diff options
Diffstat (limited to 'mem/slab.c')
| -rw-r--r-- | mem/slab.c | 209 |
1 files changed, 0 insertions, 209 deletions
diff --git a/mem/slab.c b/mem/slab.c deleted file mode 100644 index 30bc23a..0000000 --- a/mem/slab.c +++ /dev/null @@ -1,209 +0,0 @@ -#include "slab.h" -#include "memory.h" -#include "lib/format.h" -#include "lib/string.h" -#include "lib/jove.h" -#include "io/log.h" - -extern void *_kernel_end; - -static uintptr_t s_addr_next_free; - -#define GENERIC_CACHEC 8 -static struct SlabCache s_generic_caches[GENERIC_CACHEC]; - -static uintptr_t -s_next_free(size_t width) -{ - uintptr_t ret = s_addr_next_free; - s_addr_next_free += width; - mem_ensure_range( - ret, - s_addr_next_free, - (page_flags_t) { - .present = true, - .writeable = true, - .useraccess = false, - .executable = false - }); - return ret; -} - -static int -s_get_free_listw(size_t slabw, size_t objw) -{ - int freelistc = 1; - while(freelistc < 256) { - int maxobjc = (slabw - (freelistc * sizeof(uintptr_t))) / objw; - if(maxobjc <= freelistc) return maxobjc; - freelistc++; - } - return freelistc; -} - -static struct SlabDescriptor -*s_slab_new(struct SlabCache *cache, struct SlabDescriptor *last) -{ - size_t slab_width = (cache->slab_pages << PAGE_SHIFT); - uintptr_t descr_base = s_next_free(slab_width); - struct SlabDescriptor *descr = (struct SlabDescriptor*)descr_base; - - size_t free_listc = s_get_free_listw( - slab_width - sizeof(struct SlabDescriptor), - cache->obj_size); - size_t descriptor_width = sizeof(struct SlabDescriptor) - + (free_listc * sizeof(uintptr_t)); - uintptr_t obj_base = descr_base + descriptor_width; - - if(free_listc < 8) { - free_listc = ((slab_width - sizeof(struct SlabDescriptor)) / cache->obj_size); - descr = mem_alloc(sizeof(struct SlabDescriptor) + (free_listc * sizeof(uintptr_t))); - obj_base = descr_base; - } - - *descr = (struct SlabDescriptor) { - .prev = last, - .next = (last == NULL ? NULL : last->next), - .slab_base = (void*)descr_base, - .obj_base = (void*)obj_base, - .free_count = free_listc, - .free_index = free_listc - 1 - }; - for(size_t i = 0; i < free_listc; i++) { - descr->free[i] = obj_base + (i * cache->obj_size); - } - - return descr; -} - -void -mem_slabcache_new(struct SlabCache *cache, char *name, size_t objsize) -{ - if(objsize % 8 > 0) objsize += (8 - (objsize % 8)); - size_t pages = objsize > 512 ? (objsize >> 9) : 1; - *cache = (struct SlabCache){ - .obj_size = objsize, - .slab_pages = pages, - .list_free = NULL, - .list_partial = NULL, - .list_full = NULL - }; - size_t namelen = strlen(name); - namelen = namelen > 32 ? 32 : namelen; - memcpy(cache->name, name, namelen); - - //Allocate the first slab - cache->list_free = s_slab_new(cache, NULL); -} - -void* -mem_slab_alloc(struct SlabCache *cache) -{ - // Get a free slab - struct SlabDescriptor *slab = NULL; - if(cache->list_partial != NULL) slab = cache->list_partial; - if(slab == NULL && cache->list_free != NULL) { - slab = cache->list_free; - cache->list_free = slab->next; - } - if(slab == NULL) slab = s_slab_new(cache, cache->list_free); - cache->list_partial = slab; - - // Take an object from the slab. - uintptr_t objaddr = slab->free[slab->free_index]; - slab->free_index -= 1; - - if(slab->free_index < 0) { - slab->next = cache->list_full; - cache->list_full = slab; - } - return (void*)objaddr; -} - -void -mem_slab_free(struct SlabCache *cache, void *ptr) -{ - uintptr_t addr = (uintptr_t)ptr; - //Look for the pointer in the bounds of every slab - for(struct SlabDescriptor *slab = cache->list_full; - slab != NULL; slab = slab->next) - { - uintptr_t base = (uintptr_t)slab->obj_base; - uintptr_t limit = ((uintptr_t)slab->slab_base) - + (cache->slab_pages << PAGE_SHIFT); - if(addr > limit || addr < base) continue; - if((addr - base) % cache->obj_size != 0) { - klogf("Tried to free offset pointer %#016X in slab %s\n", - addr, cache->name); - return; - } - slab->free_index++; - slab->free[slab->free_index] = addr; - - cache->list_full = slab->next; - slab->next = cache->list_partial; - cache->list_partial = slab; - return; - } - for(struct SlabDescriptor *slab = cache->list_partial; - slab != NULL; slab = slab->next) - { - uintptr_t base = (uintptr_t)slab->obj_base; - uintptr_t limit = ((uintptr_t)slab->slab_base) - + (cache->slab_pages << PAGE_SHIFT); - if(addr > limit || addr < base) continue; - if((addr - base) % cache->obj_size != 0) { - klogf("Tried to free offset pointer %#016X in slab %s\n", - addr, cache->name); - return; - } - slab->free_index++; - slab->free[slab->free_index] = addr; - - if(slab->free_index == (slab->free_count - 1)) { - cache->list_partial = slab->next; - slab->next = cache->list_free; - cache->list_free = slab; - } - return; - } -} - -void* -mem_alloc(size_t width) -{ - size_t width_log2 = (__builtin_clz(width) ^ 31) + 1; - if(width_log2 < 6) width_log2 = 6; - width_log2 -= 6; - if(width_log2 >= GENERIC_CACHEC) { - klogf("Allocation size %i too big for generic caches!\n", width); - return NULL; - } - - struct SlabCache *generic_cache = &s_generic_caches[width_log2]; - return mem_slab_alloc(generic_cache); -} - -void -mem_free(void *ptr) -{ - for(int i = 0; i < GENERIC_CACHEC; i++) { - mem_slab_free(&s_generic_caches[i], ptr); - } -} - -void -mem_slab_setup(void) -{ - s_addr_next_free = (uintptr_t)&_kernel_end; - s_addr_next_free = ((s_addr_next_free >> 12) + 1) << 12; - s_get_free_listw(PAGE_SIZE - sizeof(struct SlabDescriptor), 32); - - for(int i = 0; i < GENERIC_CACHEC; i++) - { - size_t objsize = 1 << (i + 6); - char slab_name[SLABCACHE_NAME_LIMIT]; - sfmt(slab_name, SLABCACHE_NAME_LIMIT, "generic_%i", 1 << (i + 6)); - mem_slabcache_new(&s_generic_caches[i], slab_name, objsize); - } -} |