Kernel: kmalloc has now somewhat dynamic storage

Allocations bigger than PAGE_SIZE and those not forced to be identity
mapped are now done on a GeneralAllocator. This allows us to use kmalloc
for big allocations; bigger than the fixed 1 MiB storage.

This is still a hack and the whole kmalloc will have to be rewritten at
some point, but for now this does the job :D
This commit is contained in:
Bananymous 2023-06-18 23:27:00 +03:00
parent 388f530edd
commit 5e123031aa
5 changed files with 69 additions and 10 deletions

View File

@ -137,6 +137,21 @@ namespace IDT
extern "C" void cpp_isr_handler(uint64_t isr, uint64_t error, const Registers* regs)
{
if (isr == ISR::PageFault)
{
using namespace Kernel;
vaddr_t vaddr = regs->cr2 & PAGE_ADDR_MASK;
if (!PageTable::kernel().is_page_free(vaddr))
{
auto paddr = kmalloc_paddr_of(vaddr);
ASSERT(paddr.has_value());
PageTable::current().map_page_at(paddr.value(), vaddr, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
return;
}
}
pid_t tid = Kernel::Scheduler::current_tid();
pid_t pid = tid ? Kernel::Process::current().pid() : 0;

View File

@ -65,7 +65,7 @@ namespace Kernel
static uint64_t* allocate_page_aligned_page()
{
void* page = kmalloc(PAGE_SIZE, PAGE_SIZE);
void* page = kmalloc(PAGE_SIZE, PAGE_SIZE, true);
ASSERT(page);
memset(page, 0, PAGE_SIZE);
return (uint64_t*)page;

View File

@ -1,10 +1,15 @@
#pragma once
#include <BAN/Optional.h>
#include <kernel/Memory/Types.h>
#include <stddef.h>
void kmalloc_initialize();
void kmalloc_dump_info();
void* kmalloc(size_t);
void* kmalloc(size_t, size_t);
void* kmalloc(size_t size);
void* kmalloc(size_t size, size_t align, bool force_identity_map = false);
void kfree(void*);
BAN::Optional<Kernel::paddr_t> kmalloc_paddr_of(Kernel::vaddr_t);

View File

@ -1,16 +1,21 @@
#include <BAN/Errors.h>
#include <kernel/CriticalScope.h>
#include <kernel/kprint.h>
#include <kernel/Memory/GeneralAllocator.h>
#include <kernel/Memory/kmalloc.h>
#include <kernel/Thread.h>
#define MB (1 << 20)
extern uint8_t g_kernel_end[];
static constexpr size_t s_kmalloc_min_align = alignof(max_align_t);
static uint8_t s_kmalloc_storage[2 * MB];
static BAN::UniqPtr<Kernel::GeneralAllocator> s_general_allocator;
struct kmalloc_node
{
void set_align(ptrdiff_t align) { m_align = align; }
@ -277,7 +282,7 @@ static void* kmalloc_impl(size_t size, size_t align)
void* kmalloc(size_t size)
{
return kmalloc(size, s_kmalloc_min_align);
return kmalloc(size, s_kmalloc_min_align, false);
}
static constexpr bool is_power_of_two(size_t value)
@ -287,16 +292,30 @@ static constexpr bool is_power_of_two(size_t value)
return (value & (value - 1)) == 0;
}
void* kmalloc(size_t size, size_t align)
void* kmalloc(size_t size, size_t align, bool force_indentity_map)
{
const kmalloc_info& info = s_kmalloc_info;
ASSERT(is_power_of_two(align));
if (align < s_kmalloc_min_align)
align = s_kmalloc_min_align;
ASSERT(align <= PAGE_SIZE);
Kernel::CriticalScope critical;
// FIXME: this is a hack to make more dynamic kmalloc memory
if (size > PAGE_SIZE && !force_indentity_map)
{
using namespace Kernel;
if (!s_general_allocator)
s_general_allocator = MUST(GeneralAllocator::create(PageTable::kernel(), (vaddr_t)g_kernel_end));
auto vaddr = s_general_allocator->allocate(size);
if (vaddr)
return (void*)vaddr;
}
if (size == 0 || size >= info.size)
goto no_memory;
@ -331,6 +350,9 @@ void kfree(void* address)
Kernel::CriticalScope critical;
if (s_general_allocator && s_general_allocator->deallocate((Kernel::vaddr_t)address))
return;
if (s_kmalloc_fixed_info.base <= address_uint && address_uint < s_kmalloc_fixed_info.end)
{
auto& info = s_kmalloc_fixed_info;
@ -387,3 +409,20 @@ void kfree(void* address)
}
}
BAN::Optional<Kernel::paddr_t> kmalloc_paddr_of(Kernel::vaddr_t vaddr)
{
using namespace Kernel;
if (s_general_allocator)
{
auto paddr = s_general_allocator->paddr_of(vaddr);
if (paddr.has_value())
return paddr.value();
}
if ((vaddr_t)s_kmalloc_storage <= vaddr && vaddr < (vaddr_t)s_kmalloc_storage + sizeof(s_kmalloc_storage))
return V2P(vaddr);
return {};
}

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@ -133,6 +133,9 @@ extern "C" void kernel_main()
PageTable::initialize();
dprintln("PageTable initialized");
Heap::initialize();
dprintln("Heap initialzed");
TerminalDriver* terminal_driver = VesaTerminalDriver::create();
ASSERT(terminal_driver);
dprintln("VESA initialized");
@ -141,9 +144,6 @@ extern "C" void kernel_main()
ASSERT(tty1);
dprintln("TTY initialized");
Heap::initialize();
dprintln("Heap initialzed");
parse_command_line();
dprintln("command line parsed, root='{}'", cmdline.root);