From 353647418912b5b6b94473b15bee312ddc4d64a9 Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Wed, 25 Jan 2023 22:05:35 +0100
Subject: kernel: move /mem/alloc to /malloc and linker.ld to arch/amd64/
---
src/kernel/mem/alloc.c | 177 -------------------------------------------------
1 file changed, 177 deletions(-)
delete mode 100644 src/kernel/mem/alloc.c
(limited to 'src/kernel/mem/alloc.c')
diff --git a/src/kernel/mem/alloc.c b/src/kernel/mem/alloc.c
deleted file mode 100644
index a8e5aed..0000000
--- a/src/kernel/mem/alloc.c
+++ /dev/null
@@ -1,177 +0,0 @@
-#include <kernel/arch/generic.h>
-#include <kernel/mem/alloc.h>
-#include <kernel/panic.h>
-#include <kernel/util.h>
-#include <shared/mem.h>
-#include <stdbool.h>
-#include <stdint.h>
-
-#define MALLOC_MAGIC 0xACAB1312
-
-struct malloc_hdr {
- uint32_t magic;
- uint32_t page_amt;
- struct malloc_hdr *next, *prev;
- void *stacktrace[4];
-};
-
-struct malloc_hdr *malloc_last = NULL;
-
-extern uint8_t pbitmap[], pbitmap_start[]; /* linker.ld */
-static size_t pbitmap_len;
-static size_t pbitmap_searchstart = 0;
-static size_t pbitmap_taken = 0;
-
-
-static bool bitmap_get(size_t i) {
- size_t b = i / 8;
- assert(b < pbitmap_len);
- return 0 < (pbitmap[b] & (1 << (i&7)));
-}
-
-static void bitmap_set(size_t i, bool v) {
- size_t b = i / 8;
- uint8_t m = 1 << (i&7);
- assert(b < pbitmap_len);
- if ((pbitmap[b] & m) ^ v) {
- /* value changes */
- if (v) pbitmap_taken++;
- else pbitmap_taken--;
- }
- if (v) pbitmap[b] |= m;
- else pbitmap[b] &= ~m;
-}
-
-void mem_init(void *memtop) {
- kprintf("memory %8x -> %8x\n", &_bss_end, memtop);
- size_t pageamt = ((uintptr_t)memtop - (uintptr_t)pbitmap_start) / PAGE_SIZE;
- pbitmap_len = pageamt / 8;
- memset(pbitmap, 0, pbitmap_len);
- mem_reserve(pbitmap, pbitmap_len);
-}
-
-void mem_reserve(void *addr, size_t len) {
- kprintf("reserved %8x -> %8x\n", addr, addr + len);
-
- /* align to the previous page */
- size_t off = (uintptr_t)addr & PAGE_MASK;
- addr -= off;
- len += off;
- size_t first = ((uintptr_t)addr - (uintptr_t)pbitmap_start) / PAGE_SIZE;
- for (size_t i = 0; i * PAGE_SIZE < len; i++) {
- if (first + i >= pbitmap_len) break;
- if (bitmap_get(first + i))
- panic_invalid_state();
- bitmap_set(first + i, true);
- }
-}
-
-void mem_debugprint(void) {
- size_t total = 0;
- kprintf("current kmallocs:\n");
- kprintf("addr pages\n");
- for (struct malloc_hdr *iter = malloc_last; iter; iter = iter->prev) {
- kprintf("%08x %05x", iter, iter->page_amt);
- for (size_t i = 0; i < 4; i++)
- kprintf(" k/%08x", iter->stacktrace[i]);
- kprintf("\n peek 0x%x\n", *(uint32_t*)(&iter[1]));
- total++;
- }
- kprintf(" total 0x%x\n", total);
- kprintf("pbitmap usage %u/%u\n", pbitmap_taken, pbitmap_len * 8);
-}
-
-void *page_alloc(size_t pages) {
- /* i do realize how painfully slow this is */
- size_t streak = 0;
- for (size_t i = pbitmap_searchstart; i < pbitmap_len * 8; i++) {
- if (bitmap_get(i)) {
- streak = 0;
- continue;
- }
- if (++streak >= pages) {
- /* found hole big enough for this allocation */
- i = i + 1 - streak;
- for (size_t j = 0; j < streak; j++)
- bitmap_set(i + j, true);
- pbitmap_searchstart = i + streak - 1;
- return pbitmap_start + i * PAGE_SIZE;
- }
- }
- kprintf("we ran out of memory :(\ngoodbye.\n");
- panic_unimplemented();
-}
-
-void *page_zalloc(size_t pages) {
- void *p = page_alloc(pages);
- memset(p, 0, pages * PAGE_SIZE);
- return p;
-}
-
-// frees `pages` consecutive pages starting from *first
-void page_free(void *first_addr, size_t pages) {
- assert(first_addr >= (void*)pbitmap_start);
- size_t first = ((uintptr_t)first_addr - (uintptr_t)pbitmap_start) / PAGE_SIZE;
- if (pbitmap_searchstart > first)
- pbitmap_searchstart = first;
- for (size_t i = 0; i < pages; i++) {
- assert(bitmap_get(first + i));
- bitmap_set(first + i, false);
- }
-}
-
-void kmalloc_sanity(const void *addr) {
- assert(addr);
- const struct malloc_hdr *hdr = addr - sizeof(struct malloc_hdr);
- assert(hdr->magic == MALLOC_MAGIC);
- if (hdr->next) assert(hdr->next->prev == hdr);
- if (hdr->prev) assert(hdr->prev->next == hdr);
-}
-
-void *kmalloc(size_t len) {
- // TODO better kmalloc
-
- struct malloc_hdr *hdr;
- void *addr;
- uint32_t pages;
-
- len += sizeof(struct malloc_hdr);
- pages = len / PAGE_SIZE + 1;
-
- hdr = page_alloc(pages);
- hdr->magic = MALLOC_MAGIC;
- hdr->page_amt = pages;
-
- hdr->next = NULL;
- hdr->prev = malloc_last;
- if (hdr->prev) {
- assert(!hdr->prev->next);
- hdr->prev->next = hdr;
- }
-
- for (size_t i = 0; i < 4; i++)
- hdr->stacktrace[i] = debug_caller(i);
-
- malloc_last = hdr;
-
- addr = (void*)hdr + sizeof(struct malloc_hdr);
- kmalloc_sanity(addr);
- return addr;
-}
-
-void kfree(void *ptr) {
- struct malloc_hdr *hdr;
- if (ptr == NULL) return;
-
- hdr = ptr - sizeof(struct malloc_hdr);
- kmalloc_sanity(ptr);
-
- hdr->magic = ~MALLOC_MAGIC; // (hopefully) detect double frees
- if (hdr->next)
- hdr->next->prev = hdr->prev;
- if (hdr->prev)
- hdr->prev->next = hdr->next;
- if (malloc_last == hdr)
- malloc_last = hdr->prev;
- page_free(hdr, hdr->page_amt);
-}
--
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