Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * drivers/s390/cio/airq.c |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 3 | * Support for adapter interruptions |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 5 | * Copyright IBM Corp. 1999,2007 |
| 6 | * Author(s): Ingo Adlung <adlung@de.ibm.com> |
| 7 | * Cornelia Huck <cornelia.huck@de.ibm.com> |
| 8 | * Arnd Bergmann <arndb@de.ibm.com> |
| 9 | * Peter Oberparleiter <peter.oberparleiter@de.ibm.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | */ |
| 11 | |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/rcupdate.h> |
| 16 | |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 17 | #include <asm/airq.h> |
| 18 | |
| 19 | #include "cio.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include "cio_debug.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 22 | #define NR_AIRQS 32 |
| 23 | #define NR_AIRQS_PER_WORD sizeof(unsigned long) |
| 24 | #define NR_AIRQ_WORDS (NR_AIRQS / NR_AIRQS_PER_WORD) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 26 | union indicator_t { |
| 27 | unsigned long word[NR_AIRQ_WORDS]; |
| 28 | unsigned char byte[NR_AIRQS]; |
| 29 | } __attribute__((packed)); |
| 30 | |
| 31 | struct airq_t { |
| 32 | adapter_int_handler_t handler; |
| 33 | void *drv_data; |
| 34 | }; |
| 35 | |
| 36 | static union indicator_t indicators; |
| 37 | static struct airq_t *airqs[NR_AIRQS]; |
| 38 | |
| 39 | static int register_airq(struct airq_t *airq) |
| 40 | { |
| 41 | int i; |
| 42 | |
| 43 | for (i = 0; i < NR_AIRQS; i++) |
| 44 | if (!cmpxchg(&airqs[i], NULL, airq)) |
| 45 | return i; |
| 46 | return -ENOMEM; |
| 47 | } |
| 48 | |
| 49 | /** |
| 50 | * s390_register_adapter_interrupt() - register adapter interrupt handler |
| 51 | * @handler: adapter handler to be registered |
| 52 | * @drv_data: driver data passed with each call to the handler |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | * |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 54 | * Returns: |
| 55 | * Pointer to the indicator to be used on success |
| 56 | * ERR_PTR() if registration failed |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | */ |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 58 | void *s390_register_adapter_interrupt(adapter_int_handler_t handler, |
| 59 | void *drv_data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | { |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 61 | struct airq_t *airq; |
| 62 | char dbf_txt[16]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 65 | airq = kmalloc(sizeof(struct airq_t), GFP_KERNEL); |
| 66 | if (!airq) { |
| 67 | ret = -ENOMEM; |
| 68 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | } |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 70 | airq->handler = handler; |
| 71 | airq->drv_data = drv_data; |
| 72 | ret = register_airq(airq); |
| 73 | if (ret < 0) |
| 74 | kfree(airq); |
| 75 | out: |
| 76 | snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%d", ret); |
| 77 | CIO_TRACE_EVENT(4, dbf_txt); |
| 78 | if (ret < 0) |
| 79 | return ERR_PTR(ret); |
| 80 | else |
| 81 | return &indicators.byte[ret]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | } |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 83 | EXPORT_SYMBOL(s390_register_adapter_interrupt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 85 | /** |
| 86 | * s390_unregister_adapter_interrupt - unregister adapter interrupt handler |
| 87 | * @ind: indicator for which the handler is to be unregistered |
| 88 | */ |
| 89 | void s390_unregister_adapter_interrupt(void *ind) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | { |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 91 | struct airq_t *airq; |
| 92 | char dbf_txt[16]; |
| 93 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 95 | i = (int) ((addr_t) ind) - ((addr_t) &indicators.byte[0]); |
| 96 | snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%d", i); |
| 97 | CIO_TRACE_EVENT(4, dbf_txt); |
| 98 | indicators.byte[i] = 0; |
| 99 | airq = xchg(&airqs[i], NULL); |
| 100 | /* |
| 101 | * Allow interrupts to complete. This will ensure that the airq handle |
| 102 | * is no longer referenced by any interrupt handler. |
| 103 | */ |
| 104 | synchronize_sched(); |
| 105 | kfree(airq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | } |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 107 | EXPORT_SYMBOL(s390_unregister_adapter_interrupt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | |
Peter Oberparleiter | 4e8e56c | 2008-01-26 14:10:44 +0100 | [diff] [blame^] | 109 | #define INDICATOR_MASK (0xffUL << ((NR_AIRQS_PER_WORD - 1) * 8)) |
| 110 | |
| 111 | void do_adapter_IO(void) |
| 112 | { |
| 113 | int w; |
| 114 | int i; |
| 115 | unsigned long word; |
| 116 | struct airq_t *airq; |
| 117 | |
| 118 | /* |
| 119 | * Access indicator array in word-sized chunks to minimize storage |
| 120 | * fetch operations. |
| 121 | */ |
| 122 | for (w = 0; w < NR_AIRQ_WORDS; w++) { |
| 123 | word = indicators.word[w]; |
| 124 | i = w * NR_AIRQS_PER_WORD; |
| 125 | /* |
| 126 | * Check bytes within word for active indicators. |
| 127 | */ |
| 128 | while (word) { |
| 129 | if (word & INDICATOR_MASK) { |
| 130 | airq = airqs[i]; |
| 131 | if (likely(airq)) |
| 132 | airq->handler(&indicators.byte[i], |
| 133 | airq->drv_data); |
| 134 | else |
| 135 | /* |
| 136 | * Reset ill-behaved indicator. |
| 137 | */ |
| 138 | indicators.byte[i] = 0; |
| 139 | } |
| 140 | word <<= 8; |
| 141 | i++; |
| 142 | } |
| 143 | } |
| 144 | } |