linux/drivers/s390/cio/qdio_thinint.c

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/*
* linux/drivers/s390/cio/thinint_qdio.c
*
* thin interrupt support for qdio
*
* Copyright 2000-2008 IBM Corp.
* Author(s): Utz Bacher <utz.bacher@de.ibm.com>
* Cornelia Huck <cornelia.huck@de.ibm.com>
* Jan Glauber <jang@linux.vnet.ibm.com>
*/
#include <linux/io.h>
#include <asm/atomic.h>
#include <asm/debug.h>
#include <asm/qdio.h>
#include <asm/airq.h>
#include <asm/isc.h>
#include "cio.h"
#include "ioasm.h"
#include "qdio.h"
#include "qdio_debug.h"
#include "qdio_perf.h"
/*
* Restriction: only 63 iqdio subchannels would have its own indicator,
* after that, subsequent subchannels share one indicator
*/
#define TIQDIO_NR_NONSHARED_IND 63
#define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1)
#define TIQDIO_SHARED_IND 63
/* list of thin interrupt input queues */
static LIST_HEAD(tiq_list);
DEFINE_MUTEX(tiq_list_lock);
/* adapter local summary indicator */
static unsigned char *tiqdio_alsi;
/* device state change indicators */
struct indicator_t {
u32 ind; /* u32 because of compare-and-swap performance */
atomic_t count; /* use count, 0 or 1 for non-shared indicators */
};
static struct indicator_t *q_indicators;
static void tiqdio_tasklet_fn(unsigned long data);
static DECLARE_TASKLET(tiqdio_tasklet, tiqdio_tasklet_fn, 0);
static int css_qdio_omit_svs;
static inline unsigned long do_clear_global_summary(void)
{
register unsigned long __fn asm("1") = 3;
register unsigned long __tmp asm("2");
register unsigned long __time asm("3");
asm volatile(
" .insn rre,0xb2650000,2,0"
: "+d" (__fn), "=d" (__tmp), "=d" (__time));
return __time;
}
/* returns addr for the device state change indicator */
static u32 *get_indicator(void)
{
int i;
for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++)
if (!atomic_read(&q_indicators[i].count)) {
atomic_set(&q_indicators[i].count, 1);
return &q_indicators[i].ind;
}
/* use the shared indicator */
atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count);
return &q_indicators[TIQDIO_SHARED_IND].ind;
}
static void put_indicator(u32 *addr)
{
int i;
if (!addr)
return;
i = ((unsigned long)addr - (unsigned long)q_indicators) /
sizeof(struct indicator_t);
atomic_dec(&q_indicators[i].count);
}
void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
{
struct qdio_q *q;
int i;
/* No TDD facility? If we must use SIGA-s we can also omit SVS. */
if (!css_qdio_omit_svs && irq_ptr->siga_flag.sync)
css_qdio_omit_svs = 1;
mutex_lock(&tiq_list_lock);
for_each_input_queue(irq_ptr, q, i)
list_add_rcu(&q->entry, &tiq_list);
mutex_unlock(&tiq_list_lock);
xchg(irq_ptr->dsci, 1);
}
/*
* we cannot stop the tiqdio tasklet here since it is for all
* thinint qdio devices and it must run as long as there is a
* thinint device left
*/
void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
{
struct qdio_q *q;
int i;
for (i = 0; i < irq_ptr->nr_input_qs; i++) {
q = irq_ptr->input_qs[i];
/* if establish triggered an error */
if (!q || !q->entry.prev || !q->entry.next)
continue;
mutex_lock(&tiq_list_lock);
list_del_rcu(&q->entry);
mutex_unlock(&tiq_list_lock);
synchronize_rcu();
}
}
static inline int tiqdio_inbound_q_done(struct qdio_q *q)
{
unsigned char state = 0;
if (!atomic_read(&q->nr_buf_used))
return 1;
qdio_siga_sync_q(q);
get_buf_state(q, q->first_to_check, &state, 0);
if (state == SLSB_P_INPUT_PRIMED)
/* more work coming */
return 0;
return 1;
}
static inline int shared_ind(struct qdio_irq *irq_ptr)
{
return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind;
}
static void __tiqdio_inbound_processing(struct qdio_q *q)
{
qdio_perf_stat_inc(&perf_stats.thinint_inbound);
qdio_sync_after_thinint(q);
/*
* Maybe we have work on our outbound queues... at least
* we have to check the PCI capable queues.
