From 60a866685006bae0c3db20e4bae31887eb452ff1 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 26 Jun 2018 06:49:08 -0300 Subject: gpio.h: fix location of gpio legacy documentation The location of this doc file was moved. Change its reference accordingly. Fixes: 7ee2c13080c9 ("Documentation: gpio: Move legacy documentation to driver-api") Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Jonathan Corbet --- include/linux/gpio.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 91ed23468530..39745b8bdd65 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -14,7 +14,7 @@ #include -/* see Documentation/gpio/gpio-legacy.txt */ +/* see Documentation/driver-api/gpio/legacy.rst */ /* make these flag values available regardless of GPIO kconfig options */ #define GPIOF_DIR_OUT (0 << 0) -- cgit v1.2.3 From 0e3fd810c4f41dbd63fb7caddc11684959176727 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 10 Jul 2018 16:46:41 +0200 Subject: Documentation: document ktime_get_*() APIs As Dave Chinner points out, we don't have a proper documentation for the ktime_get() family of interfaces, making it rather unclear which of the over 30 (!) interfaces one should actually use in a driver or elsewhere in the kernel. I wrote up an explanation from how I personally see the interfaces, documenting what each of the functions do and hopefully making it a bit clearer which should be used where. This is the first time I tried writing .rst format documentation, so in addition to any mistakes in the content, I probably also introduce nonstandard formatting ;-) I first tried to add an extra section to Documentation/timers/timekeeping.txt, but this is currently not included in the generated API, and it seems useful to have the API docs as part of what gets generated in https://www.kernel.org/doc/html/latest/core-api/index.html#core-utilities instead, so I started a new file there. I also considered adding the documentation inline in the include/linux/timekeeping.h header, but couldn't figure out how to do that in a way that would result both in helpful inline comments as well as readable html output, so I settled for the latter, with a small note pointing to it from the header. Cc: Dave Chinner Cc: John Stultz Cc: Thomas Gleixner Cc: Stephen Boyd Tested-by: Randy Dunlap Reviewed-by: Randy Dunlap Reviewed-by: Linus Walleij Signed-off-by: Arnd Bergmann Signed-off-by: Jonathan Corbet --- Documentation/core-api/index.rst | 1 + Documentation/core-api/timekeeping.rst | 185 +++++++++++++++++++++++++++++++++ include/linux/timekeeping.h | 15 +++ 3 files changed, 201 insertions(+) create mode 100644 Documentation/core-api/timekeeping.rst (limited to 'include/linux') diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst index f5a66b72f984..989c97cc232a 100644 --- a/Documentation/core-api/index.rst +++ b/Documentation/core-api/index.rst @@ -28,6 +28,7 @@ Core utilities printk-formats circular-buffers gfp_mask-from-fs-io + timekeeping Interfaces for kernel debugging =============================== diff --git a/Documentation/core-api/timekeeping.rst b/Documentation/core-api/timekeeping.rst new file mode 100644 index 000000000000..93cbeb9daec0 --- /dev/null +++ b/Documentation/core-api/timekeeping.rst @@ -0,0 +1,185 @@ +ktime accessors +=============== + +Device drivers can read the current time using ktime_get() and the many +related functions declared in linux/timekeeping.h. As a rule of thumb, +using an accessor with a shorter name is preferred over one with a longer +name if both are equally fit for a particular use case. + +Basic ktime_t based interfaces +------------------------------ + +The recommended simplest form returns an opaque ktime_t, with variants +that return time for different clock references: + + +.. c:function:: ktime_t ktime_get( void ) + + CLOCK_MONOTONIC + + Useful for reliable timestamps and measuring short time intervals + accurately. Starts at system boot time but stops during suspend. + +.. c:function:: ktime_t ktime_get_boottime( void ) + + CLOCK_BOOTTIME + + Like ktime_get(), but does not stop when suspended. This can be + used e.g. for key expiration times that need to be synchronized + with other machines across a suspend operation. + +.. c:function:: ktime_t ktime_get_real( void ) + + CLOCK_REALTIME + + Returns the time in relative to the UNIX epoch starting in 1970 + using the Coordinated Universal Time (UTC), same as gettimeofday() + user space. This is used for all timestamps that need to + persist across a reboot, like inode times, but should be avoided + for internal uses, since it can jump backwards due to a leap + second update, NTP adjustment settimeofday() operation from user + space. + +.. c:function:: ktime_t ktime_get_clocktai( void ) + + CLOCK_TAI + + Like ktime_get_real(), but uses the International Atomic Time (TAI) + reference instead of UTC to avoid jumping on leap second updates. + This