[MIPS] kpsd and other AP/SP improvements.

	depends on MIPS_VPE_LOADER

	help

config MIPS_APSP_KSPD

	bool "Enable KSPD"

	depends on MIPS_VPE_APSP_API

	default y

	help

	  KSPD is a kernel daemon that accepts syscall requests from the SP

	  side, actions them and returns the results. It also handles the

	  "exit" syscall notifying other kernel modules the SP program is

	  exiting.  You probably want to say yes here.

config SB1_PASS_1_WORKAROUNDS

	bool

	depends on CPU_SB1_PASS_1

obj-$(CONFIG_MIPS_MT_SMP)	+= smp_mt.o

obj-$(CONFIG_MIPS_APSP_KSPD)	+= kspd.o

obj-$(CONFIG_MIPS_VPE_LOADER)	+= vpe.o

obj-$(CONFIG_MIPS_VPE_APSP_API)	+= rtlx.o

/*

 * Copyright (C) 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.

 *

 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/unistd.h>

#include <linux/file.h>

#include <linux/fs.h>

#include <linux/syscalls.h>

#include <linux/workqueue.h>

#include <linux/errno.h>

#include <linux/list.h>

#include <asm/vpe.h>

#include <asm/rtlx.h>

#include <asm/kspd.h>

static struct workqueue_struct *workqueue = NULL;

static struct work_struct work;

extern unsigned long cpu_khz;

struct mtsp_syscall {

	int cmd;

	unsigned char abi;

	unsigned char size;

};

struct mtsp_syscall_ret {

	int retval;

	int errno;

};

struct mtsp_syscall_generic {

	int arg0;

	int arg1;

	int arg2;

	int arg3;

	int arg4;

	int arg5;

	int arg6;

};

static struct list_head kspd_notifylist;

static int sp_stopping = 0;

/* these should match with those in the SDE kit */

#define MTSP_SYSCALL_BASE	0

#define MTSP_SYSCALL_EXIT	(MTSP_SYSCALL_BASE + 0)

#define MTSP_SYSCALL_OPEN	(MTSP_SYSCALL_BASE + 1)

#define MTSP_SYSCALL_READ	(MTSP_SYSCALL_BASE + 2)

#define MTSP_SYSCALL_WRITE	(MTSP_SYSCALL_BASE + 3)

#define MTSP_SYSCALL_CLOSE	(MTSP_SYSCALL_BASE + 4)

#define MTSP_SYSCALL_LSEEK32	(MTSP_SYSCALL_BASE + 5)

#define MTSP_SYSCALL_ISATTY	(MTSP_SYSCALL_BASE + 6)

#define MTSP_SYSCALL_GETTIME	(MTSP_SYSCALL_BASE + 7)

#define MTSP_SYSCALL_PIPEFREQ	(MTSP_SYSCALL_BASE + 8)

#define MTSP_SYSCALL_GETTOD	(MTSP_SYSCALL_BASE + 9)

#define MTSP_O_RDONLY		0x0000

#define MTSP_O_WRONLY		0x0001

#define MTSP_O_RDWR		0x0002

#define MTSP_O_NONBLOCK		0x0004

#define MTSP_O_APPEND		0x0008

#define MTSP_O_SHLOCK		0x0010

#define MTSP_O_EXLOCK		0x0020

#define MTSP_O_ASYNC		0x0040

#define MTSP_O_FSYNC		O_SYNC

#define MTSP_O_NOFOLLOW		0x0100

#define MTSP_O_SYNC		0x0080

#define MTSP_O_CREAT		0x0200

#define MTSP_O_TRUNC		0x0400

#define MTSP_O_EXCL		0x0800

#define MTSP_O_BINARY		0x8000

#define SP_VPE 1

struct apsp_table  {

	int sp;

	int ap;

};

