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linux/drivers/s390/cio/qdio.h
Julian Wiedmann 9c159bbc14 s390/qdio: clear DSCI early for polling drivers 
Polling drivers in a configuration with 1 Input Queue currently keep
their DSCI armed all the way through the poll cycle, until
qdio_start_irq() clears it.

_Any_ intermittent QDIO interrupt delivered to tiqdio_thinint_handler()
will thus cause
1) the 'adapter_int' statistic to be incremented,
2) a call to tiqdio_call_inq_handlers() for this device, and then
3) the 'int_discarded' statistics to be incremented.

This causes overhead & complexity in the IRQ path, along with ambiguity
in the statistics.
On the other hand the device should be in IRQ avoidance mode during a
poll cycle, so there won't be a lot of DSCI ping-pong that this
micro-optimization could prevent.

So align the DSCI handling with what we already do for devices with
multiple Input Queues: clear it right away while processing the IRQ.

For the non-polling path this means that we no longer need to handle
the 1-queue case separately.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-06 13:13:51 +02:00

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 2000, 2009
* Author(s): Utz Bacher <utz.bacher@de.ibm.com>
* Jan Glauber <jang@linux.vnet.ibm.com>
*/
#ifndef _CIO_QDIO_H
#define _CIO_QDIO_H
#include <asm/page.h>
#include <asm/schid.h>
#include <asm/debug.h>
#include "chsc.h"
#define QDIO_BUSY_BIT_PATIENCE (100 << 12) /* 100 microseconds */
#define QDIO_BUSY_BIT_RETRY_DELAY 10 /* 10 milliseconds */
#define QDIO_BUSY_BIT_RETRIES 1000 /* = 10s retry time */
#define QDIO_INPUT_THRESHOLD (500 << 12) /* 500 microseconds */
enum qdio_irq_states {
QDIO_IRQ_STATE_INACTIVE,
QDIO_IRQ_STATE_ESTABLISHED,
QDIO_IRQ_STATE_ACTIVE,
QDIO_IRQ_STATE_STOPPED,
QDIO_IRQ_STATE_CLEANUP,
QDIO_IRQ_STATE_ERR,
NR_QDIO_IRQ_STATES,
};
/* used as intparm in do_IO */
#define QDIO_DOING_ESTABLISH 1
#define QDIO_DOING_ACTIVATE 2
#define QDIO_DOING_CLEANUP 3
#define SLSB_STATE_NOT_INIT 0x0
#define SLSB_STATE_EMPTY 0x1
#define SLSB_STATE_PRIMED 0x2
#define SLSB_STATE_PENDING 0x3
#define SLSB_STATE_HALTED 0xe
#define SLSB_STATE_ERROR 0xf
#define SLSB_TYPE_INPUT 0x0
#define SLSB_TYPE_OUTPUT 0x20
#define SLSB_OWNER_PROG 0x80
#define SLSB_OWNER_CU 0x40
#define SLSB_P_INPUT_NOT_INIT \
(SLSB_OWNER_PROG | SLSB_TYPE_INPUT | SLSB_STATE_NOT_INIT) /* 0x80 */
#define SLSB_P_INPUT_ACK \
(SLSB_OWNER_PROG | SLSB_TYPE_INPUT | SLSB_STATE_EMPTY) /* 0x81 */
#define SLSB_CU_INPUT_EMPTY \
(SLSB_OWNER_CU | SLSB_TYPE_INPUT | SLSB_STATE_EMPTY) /* 0x41 */
#define SLSB_P_INPUT_PRIMED \
(SLSB_OWNER_PROG | SLSB_TYPE_INPUT | SLSB_STATE_PRIMED) /* 0x82 */
#define SLSB_P_INPUT_HALTED \
(SLSB_OWNER_PROG | SLSB_TYPE_INPUT | SLSB_STATE_HALTED) /* 0x8e */
#define SLSB_P_INPUT_ERROR \
(SLSB_OWNER_PROG | SLSB_TYPE_INPUT | SLSB_STATE_ERROR) /* 0x8f */
#define SLSB_P_OUTPUT_NOT_INIT \
(SLSB_OWNER_PROG | SLSB_TYPE_OUTPUT | SLSB_STATE_NOT_INIT) /* 0xa0 */
#define SLSB_P_OUTPUT_EMPTY \