is rarely useful in the kernel. + +.. c:function:: ktime_t ktime_get_raw( void ) + + CLOCK_MONOTONIC_RAW + + Like ktime_get(), but runs at the same rate as the hardware + clocksource without (NTP) adjustments for clock drift. This is + also rarely needed in the kernel. + +nanosecond, timespec64, and second output +----------------------------------------- + +For all of the above, there are variants that return the time in a +different format depending on what is required by the user: + +.. c:function:: u64 ktime_get_ns( void ) + u64 ktime_get_boottime_ns( void ) + u64 ktime_get_real_ns( void ) + u64 ktime_get_tai_ns( void ) + u64 ktime_get_raw_ns( void ) + + Same as the plain ktime_get functions, but returning a u64 number + of nanoseconds in the respective time reference, which may be + more convenient for some callers. + +.. c:function:: void ktime_get_ts64( struct timespec64 * ) + void ktime_get_boottime_ts64( struct timespec64 * ) + void ktime_get_real_ts64( struct timespec64 * ) + void ktime_get_clocktai_ts64( struct timespec64 * ) + void ktime_get_raw_ts64( struct timespec64 * ) + + Same above, but returns the time in a 'struct timespec64', split + into seconds and nanoseconds. This can avoid an extra division + when printing the time, or when passing it into an external + interface that expects a 'timespec' or 'timeval' structure. + +.. c:function:: time64_t ktime_get_seconds( void ) + time64_t ktime_get_boottime_seconds( void ) + time64_t ktime_get_real_seconds( void ) + time64_t ktime_get_clocktai_seconds( void ) + time64_t ktime_get_raw_seconds( void ) + + Return a coarse-grained version of the time as a scalar + time64_t. This avoids accessing the clock hardware and rounds + down the seconds to the full seconds of the last timer tick + using the respective reference. + +Coarse and fast_ns access +------------------------- + +Some additional variants exist for more specialized cases: + +.. c:function:: ktime_t ktime_get_coarse_boottime( void ) + ktime_t ktime_get_coarse_real( void ) + ktime_t ktime_get_coarse_clocktai( void ) + ktime_t ktime_get_coarse_raw( void ) + +.. c:function:: void ktime_get_coarse_ts64( struct timespec64 * ) + void ktime_get_coarse_boottime_ts64( struct timespec64 * ) + void ktime_get_coarse_real_ts64( struct timespec64 * ) + void ktime_get_coarse_clocktai_ts64( struct timespec64 * ) + void ktime_get_coarse_raw_ts64( struct timespec64 * ) + + These are quicker than the non-coarse versions, but less accurate, + corresponding to CLOCK_MONONOTNIC_COARSE and CLOCK_REALTIME_COARSE + in user space, along with the equivalent boottime/tai/raw + timebase not available in user space. + + The time returned here corresponds to the last timer tick, which + may be as much as 10ms in the past (for CONFIG_HZ=100), same as + reading the 'jiffies' variable. These are only useful when called + in a fast path and one still expects better than second accuracy, + but can't easily use 'jiffies', e.g. for inode timestamps. + Skipping the hardware clock access saves around 100 CPU cycles + on most modern machines with a reliable cycle counter, but + up to several microseconds on older hardware with an external + clocksource. + +.. c:function:: u64 ktime_get_mono_fast_ns( void ) + u64 ktime_get_raw_fast_ns( void ) + u64 ktime_get_boot_fast_ns( void ) + u64 ktime_get_real_fast_ns( void ) + + These variants are safe to call from any context, including from + a non-maskable interrupt (NMI) during a timekeeper update, and + while we are entering suspend with the clocksource powered down. + This is useful in some tracing or debugging code as well as + machine check reporting, but most drivers should never call them, + since the time is allowed to jump under certain conditions. + +Deprecated time interfaces +-------------------------- + +Older kernels used some other interfaces that are now being phased out +but may appear in third-party drivers being ported here. In particular, +all interfaces returning a 'struct timeval' or 'struct timespec' have +been replaced because the tv_sec member overflows in year 2038 on 32-bit +architectures. These are the recommended replacements: + +.. c:function:: void ktime_get_ts( struct timespec * ) + + Use ktime_get() or ktime_get_ts64() instead. + +.. c:function:: struct timeval do_gettimeofday( void ) + struct timespec getnstimeofday( void ) + struct timespec64 getnstimeofday64( void ) + void ktime_get_real_ts( struct timespec * ) + + ktime_get_real_ts64() is a direct replacement, but consider using + monotonic time (ktime_get_ts64()) and/or a ktime_t based interface + (ktime_get()/ktime_get_real()). + +.. c:function:: struct timespec current_kernel_time( void ) + struct timespec64 current_kernel_time64( void ) + struct timespec get_monotonic_coarse( void ) + struct timespec64 get_monotonic_coarse64( void ) + + These are replaced by ktime_get_coarse_real_ts64() and + ktime_get_coarse_ts64(). However, A lot of code that wants + coarse-grained times can use the simple 'jiffies' instead, while + some drivers may actually want the higher resolution accessors + these days. + +.. c:function:: struct timespec getrawmonotonic( void ) + struct timespec64 getrawmonotonic64( void ) + struct timespec timekeeping_clocktai( void ) + struct timespec64 timekeeping_clocktai64( void ) + struct timespec get_monotonic_boottime( void ) + struct timespec64 get_monotonic_boottime64( void ) + + These are replaced by ktime_get_raw()/ktime_get_raw_ts64(), + ktime_get_clocktai()/ktime_get_clocktai_ts64() as well + as ktime_get_boottime()/ktime_get_boottime_ts64(). + However, if the particular choice of clock source is not + important for the user, consider converting to + ktime_get()/ktime_get_ts64() instead for consistency. diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 86bc2026efce..947b1b8d2d01 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -20,6 +20,21 @@ extern int do_settimeofday64(const struct timespec64 *ts); extern int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz); +/* + * ktime_get() family: read the current time in a multitude of ways, + * + * The default time reference is CLOCK_MONOTONIC, starting at + * boot time but not counting the time spent in suspend. + * For other references, use the functions with "real", "clocktai", + * "boottime" and "raw" suffixes. + * + * To get the time in a different format, use the ones wit + * "ns", "ts64" and "seconds" suffix. + * + * See Documentation/core-api/timekeeping.rst for more details. + */ + + /* * timespec64 based interfaces */ -- cgit v1.2.3 From a83c0ea79d8b5705d09a39c73224332f9170a903 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Sat, 30 Jun 2018 17:54:59 +0300 Subject: docs/mm: bootmem: add kernel-doc description of 'struct bootmem_data' Signed-off-by: Mike Rapoport Signed-off-by: Jonathan Corbet --- include/linux/bootmem.h | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h index 7942a96b1a9d..42515195d7d8 100644 --- a/include/linux/bootmem.h +++ b/include/linux/bootmem.h @@ -27,9 +27,20 @@ extern unsigned long max_pfn; extern unsigned long long max_possible_pfn; #ifndef CONFIG_NO_BOOTMEM -/* - * node_bootmem_map is a map pointer - the bits represent all physical - * memory pages (including holes) on the node. +/** + * struct bootmem_data - per-node information used by the bootmem allocator + * @node_min_pfn: the starting physical address of the node's memory + * @node_low_pfn: the end physical address of the directly addressable memory + * @node_bootmem_map: is a bitmap pointer - the bits represent all physical + * memory pages (including holes) on the node. + * @last_end_off: the offset within the page of the end of the last allocation; + * if 0, the page used is full + * @hint_idx: the PFN of the page used with the last allocation; + * together with using this with the @last_end_offset field, + * a test can be made to see if allocations can be merged + * with the page used for the last allocation rather than + * using up a full new page. + * @list: list entry in the linked list ordered by the memory addresses */ typedef struct bootmem_data { unsigned long node_min_pfn; -- cgit v1.2.3 From e1720fee27246dfb84f7c433e35367170a2d4436 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Sat, 30 Jun 2018 17:55:01 +0300 Subject: mm/memblock: add a name for memblock flags enumeration Since kernel-doc does not like anonymous enums the name is required for adding documentation. While on it, I've also updated all the function declarations to use 'enum memblock_flags' instead of unsigned long. Signed-off-by: Mike Rapoport Signed-off-by: Jonathan Corbet --- include/linux/memblock.h | 22 +++++++++++----------- mm/memblock.c | 37 +++++++++++++++++++++---------------- mm/nobootmem.c | 2 +- 3 files changed, 33 insertions(+), 28 deletions(-) (limited to 'include/linux') diff --git a/include/linux/memblock.h b/include/linux/memblock.h index ca59883c8364..8b8fbceffd4d 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -21,7 +21,7 @@ #define INIT_PHYSMEM_REGIONS 4 /* Definition of memblock flags. */ -enum { +enum memblock_flags { MEMBLOCK_NONE = 0x0, /* No special request */ MEMBLOCK_HOTPLUG = 0x1, /* hotpluggable region */ MEMBLOCK_MIRROR = 0x2, /* mirrored region */ @@ -31,7 +31,7 @@ enum { struct memblock_region { phys_addr_t base; phys_addr_t size; - unsigned long flags; + enum memblock_flags flags; #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP int nid; #endif @@ -72,7 +72,7 @@ void memblock_discard(void); phys_addr_t memblock_find_in_range_node(phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end, - int nid, ulong flags); + int nid, enum memblock_flags flags); phys_addr_t memblock_find_in_range(phys_addr_t start, phys_addr_t end, phys_addr_t size, phys_addr_t align); void