/* we might want to do the mode flags too */

struct apsp_table open_flags_table[] = {

	{ MTSP_O_RDWR, O_RDWR },

	{ MTSP_O_WRONLY, O_WRONLY },

	{ MTSP_O_CREAT, O_CREAT },

	{ MTSP_O_TRUNC, O_TRUNC },

	{ MTSP_O_NONBLOCK, O_NONBLOCK },

	{ MTSP_O_APPEND, O_APPEND },

	{ MTSP_O_NOFOLLOW, O_NOFOLLOW }

};

struct apsp_table syscall_command_table[] = {

	{ MTSP_SYSCALL_OPEN, __NR_open },

	{ MTSP_SYSCALL_CLOSE, __NR_close },

	{ MTSP_SYSCALL_READ, __NR_read },

	{ MTSP_SYSCALL_WRITE, __NR_write },

	{ MTSP_SYSCALL_LSEEK32, __NR_lseek }

};

static int sp_syscall(int num, int arg0, int arg1, int arg2, int arg3)

{

	register long int _num  __asm__ ("$2") = num;

	register long int _arg0  __asm__ ("$4") = arg0;

	register long int _arg1  __asm__ ("$5") = arg1;

	register long int _arg2  __asm__ ("$6") = arg2;

	register long int _arg3  __asm__ ("$7") = arg3;

	mm_segment_t old_fs;

	old_fs = get_fs();

 	set_fs(KERNEL_DS);

  	__asm__ __volatile__ (

 	"	syscall					\n"

 	: "=r" (_num), "=r" (_arg3)

 	: "r" (_num), "r" (_arg0), "r" (_arg1), "r" (_arg2), "r" (_arg3));

	set_fs(old_fs);

	/* $a3 is error flag */

	if (_arg3)

		return -_num;

	return _num;

}

static int translate_syscall_command(int cmd)

{

	int i;

	int ret = -1;

	for (i = 0; i < ARRAY_SIZE(syscall_command_table); i++) {

		if ((cmd == syscall_command_table[i].sp))

			return syscall_command_table[i].ap;

	}

	return ret;

}

static unsigned int translate_open_flags(int flags)

{

	int i;

	unsigned int ret = 0;

	for (i = 0; i < (sizeof(open_flags_table) / sizeof(struct apsp_table));

	     i++) {

		if( (flags & open_flags_table[i].sp) ) {

			ret |= open_flags_table[i].ap;

		}

	}

	return ret;

}

static void sp_setfsuidgid( uid_t uid, gid_t gid)

{

	current->fsuid = uid;

	current->fsgid = gid;

	key_fsuid_changed(current);

	key_fsgid_changed(current);

}

/*

 * Expects a request to be on the sysio channel. Reads it.  Decides whether

 * its a linux syscall and runs it, or whatever.  Puts the return code back

 * into the request and sends the whole thing back.

 */

void sp_work_handle_request(void)

{

	struct mtsp_syscall sc;

	struct mtsp_syscall_generic generic;

	struct mtsp_syscall_ret ret;

	struct kspd_notifications *n;

	struct timeval tv;

	struct timezone tz;

	int cmd;

	char *vcwd;

	mm_segment_t old_fs;

	int size;

	ret.retval = -1;

	if (!rtlx_read(RTLX_CHANNEL_SYSIO, &sc, sizeof(struct mtsp_syscall), 0)) {

		printk(KERN_ERR "Expected request but nothing to read\n");

		return;

	}

	size = sc.size;

	if (size) {

		if (!rtlx_read(RTLX_CHANNEL_SYSIO, &generic, size, 0)) {

			printk(KERN_ERR "Expected request but nothing to read\n");

			return;

		}

	}

	/* Run the syscall at the priviledge of the user who loaded the

	   SP program */

	if (vpe_getuid(SP_VPE))

		sp_setfsuidgid( vpe_getuid(SP_VPE), vpe_getgid(SP_VPE));

	switch (sc.cmd) {

	/* needs the flags argument translating from SDE kit to

	   linux */

 	case MTSP_SYSCALL_PIPEFREQ:

 		ret.retval = cpu_khz * 1000;

 		ret.errno = 0;

 		break;

 	case MTSP_SYSCALL_GETTOD:

 		memset(&tz, 0, sizeof(tz));

 		if ((ret.retval = sp_syscall(__NR_gettimeofday, (int)&tv,

 		                             (int)&tz, 0,0)) == 0)

		ret.retval = tv.tv_sec;

		ret.errno = errno;

		break;

 	case MTSP_SYSCALL_EXIT:

		list_for_each_entry(n, &kspd_notifylist, list)

 			n->kspd_sp_exit(SP_VPE);

		sp_stopping = 1;

		printk(KERN_DEBUG "KSPD got exit syscall from SP exitcode %d\n",

		       generic.arg0);

 		break;

 	case MTSP_SYSCALL_OPEN:

 		generic.arg1 = translate_open_flags(generic.arg1);

 		vcwd = vpe_getcwd(SP_VPE);

