vpe.c

来自「linux 内核源代码」· C语言 代码 · 共 1,594 行 · 第 1/3 页

	v->plen = P_SIZE;
	v->load_addr = NULL;
	v->len = 0;

	v->uid = filp->f_uid;
	v->gid = filp->f_gid;

#ifdef CONFIG_MIPS_APSP_KSPD
	/* get kspd to tell us when a syscall_exit happens */
	if (!kspd_events_reqd) {
		kspd_notify(&kspd_events);
		kspd_events_reqd++;
	}
#endif

	v->cwd[0] = 0;
	ret = getcwd(v->cwd, VPE_PATH_MAX);
	if (ret < 0)
		printk(KERN_WARNING "VPE loader: open, getcwd returned %d\n", ret);

	v->shared_ptr = NULL;
	v->__start = 0;

	return 0;
}

static int vpe_release(struct inode *inode, struct file *filp)
{
	struct vpe *v;
	Elf_Ehdr *hdr;
	int ret = 0;

	v = get_vpe(tclimit);
	if (v == NULL)
		return -ENODEV;

	hdr = (Elf_Ehdr *) v->pbuffer;
	if (memcmp(hdr->e_ident, ELFMAG, 4) == 0) {
		if (vpe_elfload(v) >= 0) {
			vpe_run(v);
		} else {
 			printk(KERN_WARNING "VPE loader: ELF load failed.\n");
			ret = -ENOEXEC;
		}
	} else {
 		printk(KERN_WARNING "VPE loader: only elf files are supported\n");
		ret = -ENOEXEC;
	}

	/* It's good to be able to run the SP and if it chokes have a look at
	   the /dev/rt?. But if we reset the pointer to the shared struct we
	   loose what has happened. So perhaps if garbage is sent to the vpe
	   device, use it as a trigger for the reset. Hopefully a nice
	   executable will be along shortly. */
	if (ret < 0)
		v->shared_ptr = NULL;

	// cleanup any temp buffers
	if (v->pbuffer)
		vfree(v->pbuffer);
	v->plen = 0;
	return ret;
}

static ssize_t vpe_write(struct file *file, const char __user * buffer,
			 size_t count, loff_t * ppos)
{
	size_t ret = count;
	struct vpe *v;

	if (iminor(file->f_path.dentry->d_inode) != minor)
		return -ENODEV;

	v = get_vpe(tclimit);
	if (v == NULL)
		return -ENODEV;

	if (v->pbuffer == NULL) {
		printk(KERN_ERR "VPE loader: no buffer for program\n");
		return -ENOMEM;
	}

	if ((count + v->len) > v->plen) {
		printk(KERN_WARNING
		       "VPE loader: elf size too big. Perhaps strip uneeded symbols\n");
		return -ENOMEM;
	}

	count -= copy_from_user(v->pbuffer + v->len, buffer, count);
	if (!count)
		return -EFAULT;

	v->len += count;
	return ret;
}

static const struct file_operations vpe_fops = {
	.owner = THIS_MODULE,
	.open = vpe_open,
	.release = vpe_release,
	.write = vpe_write
};

/* module wrapper entry points */
/* give me a vpe */
vpe_handle vpe_alloc(void)
{
	int i;
	struct vpe *v;

	/* find a vpe */
	for (i = 1; i < MAX_VPES; i++) {
		if ((v = get_vpe(i)) != NULL) {
			v->state = VPE_STATE_INUSE;
			return v;
		}
	}
	return NULL;
}

EXPORT_SYMBOL(vpe_alloc);

/* start running from here */
int vpe_start(vpe_handle vpe, unsigned long start)
{
	struct vpe *v = vpe;

	v->__start = start;
	return vpe_run(v);
}

EXPORT_SYMBOL(vpe_start);

/* halt it for now */
int vpe_stop(vpe_handle vpe)
{
	struct vpe *v = vpe;
	struct tc *t;
	unsigned int evpe_flags;

	evpe_flags = dvpe();

	if ((t = list_entry(v->tc.next, struct tc, tc)) != NULL) {

		settc(t->index);
		write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
	}

	evpe(evpe_flags);

	return 0;
}

EXPORT_SYMBOL(vpe_stop);

