linux/drivers/s390/char/sclp_sdias.c
Michael Holzheu e206d3da58 s390/sclp_sdias: Add missing break and "fall through"
If the last block of the HSA is read, EVSTATE_ALL_STORED is returned
by SCLP. Because of a missing break in the switch statement two trace
entries are written in this case: "all stored" and "part stored".

This patch adds the missing break and also adds a "fall through"
comment to improve the readability.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reported-by: David A Gilbert <DavidAGilbert@uk.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-08-08 07:32:55 -07:00

316 lines
7.1 KiB
C

/*
* Sclp "store data in absolut storage"
*
* Copyright IBM Corp. 2003, 2007
* Author(s): Michael Holzheu
*/
#define KMSG_COMPONENT "sclp_sdias"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/completion.h>
#include <linux/sched.h>
#include <asm/sclp.h>
#include <asm/debug.h>
#include <asm/ipl.h>
#include "sclp.h"
#include "sclp_rw.h"
#define TRACE(x...) debug_sprintf_event(sdias_dbf, 1, x)
#define SDIAS_RETRIES 300
#define SDIAS_SLEEP_TICKS 50
#define EQ_STORE_DATA 0x0
#define EQ_SIZE 0x1
#define DI_FCP_DUMP 0x0
#define ASA_SIZE_32 0x0
#define ASA_SIZE_64 0x1
#define EVSTATE_ALL_STORED 0x0
#define EVSTATE_NO_DATA 0x3
#define EVSTATE_PART_STORED 0x10
static struct debug_info *sdias_dbf;
static struct sclp_register sclp_sdias_register = {
.send_mask = EVTYP_SDIAS_MASK,
};
struct sdias_evbuf {
struct evbuf_header hdr;
u8 event_qual;
u8 data_id;
u64 reserved2;
u32 event_id;
u16 reserved3;
u8 asa_size;
u8 event_status;
u32 reserved4;
u32 blk_cnt;
u64 asa;
u32 reserved5;
u32 fbn;
u32 reserved6;
u32 lbn;
u16 reserved7;
u16 dbs;
} __attribute__((packed));
struct sdias_sccb {
struct sccb_header hdr;
struct sdias_evbuf evbuf;
} __attribute__((packed));
static struct sdias_sccb sccb __attribute__((aligned(4096)));
static struct sdias_evbuf sdias_evbuf;
static DECLARE_COMPLETION(evbuf_accepted);
static DECLARE_COMPLETION(evbuf_done);
static DEFINE_MUTEX(sdias_mutex);
/*
* Called by SCLP base when read event data has been completed (async mode only)
*/
static void sclp_sdias_receiver_fn(struct evbuf_header *evbuf)
{
memcpy(&sdias_evbuf, evbuf,
min_t(unsigned long, sizeof(sdias_evbuf), evbuf->length));
complete(&evbuf_done);
TRACE("sclp_sdias_receiver_fn done\n");
}
/*
* Called by SCLP base when sdias event has been accepted
*/
static void sdias_callback(struct sclp_req *request, void *data)
{
complete(&evbuf_accepted);
TRACE("callback done\n");
}
static int sdias_sclp_send(struct sclp_req *req)
{
int retries;
int rc;
for (retries = SDIAS_RETRIES; retries; retries--) {
TRACE("add request\n");
rc = sclp_add_request(req);
if (rc) {
/* not initiated, wait some time and retry */
set_current_state(TASK_INTERRUPTIBLE);
TRACE("add request failed: rc = %i\n",rc);
schedule_timeout(SDIAS_SLEEP_TICKS);
continue;
}
/* initiated, wait for completion of service call */
wait_for_completion(&evbuf_accepted);
if (req->status == SCLP_REQ_FAILED) {
TRACE("sclp request failed\n");
continue;
}
/* if not accepted, retry */
if (!(sccb.evbuf.hdr.flags & 0x80)) {
TRACE("sclp request failed: flags=%x\n",
sccb.evbuf.hdr.flags);
continue;
}
/*
* for the sync interface the response is in the initial sccb
*/
if (!sclp_sdias_register.receiver_fn) {
memcpy(&sdias_evbuf, &sccb.evbuf, sizeof(sdias_evbuf));
TRACE("sync request done\n");
return 0;
}
/* otherwise we wait for completion */
wait_for_completion(&evbuf_done);
TRACE("request done\n");
return 0;
}
return -EIO;
}
/*
* Get number of blocks (4K) available in the HSA
*/
int sclp_sdias_blk_count(void)
{
struct sclp_req request;
int rc;
mutex_lock(&sdias_mutex);
memset(&sccb, 0, sizeof(sccb));
memset(&request, 0, sizeof(request));