memblock_allow_resize(void); @@ -89,19 +89,19 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); -ulong choose_memblock_flags(void); +enum memblock_flags choose_memblock_flags(void); /* Low level functions */ int memblock_add_range(struct memblock_type *type, phys_addr_t base, phys_addr_t size, - int nid, unsigned long flags); + int nid, enum memblock_flags flags); -void __next_mem_range(u64 *idx, int nid, ulong flags, +void __next_mem_range(u64 *idx, int nid, enum memblock_flags flags, struct memblock_type *type_a, struct memblock_type *type_b, phys_addr_t *out_start, phys_addr_t *out_end, int *out_nid); -void __next_mem_range_rev(u64 *idx, int nid, ulong flags, +void __next_mem_range_rev(u64 *idx, int nid, enum memblock_flags flags, struct memblock_type *type_a, struct memblock_type *type_b, phys_addr_t *out_start, phys_addr_t *out_end, int *out_nid); @@ -253,13 +253,13 @@ void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn, NUMA_NO_NODE, MEMBLOCK_NONE, p_start, p_end, NULL) static inline void memblock_set_region_flags(struct memblock_region *r, - unsigned long flags) + enum memblock_flags flags) { r->flags |= flags; } static inline void memblock_clear_region_flags(struct memblock_region *r, - unsigned long flags) + enum memblock_flags flags) { r->flags &= ~flags; } @@ -317,10 +317,10 @@ static inline bool memblock_bottom_up(void) phys_addr_t __init memblock_alloc_range(phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end, - ulong flags); + enum memblock_flags flags); phys_addr_t memblock_alloc_base_nid(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr, - int nid, ulong flags); + int nid, enum memblock_flags flags); phys_addr_t memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr); phys_addr_t __memblock_alloc_base(phys_addr_t size, phys_addr_t align, diff --git a/mm/memblock.c b/mm/memblock.c index 03d48d8835ba..20f48b49821a 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -60,7 +60,7 @@ static int memblock_can_resize __initdata_memblock; static int memblock_memory_in_slab __initdata_memblock = 0; static int memblock_reserved_in_slab __initdata_memblock = 0; -ulong __init_memblock choose_memblock_flags(void) +enum memblock_flags __init_memblock choose_memblock_flags(void) { return system_has_some_mirror ? MEMBLOCK_MIRROR : MEMBLOCK_NONE; } @@ -109,7 +109,7 @@ bool __init_memblock memblock_overlaps_region(struct memblock_type *type, static phys_addr_t __init_memblock __memblock_find_range_bottom_up(phys_addr_t start, phys_addr_t end, phys_addr_t size, phys_addr_t align, int nid, - ulong flags) + enum memblock_flags flags) { phys_addr_t this_start, this_end, cand; u64 i; @@ -143,7 +143,7 @@ __memblock_find_range_bottom_up(phys_addr_t start, phys_addr_t end, static phys_addr_t __init_memblock __memblock_find_range_top_down(phys_addr_t start, phys_addr_t end, phys_addr_t size, phys_addr_t align, int nid, - ulong flags) + enum memblock_flags flags) { phys_addr_t this_start, this_end, cand; u64 i; @@ -188,7 +188,8 @@ __memblock_find_range_top_down(phys_addr_t start, phys_addr_t end, */ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size, phys_addr_t align, phys_addr_t start, - phys_addr_t end, int nid, ulong flags) + phys_addr_t end, int nid, + enum memblock_flags flags) { phys_addr_t kernel_end, ret; @@ -251,7 +252,7 @@ phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start, phys_addr_t align) { phys_addr_t ret; - ulong flags = choose_memblock_flags(); + enum memblock_flags flags = choose_memblock_flags(); again: ret = memblock_find_in_range_node(size, align, start, end, @@ -472,7 +473,8 @@ static void __init_memblock memblock_merge_regions(struct memblock_type *type) static void __init_memblock memblock_insert_region(struct memblock_type *type, int idx, phys_addr_t base, phys_addr_t size, - int nid, unsigned long flags) + int nid, + enum memblock_flags flags) { struct memblock_region *rgn = &type->regions[idx]; @@ -504,7 +506,7 @@ static void __init_memblock memblock_insert_region(struct memblock_type *type, */ int __init_memblock memblock_add_range(struct memblock_type *type, phys_addr_t base, phys_addr_t size, - int nid, unsigned long flags) + int nid, enum memblock_flags flags) { bool insert = false; phys_addr_t obase = base; @@ -873,7 +875,8 @@ void __init_memblock __next_reserved_mem_region(u64 *idx, * As both region arrays are sorted, the function advances the two indices * in lockstep and returns each intersection. */ -void __init_memblock __next_mem_range(u64 *idx, int nid, ulong flags, +void __init_memblock __next_mem_range(u64 *idx, int nid, + enum memblock_flags flags, struct memblock_type *type_a, struct memblock_type *type_b, phys_addr_t *out_start, @@ -982,7 +985,8 @@ void __init_memblock __next_mem_range(u64 *idx, int nid, ulong flags, * * Reverse of __next_mem_range(). */ -void __init_memblock __next_mem_range_rev(u64 *idx, int nid, ulong flags, +void __init_memblock __next_mem_range_rev(u64 *idx, int nid, + enum memblock_flags flags, struct memblock_type *type_a, struct memblock_type *type_b, phys_addr_t *out_start, @@ -1140,7 +1144,8 @@ int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size, static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size, phys_addr_t align, phys_addr_t start, - phys_addr_t end, int nid, ulong flags) + phys_addr_t end, int nid, + enum memblock_flags flags) { phys_addr_t found; @@ -1162,7 +1167,7 @@ static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size, phys_addr_t __init memblock_alloc_range(phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end, - ulong flags) + enum memblock_flags flags) { return memblock_alloc_range_nid(size, align, start, end, NUMA_NO_NODE, flags); @@ -1170,14 +1175,14 @@ phys_addr_t __init memblock_alloc_range(phys_addr_t size, phys_addr_t align, phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr, - int nid, ulong flags) + int nid, enum memblock_flags flags) { return memblock_alloc_range_nid(size, align, 0, max_addr, nid, flags); } phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid) { - ulong flags = choose_memblock_flags(); + enum memblock_flags flags = choose_memblock_flags(); phys_addr_t ret; again: @@ -1258,7 +1263,7 @@ static void * __init memblock_virt_alloc_internal( { phys_addr_t alloc; void *ptr; - ulong flags = choose_memblock_flags(); + enum memblock_flags flags = choose_memblock_flags(); if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n")) nid = NUMA_NO_NODE; @@ -1733,7 +1738,7 @@ phys_addr_t __init_memblock memblock_get_current_limit(void) static void __init_memblock memblock_dump(struct memblock_type *type) { phys_addr_t base, end, size; - unsigned long flags; + enum memblock_flags flags; int idx; struct memblock_region *rgn; @@ -1751,7 +1756,7 @@ static void __init_memblock memblock_dump(struct memblock_type *type) snprintf(nid_buf, sizeof(nid_buf), " on node %d", memblock_get_region_node(rgn)); #endif - pr_info(" %s[%#x]\t[%pa-%pa], %pa bytes%s flags: %#lx\n", + pr_info(" %s[%#x]\t[%pa-%pa], %pa bytes%s flags: %#x\n", type->name, idx, &base, &end, &size, nid_buf, flags); } } diff --git a/mm/nobootmem.c b/mm/nobootmem.c index c2cfa04f0231..439af3b765a7 100644 --- a/mm/nobootmem.c +++ b/mm/nobootmem.c @@ -42,7 +42,7 @@ static void * __init __alloc_memory_core_early(int nid, u64 size, u64 align, { void *ptr; u64 addr; - ulong flags = choose_memblock_flags(); + enum memblock_flags flags = choose_memblock_flags(); if (limit > memblock.current_limit) limit = memblock.current_limit; -- cgit v1.2.3 From 47cec4432ab06c4ba90c241b142a016f878ac6da Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Sat, 30 Jun 2018 17:55:02 +0300 Subject: docs/mm: memblock: update kernel-doc comments * make memblock_discard description kernel-doc compatible * add brief description for memblock_setclr_flag and describe its parameters * fixup return value descriptions Signed-off-by: Mike Rapoport Signed-off-by: Jonathan Corbet --- include/linux/memblock.h | 17 +++++++--- mm/memblock.c | 84 +++++++++++++++++++++++++++--------------------- 2 files changed, 59 insertions(+), 42 deletions(-) (limited to 'include/linux') diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 8b8fbceffd4d..63704c64583a 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -239,7 +239,6 @@ void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn, /** * for_each_resv_unavail_range - iterate through reserved and unavailable memory * @i: u64 used as loop variable - * @flags: pick from blocks based on memory attributes * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL * @@ -367,8 +366,10 @@ phys_addr_t memblock_get_current_limit(void); */ /** - * memblock_region_memory_base_pfn - Return the lowest pfn intersecting with the memory region + * memblock_region_memory_base_pfn - get the lowest pfn of the memory region * @reg: memblock_region structure + * + * Return: the lowest pfn intersecting with the memory region */ static inline unsigned long memblock_region_memory_base_pfn(const struct memblock_region *reg) { @@ -376,8 +377,10 @@ static inline unsigned long memblock_region_memory_base_pfn(const struct membloc } /** - * memblock_region_memory_end_pfn - Return the end_pfn this region + * memblock_region_memory_end_pfn - get the end pfn of the memory region * @reg: memblock_region structure + * + * Return: the end_pfn of the reserved region */ static inline unsigned long memblock_region_memory_end_pfn(const struct memblock_region *reg) { @@ -385,8 +388,10 @@ static inline unsigned long memblock_region_memory_end_pfn(const struct memblock } /** - * memblock_region_reserved_base_pfn - Return the lowest pfn intersecting with the reserved region + * memblock_region_reserved_base_pfn - get the lowest pfn of the reserved region * @reg: memblock_region structure + * + * Return: the lowest pfn intersecting