thomas/mittos64
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

PMM -- simplification of code

Browse Source
This commit is contained in:
Thomas Lovén 2018-03-20 10:20:27 +01:00
parent 9bc1abceff
commit e86857dca4
1 changed files with 12 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
src/kernel/memory/pmm.c
View File

@ -1,25 +1,28 @@
#include <memory.h> #include <memory.h>
uint64_t first = 0; // Virtual addres of next free page
uint64_t next = 0;
void pmm_free(uint64_t page) void pmm_free(uint64_t page)
{ {
page = (uint64_t)P2V(page); // Write previous free pointer to freed page
*(uint64_t *)page = first; *(uint64_t *)P2V(page) = next;
first = page; // And update free pointer
next = (uint64_t)P2V(page);
} }
uint64_t pmm_alloc() uint64_t pmm_alloc()
{ {
uint64_t page = first; if(!next) return 0;
first = page?*(uint64_t *)page:0; uint64_t page = next;
page = (uint64_t)(page?V2P(page):0); // Read new free pointer from allocated page
return page; next = *(uint64_t *)page;
return (uint64_t)V2P(page);
} }
uint64_t pmm_calloc() uint64_t pmm_calloc()
{ {
uint64_t page = pmm_alloc(); uint64_t page = pmm_alloc();
memset(P2V(page), 0, 0x1000); memset(P2V(page), 0, PAGE_SIZE);
return page; return page;
} }