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authorSebastian Ott <sebott@linux.vnet.ibm.com>2015-04-10 14:34:33 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2015-04-15 12:23:53 +0200
commit80ed156a3d12819a8c839f40f5b6996c4aa117a5 (patch)
treee7cc5c5e155456168ed80b1f0f69205c2d6cc437 /arch/s390/pci
parent6001018ae8c659e624351d2e73b1272bacd68d6a (diff)
downloadlinux-80ed156a3d12819a8c839f40f5b6996c4aa117a5.tar.bz2
s390/pci: add locking for fmb access
Function measurement can be toggled at runtime. Make sure that all access to the fmb is protected via a mutex. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/pci')
-rw-r--r--arch/s390/pci/pci.c1
-rw-r--r--arch/s390/pci/pci_debug.c15
2 files changed, 10 insertions, 6 deletions
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 281893864e1b..598f023cf8a6 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -827,6 +827,7 @@ int zpci_create_device(struct zpci_dev *zdev)
if (rc)
goto out;
+ mutex_init(&zdev->lock);
if (zdev->state == ZPCI_FN_STATE_CONFIGURED) {
rc = zpci_enable_device(zdev);
if (rc)
diff --git a/arch/s390/pci/pci_debug.c b/arch/s390/pci/pci_debug.c
index 97db1a411d54..3fc9b4d90b59 100644
--- a/arch/s390/pci/pci_debug.c
+++ b/arch/s390/pci/pci_debug.c
@@ -58,8 +58,12 @@ static int pci_perf_show(struct seq_file *m, void *v)
if (!zdev)
return 0;
- if (!zdev->fmb)
+
+ mutex_lock(&zdev->lock);
+ if (!zdev->fmb) {
+ mutex_unlock(&zdev->lock);
return seq_printf(m, "FMB statistics disabled\n");
+ }
/* header */
seq_printf(m, "FMB @ %p\n", zdev->fmb);
@@ -78,6 +82,7 @@ static int pci_perf_show(struct seq_file *m, void *v)
pci_perf_names[i], *(stat + i));
pci_sw_counter_show(m);
+ mutex_unlock(&zdev->lock);
return 0;
}
@@ -95,19 +100,17 @@ static ssize_t pci_perf_seq_write(struct file *file, const char __user *ubuf,
if (rc)
return rc;
+ mutex_lock(&zdev->lock);
switch (val) {
case 0:
rc = zpci_fmb_disable_device(zdev);
- if (rc)
- return rc;
break;
case 1:
rc = zpci_fmb_enable_device(zdev);
- if (rc)
- return rc;
break;
}
- return count;
+ mutex_unlock(&zdev->lock);
+ return rc ? rc : count;
}
static int pci_perf_seq_open(struct inode *inode, struct file *filp)