with the reserved region */ static inline unsigned long memblock_region_reserved_base_pfn(const struct memblock_region *reg) { @@ -394,8 +399,10 @@ static inline unsigned long memblock_region_reserved_base_pfn(const struct membl } /** - * memblock_region_reserved_end_pfn - Return the end_pfn this region + * memblock_region_reserved_end_pfn - get the end pfn of the reserved region * @reg: memblock_region structure + * + * Return: the end_pfn of the reserved region */ static inline unsigned long memblock_region_reserved_end_pfn(const struct memblock_region *reg) { diff --git a/mm/memblock.c b/mm/memblock.c index 20f48b49821a..4b9dd76f6ae6 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -92,10 +92,11 @@ bool __init_memblock memblock_overlaps_region(struct memblock_type *type, return i < type->cnt; } -/* +/** * __memblock_find_range_bottom_up - find free area utility in bottom-up * @start: start of candidate range - * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE} + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or + * %MEMBLOCK_ALLOC_ACCESSIBLE * @size: size of free area to find * @align: alignment of free area to find * @nid: nid of the free area to find, %NUMA_NO_NODE for any node @@ -103,7 +104,7 @@ bool __init_memblock memblock_overlaps_region(struct memblock_type *type, * * Utility called from memblock_find_in_range_node(), find free area bottom-up. * - * RETURNS: + * Return: * Found address on success, 0 on failure. */ static phys_addr_t __init_memblock @@ -129,7 +130,8 @@ __memblock_find_range_bottom_up(phys_addr_t start, phys_addr_t end, /** * __memblock_find_range_top_down - find free area utility, in top-down * @start: start of candidate range - * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE} + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or + * %MEMBLOCK_ALLOC_ACCESSIBLE * @size: size of free area to find * @align: alignment of free area to find * @nid: nid of the free area to find, %NUMA_NO_NODE for any node @@ -137,7 +139,7 @@ __memblock_find_range_bottom_up(phys_addr_t start, phys_addr_t end, * * Utility called from memblock_find_in_range_node(), find free area top-down. * - * RETURNS: + * Return: * Found address on success, 0 on failure. */ static phys_addr_t __init_memblock @@ -169,7 +171,8 @@ __memblock_find_range_top_down(phys_addr_t start, phys_addr_t end, * @size: size of free area to find * @align: alignment of free area to find * @start: start of candidate range - * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE} + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or + * %MEMBLOCK_ALLOC_ACCESSIBLE * @nid: nid of the free area to find, %NUMA_NO_NODE for any node * @flags: pick from blocks based on memory attributes * @@ -183,7 +186,7 @@ __memblock_find_range_top_down(phys_addr_t start, phys_addr_t end, * * If bottom-up allocation failed, will try to allocate memory top-down. * - * RETURNS: + * Return: * Found address on success, 0 on failure. */ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size, @@ -238,13 +241,14 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size, /** * memblock_find_in_range - find free area in given range * @start: start of candidate range - * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE} + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or + * %MEMBLOCK_ALLOC_ACCESSIBLE * @size: size of free area to find * @align: alignment of free area to find * * Find @size free area aligned to @align in the specified range. * - * RETURNS: + * Return: * Found address on success, 0 on failure. */ phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start, @@ -288,7 +292,7 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK /** - * Discard memory and reserved arrays if they were allocated + * memblock_discard - discard memory and reserved arrays if they were allocated */ void __init memblock_discard(void) { @@ -318,11 +322,11 @@ void __init memblock_discard(void) * * Double the size of the @type regions array. If memblock is being used to * allocate memory for a new reserved regions array and there is a previously - * allocated memory range [@new_area_start,@new_area_start+@new_area_size] + * allocated memory range [@new_area_start, @new_area_start + @new_area_size] * waiting to be reserved, ensure the memory used by the new array does * not overlap. * - * RETURNS: + * Return: * 0 on success, -1 on failure. */ static int __init_memblock memblock_double_array(struct memblock_type *type, @@ -467,7 +471,7 @@ static void __init_memblock memblock_merge_regions(struct memblock_type *type) * @nid: node id of the new region * @flags: flags of the new region * - * Insert new memblock region [@base,@base+@size) into @type at @idx. + * Insert new memblock region [@base, @base + @size) into @type at @idx. * @type must already have extra room to accommodate the new region. */ static void __init_memblock