xref: /minix3/minix/kernel/system/do_irqctl.c (revision 9624407e7addfd8b88486acfe3a0e056e2b92ee3)
1433d6423SLionel Sambuc /* The kernel call implemented in this file:
2433d6423SLionel Sambuc  *   m_type:	SYS_IRQCTL
3433d6423SLionel Sambuc  *
4433d6423SLionel Sambuc  * The parameters for this kernel call are:
5433d6423SLionel Sambuc  *    m_lsys_krn_sys_irqctl.request	(control operation to perform)
6433d6423SLionel Sambuc  *    m_lsys_krn_sys_irqctl.vector	(irq line that must be controlled)
7433d6423SLionel Sambuc  *    m_lsys_krn_sys_irqctl.policy	(irq policy allows reenabling interrupts)
8433d6423SLionel Sambuc  *    m_lsys_krn_sys_irqctl.hook_id	(provides index to be returned on interrupt)
9433d6423SLionel Sambuc  *    m_krn_lsys_sys_irqctl.hook_id	(returns index of irq hook assigned at kernel)
10433d6423SLionel Sambuc  */
11433d6423SLionel Sambuc 
12433d6423SLionel Sambuc #include "kernel/system.h"
13433d6423SLionel Sambuc 
14433d6423SLionel Sambuc #include <minix/endpoint.h>
15433d6423SLionel Sambuc 
16433d6423SLionel Sambuc #if USE_IRQCTL
17433d6423SLionel Sambuc 
18433d6423SLionel Sambuc static int generic_handler(irq_hook_t *hook);
19433d6423SLionel Sambuc 
20433d6423SLionel Sambuc /*===========================================================================*
21433d6423SLionel Sambuc  *				do_irqctl				     *
22433d6423SLionel Sambuc  *===========================================================================*/
do_irqctl(struct proc * caller,message * m_ptr)23433d6423SLionel Sambuc int do_irqctl(struct proc * caller, message * m_ptr)
24433d6423SLionel Sambuc {
25433d6423SLionel Sambuc   /* Dismember the request message. */
26433d6423SLionel Sambuc   int irq_vec;
27433d6423SLionel Sambuc   int irq_hook_id;
28433d6423SLionel Sambuc   int notify_id;
29433d6423SLionel Sambuc   int r = OK;
30433d6423SLionel Sambuc   int i;
31433d6423SLionel Sambuc   irq_hook_t *hook_ptr;
32433d6423SLionel Sambuc   struct priv *privp;
33433d6423SLionel Sambuc 
34433d6423SLionel Sambuc   /* Hook identifiers start at 1 and end at NR_IRQ_HOOKS. */
35433d6423SLionel Sambuc   irq_hook_id = m_ptr->m_lsys_krn_sys_irqctl.hook_id - 1;
36433d6423SLionel Sambuc   irq_vec = m_ptr->m_lsys_krn_sys_irqctl.vector;
37433d6423SLionel Sambuc 
38433d6423SLionel Sambuc   /* See what is requested and take needed actions. */
39433d6423SLionel Sambuc   switch(m_ptr->m_lsys_krn_sys_irqctl.request) {
40433d6423SLionel Sambuc 
41433d6423SLionel Sambuc   /* Enable or disable IRQs. This is straightforward. */
42433d6423SLionel Sambuc   case IRQ_ENABLE:
43433d6423SLionel Sambuc   case IRQ_DISABLE:
44433d6423SLionel Sambuc       if (irq_hook_id >= NR_IRQ_HOOKS || irq_hook_id < 0 ||
45433d6423SLionel Sambuc           irq_hooks[irq_hook_id].proc_nr_e == NONE) return(EINVAL);
46433d6423SLionel Sambuc       if (irq_hooks[irq_hook_id].proc_nr_e != caller->p_endpoint) return(EPERM);
47433d6423SLionel Sambuc       if (m_ptr->m_lsys_krn_sys_irqctl.request == IRQ_ENABLE) {
48433d6423SLionel Sambuc           enable_irq(&irq_hooks[irq_hook_id]);
49433d6423SLionel Sambuc       }
50433d6423SLionel Sambuc       else
51433d6423SLionel Sambuc           disable_irq(&irq_hooks[irq_hook_id]);
52433d6423SLionel Sambuc       break;
53433d6423SLionel Sambuc 
54433d6423SLionel Sambuc   /* Control IRQ policies. Set a policy and needed details in the IRQ table.
55433d6423SLionel Sambuc    * This policy is used by a generic function to handle hardware interrupts.
