xen: cleancache shim to Xen Transcendent Memory
[linux-2.6/next.git] / arch / alpha / kernel / irq_pyxis.c
blob13c97a5b31e88848ad8c496ba1e2f163a7db660f
1 /*
2 * linux/arch/alpha/kernel/irq_pyxis.c
4 * Based on code written by David A Rusling (david.rusling@reo.mts.dec.com).
6 * IRQ Code common to all PYXIS core logic chips.
7 */
9 #include <linux/init.h>
10 #include <linux/sched.h>
11 #include <linux/irq.h>
13 #include <asm/io.h>
14 #include <asm/core_cia.h>
16 #include "proto.h"
17 #include "irq_impl.h"
20 /* Note mask bit is true for ENABLED irqs. */
21 static unsigned long cached_irq_mask;
23 static inline void
24 pyxis_update_irq_hw(unsigned long mask)
26 *(vulp)PYXIS_INT_MASK = mask;
27 mb();
28 *(vulp)PYXIS_INT_MASK;
31 static inline void
32 pyxis_enable_irq(struct irq_data *d)
34 pyxis_update_irq_hw(cached_irq_mask |= 1UL << (d->irq - 16));
37 static void
38 pyxis_disable_irq(struct irq_data *d)
40 pyxis_update_irq_hw(cached_irq_mask &= ~(1UL << (d->irq - 16)));
43 static void
44 pyxis_mask_and_ack_irq(struct irq_data *d)
46 unsigned long bit = 1UL << (d->irq - 16);
47 unsigned long mask = cached_irq_mask &= ~bit;
49 /* Disable the interrupt. */
50 *(vulp)PYXIS_INT_MASK = mask;
51 wmb();
52 /* Ack PYXIS PCI interrupt. */
53 *(vulp)PYXIS_INT_REQ = bit;
54 mb();
55 /* Re-read to force both writes. */
56 *(vulp)PYXIS_INT_MASK;
59 static struct irq_chip pyxis_irq_type = {
60 .name = "PYXIS",
61 .irq_mask_ack = pyxis_mask_and_ack_irq,
62 .irq_mask = pyxis_disable_irq,
63 .irq_unmask = pyxis_enable_irq,
66 void
67 pyxis_device_interrupt(unsigned long vector)
69 unsigned long pld;
70 unsigned int i;
72 /* Read the interrupt summary register of PYXIS */
73 pld = *(vulp)PYXIS_INT_REQ;
74 pld &= cached_irq_mask;
77 * Now for every possible bit set, work through them and call
78 * the appropriate interrupt handler.
80 while (pld) {
81 i = ffz(~pld);
82 pld &= pld - 1; /* clear least bit set */
83 if (i == 7)
84 isa_device_interrupt(vector);
85 else
86 handle_irq(16+i);
90 void __init
91 init_pyxis_irqs(unsigned long ignore_mask)
93 long i;
95 *(vulp)PYXIS_INT_MASK = 0; /* disable all */
96 *(vulp)PYXIS_INT_REQ = -1; /* flush all */
97 mb();
99 /* Send -INTA pulses to clear any pending interrupts ...*/
100 *(vuip) CIA_IACK_SC;
102 for (i = 16; i < 48; ++i) {
103 if ((ignore_mask >> i) & 1)
104 continue;
105 irq_set_chip_and_handler(i, &pyxis_irq_type, handle_level_irq);
106 irq_set_status_flags(i, IRQ_LEVEL);
109 setup_irq(16+7, &isa_cascade_irqaction);