diff options
Diffstat (limited to 'arch/powerpc/kernel/sysfs.c')
| -rw-r--r-- | arch/powerpc/kernel/sysfs.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c index fa1fd8a0c867..692873bff334 100644 --- a/arch/powerpc/kernel/sysfs.c +++ b/arch/powerpc/kernel/sysfs.c @@ -496,13 +496,34 @@ static DEVICE_ATTR(spurr, 0400, show_spurr, NULL); static DEVICE_ATTR(purr, 0400, show_purr, store_purr); static DEVICE_ATTR(pir, 0400, show_pir, NULL); +/* + * This is the system wide DSCR register default value. Any + * change to this default value through the sysfs interface + * will update all per cpu DSCR default values across the + * system stored in their respective PACA structures. + */ static unsigned long dscr_default; +/** + * read_dscr() - Fetch the cpu specific DSCR default + * @val: Returned cpu specific DSCR default value + * + * This function returns the per cpu DSCR default value + * for any cpu which is contained in it's PACA structure. + */ static void read_dscr(void *val) { *(unsigned long *)val = get_paca()->dscr_default; } + +/** + * write_dscr() - Update the cpu specific DSCR default + * @val: New cpu specific DSCR default value to update + * + * This function updates the per cpu DSCR default value + * for any cpu which is contained in it's PACA structure. + */ static void write_dscr(void *val) { get_paca()->dscr_default = *(unsigned long *)val; @@ -520,12 +541,29 @@ static void add_write_permission_dev_attr(struct device_attribute *attr) attr->attr.mode |= 0200; } +/** + * show_dscr_default() - Fetch the system wide DSCR default + * @dev: Device structure + * @attr: Device attribute structure + * @buf: Interface buffer + * + * This function returns the system wide DSCR default value. + */ static ssize_t show_dscr_default(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "%lx\n", dscr_default); } +/** + * store_dscr_default() - Update the system wide DSCR default + * @dev: Device structure + * @attr: Device attribute structure + * @buf: Interface buffer + * @count: Size of the update + * + * This function updates the system wide DSCR default value. + */ static ssize_t __used store_dscr_default(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |