linux/drivers/s390/cio/qdio_thinint.c
Linus Torvalds d60a540ac5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Heiko Carstens:
 "Since Martin is on vacation you get the s390 pull request for the
  v4.15 merge window this time from me.

  Besides a lot of cleanups and bug fixes these are the most important
  changes:

   - a new regset for runtime instrumentation registers

   - hardware accelerated AES-GCM support for the aes_s390 module

   - support for the new CEX6S crypto cards

   - support for FORTIFY_SOURCE

   - addition of missing z13 and new z14 instructions to the in-kernel
     disassembler

   - generate opcode tables for the in-kernel disassembler out of a
     simple text file instead of having to manually maintain those
     tables

   - fast memset16, memset32 and memset64 implementations

   - removal of named saved segment support

   - hardware counter support for z14

   - queued spinlocks and queued rwlocks implementations for s390

   - use the stack_depth tracking feature for s390 BPF JIT

   - a new s390_sthyi system call which emulates the sthyi (store
     hypervisor information) instruction

   - removal of the old KVM virtio transport

   - an s390 specific CPU alternatives implementation which is used in
     the new spinlock code"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (88 commits)
  MAINTAINERS: add virtio-ccw.h to virtio/s390 section
  s390/noexec: execute kexec datamover without DAT
  s390: fix transactional execution control register handling
  s390/bpf: take advantage of stack_depth tracking
  s390: simplify transactional execution elf hwcap handling
  s390/zcrypt: Rework struct ap_qact_ap_info.
  s390/virtio: remove unused header file kvm_virtio.h
  s390: avoid undefined behaviour
  s390/disassembler: generate opcode tables from text file
  s390/disassembler: remove insn_to_mnemonic()
  s390/dasd: avoid calling do_gettimeofday()
  s390: vfio-ccw: Do not attempt to free no-op, test and tic cda.
  s390: remove named saved segment support
  s390/archrandom: Reconsider s390 arch random implementation
  s390/pci: do not require AIS facility
  s390/qdio: sanitize put_indicator
  s390/qdio: use atomic_cmpxchg
  s390/nmi: avoid using long-displacement facility
  s390: pass endianness info to sparse
  s390/decompressor: remove informational messages
  ...
2017-11-13 11:47:01 -08:00