/* I've done with it thank you */
int vpe_free(vpe_handle vpe)
{
	struct vpe *v = vpe;
	struct tc *t;
	unsigned int evpe_flags;

	if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
		return -ENOEXEC;
	}

	evpe_flags = dvpe();

	/* Put MVPE's into 'configuration state' */
	set_c0_mvpcontrol(MVPCONTROL_VPC);

	settc(t->index);
	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);

	/* halt the TC */
	write_tc_c0_tchalt(TCHALT_H);
	mips_ihb();

	/* mark the TC unallocated */
	write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);

	v->state = VPE_STATE_UNUSED;

	clear_c0_mvpcontrol(MVPCONTROL_VPC);
	evpe(evpe_flags);

	return 0;
}

EXPORT_SYMBOL(vpe_free);

void *vpe_get_shared(int index)
{
	struct vpe *v;

	if ((v = get_vpe(index)) == NULL)
		return NULL;

	return v->shared_ptr;
}

EXPORT_SYMBOL(vpe_get_shared);

int vpe_getuid(int index)
{
	struct vpe *v;

	if ((v = get_vpe(index)) == NULL)
		return -1;

	return v->uid;
}

EXPORT_SYMBOL(vpe_getuid);

int vpe_getgid(int index)
{
	struct vpe *v;

	if ((v = get_vpe(index)) == NULL)
		return -1;

	return v->gid;
}

EXPORT_SYMBOL(vpe_getgid);

int vpe_notify(int index, struct vpe_notifications *notify)
{
	struct vpe *v;

	if ((v = get_vpe(index)) == NULL)
		return -1;

	list_add(&notify->list, &v->notify);
	return 0;
}

EXPORT_SYMBOL(vpe_notify);

char *vpe_getcwd(int index)
{
	struct vpe *v;

	if ((v = get_vpe(index)) == NULL)
		return NULL;

	return v->cwd;
}

EXPORT_SYMBOL(vpe_getcwd);

#ifdef CONFIG_MIPS_APSP_KSPD
static void kspd_sp_exit( int sp_id)
{
	cleanup_tc(get_tc(sp_id));
}
#endif

static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t len)
{
	struct vpe *vpe = get_vpe(tclimit);
	struct vpe_notifications *not;

	list_for_each_entry(not, &vpe->notify, list) {
		not->stop(tclimit);
	}

	release_progmem(vpe->load_addr);
	cleanup_tc(get_tc(tclimit));
	vpe_stop(vpe);
	vpe_free(vpe);

	return len;
}

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

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

static ssize_t store_ntcs(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t len)
{
	struct vpe *vpe = get_vpe(tclimit);
	unsigned long new;
	char *endp;

	new = simple_strtoul(buf, &endp, 0);
	if (endp == buf)
		goto out_einval;

	if (new == 0 || new > (hw_tcs - tclimit))
		goto out_einval;

	vpe->ntcs = new;

	return len;

out_einval:
	return -EINVAL;;
}

static struct device_attribute vpe_class_attributes[] = {
	__ATTR(kill, S_IWUSR, NULL, store_kill),
	__ATTR(ntcs, S_IRUGO | S_IWUSR, show_ntcs, store_ntcs),
	{}
};

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

struct class vpe_class = {
	.name = "vpe",
	.owner = THIS_MODULE,
	.dev_release = vpe_device_release,
	.dev_attrs = vpe_class_attributes,
};

struct device vpe_device;

static int __init vpe_module_init(void)
{
	unsigned int mtflags, vpflags;
	unsigned long flags, val;
	struct vpe *v = NULL;
	struct tc *t;
	int tc, err;

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

	if (vpelimit == 0) {
		printk(KERN_WARNING "No VPEs reserved for AP/SP, not "
		       "initializing VPE loader.\nPass maxvpes=<n> argument as "
		       "kernel argument\n");

		return -ENODEV;
	}

	if (tclimit == 0) {
		printk(KERN_WARNING "No TCs reserved for AP/SP, not "
		       "initializing VPE loader.\nPass maxtcs=<n> argument as "
		       "kernel argument\n");

		return -ENODEV;
	}

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

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

	device_initialize(&vpe_device);
	vpe_device.class	= &vpe_class,
	vpe_device.parent	= NULL,
	strlcpy(vpe_device.bus_id, "vpe1", BUS_ID_SIZE);
	vpe_device.devt = MKDEV(major, minor);
	err = device_add(&vpe_device);
	if (err) {
		printk(KERN_ERR "Adding vpe_device failed\n");
		goto out_class;
	}

	local_irq_save(flags);
	mtflags = dmt();
	vpflags = dvpe();