56433d6423SLionel Sambuc    */
57433d6423SLionel Sambuc   case IRQ_SETPOLICY:
58433d6423SLionel Sambuc 
59433d6423SLionel Sambuc       /* Check if IRQ line is acceptable. */
60433d6423SLionel Sambuc       if (irq_vec < 0 || irq_vec >= NR_IRQ_VECTORS) return(EINVAL);
61433d6423SLionel Sambuc 
62433d6423SLionel Sambuc       privp= priv(caller);
63433d6423SLionel Sambuc       if (!privp)
64433d6423SLionel Sambuc       {
65433d6423SLionel Sambuc 	printf("do_irqctl: no priv structure!\n");
66433d6423SLionel Sambuc 	return EPERM;
67433d6423SLionel Sambuc       }
68433d6423SLionel Sambuc       if (privp->s_flags & CHECK_IRQ)
69433d6423SLionel Sambuc       {
70433d6423SLionel Sambuc 	for (i= 0; i<privp->s_nr_irq; i++)
71433d6423SLionel Sambuc 	{
72433d6423SLionel Sambuc 		if (irq_vec == privp->s_irq_tab[i])
73433d6423SLionel Sambuc 			break;
74433d6423SLionel Sambuc 	}
75433d6423SLionel Sambuc 	if (i >= privp->s_nr_irq)
76433d6423SLionel Sambuc 	{
77433d6423SLionel Sambuc 		printf(
78433d6423SLionel Sambuc 		"do_irqctl: IRQ check failed for proc %d, IRQ %d\n",
79433d6423SLionel Sambuc 			caller->p_endpoint, irq_vec);
80433d6423SLionel Sambuc 		return EPERM;
81433d6423SLionel Sambuc 	}
82433d6423SLionel Sambuc     }
83433d6423SLionel Sambuc 
84433d6423SLionel Sambuc       /* When setting a policy, the caller must provide an identifier that
85433d6423SLionel Sambuc        * is returned on the notification message if a interrupt occurs.
86433d6423SLionel Sambuc        */
87433d6423SLionel Sambuc       notify_id = m_ptr->m_lsys_krn_sys_irqctl.hook_id;
88433d6423SLionel Sambuc       if (notify_id > CHAR_BIT * sizeof(irq_id_t) - 1) return(EINVAL);
89433d6423SLionel Sambuc 
90433d6423SLionel Sambuc       /* Try to find an existing mapping to override. */
91433d6423SLionel Sambuc       hook_ptr = NULL;
92433d6423SLionel Sambuc       for (i=0; !hook_ptr && i<NR_IRQ_HOOKS; i++) {
93433d6423SLionel Sambuc           if (irq_hooks[i].proc_nr_e == caller->p_endpoint
94433d6423SLionel Sambuc               && irq_hooks[i].notify_id == notify_id) {
95433d6423SLionel Sambuc               irq_hook_id = i;
96433d6423SLionel Sambuc               hook_ptr = &irq_hooks[irq_hook_id];	/* existing hook */
97433d6423SLionel Sambuc               rm_irq_handler(&irq_hooks[irq_hook_id]);
98433d6423SLionel Sambuc           }
99433d6423SLionel Sambuc       }
100433d6423SLionel Sambuc 
101433d6423SLionel Sambuc       /* If there is nothing to override, find a free hook for this mapping. */
102433d6423SLionel Sambuc       for (i=0; !hook_ptr && i<NR_IRQ_HOOKS; i++) {
103433d6423SLionel Sambuc           if (irq_hooks[i].proc_nr_e == NONE) {
104433d6423SLionel Sambuc               irq_hook_id = i;
105433d6423SLionel Sambuc               hook_ptr = &irq_hooks[irq_hook_id];	/* free hook */
106433d6423SLionel Sambuc           }
107433d6423SLionel Sambuc       }
108433d6423SLionel Sambuc       if (hook_ptr == NULL) return(ENOSPC);
109433d6423SLionel Sambuc 
110433d6423SLionel Sambuc       /* Install the handler. */
111433d6423SLionel Sambuc       hook_ptr->proc_nr_e = caller->p_endpoint;	/* process to notify */
112433d6423SLionel Sambuc       hook_ptr->notify_id = notify_id;		/* identifier to pass */
113433d6423SLionel Sambuc       hook_ptr->policy = m_ptr->m_lsys_krn_sys_irqctl.policy;	/* policy for interrupts */
114433d6423SLionel Sambuc       put_irq_handler(hook_ptr, irq_vec, generic_handler);
115433d6423SLionel Sambuc       DEBUGBASIC(("IRQ %d handler registered by %s / %d\n",
116433d6423SLionel Sambuc 			      irq_vec, caller->p_name, caller->p_endpoint));
