path: root/arch/mips/kernel/vpe.c

/*
 * Copyright (C) 2004, 2005 MIPS Technologies, Inc.  All rights reserved.
 *
 *  This program is free software; you can distribute 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 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.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 */

/*
 * VPE support module
 *
 * Provides support for loading a MIPS SP program on VPE1.
 * The SP enviroment is rather simple, no tlb's.  It needs to be relocatable
 * (or partially linked). You should initialise your stack in the startup
 * code. This loader looks for the symbol __start and sets up
 * execution to resume from there. The MIPS SDE kit contains suitable examples.
 *
 * To load and run, simply cat a SP 'program file' to /dev/vpe1.
 * i.e cat spapp >/dev/vpe1.
 */
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/moduleloader.h>
#include <linux/interrupt.h>
#include <linux/poll.h>
#include <linux/bootmem.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/cacheflush.h>
#include <asm/atomic.h>
#include <asm/cpu.h>
#include <asm/mips_mt.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/vpe.h>
#include <asm/kspd.h>

typedef void *vpe_handle;

#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif

/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))

/*
 * The number of TCs and VPEs physically available on the core
 */
static int hw_tcs, hw_vpes;
static char module_name[] = "vpe";
static int major;
static const int minor = 1;	/* fixed for now  */

#ifdef CONFIG_MIPS_APSP_KSPD
 static struct kspd_notifications kspd_events;
static int kspd_events_reqd = 0;
#endif

/* grab the likely amount of memory we will need. */
#ifdef CONFIG_MIPS_VPE_LOADER_TOM
#define P_SIZE (2 * 1024 * 1024)
#else
/* add an overhead to the max kmalloc size for non-striped symbols/etc */
#define P_SIZE (256 * 1024)
#endif

extern unsigned long physical_memsize;

#define MAX_VPES 16
#define VPE_PATH_MAX 256

enum vpe_state {
	VPE_STATE_UNUSED = 0,
	VPE_STATE_INUSE,
	VPE_STATE_RUNNING
};

enum tc_state {
	TC_STATE_UNUSED = 0,
	TC_STATE_INUSE,
	TC_STATE_RUNNING,
	TC_STATE_DYNAMIC
};

struct vpe {
	enum vpe_state state;

	/* (device) minor associated with this vpe */
	int minor;

	/* elfloader stuff */
	void *load_addr;
	unsigned long len;
	char *pbuffer;
	unsigned long plen;
	unsigned int uid, gid;
	char cwd[VPE_PATH_MAX];

	unsigned long __start;

	/* tc's associated with this vpe */
	struct list_head tc;

	/* The list of vpe's */
	struct list_head list;

	/* shared symbol address */
	void *shared_ptr;

	/* the list of who wants to know when something major happens */
	struct list_head notify;

	unsigned int ntcs;
};

struct tc {
	enum tc_state state;
	int index;

	struct vpe *pvpe;	/* parent VPE */
	struct list_head tc;	/* The list of TC's with this VPE */
	struct list_head list;	/* The global list of tc's */
};

struct {
	/* Virtual processing elements */
	struct list_head vpe_list;

	/* Thread contexts */
	struct list_head tc_list;
} vpecontrol = {
	.vpe_list = LIST_HEAD_INIT(vpecontrol.vpe_list),
	.tc_list = LIST_HEAD_INIT(vpecontrol.tc_list)
};

static void release_progmem(void *ptr);
extern void save_gp_address(unsigned int secbase, unsigned int rel);

/* get the vpe associated with this minor */
struct vpe *get_vpe(int minor)
{
	struct vpe *v;

	if (!cpu_has_mipsmt)
		return NULL;

	list_for_each_entry(v, &vpecontrol.vpe_list, list) {
		if (v->minor == minor)
			return v;
	}

	return NULL;
}

/* get the vpe associated with this minor */
struct tc *get_tc(int index)
{
	struct tc *t;

	list_for_each_entry(t, &vpecontrol.tc_list, list) {
		if (t->index == index)
			return t;
	}

	return NULL;
}

struct tc *get_tc_unused(void)
{
	struct tc *t;

	list_for_each_entry(t, &vpecontrol.tc_list, list) {
		if (t->state == TC_STATE_UNUSED)
			return t;
	}

	return NULL;
}

/* allocate a vpe and associate it with this minor (or index) */
struct vpe *alloc_vpe(int minor)
{
	struct vpe *v;

	if ((v = kzalloc(sizeof(struct vpe), GFP_KERNEL)) == NULL) {
		return NULL;
	}

	INIT_LIST_HEAD(&v->tc);
	list_add_tail(&v->list, &vpecontrol.vpe_list);

	INIT_LIST_HEAD(&v->notify);
	v->minor = minor;
	return v;
}

/* allocate a tc. At startup only tc0 is running, all other can be halted. */
struc