*/
qdio_check_outbound_after_thinint(q);
if (!qdio_inbound_q_moved(q))
return;
qdio_kick_handler(q);
if (!tiqdio_inbound_q_done(q)) {
qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop);
[S390] qdio: proper kill of qdio tasklets The queue tasklets were stopped with tasklet_disable. Although tasklet_disable prevents the tasklet from beeing executed it is still possible that a tasklet is scheduled on a CPU at that point. A following qdio_establish calls tasklet_init which clears the tasklet count and the tasklet state leading to the following Oops: <2>kernel BUG at kernel/softirq.c:392! <4>illegal operation: 0001 [#1] SMP <4>Modules linked in: iptable_filter ip_tables x_tables dm_round_robin dm_multipath scsi_dh sg sd_mod crc_t10dif nfs lockd nfs _acl sunrpc fuse loop dm_mod qeth_l3 ipv6 zfcp qeth scsi_transport_fc qdio scsi_tgt scsi_mod chsc_sch ccwgroup dasd_eckd_mod dasdm od ext3 mbcache jbd <4>Supported: Yes <4>CPU: 0 Not tainted 2.6.27.13-1.1.mz13-default #1 <4>Process blast.LzS_64 (pid: 16445, task: 000000006cc02538, ksp: 000000006cb67998) <4>Krnl PSW : 0704c00180000000 00000000001399f4 (tasklet_action+0xc8/0x1d4) <4> R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 EA:3 <4>Krnl GPRS: ffffffff00000030 0000000000000002 0000000000000002 fffffffffffffffe <4> 000000000013aabe 00000000003b6a18 fffffffffffffffd 0000000000000000 <4> 00000000006705a8 000000007d0914a8 000000007d0914b0 000000007fecfd30 <4> 0000000000000000 00000000003b63e8 000000007fecfd90 000000007fecfd30 <4>Krnl Code: 00000000001399e8: b9200021 cgr %r2,%r1 <4> 00000000001399ec: a7740004 brc 7,1399f4 <4> 00000000001399f0: a7f40001 brc 15,1399f2 <4> >00000000001399f4: c0100027e8ee larl %r1,636bd0 <4> 00000000001399fa: bf1f1008 icm %r1,15,8(%r1) <4> 00000000001399fe: a7840019 brc 8,139a30 <4> 0000000000139a02: c0300027e8ef larl %r3,636be0 <4> 0000000000139a08: e3c030000004 lg %r12,0(%r3) <4>Call Trace: <4>([<0000000000139c12>] tasklet_hi_action+0x112/0x1d4) <4> [<000000000013aabe>] __do_softirq+0xde/0x1c4 <4> [<000000000010fa2e>] do_softirq+0x96/0xb0 <4> [<000000000013a8d8>] irq_exit+0x70/0xcc <4> [<000000000010d1d8>] do_extint+0xf0/0x110 <4> [<0000000000113b10>] ext_no_vtime+0x16/0x1a <4> [<000003e0000a3662>] ext3_dirty_inode+0xe6/0xe8 [ext3] <4>([<00000000001f6cf2>] __mark_inode_dirty+0x52/0x1d4) <4> [<000003e0000a44f0>] ext3_ordered_write_end+0x138/0x190 [ext3] <4> [<000000000018d5ec>] generic_perform_write+0x174/0x230 <4> [<0000000000190144>] generic_file_buffered_write+0xb4/0x194 <4> [<0000000000190864>] __generic_file_aio_write_nolock+0x418/0x454 <4> [<0000000000190ee2>] generic_file_aio_write+0x76/0xe4 <4> [<000003e0000a05c2>] ext3_file_write+0x3e/0xc8 [ext3] <4> [<00000000001cc2fe>] do_sync_write+0xd6/0x120 <4> [<00000000001ccfc8>] vfs_write+0xac/0x184 <4> [<00000000001cd218>] SyS_write+0x68/0xe0 <4> [<0000000000113402>] sysc_noemu+0x10/0x16 <4> [<0000020000043188>] 0x20000043188 <4>Last Breaking-Event-Address: <4> [<00000000001399f0>] tasklet_action+0xc4/0x1d4 <6>qdio: 0.0.c61b ZFCP on SC f67 using AI:1 QEBSM:0 PCI:1 TDD:1 SIGA: W AOP <4> <0>Kernel panic - not syncing: Fatal exception in interrupt Use tasklet_kill instead of tasklet_disbale. Since tasklet_schedule must not be called after tasklet_kill use the QDIO_IRQ_STATE_STOPPED to inidicate that a queue is going down and prevent further tasklet schedules in that case. Remove superflous tasklet_schedule from input queue setup, at that time the queues are not ready so the schedule results in a NOP. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26 14:24:26 +00:00
if (likely(q->irq_ptr->state != QDIO_IRQ_STATE_STOPPED))
tasklet_schedule(&q->tasklet);
}
qdio_stop_polling(q);
/*
* We need to check again to not lose initiative after
* resetting the ACK state.
*/
if (!tiqdio_inbound_q_done(q)) {
qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop2);
[S390] qdio: proper kill of qdio tasklets The queue tasklets were stopped with tasklet_disable. Although tasklet_disable prevents the tasklet from beeing executed it is still possible that a tasklet is scheduled on a CPU at that point. A following qdio_establish calls tasklet_init which clears the tasklet count and the tasklet state leading to the following Oops: <2>kernel BUG at kernel/softirq.c:392! <4>illegal operation: 0001 [#1] SMP <4>Modules linked in: iptable_filter ip_tables x_tables dm_round_robin dm_multipath scsi_dh sg sd_mod crc_t10dif nfs lockd nfs _acl sunrpc fuse loop dm_mod qeth_l3 ipv6 zfcp qeth scsi_transport_fc qdio scsi_tgt scsi_mod chsc_sch ccwgroup dasd_eckd_mod dasdm od ext3 mbcache jbd <4>Supported: Yes <4>CPU: 0 Not tainted 2.6.27.13-1.1.mz13-default #1 <4>Process blast.LzS_64 (pid: 16445, task: 000000006cc02538, ksp: 000000006cb67998) <4>Krnl PSW : 0704c00180000000 00000000001399f4 (tasklet_action+0xc8/0x1d4) <4> R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 EA:3 <4>Krnl GPRS: ffffffff00000030 0000000000000002 0000000000000002 fffffffffffffffe <4> 000000000013aabe 00000000003b6a18 fffffffffffffffd 0000000000000000 <4> 00000000006705a8 000000007d0914a8 000000007d0914b0 000000007fecfd30 <4> 0000000000000000 00000000003b63e8 000000007fecfd90 000000007fecfd30 <4>Krnl Code: 00000000001399e8: b9200021 cgr %r2,%r1 <4> 00000000001399ec: a7740004 brc 7,1399f4 <4> 00000000001399f0: a7f40001 brc 15,1399f2 <4> >00000000001399f4: c0100027e8ee larl %r1,636bd0 <4> 00000000001399fa: bf1f1008 icm %r1,15,8(%r1) <4> 00000000001399fe: a7840019 brc 8,139a30 <4> 0000000000139a02: c0300027e8ef larl %r3,636be0 <4> 0000000000139a08: e3c030000004 lg %r12,0(%r3) <4>Call Trace: <4>([<0000000000139c12>] tasklet_hi_action+0x112/0x1d4) <4> [<000000000013aabe>] __do_softirq+0xde/0x1c4 <4> [<000000000010fa2e>] do_softirq+0x96/0xb0 <4> [<000000000013a8d8>] irq_exit+0x70/0xcc <4> [<000000000010d1d8>] do_extint+0xf0/0x110 <4> [<0000000000113b10>] ext_no_vtime+0x16/0x1a <4> [<000003e0000a3662>] ext3_dirty_inode+0xe6/0xe8 [ext3] <4>([<00000000001f6cf2>] __mark_inode_dirty+0x52/0x1d4) <4> [<000003e0000a44f0>] ext3_ordered_write_end+0x138/0x190 [ext3] <4> [<000000000018d5ec>] generic_perform_write+0x174/0x230 <4> [<0000000000190144>] generic_file_buffered_write+0xb4/0x194 <4> [<0000000000190864>] __generic_file_aio_write_nolock+0x418/0x454 <4> [<0000000000190ee2>] generic_file_aio_write+0x76/0xe4 <4> [<000003e0000a05c2>] ext3_file_write+0x3e/0xc8 [ext3] <4> [<00000000001cc2fe>] do_sync_write+0xd6/0x120 <4> [<00000000001ccfc8>] vfs_write+0xac/0x184 <4> [<00000000001cd218>] SyS_write+0x68/0xe0 <4> [<0000000000113402>] sysc_noemu+0x10/0x16 <4> [<0000020000043188>] 0x20000043188 <4>Last Breaking-Event-Address: <4> [<00000000001399f0>] tasklet_action+0xc4/0x1d4 <6>qdio: 0.0.c61b ZFCP on SC f67 using AI:1 QEBSM:0 PCI:1 TDD:1 SIGA: W AOP <4> <0>Kernel panic - not syncing: Fatal exception in interrupt Use tasklet_kill instead of tasklet_disbale. Since tasklet_schedule must not be called after tasklet_kill use the QDIO_IRQ_STATE_STOPPED to inidicate that a queue is going down and prevent further tasklet schedules in that case. Remove superflous tasklet_schedule from input queue setup, at that time the queues are not ready so the schedule results in a NOP. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26 14:24:26 +00:00
if (likely(q->irq_ptr->state != QDIO_IRQ_STATE_STOPPED))
tasklet_schedule(&q->tasklet);
}
}
void tiqdio_inbound_processing(unsigned long data)
{
struct qdio_q *q = (struct qdio_q *)data;
__tiqdio_inbound_processing(q);
}
/* check for work on all inbound thinint queues */
static void tiqdio_tasklet_fn(unsigned long data)
{
struct qdio_q *q;
qdio_perf_stat_inc(&perf_stats.tasklet_thinint);
again:
/* protect tiq_list entries, only changed in activate or shutdown */
rcu_read_lock();
list_for_each_entry_rcu(q, &tiq_list, entry)
/* only process queues from changed sets */
if (*q->irq_ptr->dsci) {
/* only clear it if the indicator is non-shared */
if (!shared_ind(q->irq_ptr))
xchg(q->irq_ptr->dsci, 0);
/*
* don't call inbound processing directly since
* that could starve other thinint queues
*/
tasklet_schedule(&q->tasklet);
}
rcu_read_unlock();
/*
* if we used the shared indicator clear it now after all queues
* were processed
*/
if (atomic_read(&q_indicators[TIQDIO_SHARED_IND].count)) {
xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
/* prevent racing */
if (*tiqdio_alsi)
xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 1);
}
/* check for more work */
if (*tiqdio_alsi) {
xchg(tiqdio_alsi, 0);
qdio_perf_stat_inc(&perf_stats.tasklet_thinint_loop);
goto again;
}
}
/**
* tiqdio_thinint_handler - thin interrupt handler for qdio
* @ind: pointer to adapter local summary indicator
* @drv_data: NULL
*/
static void tiqdio_thinint_handler(void *ind, void *drv_data)
{
qdio_perf_stat_inc(&perf_stats.thin_int);
/*
* SVS only when needed: issue SVS to benefit from iqdio interrupt
* avoidance (SVS clears adapter interrupt suppression overwrite)
