To prepare for supporting boot-time page size selection, refactor code to remove assumptions about PAGE_SIZE being compile-time constant. Code intended to be equivalent when compile-time page size is active. Update BUILD_BUG_ON() to test against page size limits. CPUMAP_FILE_MAX_BYTES and CPULIST_FILE_MAX_BYTES are both defined relative to PAGE_SIZE, so when these values are assigned to global variables via BIN_ATTR_RO(), let's wrap them with DEFINE_GLOBAL_PAGE_SIZE_VAR() so that their assignment can be deferred until boot-time. Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx> --- ***NOTE*** Any confused maintainers may want to read the cover note here for context: https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@xxxxxxx/ drivers/base/node.c | 6 +++--- drivers/base/topology.c | 32 ++++++++++++++++---------------- include/linux/cpumask.h | 5 +++++ 3 files changed, 24 insertions(+), 19 deletions(-) diff --git a/drivers/base/node.c b/drivers/base/node.c index eb72580288e62..30e6549e4c438 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -45,7 +45,7 @@ static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj, return n; } -static BIN_ATTR_RO(cpumap, CPUMAP_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(cpumap, CPUMAP_FILE_MAX_BYTES); static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj, struct bin_attribute *attr, char *buf, @@ -66,7 +66,7 @@ static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj, return n; } -static BIN_ATTR_RO(cpulist, CPULIST_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(cpulist, CPULIST_FILE_MAX_BYTES); /** * struct node_access_nodes - Access class device to hold user visible @@ -558,7 +558,7 @@ static ssize_t node_read_distance(struct device *dev, * buf is currently PAGE_SIZE in length and each node needs 4 chars * at the most (distance + space or newline). */ - BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE); + BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE_MIN); for_each_online_node(i) { len += sysfs_emit_at(buf, len, "%s%d", diff --git a/drivers/base/topology.c b/drivers/base/topology.c index 89f98be5c5b99..bdbdbefd95b15 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -62,47 +62,47 @@ define_id_show_func(ppin, "0x%llx"); static DEVICE_ATTR_ADMIN_RO(ppin); define_siblings_read_func(thread_siblings, sibling_cpumask); -static BIN_ATTR_RO(thread_siblings, CPUMAP_FILE_MAX_BYTES); -static BIN_ATTR_RO(thread_siblings_list, CPULIST_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(thread_siblings, CPUMAP_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(thread_siblings_list, CPULIST_FILE_MAX_BYTES); define_siblings_read_func(core_cpus, sibling_cpumask); -static BIN_ATTR_RO(core_cpus, CPUMAP_FILE_MAX_BYTES); -static BIN_ATTR_RO(core_cpus_list, CPULIST_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(core_cpus, CPUMAP_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(core_cpus_list, CPULIST_FILE_MAX_BYTES); define_siblings_read_func(core_siblings, core_cpumask); -static BIN_ATTR_RO(core_siblings, CPUMAP_FILE_MAX_BYTES); -static BIN_ATTR_RO(core_siblings_list, CPULIST_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(core_siblings, CPUMAP_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(core_siblings_list, CPULIST_FILE_MAX_BYTES); #ifdef TOPOLOGY_CLUSTER_SYSFS define_siblings_read_func(cluster_cpus, cluster_cpumask); -static BIN_ATTR_RO(cluster_cpus, CPUMAP_FILE_MAX_BYTES); -static BIN_ATTR_RO(cluster_cpus_list, CPULIST_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(cluster_cpus, CPUMAP_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(cluster_cpus_list, CPULIST_FILE_MAX_BYTES); #endif #ifdef TOPOLOGY_DIE_SYSFS define_siblings_read_func(die_cpus, die_cpumask); -static BIN_ATTR_RO(die_cpus, CPUMAP_FILE_MAX_BYTES); -static BIN_ATTR_RO(die_cpus_list, CPULIST_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(die_cpus, CPUMAP_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(die_cpus_list, CPULIST_FILE_MAX_BYTES); #endif define_siblings_read_func(package_cpus, core_cpumask); -static BIN_ATTR_RO(package_cpus, CPUMAP_FILE_MAX_BYTES); -static BIN_ATTR_RO(package_cpus_list, CPULIST_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(package_cpus, CPUMAP_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(package_cpus_list, CPULIST_FILE_MAX_BYTES); #ifdef TOPOLOGY_BOOK_SYSFS define_id_show_func(book_id, "%d"); static DEVICE_ATTR_RO(book_id); define_siblings_read_func(book_siblings, book_cpumask); -static BIN_ATTR_RO(book_siblings, CPUMAP_FILE_MAX_BYTES); -static BIN_ATTR_RO(book_siblings_list, CPULIST_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(book_siblings, CPUMAP_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(book_siblings_list, CPULIST_FILE_MAX_BYTES); #endif #ifdef TOPOLOGY_DRAWER_SYSFS define_id_show_func(drawer_id, "%d"); static DEVICE_ATTR_RO(drawer_id); define_siblings_read_func(drawer_siblings, drawer_cpumask); -static BIN_ATTR_RO(drawer_siblings, CPUMAP_FILE_MAX_BYTES); -static BIN_ATTR_RO(drawer_siblings_list, CPULIST_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(drawer_siblings, CPUMAP_FILE_MAX_BYTES); +static CPU_FILE_BIN_ATTR_RO(drawer_siblings_list, CPULIST_FILE_MAX_BYTES); #endif static struct bin_attribute *bin_attrs[] = { diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 53158de44b837..f654b4198abc2 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -1292,4 +1292,9 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask, ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE) #define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE) +#define CPU_FILE_BIN_ATTR_RO(_name, _size) \ + DEFINE_GLOBAL_PAGE_SIZE_VAR(struct bin_attribute, \ + bin_attr_##_name, \ + __BIN_ATTR_RO(_name, _size)) + #endif /* __LINUX_CPUMASK_H */ -- 2.43.0