(SLSB_OWNER_PROG | SLSB_TYPE_OUTPUT | SLSB_STATE_EMPTY) /* 0xa1 */
#define SLSB_P_OUTPUT_PENDING \
(SLSB_OWNER_PROG | SLSB_TYPE_OUTPUT | SLSB_STATE_PENDING) /* 0xa3 */
#define SLSB_CU_OUTPUT_PRIMED \
(SLSB_OWNER_CU | SLSB_TYPE_OUTPUT | SLSB_STATE_PRIMED) /* 0x62 */
#define SLSB_P_OUTPUT_HALTED \
(SLSB_OWNER_PROG | SLSB_TYPE_OUTPUT | SLSB_STATE_HALTED) /* 0xae */
#define SLSB_P_OUTPUT_ERROR \
(SLSB_OWNER_PROG | SLSB_TYPE_OUTPUT | SLSB_STATE_ERROR) /* 0xaf */
#define SLSB_ERROR_DURING_LOOKUP 0xff
/* additional CIWs returned by extended Sense-ID */
#define CIW_TYPE_EQUEUE 0x3 /* establish QDIO queues */
#define CIW_TYPE_AQUEUE 0x4 /* activate QDIO queues */
/* flags for st qdio sch data */
#define CHSC_FLAG_QDIO_CAPABILITY 0x80
#define CHSC_FLAG_VALIDITY 0x40
/* SIGA flags */
#define QDIO_SIGA_WRITE 0x00
#define QDIO_SIGA_READ 0x01
#define QDIO_SIGA_SYNC 0x02
#define QDIO_SIGA_WRITEM 0x03
#define QDIO_SIGA_WRITEQ 0x04
#define QDIO_SIGA_QEBSM_FLAG 0x80
static inline int do_sqbs(u64 token, unsigned char state, int queue,
int *start, int *count)
{
register unsigned long _ccq asm ("0") = *count;
register unsigned long _token asm ("1") = token;
unsigned long _queuestart = ((unsigned long)queue << 32) | *start;
asm volatile(
" .insn rsy,0xeb000000008A,%1,0,0(%2)"
: "+d" (_ccq), "+d" (_queuestart)
: "d" ((unsigned long)state), "d" (_token)
: "memory", "cc");
*count = _ccq & 0xff;
*start = _queuestart & 0xff;
return (_ccq >> 32) & 0xff;
}
static inline int do_eqbs(u64 token, unsigned char *state, int queue,
int *start, int *count, int ack)
{
register unsigned long _ccq asm ("0") = *count;
register unsigned long _token asm ("1") = token;
unsigned long _queuestart = ((unsigned long)queue << 32) | *start;
unsigned long _state = (unsigned long)ack << 63;
asm volatile(
" .insn rrf,0xB99c0000,%1,%2,0,0"
: "+d" (_ccq), "+d" (_queuestart), "+d" (_state)
: "d" (_token)
: "memory", "cc");
*count = _ccq & 0xff;
*start = _queuestart & 0xff;
*state = _state & 0xff;
return (_ccq >> 32) & 0xff;
}
struct qdio_irq;
struct siga_flag {
u8 input:1;
u8 output:1;
u8 sync:1;
u8 sync_after_ai:1;
u8 sync_out_after_pci:1;
u8:3;
} __attribute__ ((packed));
struct qdio_dev_perf_stat {
unsigned int adapter_int;
unsigned int qdio_int;
unsigned int pci_request_int;
unsigned int tasklet_inbound;
unsigned int tasklet_inbound_resched;
unsigned int tasklet_inbound_resched2;
unsigned int tasklet_outbound;
unsigned int siga_read;
unsigned int siga_write;
unsigned int siga_sync;
unsigned int inbound_call;
unsigned int inbound_handler;
unsigned int stop_polling;
unsigned int inbound_queue_full;
unsigned int outbound_call;
unsigned int outbound_handler;
unsigned int outbound_queue_full;
unsigned int fast_requeue;
unsigned int target_full;
unsigned int eqbs;
unsigned int eqbs_partial;
unsigned int sqbs;
unsigned int sqbs_partial;
unsigned int int_discarded;
} ____cacheline_aligned;
struct qdio_queue_perf_stat {
/*
* Sorted into order-2 buckets: 1, 2-3, 4-7, ... 64-127, 128.