117433d6423SLionel Sambuc 
118433d6423SLionel Sambuc       /* Return index of the IRQ hook in use. */
119433d6423SLionel Sambuc       m_ptr->m_krn_lsys_sys_irqctl.hook_id = irq_hook_id + 1;
120433d6423SLionel Sambuc       break;
121433d6423SLionel Sambuc 
122433d6423SLionel Sambuc   case IRQ_RMPOLICY:
123433d6423SLionel Sambuc       if (irq_hook_id < 0 || irq_hook_id >= NR_IRQ_HOOKS ||
124433d6423SLionel Sambuc                irq_hooks[irq_hook_id].proc_nr_e == NONE) {
125433d6423SLionel Sambuc            return(EINVAL);
126433d6423SLionel Sambuc       } else if (caller->p_endpoint != irq_hooks[irq_hook_id].proc_nr_e) {
127433d6423SLionel Sambuc            return(EPERM);
128433d6423SLionel Sambuc       }
129433d6423SLionel Sambuc       /* Remove the handler and return. */
130433d6423SLionel Sambuc       rm_irq_handler(&irq_hooks[irq_hook_id]);
131433d6423SLionel Sambuc       irq_hooks[irq_hook_id].proc_nr_e = NONE;
132433d6423SLionel Sambuc       break;
133433d6423SLionel Sambuc 
134433d6423SLionel Sambuc   default:
135433d6423SLionel Sambuc       r = EINVAL;				/* invalid IRQ REQUEST */
136433d6423SLionel Sambuc   }
137433d6423SLionel Sambuc   return(r);
138433d6423SLionel Sambuc }
139433d6423SLionel Sambuc 
140433d6423SLionel Sambuc /*===========================================================================*
141433d6423SLionel Sambuc  *			       generic_handler				     *
142433d6423SLionel Sambuc  *===========================================================================*/
generic_handler(irq_hook_t * hook)143*6077d1adSDr. Florian Grätz static int generic_handler(irq_hook_t * hook)
144433d6423SLionel Sambuc {
145433d6423SLionel Sambuc /* This function handles hardware interrupt in a simple and generic way. All
146433d6423SLionel Sambuc  * interrupts are transformed into messages to a driver. The IRQ line will be
147433d6423SLionel Sambuc  * reenabled if the policy says so.
148433d6423SLionel Sambuc  */
149433d6423SLionel Sambuc   int proc_nr;
150433d6423SLionel Sambuc 
151433d6423SLionel Sambuc   /* As a side-effect, the interrupt handler gathers random information by
152433d6423SLionel Sambuc    * timestamping the interrupt events. This is used for /dev/random.
153433d6423SLionel Sambuc    */
154433d6423SLionel Sambuc   get_randomness(&krandom, hook->irq);
155433d6423SLionel Sambuc 
156433d6423SLionel Sambuc   /* Check if the handler is still alive.
157433d6423SLionel Sambuc    * If it's dead, this should never happen, as processes that die
158433d6423SLionel Sambuc    * automatically get their interrupt hooks unhooked.
159433d6423SLionel Sambuc    */
160433d6423SLionel Sambuc   if(!isokendpt(hook->proc_nr_e, &proc_nr))
161433d6423SLionel Sambuc      panic("invalid interrupt handler: %d", hook->proc_nr_e);
162433d6423SLionel Sambuc 
163433d6423SLionel Sambuc   /* Add a bit for this interrupt to the process' pending interrupts. When
164433d6423SLionel Sambuc    * sending the notification message, this bit map will be magically set
165433d6423SLionel Sambuc    * as an argument.
166433d6423SLionel Sambuc    */
167433d6423SLionel Sambuc   priv(proc_addr(proc_nr))->s_int_pending |= (1 << hook->notify_id);
168433d6423SLionel Sambuc 
169433d6423SLionel Sambuc   /* Build notification message and return. */
170433d6423SLionel Sambuc   mini_notify(proc_addr(HARDWARE), hook->proc_nr_e);
171433d6423SLionel Sambuc   return(hook->policy & IRQ_REENABLE);
172433d6423SLionel Sambuc }
173433d6423SLionel Sambuc 
174433d6423SLionel Sambuc #endif /* USE_IRQCTL */
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