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s390/sclp: Add timeout to Store Data requests

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Due to a bug in some firmware versions, Store Data requests might not
get an event response in certain situations. As a result, the boot
process will be blocked indefinitely.

Fix this by introducing timeout handling for Store Data requests. In
case a timeout occurs, the Store Data operation is halted and no data
is retrieved from the SCLP facility.

Note: A minority of installed systems rely on Store Data result for
device auto-configuration. These systems will fail to boot in case of a
Store Data timeout and will need to be switched to manual device
configuration as workaround.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Peter Oberparleiter 2024-06-20 14:20:28 +02:00 committed by Alexander Gordeev
parent bf365071ea
commit bb748badfd
1 changed files with 10 additions and 4 deletions
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14
drivers/s390/char/sclp_sd.c
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@ -9,6 +9,7 @@
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/completion.h>
#include <linux/jiffies.h>
#include <linux/kobject.h>
#include <linux/list.h>
#include <linux/printk.h>
@ -28,6 +29,8 @@
#define SD_DI_CONFIG 3
#define SD_TIMEOUT msecs_to_jiffies(30000)
struct sclp_sd_evbuf {
struct evbuf_header hdr;
u8 eq;
@ -234,9 +237,12 @@ static int sclp_sd_sync(unsigned long page, u8 eq, u8 di, u64 sat, u64 sa,
goto out;
}
if (!(evbuf->rflags & 0x80)) {
rc = wait_for_completion_interruptible(&listener.completion);
if (rc)
rc = wait_for_completion_interruptible_timeout(&listener.completion, SD_TIMEOUT);
if (rc == 0)
rc = -ETIME;
if (rc < 0)
goto out;
rc = 0;
evbuf = &listener.evbuf;
}
switch (evbuf->status) {
@ -323,8 +329,8 @@ static int sclp_sd_store_data(struct sclp_sd_data *result, u8 di)
rc = sclp_sd_sync(page, SD_EQ_STORE_DATA, di, asce, (u64) data, &dsize,
&esize);
if (rc) {
/* Cancel running request if interrupted */
if (rc == -ERESTARTSYS) {
/* Cancel running request if interrupted or timed out */
if (rc == -ERESTARTSYS || rc == -ETIME) {
if (sclp_sd_sync(page, SD_EQ_HALT, di, 0, 0, NULL, NULL)) {
pr_warn("Could not stop Store Data request - leaking at least %zu bytes\n",
(size_t)dsize * PAGE_SIZE);