	/* Put MVPE's into 'configuration state' */
	set_c0_mvpcontrol(MVPCONTROL_VPC);

	/* dump_mtregs(); */

	val = read_c0_mvpconf0();
	hw_tcs = (val & MVPCONF0_PTC) + 1;
	hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;

	for (tc = tclimit; tc < hw_tcs; tc++) {
		/*
		 * Must re-enable multithreading temporarily or in case we
		 * reschedule send IPIs or similar we might hang.
		 */
		clear_c0_mvpcontrol(MVPCONTROL_VPC);
		evpe(vpflags);
		emt(mtflags);
		local_irq_restore(flags);
		t = alloc_tc(tc);
		if (!t) {
			err = -ENOMEM;
			goto out;
		}

		local_irq_save(flags);
		mtflags = dmt();
		vpflags = dvpe();
		set_c0_mvpcontrol(MVPCONTROL_VPC);

		/* VPE's */
		if (tc < hw_tcs) {
			settc(tc);

			if ((v = alloc_vpe(tc)) == NULL) {
				printk(KERN_WARNING "VPE: unable to allocate VPE\n");

				goto out_reenable;
			}

			v->ntcs = hw_tcs - tclimit;

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

			/* deactivate all but vpe0 */
			if (tc >= tclimit) {
				unsigned long tmp = read_vpe_c0_vpeconf0();

				tmp &= ~VPECONF0_VPA;

				/* master VPE */
				tmp |= VPECONF0_MVP;
				write_vpe_c0_vpeconf0(tmp);
			}

			/* disable multi-threading with TC's */
			write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);

			if (tc >= vpelimit) {
				/*
				 * Set config to be the same as vpe0,
				 * particularly kseg0 coherency alg
				 */
				write_vpe_c0_config(read_c0_config());
			}
		}

		/* TC's */
		t->pvpe = v;	/* set the parent vpe */

		if (tc >= tclimit) {
			unsigned long tmp;

			settc(tc);

			/* Any TC that is bound to VPE0 gets left as is - in case
			   we are running SMTC on VPE0. A TC that is bound to any
			   other VPE gets bound to VPE0, ideally I'd like to make
			   it homeless but it doesn't appear to let me bind a TC
			   to a non-existent VPE. Which is perfectly reasonable.

			   The (un)bound state is visible to an EJTAG probe so may
			   notify GDB...
			*/

			if (((tmp = read_tc_c0_tcbind()) & TCBIND_CURVPE)) {
				/* tc is bound >vpe0 */
				write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE);

				t->pvpe = get_vpe(0);	/* set the parent vpe */
			}

			/* halt the TC */
			write_tc_c0_tchalt(TCHALT_H);
			mips_ihb();

			tmp = read_tc_c0_tcstatus();

			/* mark not activated and not dynamically allocatable */
			tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
			tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
			write_tc_c0_tcstatus(tmp);
		}
	}

out_reenable:
	/* release config state */
	clear_c0_mvpcontrol(MVPCONTROL_VPC);

	evpe(vpflags);
	emt(mtflags);
	local_irq_restore(flags);

#ifdef CONFIG_MIPS_APSP_KSPD
	kspd_events.kspd_sp_exit = kspd_sp_exit;
#endif
	return 0;

out_class:
	class_unregister(&vpe_class);
out_chrdev:
	unregister_chrdev(major, module_name);

out:
	return err;
}

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

	list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) {
		if (v->state != VPE_STATE_UNUSED) {
			release_vpe(v);
		}
	}

	device_del(&vpe_device);
	unregister_chrdev(major, module_name);
}

module_init(vpe_module_init);
module_exit(vpe_module_exit);
MODULE_DESCRIPTION("MIPS VPE Loader");
MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
MODULE_LICENSE("GPL");