chandev.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

static void chandev_wait_for_root_fs(void)
{
	wait_queue_head_t      wait;

	init_waitqueue_head(&wait);
	/* We need to wait till there is a root filesystem */
	while(init_task.fs->root==NULL)
	{
		sleep_on_timeout(&wait,HZ);
	}
}

/* We are now hotplug compliant i.e. */
/* we typically get called in /sbin/hotplug chandev our parameters */
static int chandev_exec_start_script(void *unused)
{
	
	char **argv,*tempname;
	int retval=-ENOMEM;
	int argc,loopcnt;
	size_t allocsize;
	chandev_userland_notify_list *member;
	wait_queue_head_t      wait;
	int                    have_tag[chandev_num_notify_tags]={FALSE,};
	chandev_userland_notify_tag tagidx;
	static char * envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
	
	init_waitqueue_head(&wait);
	strcpy(current->comm,"chandev_script");

	for(loopcnt=0;loopcnt<10&&(jiffies-chandev_last_startmsck_list_update)<HZ;loopcnt++)
	{
		sleep_on_timeout(&wait,HZ);
	}
	if(!chandev_userland_notify_head)
		return(0);
	chandev_lock();
	argc=2;
	for(tagidx=chandev_first_tag;tagidx<chandev_num_notify_tags;tagidx++)
	{
		for_each(member,chandev_userland_notify_head)
		{
			if(member->tag==tagidx)
			{
				switch(tagidx)
				{
				case chandev_start:
					argc++;
					break;
				case chandev_msck:
					argc+=3;
					break;
				default:
				}
				if(have_tag[tagidx]==FALSE)
					argc++;
				have_tag[tagidx]=TRUE;

			}
		}
	}
	allocsize=(argc+1)*sizeof(char *);
        /* Warning possible stack overflow */
	/* We can't kmalloc the parameters here as execve will */
	/* not return if successful */
	argv=alloca(allocsize);
	if(argv)
	{
		memset(argv,0,allocsize);
		argv[0]=hotplug_path;
		argv[1]="chandev";
		argc=2;
		for(tagidx=chandev_first_tag;tagidx<chandev_num_notify_tags;tagidx++)
		{
			if(have_tag[tagidx])
			{
				argv[argc++]=userland_notify_strs[tagidx];
				for_each(member,chandev_userland_notify_head)
				{
					if(member->tag==tagidx)
					{
						tempname=alloca(strlen(member->devname)+1);
						if(tempname)
						{
							strcpy(tempname,member->devname);
							argv[argc++]=tempname;
						}
						else
							goto Fail;
						if(member->tag==chandev_msck)
						{
							argv[argc++]=msck_status_strs[member->prev_status];
							argv[argc++]=msck_status_strs[member->curr_status];
						}
					}
				}
			}
		}
		chandev_free_all_list((list **)&chandev_userland_notify_head);
		chandev_unlock();
		chandev_wait_for_root_fs();
		/* We are basically execve'ing here there normally is no */
		/* return */
		retval=exec_usermodehelper(hotplug_path, argv, envp);
		goto Fail2;
	}
 Fail:
	
	chandev_unlock();
 Fail2:
	return(retval);
}


void *chandev_allocstr(const char *str,size_t offset)
{
	char *member;

	if((member=chandev_alloc(offset+strlen(str)+1)))
	{
		strcpy(&member[offset],str);
	}
	return((void *)member);
}


static int chandev_add_to_userland_notify_list(chandev_userland_notify_tag tag,
char *devname, chandev_msck_status prev_status,chandev_msck_status curr_status)
{
	chandev_userland_notify_list *member,*nextmember;
	int pid;
	
	chandev_lock();
	/* remove operations still outstanding for this device */
	for_each_allow_delete(member,nextmember,chandev_userland_notify_head)
		if(strcmp(member->devname,devname)==0)
			chandev_free_listmember((list **)&chandev_userland_notify_head,(list *)member);
	

	if((member=chandev_allocstr(devname,offsetof(chandev_userland_notify_list,devname))))
	{
		member->tag=tag;
		member->prev_status=prev_status;
		member->curr_status=curr_status;
		add_to_list((list **)&chandev_userland_notify_head,(list *)member);
		chandev_last_startmsck_list_update=jiffies;
		chandev_unlock();
		pid = kernel_thread(chandev_exec_start_script,NULL,SIGCHLD);
		if(pid<0)
		{
			printk("error making kernel thread for chandev_exec_start_script\n");
			return(pid);
		}
		else
			return(0);