memblock_insert_region(struct memblock_type *type, @@ -496,12 +500,12 @@ static void __init_memblock memblock_insert_region(struct memblock_type *type, * @nid: nid of the new region * @flags: flags of the new region * - * Add new memblock region [@base,@base+@size) into @type. The new region + * Add new memblock region [@base, @base + @size) into @type. The new region * is allowed to overlap with existing ones - overlaps don't affect already * existing regions. @type is guaranteed to be minimal (all neighbouring * compatible regions are merged) after the addition. * - * RETURNS: + * Return: * 0 on success, -errno on failure. */ int __init_memblock memblock_add_range(struct memblock_type *type, @@ -615,11 +619,11 @@ int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size) * @end_rgn: out parameter for the end of isolated region * * Walk @type and ensure that regions don't cross the boundaries defined by - * [@base,@base+@size). Crossing regions are split at the boundaries, + * [@base, @base + @size). Crossing regions are split at the boundaries, * which may create at most two more regions. The index of the first * region inside the range is returned in *@start_rgn and end in *@end_rgn. * - * RETURNS: + * Return: * 0 on success, -errno on failure. */ static int __init_memblock memblock_isolate_range(struct memblock_type *type, @@ -730,10 +734,15 @@ int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size) } /** + * memblock_setclr_flag - set or clear flag for a memory region + * @base: base address of the region + * @size: size of the region + * @set: set or clear the flag + * @flag: the flag to udpate * * This function isolates region [@base, @base + @size), and sets/clears flag * - * Return 0 on success, -errno on failure. + * Return: 0 on success, -errno on failure. */ static int __init_memblock memblock_setclr_flag(phys_addr_t base, phys_addr_t size, int set, int flag) @@ -760,7 +769,7 @@ static int __init_memblock memblock_setclr_flag(phys_addr_t base, * @base: the base phys addr of the region * @size: the size of the region * - * Return 0 on success, -errno on failure. + * Return: 0 on success, -errno on failure. */ int __init_memblock memblock_mark_hotplug(phys_addr_t base, phys_addr_t size) { @@ -772,7 +781,7 @@ int __init_memblock memblock_mark_hotplug(phys_addr_t base, phys_addr_t size) * @base: the base phys addr of the region * @size: the size of the region * - * Return 0 on success, -errno on failure. + * Return: 0 on success, -errno on failure. */ int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size) { @@ -784,7 +793,7 @@ int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size) * @base: the base phys addr of the region * @size: the size of the region * - * Return 0 on success, -errno on failure. + * Return: 0 on success, -errno on failure. */ int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size) { @@ -798,7 +807,7 @@ int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size) * @base: the base phys addr of the region * @size: the size of the region * - * Return 0 on success, -errno on failure. + * Return: 0 on success, -errno on failure. */ int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size) { @@ -810,7 +819,7 @@ int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size) * @base: the base phys addr of the region * @size: the size of the region * - * Return 0 on success, -errno on failure. + * Return: 0 on success, -errno on failure. */ int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size) { @@ -971,9 +980,6 @@ void __init_memblock __next_mem_range(u64 *idx, int nid, /** * __next_mem_range_rev - generic next function for for_each_*_range_rev() * - * Finds the next range from type_a which is not marked as unsuitable - * in type_b. - * * @idx: pointer to u64 loop variable * @nid: node selector, %NUMA_NO_NODE for all nodes * @flags: pick from blocks based on memory attributes @@ -983,6 +989,9 @@ void __init_memblock __next_mem_range(u64 *idx, int nid, * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL * @out_nid: ptr to int for nid of the range, can be %NULL * + * Finds the next range from type_a which is not marked as unsuitable + * in type_b. + * * Reverse of __next_mem_range(). */ void __init_memblock __next_mem_range_rev(u64 *idx, int nid, @@ -1118,10 +1127,10 @@ void __init_memblock __next_mem_pfn_range(int *idx, int nid, * @type: memblock type to set node ID for * @nid: node ID to set * - * Set the nid of memblock @type regions in [@base,@base+@size) to @nid. + * Set the nid of memblock @type regions in [@base, @base + @size) to @nid. * Regions which cross the area boundaries are split as necessary. * - * RETURNS: + * Return: * 0 on success, -errno on failure. */ int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size, @@ -1245,7 +1254,7 @@ phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, i * The allocation is performed from