vpe.c

LINUX 2.6.17.4的源码

	if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &mod)) < 0) {
		if (v->__start == 0) {
			printk(KERN_WARNING "VPE loader: program does not contain "
			       "a __start symbol\n");
			return -ENOEXEC;
		}

		if (v->shared_ptr == NULL)
			printk(KERN_WARNING "VPE loader: "
			       "program does not contain vpe_shared symbol.\n"
			       " Unable to use AMVP (AP/SP) facilities.\n");
	}

	printk(" elf loaded\n");
	return 0;
}

__attribute_used__ void dump_vpe(struct vpe * v)
{
	struct tc *t;

	settc(v->minor);

	printk(KERN_DEBUG "VPEControl 0x%lx\n", read_vpe_c0_vpecontrol());
	printk(KERN_DEBUG "VPEConf0 0x%lx\n", read_vpe_c0_vpeconf0());

	list_for_each_entry(t, &vpecontrol.tc_list, list)
		dump_tc(t);
}

static void cleanup_tc(struct tc *tc)
{
	int tmp;

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

	settc(tc->index);
	tmp = read_tc_c0_tcstatus();

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

	write_tc_c0_tchalt(TCHALT_H);

	/* bind it to anything other than VPE1 */
	write_tc_c0_tcbind(read_tc_c0_tcbind() & ~TCBIND_CURVPE); // | TCBIND_CURVPE

	clear_c0_mvpcontrol(MVPCONTROL_VPC);
}

static int getcwd(char *buff, int size)
{
	mm_segment_t old_fs;
	int ret;

	old_fs = get_fs();
	set_fs(KERNEL_DS);

	ret = sys_getcwd(buff,size);

	set_fs(old_fs);

	return ret;
}

/* checks VPE is unused and gets ready to load program  */
static int vpe_open(struct inode *inode, struct file *filp)
{
	int minor, ret;
	struct vpe *v;
	struct vpe_notifications *not;

	/* assume only 1 device at the mo. */
	if ((minor = iminor(inode)) != 1) {
		printk(KERN_WARNING "VPE loader: only vpe1 is supported\n");
		return -ENODEV;
	}

	if ((v = get_vpe(minor)) == NULL) {
		printk(KERN_WARNING "VPE loader: unable to get vpe\n");
		return -ENODEV;
	}

	if (v->state != VPE_STATE_UNUSED) {
		dvpe();

		printk(KERN_DEBUG "VPE loader: tc in use dumping regs\n");

		dump_tc(get_tc(minor));

		list_for_each_entry(not, &v->notify, list) {
			not->stop(minor);
		}

		release_progmem(v->load_addr);
		cleanup_tc(get_tc(minor));
	}

	// allocate it so when we get write ops we know it's expected.
	v->state = VPE_STATE_INUSE;

	/* this of-course trashes what was there before... */
	v->pbuffer = vmalloc(P_SIZE);
	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)
{
	int minor, ret = 0;
	struct vpe *v;
	Elf_Ehdr *hdr;

	minor = iminor(inode);
	if ((v = get_vpe(minor)) == NULL)
		return -ENODEV;

	// simple case of fire and forget, so tell the VPE to run...

	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)
{
	int minor;
	size_t ret = count;
	struct vpe *v;

	minor = iminor(file->f_dentry->d_inode);
	if ((v = get_vpe(minor)) == 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 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);

	/* mark the TC unallocated and halt'ed */
	write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
	write_tc_c0_tchalt(TCHALT_H);

	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 int __init vpe_module_init(void)
{
	struct vpe *v = NULL;
	struct tc *t;
	unsigned long val;
	int i;

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

	dmt();
	dvpe();

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

	/* dump_mtregs(); */

	INIT_LIST_HEAD(&vpecontrol.vpe_list);
	INIT_LIST_HEAD(&vpecontrol.tc_list);

	val = read_c0_mvpconf0();
	for (i = 0; i < ((val & MVPCONF0_PTC) + 1); i++) {
		t = alloc_tc(i);

		/* VPE's */
		if (i < ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1) {
			settc(i);

			if ((v = alloc_vpe(i)) == NULL) {
				printk(KERN_WARNING "VPE: unable to allocate VPE\n");
				return -ENODEV;
			}

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

			/* deactivate all but vpe0 */
			if (i != 0) {
				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 (i != 0) {
				write_vpe_c0_status((read_c0_status() &
						     ~(ST0_IM | ST0_IE | ST0_KSU))
						    | ST0_CU0);

				/*
				 * 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 (i != 0) {
			unsigned long tmp;

			settc(i);

			/* 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 */
			}

			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);

			write_tc_c0_tchalt(TCHALT_H);
		}
	}

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

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

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);
		}
	}

	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");