[S390] cio: allow enable_facility from outside init functions
Prepare chsc_enable_facility to be used from outside init functions.
Use static memory for the chsc call and protect its access by a
spinlock (although there is no concurrent usage).
Cc: <stable@kernel.org>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 4038f5b4..ce7cb87 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -29,6 +29,7 @@
#include "chsc.h"
static void *sei_page;
+static DEFINE_SPINLOCK(sda_lock);
/**
* chsc_error_from_response() - convert a chsc response to an error
@@ -832,11 +833,10 @@
kfree(sei_page);
}
-int __init
-chsc_enable_facility(int operation_code)
+int chsc_enable_facility(int operation_code)
{
int ret;
- struct {
+ static struct {
struct chsc_header request;
u8 reserved1:4;
u8 format:4;
@@ -849,33 +849,32 @@
u32 reserved5:4;
u32 format2:4;
u32 reserved6:24;
- } __attribute__ ((packed)) *sda_area;
+ } __attribute__ ((packed, aligned(4096))) sda_area;
- sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
- if (!sda_area)
- return -ENOMEM;
- sda_area->request.length = 0x0400;
- sda_area->request.code = 0x0031;
- sda_area->operation_code = operation_code;
+ spin_lock(&sda_lock);
+ memset(&sda_area, 0, sizeof(sda_area));
+ sda_area.request.length = 0x0400;
+ sda_area.request.code = 0x0031;
+ sda_area.operation_code = operation_code;
- ret = chsc(sda_area);
+ ret = chsc(&sda_area);
if (ret > 0) {
ret = (ret == 3) ? -ENODEV : -EBUSY;
goto out;
}
- switch (sda_area->response.code) {
+ switch (sda_area.response.code) {
case 0x0101:
ret = -EOPNOTSUPP;
break;
default:
- ret = chsc_error_from_response(sda_area->response.code);
+ ret = chsc_error_from_response(sda_area.response.code);
}
if (ret != 0)
CIO_CRW_EVENT(2, "chsc: sda (oc=%x) failed (rc=%04x)\n",
- operation_code, sda_area->response.code);
+ operation_code, sda_area.response.code);
out:
- free_page((unsigned long)sda_area);
+ spin_unlock(&sda_lock);
return ret;
}
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 2769da5..19635d4 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -870,15 +870,10 @@
/* Try to enable MSS. */
ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
- switch (ret) {
- case 0: /* Success. */
- max_ssid = __MAX_SSID;
- break;
- case -ENOMEM:
- goto out;
- default:
+ if (ret)
max_ssid = 0;
- }
+ else /* Success. */
+ max_ssid = __MAX_SSID;
ret = slow_subchannel_init();
if (ret)