* Since max. 127 SBALs are scanned reuse entry for 128 as queue full
* aka 127 SBALs found.
*/
unsigned int nr_sbals[8];
unsigned int nr_sbal_error;
unsigned int nr_sbal_nop;
unsigned int nr_sbal_total;
};
enum qdio_irq_poll_states {
QDIO_IRQ_DISABLED,
};
struct qdio_input_q {
/* first ACK'ed buffer */
int ack_start;
/* how many SBALs are acknowledged */
int ack_count;
/* last time of noticing incoming data */
u64 timestamp;
};
struct qdio_output_q {
/* PCIs are enabled for the queue */
int pci_out_enabled;
/* cq: use asynchronous output buffers */
int use_cq;
/* cq: aobs used for particual SBAL */
struct qaob **aobs;
/* cq: sbal state related to asynchronous operation */
struct qdio_outbuf_state *sbal_state;
/* timer to check for more outbound work */
struct timer_list timer;
};
/*
* Note on cache alignment: grouped slsb and write mostly data at the beginning
* sbal[] is read-only and starts on a new cacheline followed by read mostly.
*/
struct qdio_q {
struct slsb slsb;
union {
struct qdio_input_q in;
struct qdio_output_q out;
} u;
/*
* inbound: next buffer the program should check for
* outbound: next buffer to check if adapter processed it
*/
int first_to_check;
/* beginning position for calling the program */
int first_to_kick;
/* number of buffers in use by the adapter */
atomic_t nr_buf_used;
/* error condition during a data transfer */
unsigned int qdio_error;
/* last scan of the queue */
u64 timestamp;
struct tasklet_struct tasklet;
struct qdio_queue_perf_stat q_stats;
struct qdio_buffer *sbal[QDIO_MAX_BUFFERS_PER_Q] ____cacheline_aligned;
/* queue number */
int nr;
/* bitmask of queue number */
int mask;
/* input or output queue */
int is_input_q;
/* upper-layer program handler */
qdio_handler_t (*handler);
struct qdio_irq *irq_ptr;
struct sl *sl;
/*
* A page is allocated under this pointer and used for slib and sl.
* slib is 2048 bytes big and sl points to offset PAGE_SIZE / 2.
*/
struct slib *slib;
} __attribute__ ((aligned(256)));
struct qdio_irq {
struct qib qib;
u32 *dsci; /* address of device state change indicator */
struct ccw_device *cdev;
struct list_head entry; /* list of thinint devices */
struct dentry *debugfs_dev;
unsigned long int_parm;
struct subchannel_id schid;
unsigned long sch_token; /* QEBSM facility */
enum qdio_irq_states state;
struct siga_flag siga_flag; /* siga sync information from qdioac */
int nr_input_qs;
int nr_output_qs;
struct ccw1 ccw;
struct ciw equeue;
struct ciw aqueue;
struct qdio_ssqd_desc ssqd_desc;
void (*orig_handler) (struct ccw_device *, unsigned long, struct irb *);
unsigned int scan_threshold; /* used SBALs before tasklet schedule */
int perf_stat_enabled;
struct qdr *qdr;
unsigned long chsc_page;
struct qdio_q *input_qs[QDIO_MAX_QUEUES_PER_IRQ];
struct qdio_q *output_qs[QDIO_MAX_QUEUES_PER_IRQ];
void (*irq_poll)(struct ccw_device *cdev, unsigned long data);
unsigned long poll_state;
debug_info_t *debug_area;
struct mutex setup_mutex;
struct qdio_dev_perf_stat perf_stat;
};
/* helper functions */
#define queue_type(q) q->irq_ptr->qib.qfmt
#define SCH_NO(q) (q->irq_ptr->schid.sch_no)
#define is_thinint_irq(irq) \
(irq->qib.qfmt == QDIO_IQDIO_QFMT || \
css_general_characteristics.aif_osa)
#define qperf(__qdev, __attr) ((__qdev)->perf_stat.(__attr))
#define QDIO_PERF_STAT_INC(__irq, __attr) \