	}
	else
	{
		chandev_unlock();
		printk("chandev_add_to_startmscklist memory allocation failed devname=%s\n",devname);
		return(-ENOMEM);
	}
}





int chandev_oper_func(int irq,devreg_t *dreg)
{
	chandev_last_machine_check=jiffies;
	if(atomic_dec_and_test(&chandev_msck_thread_lock))
	{
		schedule_task(&chandev_msck_task_tq);
	}
	atomic_set(&chandev_new_msck,TRUE);
	return(0);
}

static void chandev_not_oper_handler(int irq,int status )
{
	chandev_not_oper_struct *new_not_oper;

	chandev_last_machine_check=jiffies;
	if((new_not_oper=kmalloc(sizeof(chandev_not_oper_struct),GFP_ATOMIC)))
	{
		new_not_oper->irq=irq;
		new_not_oper->status=status;
		spin_lock(&chandev_not_oper_spinlock);
		enqueue_tail(&chandev_not_oper_head,(queue *)new_not_oper);
		spin_unlock(&chandev_not_oper_spinlock);
		if(atomic_dec_and_test(&chandev_msck_thread_lock))
		{
			schedule_task(&chandev_msck_task_tq);
		}
	}
	else
		printk("chandev_not_oper_handler failed to allocate memory & "
		       "lost a not operational interrupt %d %x",
		       irq,status);
}

chandev_irqinfo *chandev_get_irqinfo_by_irq(int irq)
{
	chandev_irqinfo *curr_irqinfo;
	for_each(curr_irqinfo,chandev_irqinfo_head)
		if(irq==curr_irqinfo->sch.irq)
			return(curr_irqinfo);
	return(NULL);
}

chandev *chandev_get_by_irq(int irq)
{
	chandev *curr_chandev;

	for_each(curr_chandev,(chandev *)chandev_head.head)
		if(curr_chandev->sch.irq==irq)
		{
			return(curr_chandev);
		}
	return(NULL);
}

chandev_activelist *chandev_get_activelist_by_irq(int irq)
{
	chandev_activelist *curr_device;

	for_each(curr_device,chandev_activelist_head)
	{
			if(curr_device->read_irqinfo->sch.irq==irq||
			   curr_device->write_irqinfo->sch.irq==irq||
			   (curr_device->data_irqinfo&&curr_device->data_irqinfo->sch.irq==irq))
				return(curr_device);
	}
	return(NULL);
}


void chandev_remove_irqinfo_by_irq(unsigned int irq)
{
	chandev_irqinfo *remove_irqinfo;
	chandev_activelist *curr_device;

	chandev_lock();
	/* remove any orphan irqinfo left lying around. */
        if((remove_irqinfo=chandev_get_irqinfo_by_irq(irq)))
	{
		for_each(curr_device,chandev_activelist_head)
		{
			if(curr_device->read_irqinfo==remove_irqinfo)
			{
				curr_device->read_irqinfo=NULL;
				break;
			}
			if(curr_device->write_irqinfo==remove_irqinfo)
			{
				curr_device->write_irqinfo=NULL;
				break;
			}
			if(curr_device->data_irqinfo&&curr_device->data_irqinfo==remove_irqinfo)
			{
				curr_device->data_irqinfo=NULL;
				break;
			}
		}
		chandev_free_listmember((list **)&chandev_irqinfo_head,
					 (list *)remove_irqinfo);
	}
	chandev_unlock();
	
