From 38a6be525460f52ac6f2de1c3f73c5615a8853cd Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 4 Jul 2009 08:10:59 +0900 Subject: percpu: simplify pcpu_setup_first_chunk() Now that all first chunk allocator helpers allocate and map the first chunk themselves, there's no need to have optional default alloc/map in pcpu_setup_first_chunk(). Drop @populate_pte_fn and only leave @dyn_size optional and make all other params mandatory. This makes it much easier to follow what pcpu_setup_first_chunk() is doing and what actual differences tweaking each parameter results in. [ Impact: drop unused code path ] Signed-off-by: Tejun Heo Cc: Ingo Molnar --- mm/percpu.c | 104 ++++++++++++++++++------------------------------------------ 1 file changed, 30 insertions(+), 74 deletions(-) (limited to 'mm/percpu.c') diff --git a/mm/percpu.c b/mm/percpu.c index 17db527ee2e2..21d938a10662 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -983,24 +983,22 @@ EXPORT_SYMBOL_GPL(free_percpu); * pcpu_setup_first_chunk - initialize the first percpu chunk * @get_page_fn: callback to fetch page pointer * @static_size: the size of static percpu area in bytes - * @reserved_size: the size of reserved percpu area in bytes + * @reserved_size: the size of reserved percpu area in bytes, 0 for none * @dyn_size: free size for dynamic allocation in bytes, -1 for auto - * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto - * @base_addr: mapped address, NULL for auto - * @populate_pte_fn: callback to allocate pagetable, NULL if unnecessary + * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE + * @base_addr: mapped address * * Initialize the first percpu chunk which contains the kernel static * perpcu area. This function is to be called from arch percpu area - * setup path. The first two parameters are mandatory. The rest are - * optional. + * setup path. * * @get_page_fn() should return pointer to percpu page given cpu * number and page number. It should at least return enough pages to * cover the static area. The returned pages for static area should - * have been initialized with valid data. If @unit_size is specified, - * it can also return pages after the static area. NULL return - * indicates end of pages for the cpu. Note that @get_page_fn() must - * return the same number of pages for all cpus. + * have been initialized with valid data. It can also return pages + * after the static area. NULL return indicates end of pages for the + * cpu. Note that @get_page_fn() must return the same number of pages + * for all cpus. * * @reserved_size, if non-zero, specifies the amount of bytes to * reserve after the static area in the first chunk. This reserves @@ -1015,17 +1013,12 @@ EXPORT_SYMBOL_GPL(free_percpu); * non-negative value makes percpu leave alone the area beyond * @static_size + @reserved_size + @dyn_size. * - * @unit_size, if non-negative, specifies unit size and must be - * aligned to PAGE_SIZE and equal to or larger than @static_size + - * @reserved_size + if non-negative, @dyn_size. - * - * Non-null @base_addr means that the caller already allocated virtual - * region for the first chunk and mapped it. percpu must not mess - * with the chunk. Note that @base_addr with 0 @unit_size or non-NULL - * @populate_pte_fn doesn't make any sense. + * @unit_size specifies unit size and must be aligned to PAGE_SIZE and + * equal to or larger than @static_size + @reserved_size + if + * non-negative, @dyn_size. * - * @populate_pte_fn is used to populate the pagetable. NULL means the - * caller already populated the pagetable. + * The caller should have mapped the first chunk at @base_addr and + * copied static data to each unit. * * If the first chunk ends up with both reserved and dynamic areas, it * is served by two chunks - one to serve the core static and reserved @@ -1040,9 +1033,8 @@ EXPORT_SYMBOL_GPL(free_percpu); */ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, size_t static_size, size_t reserved_size, - ssize_t dyn_size, ssize_t unit_size, - void *base_addr, - pcpu_fc_populate_pte_fn_t populate_pte_fn) + ssize_t dyn_size, size_t unit_size, + void *base_addr) { static struct vm_struct first_vm; static int smap[2], dmap[2]; @@ -1050,27 +1042,18 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, (dyn_size >= 0 ? dyn_size : 0); struct pcpu_chunk *schunk, *dchunk = NULL; unsigned int cpu; - int nr_pages; - int err, i; + int i, nr_pages; /* santiy checks */ BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC || ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC); BUG_ON(!static_size); - if (unit_size >= 0) { - BUG_ON(unit_size < size_sum); - BUG_ON(unit_size & ~PAGE_MASK); - BUG_ON(unit_size < PCPU_MIN_UNIT_SIZE); - } else - BUG_ON(base_addr); - BUG_ON(base_addr && populate_pte_fn); - - if (unit_size >= 0) - pcpu_unit_pages = unit_size >> PAGE_SHIFT; - else - pcpu_unit_pages = max_t(int, PCPU_MIN_UNIT_SIZE >> PAGE_SHIFT, - PFN_UP(size_sum)); + BUG_ON(!base_addr); + BUG_ON(unit_size < size_sum); + BUG_ON(unit_size & ~PAGE_MASK); + BUG_ON(unit_size < PCPU_MIN_UNIT_SIZE); + pcpu_unit_pages = unit_size >> PAGE_SHIFT; pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; pcpu_chunk_size = num_possible_cpus() * pcpu_unit_size; pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) @@ -1079,6 +1062,10 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, if (dyn_size < 0) dyn_size = pcpu_unit_size - static_size - reserved_size; + first_vm.flags = VM_ALLOC; + first_vm.size = pcpu_chunk_size; + first_vm.addr = base_addr; + /* * Allocate chunk slots. The additional last slot is for * empty chunks. @@ -1101,6 +1088,7 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, schunk->map = smap; schunk->map_alloc = ARRAY_SIZE(smap); schunk->page = schunk->page_ar; + schunk->immutable = true; if (reserved_size) { schunk->free_size = reserved_size; @@ -1124,31 +1112,13 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, dchunk->map = dmap; dchunk->map_alloc = ARRAY_SIZE(dmap); dchunk->page = schunk->page_ar; /* share page map with schunk */ + dchunk->immutable = true; dchunk->contig_hint = dchunk->free_size = dyn_size; dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit; dchunk->map[dchunk->map_used++] = dchunk->free_size; } - /* allocate vm address */ - first_vm.flags = VM_ALLOC; - first_vm.size = pcpu_chunk_size; - - if (!base_addr) - vm_area_register_early(&first_vm, PAGE_SIZE); - else { - /* - * Pages already mapped. No need to remap into - * vmalloc area. In this case the first chunks can't - * be mapped or unmapped by percpu and are marked - * immutable. - */ - first_vm.addr = base_addr; - schunk->immutable = true; - if (dchunk) - dchunk->immutable = true; - } - /* assign pages */ nr_pages = -1; for_each_possible_cpu(cpu) { @@ -1168,19 +1138,6 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, BUG_ON(nr_pages != i); } - /* map them */ - if (populate_pte_fn) { - for_each_possible_cpu(cpu) - for (i = 0; i < nr_pages; i++) - populate_pte_fn(pcpu_chunk_addr(schunk, - cpu, i)); - - err = pcpu_map(schunk, 0, nr_pages); - if (err) - panic("failed to setup static percpu area, err=%d\n", - err); - } - /* link the first chunk in */ pcpu_first_chunk = dchunk ?: schunk; pcpu_chunk_relocate(pcpu_first_chunk, -1); @@ -1282,7 +1239,7 @@ ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size, return pcpu_setup_first_chunk(pcpue_get_page, static_size, reserved_size, dyn_size, - pcpue_unit_size, pcpue_ptr, NULL); + pcpue_unit_size, pcpue_ptr); } /* @@ -1387,8 +1344,7 @@ ssize_t __init pcpu_4k_first_chunk(size_t static_size, size_t reserved_size, ret = pcpu_setup_first_chunk(pcpu4k_get_page, static_size, reserved_size, -1, - pcpu4k_unit_pages << PAGE_SHIFT, vm.addr, - NULL); + pcpu4k_unit_pages << PAGE_SHIFT, vm.addr); goto out_free_ar; enomem: @@ -1521,7 +1477,7 @@ ssize_t __init pcpu_lpage_first_chunk(size_t static_size, size_t reserved_size, ret = pcpu_setup_first_chunk(pcpul_get_page, static_size, reserved_size, dyn_size, pcpul_unit_size, - pcpul_vm.addr, NULL); + pcpul_vm.addr); /* sort pcpul_map array for pcpu_lpage_remapped() */ for (i = 0; i < num_possible_cpus() - 1; i++) -- cgit v1.2.2