({ \
struct qdio_irq *qdev = __irq; \
if (qdev->perf_stat_enabled) \
(qdev->perf_stat.__attr)++; \
})
#define qperf_inc(__q, __attr) QDIO_PERF_STAT_INC((__q)->irq_ptr, __attr)
static inline void account_sbals_error(struct qdio_q *q, int count)
{
q->q_stats.nr_sbal_error += count;
q->q_stats.nr_sbal_total += count;
}
/* the highest iqdio queue is used for multicast */
static inline int multicast_outbound(struct qdio_q *q)
{
return (q->irq_ptr->nr_output_qs > 1) &&
(q->nr == q->irq_ptr->nr_output_qs - 1);
}
#define pci_out_supported(irq) ((irq)->qib.ac & QIB_AC_OUTBOUND_PCI_SUPPORTED)
#define is_qebsm(q) (q->irq_ptr->sch_token != 0)
#define need_siga_in(q) (q->irq_ptr->siga_flag.input)
#define need_siga_out(q) (q->irq_ptr->siga_flag.output)
#define need_siga_sync(q) (unlikely(q->irq_ptr->siga_flag.sync))
#define need_siga_sync_after_ai(q) \
(unlikely(q->irq_ptr->siga_flag.sync_after_ai))
#define need_siga_sync_out_after_pci(q) \
(unlikely(q->irq_ptr->siga_flag.sync_out_after_pci))
#define for_each_input_queue(irq_ptr, q, i) \
for (i = 0; i < irq_ptr->nr_input_qs && \
({ q = irq_ptr->input_qs[i]; 1; }); i++)
#define for_each_output_queue(irq_ptr, q, i) \
for (i = 0; i < irq_ptr->nr_output_qs && \
({ q = irq_ptr->output_qs[i]; 1; }); i++)
#define add_buf(bufnr, inc) QDIO_BUFNR((bufnr) + (inc))
#define next_buf(bufnr) add_buf(bufnr, 1)
#define sub_buf(bufnr, dec) QDIO_BUFNR((bufnr) - (dec))
#define prev_buf(bufnr) sub_buf(bufnr, 1)
#define queue_irqs_enabled(q) \
(test_bit(QDIO_QUEUE_IRQS_DISABLED, &q->u.in.queue_irq_state) == 0)
#define queue_irqs_disabled(q) \
(test_bit(QDIO_QUEUE_IRQS_DISABLED, &q->u.in.queue_irq_state) != 0)
extern u64 last_ai_time;
/* prototypes for thin interrupt */
void qdio_setup_thinint(struct qdio_irq *irq_ptr);
int qdio_establish_thinint(struct qdio_irq *irq_ptr);
void qdio_shutdown_thinint(struct qdio_irq *irq_ptr);
void tiqdio_add_device(struct qdio_irq *irq_ptr);
void tiqdio_remove_device(struct qdio_irq *irq_ptr);
void tiqdio_inbound_processing(unsigned long q);
int tiqdio_allocate_memory(void);
void tiqdio_free_memory(void);
int tiqdio_register_thinints(void);
void tiqdio_unregister_thinints(void);
int test_nonshared_ind(struct qdio_irq *);
/* prototypes for setup */
void qdio_inbound_processing(unsigned long data);
void qdio_outbound_processing(unsigned long data);
void qdio_outbound_timer(struct timer_list *t);
void qdio_int_handler(struct ccw_device *cdev, unsigned long intparm,
struct irb *irb);
int qdio_allocate_qs(struct qdio_irq *irq_ptr, int nr_input_qs,
int nr_output_qs);
void qdio_setup_ssqd_info(struct qdio_irq *irq_ptr);
int qdio_setup_get_ssqd(struct qdio_irq *irq_ptr,
struct subchannel_id *schid,
struct qdio_ssqd_desc *data);
int qdio_setup_irq(struct qdio_irq *irq_ptr, struct qdio_initialize *init_data);
void qdio_print_subchannel_info(struct qdio_irq *irq_ptr);
void qdio_release_memory(struct qdio_irq *irq_ptr);
int qdio_setup_init(void);
void qdio_setup_exit(void);
int qdio_enable_async_operation(struct qdio_output_q *q);
void qdio_disable_async_operation(struct qdio_output_q *q);
struct qaob *qdio_allocate_aob(void);
int debug_get_buf_state(struct qdio_q *q, unsigned int bufnr,
unsigned char *state);
#endif /* _CIO_QDIO_H */
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