*/
if (!css_qdio_omit_svs)
do_clear_global_summary();
/*
* reset local summary indicator (tiqdio_alsi) to stop adapter
* interrupts for now, the tasklet will clean all dsci's
*/
xchg((u8 *)ind, 0);
tasklet_hi_schedule(&tiqdio_tasklet);
}
static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset)
{
struct scssc_area *scssc_area;
int rc;
scssc_area = (struct scssc_area *)irq_ptr->chsc_page;
memset(scssc_area, 0, PAGE_SIZE);
if (reset) {
scssc_area->summary_indicator_addr = 0;
scssc_area->subchannel_indicator_addr = 0;
} else {
scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi);
scssc_area->subchannel_indicator_addr =
virt_to_phys(irq_ptr->dsci);
}
scssc_area->request = (struct chsc_header) {
.length = 0x0fe0,
.code = 0x0021,
};
scssc_area->operation_code = 0;
scssc_area->ks = PAGE_DEFAULT_KEY;
scssc_area->kc = PAGE_DEFAULT_KEY;
scssc_area->isc = QDIO_AIRQ_ISC;
scssc_area->schid = irq_ptr->schid;
/* enable the time delay disablement facility */
if (css_general_characteristics.aif_tdd)
scssc_area->word_with_d_bit = 0x10000000;
rc = chsc(scssc_area);
if (rc)
return -EIO;
rc = chsc_error_from_response(scssc_area->response.code);
if (rc) {
DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no,
scssc_area->response.code);
DBF_ERROR_HEX(&scssc_area->response, sizeof(void *));
return rc;
}
DBF_EVENT("setscind");
DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long));
DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long));
return 0;
}
/* allocate non-shared indicators and shared indicator */
int __init tiqdio_allocate_memory(void)
{
q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS,
GFP_KERNEL);
if (!q_indicators)
return -ENOMEM;
return 0;
}
void tiqdio_free_memory(void)
{
kfree(q_indicators);
}
int __init tiqdio_register_thinints(void)
{
isc_register(QDIO_AIRQ_ISC);
tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler,
NULL, QDIO_AIRQ_ISC);
if (IS_ERR(tiqdio_alsi)) {
DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi));
tiqdio_alsi = NULL;
isc_unregister(QDIO_AIRQ_ISC);
return -ENOMEM;
}
return 0;
}
int qdio_establish_thinint(struct qdio_irq *irq_ptr)
{
if (!is_thinint_irq(irq_ptr))
return 0;
/* Check for aif time delay disablement. If installed,
* omit SVS even under LPAR
*/
if (css_general_characteristics.aif_tdd)
css_qdio_omit_svs = 1;
return set_subchannel_ind(irq_ptr, 0);
}
void qdio_setup_thinint(struct qdio_irq *irq_ptr)
{
if (!is_thinint_irq(irq_ptr))
return;
irq_ptr->dsci = get_indicator();
DBF_HEX(&irq_ptr->dsci, sizeof(void *));
}
void qdio_shutdown_thinint(struct qdio_irq *irq_ptr)
{
if (!is_thinint_irq(irq_ptr))
return;
/* reset adapter interrupt indicators */
put_indicator(irq_ptr->dsci);
set_subchannel_ind(irq_ptr, 1);
}
void __exit tiqdio_unregister_thinints(void)
{
WARN_ON(!list_empty(&tiq_list));
if (tiqdio_alsi) {
s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC);
isc_unregister(QDIO_AIRQ_ISC);
}
tasklet_kill(&tiqdio_tasklet);
}