Files
jsix_import/src/kernel/vm_space.h
Justin C. Miller 186724e751 [project] Generate syscalls from new interface DSL
This change adds a new interface DSL for specifying objects (with
methods) and interfaces (that expose objects, and optionally have their
own methods).

Significant changes:

- Add the new scripts/definitions Python module to parse the DSL
- Add the new definitions directory containing DSL definition files
- Use cog to generate syscall-related code in kernel and libj6
- Unify ordering of pointer + length pairs in interfaces
2021-08-30 01:05:32 -07:00

136 lines
4.6 KiB
C++

#pragma once
/// \file vm_space.h
/// Structure for tracking a range of virtual memory addresses
#include <stdint.h>
#include "enum_bitfields.h"
#include "kutil/spinlock.h"
#include "kutil/vector.h"
#include "page_table.h"
class process;
struct TCB;
class vm_area;
/// Tracks a region of virtual memory address space
class vm_space
{
public:
/// Constructor for the kernel address space
/// \arg pml4 The existing kernel PML4
vm_space(page_table *pml4);
/// Constructor. Creates a new address space.
vm_space();
~vm_space();
/// Add a virtual memorty area to this address space
/// \arg base The starting address of the area
/// \arg area The area to add
/// \returns True if the add succeeded
bool add(uintptr_t base, vm_area *area);
/// Remove a virtual memory area from this address space
/// \arg area The area to remove
/// \returns True if the area was removed
bool remove(vm_area *area);
/// Get the virtual memory area corresponding to an address
/// \arg addr The address to check
/// \arg base [out] if not null, receives the base address of the area
/// \returns The vm_area, or nullptr if not found
vm_area * get(uintptr_t addr, uintptr_t *base = nullptr);
/// Check if this is the kernel space
inline bool is_kernel() const { return m_kernel; }
/// Get the kernel virtual memory space
static vm_space & kernel_space();
/// Map virtual addressses to the given physical pages
/// \arg area The VMA this mapping applies to
/// \arg offset Offset of the starting virutal address from the VMA base
/// \arg phys The starting physical address
/// \arg count The number of contiugous physical pages to map
void page_in(const vm_area &area, uintptr_t offset, uintptr_t phys, size_t count);
/// Clear mappings from the given region
/// \arg area The VMA these mappings applies to
/// \arg offset Offset of the starting virutal address from the VMA base
/// \arg count The number of pages worth of mappings to clear
/// \arg free If true, free the pages back to the system
void clear(const vm_area &vma, uintptr_t start, size_t count, bool free = false);
/// Look up the address of a given VMA's offset
uintptr_t lookup(const vm_area &vma, uintptr_t offset);
/// Check if this space is the current active space
bool active() const;
/// Set this space as the current active space
void activate() const;
enum class fault_type : uint8_t {
none = 0x00,
present = 0x01,
write = 0x02,
user = 0x04,
reserved = 0x08,
fetch = 0x10
};
/// Allocate pages into virtual memory. May allocate less than requested.
/// \arg virt The virtual address at which to allocate
/// \arg count The number of pages to allocate
/// \arg phys [out] The physical address of the pages allocated
/// \returns The number of pages actually allocated
size_t allocate(uintptr_t virt, size_t count, uintptr_t *phys);
/// Handle a page fault.
/// \arg addr Address which caused the fault
/// \arg ft Flags from the interrupt about the kind of fault
/// \returns True if the fault was successfully handled
bool handle_fault(uintptr_t addr, fault_type fault);
/// Set up a TCB to operate in this address space.
void initialize_tcb(TCB &tcb);
/// Copy data from one address space to another
/// \arg source The address space data is being copied from
/// \arg dest The address space data is being copied to
/// \arg from Pointer to the data in the source address space
/// \arg to Pointer to the destination in the dest address space
/// \arg length Amount of data to copy, in bytes
/// \returnd The number of bytes copied
static size_t copy(vm_space &source, vm_space &dest, const void *from, void *to, size_t length);
private:
friend class vm_area;
friend class vm_mapper_multi;
/// Find a given VMA in this address space
bool find_vma(const vm_area &vma, uintptr_t &base) const;
/// Check if a VMA can be resized
bool can_resize(const vm_area &vma, size_t size) const;
/// Copy a range of mappings from the given address space
void copy_from(const vm_space &source, const vm_area &vma);
bool m_kernel;
page_table *m_pml4;
struct area {
uintptr_t base;
vm_area *area;
int compare(const struct area &o) const;
bool operator==(const struct area &o) const;
};
kutil::vector<area> m_areas;
kutil::spinlock m_lock;
};
is_bitfield(vm_space::fault_type);