diff options
Diffstat (limited to 'arch/ppc/mm/mem_pieces.c')
| -rw-r--r-- | arch/ppc/mm/mem_pieces.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/arch/ppc/mm/mem_pieces.c b/arch/ppc/mm/mem_pieces.c new file mode 100644 index 000000000000..3d639052017e --- /dev/null +++ b/arch/ppc/mm/mem_pieces.c @@ -0,0 +1,163 @@ +/* + * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au> + * Changes to accommodate Power Macintoshes. + * Cort Dougan <cort@cs.nmt.edu> + * Rewrites. + * Grant Erickson <grant@lcse.umn.edu> + * General rework and split from mm/init.c. + * + * Module name: mem_pieces.c + * + * Description: + * Routines and data structures for manipulating and representing + * phyiscal memory extents (i.e. address/length pairs). + * + */ + +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/stddef.h> +#include <linux/init.h> +#include <asm/page.h> + +#include "mem_pieces.h" + +extern struct mem_pieces phys_avail; + +static void mem_pieces_print(struct mem_pieces *); + +/* + * Scan a region for a piece of a given size with the required alignment. + */ +void __init * +mem_pieces_find(unsigned int size, unsigned int align) +{ + int i; + unsigned a, e; + struct mem_pieces *mp = &phys_avail; + + for (i = 0; i < mp->n_regions; ++i) { + a = mp->regions[i].address; + e = a + mp->regions[i].size; + a = (a + align - 1) & -align; + if (a + size <= e) { + mem_pieces_remove(mp, a, size, 1); + return (void *) __va(a); + } + } + panic("Couldn't find %u bytes at %u alignment\n", size, align); + + return NULL; +} + +/* + * Remove some memory from an array of pieces + */ +void __init +mem_pieces_remove(struct mem_pieces *mp, unsigned int start, unsigned int size, + int must_exist) +{ + int i, j; + unsigned int end, rs, re; + struct reg_property *rp; + + end = start + size; + for (i = 0, rp = mp->regions; i < mp->n_regions; ++i, ++rp) { + if (end > rp->address && start < rp->address + rp->size) + break; + } + if (i >= mp->n_regions) { + if (must_exist) + printk("mem_pieces_remove: [%x,%x) not in any region\n", + start, end); + return; + } + for (; i < mp->n_regions && end > rp->address; ++i, ++rp) { + rs = rp->address; + re = rs + rp->size; + if (must_exist && (start < rs || end > re)) { + printk("mem_pieces_remove: bad overlap [%x,%x) with", + start, end); + mem_pieces_print(mp); + must_exist = 0; + } + if (start > rs) { + rp->size = start - rs; + if (end < re) { + /* need to split this entry */ + if (mp->n_regions >= MEM_PIECES_MAX) + panic("eek... mem_pieces overflow"); + for (j = mp->n_regions; j > i + 1; --j) + mp->regions[j] = mp->regions[j-1]; + ++mp->n_regions; + rp[1].address = end; + rp[1].size = re - end; + } + } else { + if (end < re) { + rp->address = end; + rp->size = re - end; + } else { + /* need to delete this entry */ + for (j = i; j < mp->n_regions - 1; ++j) + mp->regions[j] = mp->regions[j+1]; + --mp->n_regions; + --i; + --rp; + } + } + } +} + +static void __init +mem_pieces_print(struct mem_pieces *mp) +{ + int i; + + for (i = 0; i < mp->n_regions; ++i) + printk(" [%x, %x)", mp->regions[i].address, + mp->regions[i].address + mp->regions[i].size); + printk("\n"); +} + +void __init +mem_pieces_sort(struct mem_pieces *mp) +{ + unsigned long a, s; + int i, j; + + for (i = 1; i < mp->n_regions; ++i) { + a = mp->regions[i].address; + s = mp->regions[i].size; + for (j = i - 1; j >= 0; --j) { + if (a >= mp->regions[j].address) + break; + mp->regions[j+1] = mp->regions[j]; + } + mp->regions[j+1].address = a; + mp->regions[j+1].size = s; + } +} + +void __init +mem_pieces_coalesce(struct mem_pieces *mp) +{ + unsigned long a, s, ns; + int i, j, d; + + d = 0; + for (i = 0; i < mp->n_regions; i = j) { + a = mp->regions[i].address; + s = mp->regions[i].size; + for (j = i + 1; j < mp->n_regions + && mp->regions[j].address - a <= s; ++j) { + ns = mp->regions[j].address + mp->regions[j].size - a; + if (ns > s) + s = ns; + } + mp->regions[d].address = a; + mp->regions[d].size = s; + ++d; + } + mp->n_regions = d; +} |