 		/* change to the cwd of the process that loaded the SP program */

		old_fs = get_fs();

		set_fs(KERNEL_DS);

		sys_chdir(vcwd);

		set_fs(old_fs);

 		sc.cmd = __NR_open;

		/* fall through */

  	default:

 		if ((sc.cmd >= __NR_Linux) &&

		    (sc.cmd <= (__NR_Linux +  __NR_Linux_syscalls)) )

			cmd = sc.cmd;

		else

			cmd = translate_syscall_command(sc.cmd);

		if (cmd >= 0) {

			ret.retval = sp_syscall(cmd, generic.arg0, generic.arg1,

			                        generic.arg2, generic.arg3);

			ret.errno = errno;

		} else

 			printk(KERN_WARNING

			       "KSPD: Unknown SP syscall number %d\n", sc.cmd);

		break;

 	} /* switch */

	if (vpe_getuid(SP_VPE))

		sp_setfsuidgid( 0, 0);

	if ((rtlx_write(RTLX_CHANNEL_SYSIO, &ret, sizeof(struct mtsp_syscall_ret), 0))

	    < sizeof(struct mtsp_syscall_ret))

		printk("KSPD: sp_work_handle_request failed to send to SP\n");

}

static void sp_cleanup(void)

{

	struct files_struct *files = current->files;

	int i, j;

	struct fdtable *fdt;

	j = 0;

	/*

	 * It is safe to dereference the fd table without RCU or

	 * ->file_lock

	 */

	fdt = files_fdtable(files);

	for (;;) {

		unsigned long set;

		i = j * __NFDBITS;

		if (i >= fdt->max_fdset || i >= fdt->max_fds)

			break;

		set = fdt->open_fds->fds_bits[j++];

		while (set) {

			if (set & 1) {

				struct file * file = xchg(&fdt->fd[i], NULL);

				if (file)

					filp_close(file, files);

			}

			i++;

			set >>= 1;

		}

	}

}

static int channel_open = 0;

/* the work handler */

static void sp_work(void *data)

{

	if (!channel_open) {

		if( rtlx_open(RTLX_CHANNEL_SYSIO, 1) != 0) {

			printk("KSPD: unable to open sp channel\n");

			sp_stopping = 1;

		} else {

			channel_open++;

			printk(KERN_DEBUG "KSPD: SP channel opened\n");

		}

	} else {

		/* wait for some data, allow it to sleep */

		rtlx_read_poll(RTLX_CHANNEL_SYSIO, 1);

		/* Check we haven't been woken because we are stopping */

		if (!sp_stopping)

			sp_work_handle_request();

	}

	if (!sp_stopping)

		queue_work(workqueue, &work);

	else

		sp_cleanup();

}

static void startwork(int vpe)

{

	sp_stopping = channel_open = 0;

	if (workqueue == NULL) {

		if ((workqueue = create_singlethread_workqueue("kspd")) == NULL) {

			printk(KERN_ERR "unable to start kspd\n");

			return;

		}

		INIT_WORK(&work, sp_work, NULL);

		queue_work(workqueue, &work);

	} else

		queue_work(workqueue, &work);

}

static void stopwork(int vpe)

{

	sp_stopping = 1;

	printk(KERN_DEBUG "KSPD: SP stopping\n");

}

void kspd_notify(struct kspd_notifications *notify)

{

	list_add(&notify->list, &kspd_notifylist);

}

static struct vpe_notifications notify;

static int kspd_module_init(void)

{

	INIT_LIST_HEAD(&kspd_notifylist);

	notify.start = startwork;

	notify.stop = stopwork;

	vpe_notify(SP_VPE, &notify);

	return 0;

}

static void kspd_module_exit(void)

{

}

module_init(kspd_module_init);

module_exit(kspd_module_exit);

MODULE_DESCRIPTION("MIPS KSPD");

MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");

MODULE_LICENSE("GPL");