&vpe_device);

out_class:
	class_unregister(&vpe_class);

out_chrdev:
	unregister_chrdev(major, VPE_MODULE_NAME);

	return err;
}

void __exit vpe_module_exit(void)
{
	struct vpe *v, *n;

	device_del(&vpe_device);
	class_unregister(&vpe_class);
	unregister_chrdev(major, VPE_MODULE_NAME);

	/* No locking needed here */
	list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list)
		if (v->state != VPE_STATE_UNUSED)
			release_vpe(v);
}