On Fri, Sep 25, 2020 at 05:47:23PM -0600, Shuah Khan wrote: > counter_atomic* is introduced to be used when a variable is used as > a simple counter and doesn't guard object lifetimes. This clearly > differentiates atomic_t usages that guard object lifetimes. > > counter_atomic* variables will wrap around to 0 when it overflows and > should not be used to guard resource lifetimes, device usage and > open counts that control state changes, and pm states. > > atomic_t variables used for stats are atomic counters. Overflow will > wrap around and reset the stats and no change with the conversion. > > Convert them to use counter_atomic32. > > Signed-off-by: Shuah Khan <sk...@linuxfoundation.org>
Reviewed-by: Corey Minyard <cminy...@mvista.com> I assume for this conversion that the plan is to eliminate atomic_t completely and convert all atomic counters used for object lifetime to struct kref? The new naming is certainly more clear and I'm happy with this change. -corey > --- > drivers/char/ipmi/ipmi_msghandler.c | 9 +++++---- > drivers/char/ipmi/ipmi_si_intf.c | 9 +++++---- > 2 files changed, 10 insertions(+), 8 deletions(-) > > diff --git a/drivers/char/ipmi/ipmi_msghandler.c > b/drivers/char/ipmi/ipmi_msghandler.c > index 737c0b6b24ea..36c0b1be22fb 100644 > --- a/drivers/char/ipmi/ipmi_msghandler.c > +++ b/drivers/char/ipmi/ipmi_msghandler.c > @@ -34,6 +34,7 @@ > #include <linux/uuid.h> > #include <linux/nospec.h> > #include <linux/vmalloc.h> > +#include <linux/counters.h> > > #define IPMI_DRIVER_VERSION "39.2" > > @@ -584,7 +585,7 @@ struct ipmi_smi { > struct ipmi_my_addrinfo addrinfo[IPMI_MAX_CHANNELS]; > bool channels_ready; > > - atomic_t stats[IPMI_NUM_STATS]; > + struct counter_atomic32 stats[IPMI_NUM_STATS]; > > /* > * run_to_completion duplicate of smb_info, smi_info > @@ -630,9 +631,9 @@ static LIST_HEAD(smi_watchers); > static DEFINE_MUTEX(smi_watchers_mutex); > > #define ipmi_inc_stat(intf, stat) \ > - atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat]) > + counter_atomic32_inc(&(intf)->stats[IPMI_STAT_ ## stat]) > #define ipmi_get_stat(intf, stat) \ > - ((unsigned int) atomic_read(&(intf)->stats[IPMI_STAT_ ## stat])) > + ((unsigned int) counter_atomic32_read(&(intf)->stats[IPMI_STAT_ ## > stat])) > > static const char * const addr_src_to_str[] = { > "invalid", "hotmod", "hardcoded", "SPMI", "ACPI", "SMBIOS", "PCI", > @@ -3448,7 +3449,7 @@ int ipmi_add_smi(struct module *owner, > INIT_LIST_HEAD(&intf->cmd_rcvrs); > init_waitqueue_head(&intf->waitq); > for (i = 0; i < IPMI_NUM_STATS; i++) > - atomic_set(&intf->stats[i], 0); > + counter_atomic32_set(&intf->stats[i], 0); > > mutex_lock(&ipmi_interfaces_mutex); > /* Look for a hole in the numbers. */ > diff --git a/drivers/char/ipmi/ipmi_si_intf.c > b/drivers/char/ipmi/ipmi_si_intf.c > index 77b8d551ae7f..0909a3461f05 100644 > --- a/drivers/char/ipmi/ipmi_si_intf.c > +++ b/drivers/char/ipmi/ipmi_si_intf.c > @@ -43,6 +43,7 @@ > #include "ipmi_si_sm.h" > #include <linux/string.h> > #include <linux/ctype.h> > +#include <linux/counters.h> > > /* Measure times between events in the driver. */ > #undef DEBUG_TIMING > @@ -237,7 +238,7 @@ struct smi_info { > bool dev_group_added; > > /* Counters and things for the proc filesystem. */ > - atomic_t stats[SI_NUM_STATS]; > + struct counter_atomic32 stats[SI_NUM_STATS]; > > struct task_struct *thread; > > @@ -245,9 +246,9 @@ struct smi_info { > }; > > #define smi_inc_stat(smi, stat) \ > - atomic_inc(&(smi)->stats[SI_STAT_ ## stat]) > + counter_atomic32_inc(&(smi)->stats[SI_STAT_ ## stat]) > #define smi_get_stat(smi, stat) \ > - ((unsigned int) atomic_read(&(smi)->stats[SI_STAT_ ## stat])) > + ((unsigned int) counter_atomic32_read(&(smi)->stats[SI_STAT_ ## stat])) > > #define IPMI_MAX_INTFS 4 > static int force_kipmid[IPMI_MAX_INTFS]; > @@ -2013,7 +2014,7 @@ static int try_smi_init(struct smi_info *new_smi) > atomic_set(&new_smi->req_events, 0); > new_smi->run_to_completion = false; > for (i = 0; i < SI_NUM_STATS; i++) > - atomic_set(&new_smi->stats[i], 0); > + counter_atomic32_set(&new_smi->stats[i], 0); > > new_smi->interrupt_disabled = true; > atomic_set(&new_smi->need_watch, 0); > -- > 2.25.1 >