[PATCH] genirq/irqdesc: Use sysfs_emit in the <foo>_show functions
From: Joe Perches
Date: Tue Aug 10 2021 - 13:59:58 EST
Convert the nominally unbounded sprintf output to use sysfs_emit and the
scnprintf uses to sysfs_emit_at.
Miscellanea:
o sysfs_emit: Use the more common int len not ssize_t ret
o hwirq_show: Add a minimum newline output when irq_data.domain is not set
and remove an unnecessary cast of an unsigned long to int ("%d" -> "%lu)
o name_show: Add a minimum newline output when desc->name is not set
trivially reduces object size (x86-64 defconfig, gcc 10.3)
$ size kernel/irq/irqdesc.o*
text data bss dec hex filename
5809 576 1608 7993 1f39 kernel/irq/irqdesc.o.new
5896 576 1608 8080 1f90 kernel/irq/irqdesc.o.old
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
kernel/irq/irqdesc.c | 65 ++++++++++++++++++++++++++--------------------------
1 file changed, 32 insertions(+), 33 deletions(-)
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index fadb937660202..8d47b8667c989 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -147,19 +147,20 @@ static ssize_t per_cpu_count_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
- ssize_t ret = 0;
- char *p = "";
+ int len = 0;
+ const char *p = "";
int cpu;
for_each_possible_cpu(cpu) {
unsigned int c = irq_desc_kstat_cpu(desc, cpu);
- ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
+ len += sysfs_emit_at(buf, len, "%s%u", p, c);
p = ",";
}
- ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
- return ret;
+ len += sysfs_emit_at(buf, len, "\n");
+
+ return len;
}
IRQ_ATTR_RO(per_cpu_count);
@@ -167,16 +168,15 @@ static ssize_t chip_name_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
- ssize_t ret = 0;
+ int len = 0;
raw_spin_lock_irq(&desc->lock);
- if (desc->irq_data.chip && desc->irq_data.chip->name) {
- ret = scnprintf(buf, PAGE_SIZE, "%s\n",
- desc->irq_data.chip->name);
- }
+ len = sysfs_emit(buf, "%s\n",
+ desc->irq_data.chip && desc->irq_data.chip->name ?
+ desc->irq_data.chip->name : "");
raw_spin_unlock_irq(&desc->lock);
- return ret;
+ return len;
}
IRQ_ATTR_RO(chip_name);
@@ -184,14 +184,16 @@ static ssize_t hwirq_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
- ssize_t ret = 0;
+ int len = 0;
raw_spin_lock_irq(&desc->lock);
if (desc->irq_data.domain)
- ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
+ len = sysfs_emit(buf, "%lu\n", desc->irq_data.hwirq);
+ else
+ len = sysfs_emit(buf, "\n");
raw_spin_unlock_irq(&desc->lock);
- return ret;
+ return len;
}
IRQ_ATTR_RO(hwirq);
@@ -199,14 +201,14 @@ static ssize_t type_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
- ssize_t ret = 0;
+ int len = 0;
raw_spin_lock_irq(&desc->lock);
- ret = sprintf(buf, "%s\n",
- irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
+ len = sysfs_emit(buf, "%s\n",
+ irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
raw_spin_unlock_irq(&desc->lock);
- return ret;
+ return len;
}
IRQ_ATTR_RO(type);
@@ -215,14 +217,14 @@ static ssize_t wakeup_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
- ssize_t ret = 0;
+ int len = 0;
raw_spin_lock_irq(&desc->lock);
- ret = sprintf(buf, "%s\n",
- irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
+ len = sysfs_emit(buf, "%s\n",
+ irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
raw_spin_unlock_irq(&desc->lock);
- return ret;
+ return len;
}
IRQ_ATTR_RO(wakeup);
@@ -231,14 +233,13 @@ static ssize_t name_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
- ssize_t ret = 0;
+ int len = 0;
raw_spin_lock_irq(&desc->lock);
- if (desc->name)
- ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
+ len = sysfs_emit(buf, "%s\n", desc->name ?: "");
raw_spin_unlock_irq(&desc->lock);
- return ret;
+ return len;
}
IRQ_ATTR_RO(name);
@@ -247,21 +248,19 @@ static ssize_t actions_show(struct kobject *kobj,
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
struct irqaction *action;
- ssize_t ret = 0;
- char *p = "";
+ int len = 0;
+ const char *p = "";
raw_spin_lock_irq(&desc->lock);
for (action = desc->action; action != NULL; action = action->next) {
- ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
- p, action->name);
+ len += sysfs_emit_at(buf, len, "%s%s", p, action->name);
p = ",";
}
raw_spin_unlock_irq(&desc->lock);
- if (ret)
- ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
+ len += sysfs_emit_at(buf, len, "\n");
- return ret;
+ return len;
}
IRQ_ATTR_RO(actions);