xref: /openbmc/linux/drivers/sh/intc/balancing.c (revision 293d5b43)
1 /*
2  * Support for hardware-managed IRQ auto-distribution.
3  *
4  * Copyright (C) 2010  Paul Mundt
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 #include "internals.h"
11 
12 static unsigned long dist_handle[INTC_NR_IRQS];
13 
14 void intc_balancing_enable(unsigned int irq)
15 {
16 	struct intc_desc_int *d = get_intc_desc(irq);
17 	unsigned long handle = dist_handle[irq];
18 	unsigned long addr;
19 
20 	if (irq_balancing_disabled(irq) || !handle)
21 		return;
22 
23 	addr = INTC_REG(d, _INTC_ADDR_D(handle), 0);
24 	intc_reg_fns[_INTC_FN(handle)](addr, handle, 1);
25 }
26 
27 void intc_balancing_disable(unsigned int irq)
28 {
29 	struct intc_desc_int *d = get_intc_desc(irq);
30 	unsigned long handle = dist_handle[irq];
31 	unsigned long addr;
32 
33 	if (irq_balancing_disabled(irq) || !handle)
34 		return;
35 
36 	addr = INTC_REG(d, _INTC_ADDR_D(handle), 0);
37 	intc_reg_fns[_INTC_FN(handle)](addr, handle, 0);
38 }
39 
40 static unsigned int intc_dist_data(struct intc_desc *desc,
41 				   struct intc_desc_int *d,
42 				   intc_enum enum_id)
43 {
44 	struct intc_mask_reg *mr = desc->hw.mask_regs;
45 	unsigned int i, j, fn, mode;
46 	unsigned long reg_e, reg_d;
47 
48 	for (i = 0; mr && enum_id && i < desc->hw.nr_mask_regs; i++) {
49 		mr = desc->hw.mask_regs + i;
50 
51 		/*
52 		 * Skip this entry if there's no auto-distribution
53 		 * register associated with it.
54 		 */
55 		if (!mr->dist_reg)
56 			continue;
57 
58 		for (j = 0; j < ARRAY_SIZE(mr->enum_ids); j++) {
59 			if (mr->enum_ids[j] != enum_id)
60 				continue;
61 
62 			fn = REG_FN_MODIFY_BASE;
63 			mode = MODE_ENABLE_REG;
64 			reg_e = mr->dist_reg;
65 			reg_d = mr->dist_reg;
66 
67 			fn += (mr->reg_width >> 3) - 1;
68 			return _INTC_MK(fn, mode,
69 					intc_get_reg(d, reg_e),
70 					intc_get_reg(d, reg_d),
71 					1,
72 					(mr->reg_width - 1) - j);
73 		}
74 	}
75 
76 	/*
77 	 * It's possible we've gotten here with no distribution options
78 	 * available for the IRQ in question, so we just skip over those.
79 	 */
80 	return 0;
81 }
82 
83 void intc_set_dist_handle(unsigned int irq, struct intc_desc *desc,
84 			  struct intc_desc_int *d, intc_enum id)
85 {
86 	unsigned long flags;
87 
88 	/*
89 	 * Nothing to do for this IRQ.
90 	 */
91 	if (!desc->hw.mask_regs)
92 		return;
93 
94 	raw_spin_lock_irqsave(&intc_big_lock, flags);
95 	dist_handle[irq] = intc_dist_data(desc, d, id);
96 	raw_spin_unlock_irqrestore(&intc_big_lock, flags);
97 }
98