memory region limited by * memblock.current_limit if @max_addr == %BOOTMEM_ALLOC_ACCESSIBLE. * - * The memory block is aligned on SMP_CACHE_BYTES if @align == 0. + * The memory block is aligned on %SMP_CACHE_BYTES if @align == 0. * * The phys address of allocated boot memory block is converted to virtual and * allocated memory is reset to 0. @@ -1253,7 +1262,7 @@ phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, i * In addition, function sets the min_count to 0 using kmemleak_alloc for * allocated boot memory block, so that it is never reported as leaks. * - * RETURNS: + * Return: * Virtual address of allocated memory block on success, NULL on failure. */ static void * __init memblock_virt_alloc_internal( @@ -1338,7 +1347,7 @@ done: * info), if enabled. Does not zero allocated memory, does not panic if request * cannot be satisfied. * - * RETURNS: + * Return: * Virtual address of allocated memory block on success, NULL on failure. */ void * __init memblock_virt_alloc_try_nid_raw( @@ -1375,7 +1384,7 @@ void * __init memblock_virt_alloc_try_nid_raw( * Public function, provides additional debug information (including caller * info), if enabled. This function zeroes the allocated memory. * - * RETURNS: + * Return: * Virtual address of allocated memory block on success, NULL on failure. */ void * __init memblock_virt_alloc_try_nid_nopanic( @@ -1411,7 +1420,7 @@ void * __init memblock_virt_alloc_try_nid_nopanic( * which provides debug information (including caller info), if enabled, * and panics if the request can not be satisfied. * - * RETURNS: + * Return: * Virtual address of allocated memory block on success, NULL on failure. */ void * __init memblock_virt_alloc_try_nid( @@ -1668,9 +1677,9 @@ int __init_memblock memblock_search_pfn_nid(unsigned long pfn, * @base: base of region to check * @size: size of region to check * - * Check if the region [@base, @base+@size) is a subset of a memory block. + * Check if the region [@base, @base + @size) is a subset of a memory block. * - * RETURNS: + * Return: * 0 if false, non-zero if true */ bool __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size) @@ -1689,9 +1698,10 @@ bool __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t siz * @base: base of region to check * @size: size of region to check * - * Check if the region [@base, @base+@size) intersects a reserved memory block. + * Check if the region [@base, @base + @size) intersects a reserved + * memory block. * - * RETURNS: + * Return: * True if they intersect, false if not. */ bool __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size) -- cgit v1.2.3 From 9a0de1bfe191220cb0437865261ab2f95cbb13ef Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Sat, 30 Jun 2018 17:55:04 +0300 Subject: docs/mm: memblock: add kernel-doc description for memblock types Signed-off-by: Mike Rapoport Signed-off-by: Jonathan Corbet --- include/linux/memblock.h | 37 +++++++++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 63704c64583a..516920549378 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -20,7 +20,13 @@ #define INIT_MEMBLOCK_REGIONS 128 #define INIT_PHYSMEM_REGIONS 4 -/* Definition of memblock flags. */ +/** + * enum memblock_flags - definition of memory region attributes + * @MEMBLOCK_NONE: no special request + * @MEMBLOCK_HOTPLUG: hotpluggable region + * @MEMBLOCK_MIRROR: mirrored region + * @MEMBLOCK_NOMAP: don't add to kernel direct mapping + */ enum memblock_flags { MEMBLOCK_NONE = 0x0, /* No special request */ MEMBLOCK_HOTPLUG = 0x1, /* hotpluggable region */ @@ -28,6 +34,13 @@ enum memblock_flags { MEMBLOCK_NOMAP = 0x4, /* don't add to kernel direct mapping */ }; +/** + * struct memblock_region - represents a memory region + * @base: physical address of the region + * @size: size of the region + * @flags: memory region attributes + * @nid: NUMA node id + */ struct memblock_region { phys_addr_t base; phys_addr_t size; @@ -37,14 +50,30 @@ struct memblock_region { #endif }; +/** + * struct memblock_type - collection of memory regions of certain type + * @cnt: number of regions + * @max: size of the allocated array + * @total_size: size of all regions + * @regions: array of regions + * @name: the memory type symbolic name + */ struct memblock_type { - unsigned long cnt; /* number of regions */ - unsigned long max; /* size of the allocated array */ - phys_addr_t total_size; /* size of all regions */ + unsigned long cnt; + unsigned long max; + phys_addr_t total_size; struct memblock_region *regions; char *name; }; +/** + * struct memblock - memblock allocator metadata + * @bottom_up: is bottom up direction? + * @current_limit: physical address of the current allocation limit + * @memory: usabe memory regions + * @reserved: reserved memory regions + * @physmem: all physical memory + */ struct memblock { bool bottom_up; /* is bottom up direction? */ phys_addr_t current_limit; -- cgit v1.2.3