298 lines
6.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2000, 2009
* 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 <linux/slab.h>
#include <linux/kernel_stat.h>
#include <linux/atomic.h>
#include <linux/rculist.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"
/*
* 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
/* 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 */
};
/* list of thin interrupt input queues */
static LIST_HEAD(tiq_list);
static DEFINE_MUTEX(tiq_list_lock);
/* Adapter interrupt definitions */
static void tiqdio_thinint_handler(struct airq_struct *airq);
static struct airq_struct tiqdio_airq = {
.handler = tiqdio_thinint_handler,
.isc = QDIO_AIRQ_ISC,
};
static struct indicator_t *q_indicators;
u64 last_ai_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_cmpxchg(&q_indicators[i].count, 0, 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)
{
struct indicator_t *ind = container_of(addr, struct indicator_t, ind);
if (!addr)
return;
atomic_dec(&ind->count);
}
void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
{
mutex_lock(&tiq_list_lock);
list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list);
mutex_unlock(&tiq_list_lock);
xchg(irq_ptr->dsci, 1 << 7);
}
void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
{
struct qdio_q *q;
q = irq_ptr->input_qs[0];
/* if establish triggered an error */
if (!q || !q->entry.prev || !q->entry.next)
return;
mutex_lock(&tiq_list_lock);
list_del_rcu(&q->entry);
mutex_unlock(&tiq_list_lock);
synchronize_rcu();
}
static inline int has_multiple_inq_on_dsci(struct qdio_irq *irq_ptr)
{
return irq_ptr->nr_input_qs > 1;
}
static inline int references_shared_dsci(struct qdio_irq *irq_ptr)
{
return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind;
}
static inline int shared_ind(struct qdio_irq *irq_ptr)
{
return references_shared_dsci(irq_ptr) ||
has_multiple_inq_on_dsci(irq_ptr);
}
void clear_nonshared_ind(struct qdio_irq *irq_ptr)
{
if (!is_thinint_irq(irq_ptr))
return;
if (shared_ind(irq_ptr))
return;
xchg(irq_ptr->dsci, 0);
}
int test_nonshared_ind(struct qdio_irq *irq_ptr)
{
if (!is_thinint_irq(irq_ptr))
return 0;
if (shared_ind(irq_ptr))
return 0;
if (*irq_ptr->dsci)
return 1;
else
return 0;
}
static inline u32 clear_shared_ind(void)
{
if (!atomic_read(&q_indicators[TIQDIO_SHARED_IND].count))
return 0;
return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0);
}
static inline void tiqdio_call_inq_handlers(struct qdio_irq *irq)
{
struct qdio_q *q;
int i;
if (!references_shared_dsci(irq) &&
has_multiple_inq_on_dsci(irq))
xchg(irq->dsci, 0);
for_each_input_queue(irq, q, i) {
if (q->u.in.queue_start_poll) {
/* skip if polling is enabled or already in work */
if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED,
&q->u.in.queue_irq_state)) {
qperf_inc(q, int_discarded);
continue;
}
/* avoid dsci clear here, done after processing */
q->u.in.queue_start_poll(irq->cdev, q->nr,
irq->int_parm);
} else {
if (!shared_ind(irq))
xchg(irq->dsci, 0);
/*
* Call inbound processing but not directly
* since that could starve other thinint queues.
*/
tasklet_schedule(&q->tasklet);
}
}
}
/**
* tiqdio_thinint_handler - thin interrupt handler for qdio
* @airq: pointer to adapter interrupt descriptor
*/
static void tiqdio_thinint_handler(struct airq_struct *airq)
{
u32 si_used = clear_shared_ind();
struct qdio_q *q;
last_ai_time = S390_lowcore.int_clock;
inc_irq_stat(IRQIO_QAI);
/* protect tiq_list entries, only changed in activate or shutdown */
rcu_read_lock();
/* check for work on all inbound thinint queues */
list_for_each_entry_rcu(q, &tiq_list, entry) {
struct qdio_irq *irq;
/* only process queues from changed sets */
irq = q->irq_ptr;
if (unlikely(references_shared_dsci(irq))) {
if (!si_used)
continue;
} else if (!*irq->dsci)
continue;
tiqdio_call_inq_handlers(irq);
qperf_inc(q, adapter_int);
}
rcu_read_unlock();
}
static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset)
{
struct chsc_scssc_area *scssc = (void *)irq_ptr->chsc_page;
u64 summary_indicator_addr, subchannel_indicator_addr;
int rc;
if (reset) {
summary_indicator_addr = 0;
subchannel_indicator_addr = 0;
} else {
summary_indicator_addr = virt_to_phys(tiqdio_airq.lsi_ptr);
subchannel_indicator_addr = virt_to_phys(irq_ptr->dsci);
}
rc = chsc_sadc(irq_ptr->schid, scssc, summary_indicator_addr,
subchannel_indicator_addr);
if (rc) {
DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no,
scssc->response.code);
goto out;
}
DBF_EVENT("setscind");
DBF_HEX(&summary_indicator_addr, sizeof(summary_indicator_addr));
DBF_HEX(&subchannel_indicator_addr, sizeof(subchannel_indicator_addr));
out:
return rc;
}
/* 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)
{
int rc;
rc = register_adapter_interrupt(&tiqdio_airq);
if (rc) {
DBF_EVENT("RTI:%x", rc);
return rc;
}
return 0;
}
int qdio_establish_thinint(struct qdio_irq *irq_ptr)
{
if (!is_thinint_irq(irq_ptr))
return 0;
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 */
set_subchannel_ind(irq_ptr, 1);
put_indicator(irq_ptr->dsci);
}
void __exit tiqdio_unregister_thinints(void)
{
WARN_ON(!list_empty(&tiq_list));
unregister_adapter_interrupt(&tiqdio_airq);
}