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/*
* Copyright (c) 2023 Ian Marco Moffett and the VegaOS team.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of VegaOS nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/limine.h>
#include <sys/cdefs.h>
#include <sys/syslog.h>
#include <vm/vm_physseg.h>
#include <vm/vm.h>
#include <bitmap.h>
#include <string.h>
__MODULE_NAME("vm_physseg");
__KERNEL_META("$Vega$: vm_physseg.c, Ian Marco Moffett, "
"The Vega physical memory manager");
#if defined(VM_PHYSSEG_DEBUG)
#define DPRINTF(...) KDEBUG(__VA_ARGS__)
#else
#define DPRINTF(...) __nothing
#endif /* defined(VM_PHYSSEG_DEBUG) */
static struct limine_memmap_request mmap_req = {
.id = LIMINE_MEMMAP_REQUEST,
.revision = 0
};
static struct limine_memmap_response *resp = NULL;
__used static const char *segment_name[] = {
[LIMINE_MEMMAP_USABLE] = "usable",
[LIMINE_MEMMAP_RESERVED] = "reserved",
[LIMINE_MEMMAP_ACPI_RECLAIMABLE] = "ACPI reclaimable",
[LIMINE_MEMMAP_ACPI_NVS] = "ACPI NVS",
[LIMINE_MEMMAP_BAD_MEMORY] = "bad",
[LIMINE_MEMMAP_BOOTLOADER_RECLAIMABLE] = "bootloader reclaimable",
[LIMINE_MEMMAP_KERNEL_AND_MODULES] = "kernel and modules",
[LIMINE_MEMMAP_FRAMEBUFFER] = "framebuffer"
};
static const int MAX_SEGMENTS = __ARRAY_COUNT(segment_name);
static bitmap_t bitmap = NULL;
static size_t bitmap_size = 0;
static size_t bitmap_free_start; /* Beginning bit of free region */
static void
vm_physseg_bitmap_alloc(void)
{
struct limine_memmap_entry *entry;
for (size_t i = 0; i < resp->entry_count; ++i) {
entry = resp->entries[i];
/* Drop any entries with an invalid type */
if (entry->type >= MAX_SEGMENTS) {
continue;
}
if (entry->type != LIMINE_MEMMAP_USABLE) {
/* This memory is not usable */
continue;
}
if (entry->length >= bitmap_size) {
bitmap = PHYS_TO_VIRT(entry->base);
memset(bitmap, 0xFF, bitmap_size);
entry->length -= bitmap_size;
entry->base += bitmap_size;
return;
}
}
}
static void
vm_physseg_bitmap_populate(void)
{
struct limine_memmap_entry *entry;
#if defined(VM_PHYSSEG_DEBUG)
size_t start, end;
#endif /* defined(VM_PHYSSEG_DEBUG) */
for (size_t i = 0; i < resp->entry_count; ++i) {
entry = resp->entries[i];
/* Drop any entries with an invalid type */
if (entry->type >= MAX_SEGMENTS) {
continue;
}
#if defined(VM_PHYSSEG_DEBUG)
/* Dump the memory map if we are debugging */
start = entry->base;
end = entry->base + entry->length;
DPRINTF("0x%x - 0x%x, size: 0x%x, type: %s\n",
start, end, entry->length,
segment_name[entry->type]);
#endif /* defined(VM_PHYSSEG_DEBUG) */
/* Don't set non-usable entries as free */
if (entry->type != LIMINE_MEMMAP_USABLE) {
continue;
}
/* Populate */
if (bitmap_free_start == 0) {
bitmap_free_start = entry->base/0x1000;
}
for (size_t j = 0; j < entry->length; j += 0x1000) {
bitmap_unset_bit(bitmap, (entry->base + j) / 0x1000);
}
}
}
static void
vm_physseg_bitmap_init(void)
{
uintptr_t highest_addr;
size_t highest_page_idx;
struct limine_memmap_entry *entry;
highest_addr = 0;
highest_page_idx = 0;
/* Find the highest entry */
for (size_t i = 0; i < resp->entry_count; ++i) {
entry = resp->entries[i];
if (entry->type != LIMINE_MEMMAP_USABLE) {
/* Memeory not usable */
continue;
}
highest_addr = __MAX(highest_addr, entry->base + entry->length);
}
highest_page_idx = highest_addr / 0x1000;
bitmap_size = __ALIGN_UP(highest_page_idx / 8, 0x1000);
DPRINTF("Bitmap size: %d bytes\n", bitmap_size);
DPRINTF("Allocating and populating bitmap now...\n");
vm_physseg_bitmap_alloc();
vm_physseg_bitmap_populate();
}
void
vm_physseg_init(void)
{
resp = mmap_req.response;
vm_physseg_bitmap_init();
}
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