}

int chandev_add_schib_info(int irq,chandev_subchannel_info *sch)
{
	schib_t *new_schib;
	
	if((new_schib=s390_get_schib(irq)))
	{
		sch->pim=new_schib->pmcw.pim;
		memcpy(&sch->chpid,&new_schib->pmcw.chpid,sizeof(sch->chpid));
		return(0);
	}
	return(-ENODEV);
}

int chandev_request_irq(unsigned int   irq,
                      void           (*handler)(int, void *, struct pt_regs *),
                      unsigned long  irqflags,
                      const char    *devname,
                      void          *dev_id)
{
	chandev_irqinfo *new_irqinfo;
	chandev_activelist *curr_device;
	s390_dev_info_t         devinfo;
	int          retval;
	

	chandev_lock();
	if((curr_device=chandev_get_activelist_by_irq(irq)))
	{
		printk("chandev_request_irq failed devname=%s irq=%d "
		       "it already belongs to %s shutdown this device first.\n",
		       devname,irq,curr_device->devname);
		chandev_unlock();
		return(-EPERM);
	}
	/* remove any orphan irqinfo left lying around. */
	chandev_remove_irqinfo_by_irq(irq);
	chandev_unlock();
	if((new_irqinfo=chandev_allocstr(devname,offsetof(chandev_irqinfo,devname))))
	{
		
		if((retval=get_dev_info_by_irq(irq,&devinfo))||
		   (retval=s390_request_irq_special(irq,handler,
						chandev_not_oper_handler,
						irqflags,devname,dev_id)))
			kfree(new_irqinfo);
		else
		{
			new_irqinfo->msck_status=chandev_status_good;
			new_irqinfo->sch.devno=devinfo.devno;
			new_irqinfo->sch.irq=irq;
			new_irqinfo->sch.cu_type=devinfo.sid_data.cu_type; /* control unit type */
			new_irqinfo->sch.cu_model=devinfo.sid_data.cu_model; /* control unit model */
			new_irqinfo->sch.dev_type=devinfo.sid_data.dev_type; /* device type */
			new_irqinfo->sch.dev_model=devinfo.sid_data.dev_model; /* device model */
			chandev_add_schib_info(irq,&new_irqinfo->sch);
			new_irqinfo->handler=handler;
			new_irqinfo->dev_id=dev_id;
			chandev_add_to_list((list **)&chandev_irqinfo_head,new_irqinfo);
		}
	}
	else
	{
		printk("chandev_request_irq memory allocation failed devname=%s irq=%d\n",devname,irq);
		retval=-ENOMEM;
	}
	return(retval);
}

/* This should be safe to call even multiple times. */
void chandev_free_irq(unsigned int irq, void *dev_id)
{
	s390_dev_info_t devinfo;
	int err;
	
	/* remove any orphan irqinfo left lying around. */
	chandev_remove_irqinfo_by_irq(irq);
	if((err=get_dev_info_by_irq(irq,&devinfo)))
	{
		printk("chandev_free_irq get_dev_info_by_irq reported err=%X on irq %d\n"
		       "should not happen\n",err,irq);
		return;
	 }
	if(devinfo.status&DEVSTAT_DEVICE_OWNED)
	   free_irq(irq,dev_id);
}

/* This should be safe even if chandev_free_irq is already called by the device */
void chandev_free_irq_by_irqinfo(chandev_irqinfo *irqinfo)
{
	if(irqinfo)
		chandev_free_irq(irqinfo->sch.irq,irqinfo->dev_id);
}



void chandev_sprint_type_model(char *buff,s32 type,s16 model)
{
	if(type==-1)
		strcpy(buff,"    *    ");
	else
		sprintf(buff," 0x%04x  ",(int)type);
	buff+=strlen(buff);
	if(model==-1)
		strcpy(buff,"    *   ");
	else
		sprintf(buff," 0x%02x  ",(int)model);
}

void chandev_sprint_devinfo(char *buff,s32 cu_type,s16 cu_model,s32 dev_type,s16 dev_model)
{
	chandev_sprint_type_model(buff,cu_type,cu_model);
	chandev_sprint_type_model(&buff[strlen(buff)],dev_type,dev_model);
}

void chandev_remove_parms(chandev_type chan_type,int exact_match,int lo_devno)
{
	chandev_parms      *curr_parms,*next_parms;

