[MIPS] kpsd and other AP/SP improvements.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 398 insertions, 0 deletions

diff --git a/arch/mips/kernel/kspd.c b/arch/mips/kernel/kspd.c
new file mode 100644
index 0000000..f06a144
--- /dev/null
+++ b/arch/mips/kernel/kspd.c
@@ -0,0 +1,398 @@
+/*
+ * 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");