sccb.hdr.length = sizeof(sccb);
sccb.evbuf.hdr.length = sizeof(struct sdias_evbuf);
sccb.evbuf.hdr.type = EVTYP_SDIAS;
sccb.evbuf.event_qual = EQ_SIZE;
sccb.evbuf.data_id = DI_FCP_DUMP;
sccb.evbuf.event_id = 4712;
sccb.evbuf.dbs = 1;
request.sccb = &sccb;
request.command = SCLP_CMDW_WRITE_EVENT_DATA;
request.status = SCLP_REQ_FILLED;
request.callback = sdias_callback;
rc = sdias_sclp_send(&request);
if (rc) {
pr_err("sclp_send failed for get_nr_blocks\n");
goto out;
}
if (sccb.hdr.response_code != 0x0020) {
TRACE("send failed: %x\n", sccb.hdr.response_code);
rc = -EIO;
goto out;
}
switch (sdias_evbuf.event_status) {
case 0:
rc = sdias_evbuf.blk_cnt;
break;
default:
pr_err("SCLP error: %x\n", sdias_evbuf.event_status);
rc = -EIO;
goto out;
}
TRACE("%i blocks\n", rc);
out:
mutex_unlock(&sdias_mutex);
return rc;
}
/*
* Copy from HSA to absolute storage (not reentrant):
*
* @dest : Address of buffer where data should be copied
* @start_blk: Start Block (beginning with 1)
* @nr_blks : Number of 4K blocks to copy
*
* Return Value: 0 : Requested 'number' of blocks of data copied
* <0: ERROR - negative event status
*/
int sclp_sdias_copy(void *dest, int start_blk, int nr_blks)
{
struct sclp_req request;
int rc;
mutex_lock(&sdias_mutex);
memset(&sccb, 0, sizeof(sccb));
memset(&request, 0, sizeof(request));
sccb.hdr.length = sizeof(sccb);
sccb.evbuf.hdr.length = sizeof(struct sdias_evbuf);
sccb.evbuf.hdr.type = EVTYP_SDIAS;
sccb.evbuf.hdr.flags = 0;
sccb.evbuf.event_qual = EQ_STORE_DATA;
sccb.evbuf.data_id = DI_FCP_DUMP;
sccb.evbuf.event_id = 4712;
#ifdef CONFIG_64BIT
sccb.evbuf.asa_size = ASA_SIZE_64;
#else
sccb.evbuf.asa_size = ASA_SIZE_32;
#endif
sccb.evbuf.event_status = 0;
sccb.evbuf.blk_cnt = nr_blks;
sccb.evbuf.asa = (unsigned long)dest;
sccb.evbuf.fbn = start_blk;
sccb.evbuf.lbn = 0;
sccb.evbuf.dbs = 1;
request.sccb = &sccb;
request.command = SCLP_CMDW_WRITE_EVENT_DATA;
request.status = SCLP_REQ_FILLED;
request.callback = sdias_callback;
rc = sdias_sclp_send(&request);
if (rc) {
pr_err("sclp_send failed: %x\n", rc);
goto out;
}
if (sccb.hdr.response_code != 0x0020) {
TRACE("copy failed: %x\n", sccb.hdr.response_code);
rc = -EIO;
goto out;
}
switch (sdias_evbuf.event_status) {
case EVSTATE_ALL_STORED:
TRACE("all stored\n");
break;
case EVSTATE_PART_STORED:
TRACE("part stored: %i\n", sdias_evbuf.blk_cnt);
break;
case EVSTATE_NO_DATA:
TRACE("no data\n");
/* fall through */
default:
pr_err("Error from SCLP while copying hsa. "
"Event status = %x\n",
sdias_evbuf.event_status);
rc = -EIO;
}
out:
mutex_unlock(&sdias_mutex);
return rc;
}
static int __init sclp_sdias_register_check(void)
{
int rc;
rc = sclp_register(&sclp_sdias_register);
if (rc)
return rc;
if (sclp_sdias_blk_count() == 0) {
sclp_unregister(&sclp_sdias_register);
return -ENODEV;
}
return 0;
}
static int __init sclp_sdias_init_sync(void)
{
TRACE("Try synchronous mode\n");
sclp_sdias_register.receive_mask = 0;
sclp_sdias_register.receiver_fn = NULL;
return sclp_sdias_register_check();
}
static int __init sclp_sdias_init_async(void)
{
TRACE("Try asynchronous mode\n");
sclp_sdias_register.receive_mask = EVTYP_SDIAS_MASK;
sclp_sdias_register.receiver_fn = sclp_sdias_receiver_fn;
return sclp_sdias_register_check();
}
int __init sclp_sdias_init(void)
{
if (ipl_info.type != IPL_TYPE_FCP_DUMP)
return 0;
sdias_dbf = debug_register("dump_sdias", 4, 1, 4 * sizeof(long));
debug_register_view(sdias_dbf, &debug_sprintf_view);
debug_set_level(sdias_dbf, 6);
if (sclp_sdias_init_sync() == 0)
goto out;
if (sclp_sdias_init_async() == 0)
goto out;
TRACE("init failed\n");
return -ENODEV;
out:
TRACE("init done\n");
return 0;
}
void __exit sclp_sdias_exit(void)
{
debug_unregister(sdias_dbf);
sclp_unregister(&sclp_sdias_register);
}