	chandev_lock();
	for_each_allow_delete(curr_parms,next_parms,chandev_parms_head)
	{
		if(((chan_type&(curr_parms->chan_type)&&!exact_match)||
		   (chan_type==(curr_parms->chan_type)&&exact_match))&&
		   (lo_devno==-1||lo_devno==curr_parms->lo_devno))
			chandev_free_listmember((list **)&chandev_parms_head,(list *)curr_parms);
	}
	chandev_unlock();
}


void chandev_add_parms(chandev_type chan_type,u16 lo_devno,u16 hi_devno,char *parmstr)
{
	chandev_parms      *parms;

	if(lo_devno>hi_devno)
	{
		printk("chandev_add_parms detected bad device range lo_devno=0x%04x  hi_devno=0x%04x\n,",
		       (int)lo_devno,(int)hi_devno);
		return;
	}
	chandev_lock();
	for_each(parms,chandev_parms_head)
	{
		if(chan_type&(parms->chan_type))
		{
			u16 lomax=MAX(parms->lo_devno,lo_devno),
				himin=MIN(parms->hi_devno,lo_devno);
			if(lomax<=himin)
			{
				chandev_unlock();
				printk("chandev_add_parms detected overlapping "
				       "parameter definitions for chan_type=0x%02x"
				       " lo_devno=0x%04x  hi_devno=0x%04x\n,"
				       " do a del_parms.",chan_type,(int)lo_devno,(int)hi_devno);
				return;
			}
		}
	}
	chandev_unlock();
	if((parms=chandev_allocstr(parmstr,offsetof(chandev_parms,parmstr))))
	{
		parms->chan_type=chan_type;
		parms->lo_devno=lo_devno;
		parms->hi_devno=hi_devno;
		chandev_add_to_list((list **)&chandev_parms_head,(void *)parms);
	}
	else
		printk("chandev_add_parms memory request failed\n");
}


void chandev_add_model(chandev_type chan_type,s32 cu_type,s16 cu_model,
		       s32 dev_type,s16 dev_model,u8 max_port_no,int auto_msck_recovery,
		       u8 default_checksum_received_ip_pkts,u8 default_use_hw_stats)
{
	chandev_model_info *newmodel;
	int                err;
	char buff[40];

	if((newmodel=chandev_alloc(sizeof(chandev_model_info))))
	{
		devreg_t *drinfo=&newmodel->drinfo;
		newmodel->chan_type=chan_type;
		newmodel->cu_type=cu_type;
		newmodel->cu_model=cu_model;
		newmodel->dev_type=dev_type;
		newmodel->dev_model=dev_model;
		newmodel->max_port_no=max_port_no;
		newmodel->auto_msck_recovery=auto_msck_recovery;
		newmodel->default_checksum_received_ip_pkts=default_checksum_received_ip_pkts;
		newmodel->default_use_hw_stats=default_use_hw_stats; /* where available e.g. lcs */
		if(cu_type==-1&&dev_type==-1)
		{
			chandev_sprint_devinfo(buff,newmodel->cu_type,newmodel->cu_model,
					       newmodel->dev_type,newmodel->dev_model);
			printk(KERN_INFO"can't call s390_device_register for this device chan_type/chan_model/dev_type/dev_model %s\n",buff);
			kfree(newmodel);
			return;
		}
		drinfo->flag=DEVREG_TYPE_DEVCHARS;
		if(cu_type!=-1)
			drinfo->flag|=DEVREG_MATCH_CU_TYPE;
		if(cu_model!=-1)
			drinfo->flag|=DEVREG_MATCH_CU_MODEL;
		if(dev_type!=-1)
			drinfo->flag|=DEVREG_MATCH_DEV_TYPE;
		if(dev_model!=-1)
			drinfo->flag|=DEVREG_MATCH_DEV_MODEL;
		drinfo->ci.hc.ctype=cu_type;
		drinfo->ci.hc.cmode=cu_model;
		drinfo->ci.hc.dtype=dev_type;
		drinfo->ci.hc.dmode=dev_model;
		drinfo->oper_func=chandev_oper_func;
		if((err=s390_device_register(&newmodel->drinfo)))
		{
			chandev_sprint_devinfo(buff,newmodel->cu_type,newmodel->cu_model,
					       newmodel->dev_type,newmodel->dev_model);
			printk("s390_device_register failed in chandev_add_model"